2617 lines
121 KiB
Rust
2617 lines
121 KiB
Rust
//! # avhw — FFmpeg / VAAPI 硬件加速 FFI 绑定（FFI 最密集的文件）
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//!
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//! 本文件是整个 crate 中 `unsafe` 块密度最高的模块：直接调用 FFmpeg C API。
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//! `ffmpeg-next` 是 ffmpeg-sys-next（C FFI 绑定）的薄包装；硬件加速相关 API
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//! （`AVBufferRef`/`av_hwframe_*`）仍是裸 C 接口。
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//!
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//! ## FFmpeg 引用计数对象的生命周期
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//! - `AVBufferRef`：FFmpeg 引用计数句柄，`av_buffer_ref` 加 1、`av_buffer_unref` 减 1。
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//! `AvHwDevCtx`/`AvHwFrameCtx` 用 RAII 包装：`new` alloc，`Drop` unref。
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//! - `AVFrame`：硬件帧（`AV_PIX_FMT_VAAPI`）的 `data[0]` 是 GPU 表面指针。
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//!
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//! ## `unsafe impl Send` 的存在原因（AGENTS.md 明确警告）
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//! `*mut AVBufferRef` 默认 `!Send`；wrapper 显式声明 Send 的前提是**外部调用方
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//! 保证 `&mut self` 独占访问**。AGENTS.md：不要跨线程移动这些 wrapper 而不重新
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//! 检查 exclusivity 假设。
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//!
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//! ## 与 Go cgo 的类比
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//! - `extern "C" fn` ≈ Go `//export` C 回调；
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//! - `unsafe { ffi::av_*() }` ≈ Go `C.av_xxx()`；
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//! - RAII `Drop` ≈ Go `runtime.SetFinalizer`（但 Rust Drop 是确定性的）。
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// std 导入：CString（C 字符串）、mem::zeroed（FFI 零初始化）、RawFd/AsRawFd（fd 桥），
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// c_void（C void 跨语言）、Path（DRM 设备路径）、ptr（null_mut 等裸指针工具），
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// slice（从裸指针构造切片）、AtomicBool/Ordering/Arc（跨线程暂停标志，T10b 用），
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// Instant（编码计时，T10b 用）。本 sub-todo（lines 1-330）仅部分使用。
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use std::ffi::CString;
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use std::mem;
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use std::os::fd::{AsRawFd, RawFd};
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use std::os::raw::c_void;
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use std::path::Path;
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use std::ptr;
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use std::slice;
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use std::sync::atomic::{AtomicBool, Ordering};
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use std::sync::Arc;
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use std::time::Instant;
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// anyhow 错误处理：bail!（提前返回 Err）、Result<T>（错误传播）。
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// ffmpeg-next：稍安全的 API（ff::frame::Video、ff::format::Pixel、ff::codec 等）。
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// ffmpeg_next::ffi：FFmpeg C 头绑定的裸 API（AVBufferRef、av_hwdevice_ctx_create 等），
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// 所有 `unsafe` FFI 调用的入口。`packet::Mut as _`：导入 packet 的 Mut trait 但匿名，
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// 仅用于 trait method 解析，不污染命名空间。
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use anyhow::{bail, Result};
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use ffmpeg_next as ff;
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use ffmpeg_next::ffi;
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use ffmpeg_next::packet::Mut as _;
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// crate 内部模块：PwDmaBufFrame（PipeWire DMA-BUF 帧元数据：fd/width/height/stride/modifier），
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// Transform（Wayland wl_output 变换，决定 ROI 是否需要转置处理）。
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use crate::cap_portal::PwDmaBufFrame;
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use crate::transform::{transpose_if_transform_transposed, Transform};
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// ---------------------------------------------------------------------------
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// Bitrate feedback command (WebRTC BWE → SW encoder)
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// ---------------------------------------------------------------------------
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// 跨线程控制信令：WebRTC 线程根据 BWE（bandwidth estimation）估算的可用带宽，
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// 通过 MPSC channel 把 `BitrateCommand` 发给软件编码线程，由后者调整 x264 参数。
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// 注意：硬件（VAAPI）路径目前不接受动态码率调整，只有软件（x264）路径消费这些命令。
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// 类比 Go：`chan BitrateCommand` 单向 channel。
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/// Commands sent from the WebRTC thread to the SW encoder when the
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/// bandwidth estimate changes significantly.
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pub enum BitrateCommand {
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UpdateBitrate { target_bps: u64 },
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UpdateResolution { width: u32, height: u32 },
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/// Force the next encoded frame to be an IDR. Sent by the WebRTC thread
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/// in response to str0m `Event::KeyframeRequest` or a resolution change.
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ForceKeyframe,
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}
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// 分辨率变更事件：WebRTC 线程根据对端能力（SVC/layered encoding 协商）建议切换分辨率，
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// 编码线程收到后重建 encoder（x264 不支持运行时改变 width/height，必须销毁重建）。
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// `#[derive(Clone, Copy, Debug)]`：Copy 表示按位拷贝（小值类型，无需 clone 调用），
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// 类比 Go 的 `type ResolutionChange struct{...}`（Go 默认值语义即 Copy）。
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#[derive(Clone, Copy, Debug)]
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pub struct ResolutionChange {
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pub width: u32,
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pub height: u32,
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}
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// 每帧编码耗时快照，由编码线程填好后通过 channel 发给统计线程（stats thread）。
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// `#[derive(Default, Clone, Copy, Debug)]`：Default 允许 `SwEncodeTiming::default()` 全零初始化；
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// Copy/Clone 表示小值类型按位拷贝（无堆字段）。
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//
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// 字段语义：
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// - sws_us：libswscale 把 NV12（VAAPI 输出）转 YUV420P（x264 输入）的耗时（微秒）
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// - encode_us：`avcodec_send_frame` + drain 接收所有 packet 的总耗时（微秒）
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// - output_bytes：本帧产出的 H.264 字节数（即使下游 WebRTC 因暂停丢帧也计入）
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//
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// 类比 Go：`type SwEncodeTiming struct{...}` + atomic store/load 跨 goroutine 传递。
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/// Per-frame timing snapshot for the software encoder, consumed by the stats
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/// thread. `sws_us` measures NV12→YUV420P conversion, `encode_us` measures
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/// `avcodec_send_frame` + drain, and `output_bytes` counts encoded bytes
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/// produced by libavcodec (even if downstream delivery later drops them).
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#[derive(Default, Clone, Copy, Debug)]
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pub struct SwEncodeTiming {
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pub sws_us: u64,
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pub encode_us: u64,
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pub output_bytes: usize,
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}
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// `encode_cpu_frame` 的返回值，编码线程据此判断是否计 encoded_fps（只有 `Encoded`
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// 才算一次真实编码）。`#[derive(Debug, Clone, Copy, PartialEq, Eq)]`：PartialEq/Eq
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// 允许 `==` 比较（测试和 stats 聚合用），Copy 表示小值类型按位拷贝。
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// 类比 Go：`type EncodeOutcome int` + const 枚举值。
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/// Outcome of a single `encode_cpu_frame` call. Used by the encode thread
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/// to decide whether to report timing stats (only real encodes tick encoded_fps).
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#[derive(Debug, Clone, Copy, PartialEq, Eq)]
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pub enum EncodeOutcome {
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/// Frame was actually encoded and produced output bytes.
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Encoded,
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/// Frame was dropped because WebRTC is paused (no client connected).
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SkippedPaused,
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/// Frame was dropped because the encoder is in disconnected state.
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SkippedDisconnected,
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/// Frame was dropped because its Y-plane hash matched the previous frame.
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SkippedDuplicate,
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}
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// ---------------------------------------------------------------------------
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// AvHwDevCtx
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// ---------------------------------------------------------------------------
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// VAAPI 设备上下文的 RAII 包装。`ptr` 是 FFmpeg 引用计数的 `AVBufferRef`，
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// 包装 `AVHWDeviceContext`（VAAPI 内部的 `VADisplay`）。`new_vaapi` 时 alloc，
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// `Drop` 时 `av_buffer_unref`；`ref_clone` 用于把内部 ref 传递给编码器的
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// `AVCodecContext::hw_device_ctx`（FFmpeg 会再 `av_buffer_ref` 一次）。
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// **独占访问假设**：`unsafe impl Send` 的前提是外部调用方保证 `&mut self`，
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// 不允许多线程共享 `&AvHwDevCtx` 同时调用 mut method（详见 AGENTS.md 警告）。
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pub struct AvHwDevCtx {
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// FFmpeg 内部引用计数句柄，类型擦除为 `*mut AVBufferRef`。
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// 永不为 null（除非在 Drop 中被置 null）。
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ptr: *mut ffi::AVBufferRef,
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}
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// 中文概述：声明 `AvHwDevCtx` 可以跨线程 `Send`。前提是调用方用 `&mut self`
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// 独占访问（无并发可变借用）。VAAPI 的 `VADisplay` 在硬件驱动层线程安全，
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// FFmpeg 的 `AVHWDeviceContext` 内部状态在 send/receive 编码模式下也线程安全。
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// 不修复：保留 AGENTS.md 文档的 exclusivity 假设（这是本 crate 的并发模型基础）。
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// SAFETY: AvHwDevCtx wraps an FFmpeg AVBufferRef which is not Send by default,
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// but we guarantee exclusive access through &mut self. The underlying VAAPI
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// device context is thread-safe for the operations we perform.
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unsafe impl Send for AvHwDevCtx {}
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impl AvHwDevCtx {
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// 创建 VAAPI 设备上下文。`drm_device` 通常是 `/dev/dri/renderD128`。
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// 失败原因：设备不存在、无 VAAPI 驱动、权限不足（用户不在 `video` 组）。
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// 成功时返回 `AvHwDevCtx`，ptr 持有一个 ref（refcount=1）。
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pub fn new_vaapi(drm_device: &Path) -> Result<Self> {
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// CString::new 在路径含内部 NUL 时返回 Err（FFmpeg C API 要求 NUL 结尾）。
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// `to_str().unwrap()`：路径非 UTF-8 时 panic（Linux DRM 设备路径通常 ASCII）。
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let device_cstr = CString::new(drm_device.to_str().unwrap())?;
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// 初始化为 null_mut：FFmpeg 的 out-pointer 约定（调用者置 null，被调者赋值）。
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let mut p: *mut ffi::AVBufferRef = ptr::null_mut();
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// 中文概述：调用 FFmpeg C API 创建 VAAPI `AVHWDeviceContext`，写入 `*p`。
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// 失败返回负的 AVERROR；成功返回 0 且 `p` 指向新分配的 `AVBufferRef`（refcount=1）。
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// SAFETY: device_cstr is a valid C string for the duration of the call;
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// p is a valid out-pointer that FFmpeg initializes on success.
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let ret = unsafe {
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ffi::av_hwdevice_ctx_create(
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&mut p,
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ffi::AVHWDeviceType::AV_HWDEVICE_TYPE_VAAPI,
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device_cstr.as_ptr(),
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ptr::null_mut(),
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0,
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)
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};
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if ret < 0 {
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bail!(
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"Failed to create VAAPI device context from {}: {}",
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drm_device.display(),
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ff_err(ret)
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);
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}
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Ok(Self { ptr: p })
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}
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// 返回裸 `*mut AVBufferRef`，调用方负责管理引用计数。
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// 通常用于传给 FFmpeg API 的 `hw_device_ctx` 字段（FFmpeg 内部会 av_buffer_ref）。
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pub fn as_ptr(&self) -> *mut ffi::AVBufferRef {
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self.ptr
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}
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// 增加 refcount，返回新的 `*mut AVBufferRef`（不复制底层缓冲）。
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// 用于把设备 ref 传给编码器的 `AVCodecContext::hw_device_ctx`，编码器 Drop 时
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// 调用 `av_buffer_unref` 释放自己持有的 ref，不影响本 wrapper。
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pub fn ref_clone(&self) -> *mut ffi::AVBufferRef {
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// 中文概述：FFmpeg 引用计数 +1，返回新 ref；线程安全（内部原子操作）。
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// SAFETY: av_buffer_ref atomically increments refcount and returns a new ref.
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unsafe { ffi::av_buffer_ref(self.ptr) }
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}
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}
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// RAII 析构：减少 refcount。如果是最后一个 ref（refcount→0），FFmpeg 释放
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// 底层的 `AVHWDeviceContext` 和 `VADisplay`。`is_null()` 守卫是为了应对
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// `Drop` 被多次调用或 `new_vaapi` 失败后 ptr 仍为 null 的边缘情况（实际上
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// Rust 的 Drop 不会被调用两次，但 FFmpeg 的 av_buffer_unref 接受 null 入参）。
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impl Drop for AvHwDevCtx {
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fn drop(&mut self) {
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if !self.ptr.is_null() {
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// 中文概述：FFmpeg 引用计数 -1，refcount=0 时释放底层设备上下文。
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// SAFETY: av_buffer_unref decrements refcount; frees the buffer when it hits zero.
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unsafe { ffi::av_buffer_unref(&mut self.ptr) };
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}
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}
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}
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// ---------------------------------------------------------------------------
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// AvHwFrameCtx
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// ---------------------------------------------------------------------------
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// VAAPI 硬件帧池的 RAII 包装。`AVHWFramesContext` 是 FFmpeg 的硬件帧分配器，
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// 编码器通过它分配 `AV_PIX_FMT_VAAPI` 帧（GPU 表面）。`initial_pool_size=4`
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// 表示池大小为 4（足够 send/receive pipeline：1 帧 encode 中 + 1 帧 queue + 2 缓冲）。
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// 字段配置（width/height/sw_format）必须在 `av_hwframe_ctx_init` 前设置；
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// `sw_fmt` 是 CPU 可读的软件格式（VAAPI 内部从该格式上传/下载）。
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pub struct AvHwFrameCtx {
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ptr: *mut ffi::AVBufferRef,
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}
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// 中文概述：声明 `AvHwFrameCtx` 可以跨线程 `Send`。前提是 `&mut self` 独占访问，
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// 且底层硬件帧池在 send/receive 模式下线程安全。与 `AvHwDevCtx` 同样的 exclusivity 假设。
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// 不修复：保留 AGENTS.md 文档的并发约束。
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// SAFETY: AvHwFrameCtx wraps an FFmpeg AVBufferRef to an AVHWFramesContext.
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// It is only accessed through &mut self, ensuring no concurrent mutation.
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// The underlying hardware frames pool is thread-safe for the send/receive pattern.
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unsafe impl Send for AvHwFrameCtx {}
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impl AvHwFrameCtx {
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// 内部构造函数：分配 `AVHWFramesContext`、配置字段、调用 `av_hwframe_ctx_init`。
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// 失败时（alloc 或 init 失败）返回 Err，确保 ptr 不泄漏。
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fn new_inner(hw_dev: &AvHwDevCtx, w: u32, h: u32, sw_fmt: ff::format::Pixel) -> Result<Self> {
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// 中文概述：分配 `AVHWFramesContext`，refcount=1，关联到 hw_dev 的设备上下文。
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// 返回的 ref 的 `data` 字段指向未初始化的 `AVHWFramesContext`，需手动配置。
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// SAFETY: hw_dev is a live AVHWDeviceContext; FFmpeg returns either a valid
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// frames context ref or null (checked below).
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let mut p = unsafe { ffi::av_hwframe_ctx_alloc(hw_dev.as_ptr()) };
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if p.is_null() {
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bail!("av_hwframe_ctx_alloc returned null");
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}
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// 中文概述：通过 `(*p).data as *mut AVHWFramesContext` 访问 FFmpeg 内部类型擦除的
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// 字段（`AVBufferRef::data` 是 `*mut u8`，实际指向具体 context 类型）。
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// 直接赋值 `format`/`sw_format`/`width`/`height`/`initial_pool_size` 5 个字段。
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// SAFETY: p is a valid AVBufferRef from av_hwframe_ctx_alloc.
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// Its .data field points to an AVHWFramesContext that we must configure.
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unsafe {
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let fc = (*p).data as *mut ffi::AVHWFramesContext;
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(*fc).format = ff::format::Pixel::VAAPI.into();
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(*fc).sw_format = sw_fmt.into();
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(*fc).width = w as i32;
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(*fc).height = h as i32;
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(*fc).initial_pool_size = 4;
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}
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// 中文概述：初始化帧池（实际分配 GPU 表面）。失败时必须手动 unref p 否则泄漏。
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// SAFETY: p is a valid AVHWFramesContext ref configured above and not yet
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// transferred or freed.
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let ret = unsafe { ffi::av_hwframe_ctx_init(p) };
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if ret < 0 {
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// 中文概述：init 失败的清理路径——p 仍有效但不可用，unref 释放。
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// SAFETY: p is valid but init failed; clean up.
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unsafe { ffi::av_buffer_unref(&mut p) };
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bail!("av_hwframe_ctx_init failed: {}", ff_err(ret));
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}
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Ok(Self { ptr: p })
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}
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// 为采集路径创建硬件帧池。`sw_fmt` 通常是 `BGRA`（PipeWire DMA-BUF 像素格式）。
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pub fn for_capture(
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hw_dev: &AvHwDevCtx,
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w: u32,
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h: u32,
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sw_fmt: ff::format::Pixel,
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) -> Result<Self> {
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Self::new_inner(hw_dev, w, h, sw_fmt)
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}
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pub fn as_ptr(&self) -> *mut ffi::AVBufferRef {
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self.ptr
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}
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pub fn ref_clone(&self) -> *mut ffi::AVBufferRef {
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// 中文概述：FFmpeg 引用计数 +1，返回新 ref；用于把帧池 ref 传给编码器。
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// SAFETY: av_buffer_ref atomically increments refcount and returns a new ref.
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unsafe { ffi::av_buffer_ref(self.ptr) }
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}
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}
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// RAII 析构：与 AvHwDevCtx::Drop 同样的模式（unref 释放 ref）。
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impl Drop for AvHwFrameCtx {
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fn drop(&mut self) {
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if !self.ptr.is_null() {
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// 中文概述：FFmpeg 引用计数 -1，refcount=0 时释放帧池和 GPU 表面。
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// SAFETY: av_buffer_unref decrements refcount; frees when zero.
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unsafe { ffi::av_buffer_unref(&mut self.ptr) };
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}
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}
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}
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// 启动时探针：测试 `drm_device` 能否通过 VAAPI 导入 PipeWire 给的 DMA-BUF 帧。
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// 用于 backend_detect 决定走硬件（VAAPI）还是软件（x264）编码路径。
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// 失败原因：硬件不支持给定格式/修饰符组合、DRM 设备无 VAAPI、内核 driver 限制。
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// 成功只是"探针通过"，不代表实际编码时一直可用（运行时仍可能因 OOM 等失败）。
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/// Test whether `drm_device` can import the PipeWire DMA-BUF frame via VAAPI.
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pub fn test_dma_buf_import(drm_device: &Path, frame: &PwDmaBufFrame) -> Result<()> {
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let hw_dev = AvHwDevCtx::new_vaapi(drm_device)?;
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let frames =
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AvHwFrameCtx::for_capture(&hw_dev, frame.width, frame.height, ff::format::Pixel::BGRA)?;
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||
|
||
// 中文概述：调用下面的 `import_dma_buf_to_vaapi`，用 `av_hwframe_map` 把 DMA-BUF
|
||
// 映射到 VAAPI 表面（零拷贝）。`as_raw_fd()` 把 `OwnedFd` 转为裸 fd 传给 FFI。
|
||
// SAFETY: frames is a live VAAPI frames context; frame carries valid DMA-BUF metadata.
|
||
unsafe {
|
||
import_dma_buf_to_vaapi(
|
||
frames.as_ptr(),
|
||
frame.fd.as_raw_fd(),
|
||
frame.width,
|
||
frame.height,
|
||
frame.format,
|
||
frame.modifier,
|
||
frame.stride,
|
||
frame.offset,
|
||
)
|
||
}?;
|
||
|
||
Ok(())
|
||
}
|
||
|
||
// 中文概述：把 PipeWire 的 DMA-BUF 帧零拷贝映射为 VAAPI `AVFrame`。
|
||
// DMA-BUF 是 Linux 内核的 GPU 缓冲共享机制（fd 指向 GPU 内存）；`av_hwframe_map`
|
||
// 在 VAAPI 内部通过 `vaCreateSurfaces` + `vaMapBuffer` 直接 GPU 映射，无需 CPU 拷贝。
|
||
// 类比 Go：Go 没有等价物——cgo + libavutil 才能实现同样的零拷贝路径。
|
||
/// Import a DMA-BUF into a VAAPI hardware frame via zero-copy `av_hwframe_map`.
|
||
///
|
||
/// # Safety
|
||
/// - `frames_ctx` must point to an initialized AVHWCramesContext for VAAPI
|
||
/// - `raw_fd` must be a valid DMA-BUF file descriptor
|
||
pub unsafe fn import_dma_buf_to_vaapi(
|
||
frames_ctx: *mut ffi::AVBufferRef,
|
||
raw_fd: RawFd,
|
||
width: u32,
|
||
height: u32,
|
||
drm_format: u32,
|
||
modifier: u64,
|
||
stride: u32,
|
||
offset: u64,
|
||
) -> Result<ff::frame::Video> {
|
||
// `libc::dup` 复制 fd——`AVDRMFrameDescriptor` 持有 dup 后的 fd，
|
||
// 当 descriptor 释放时 `cleanup_drm_descriptor` 会 `libc::close` 它；
|
||
// 原始 `raw_fd` 不被本函数消费（仍由调用方拥有，通常是 PipeWire）。
|
||
let duped_fd = libc::dup(raw_fd);
|
||
if duped_fd < 0 {
|
||
bail!("dup(fd) failed: {}", std::io::Error::last_os_error());
|
||
}
|
||
|
||
// `mem::zeroed()`：FFI 零初始化（所有字段置 0），类似 Go 的 `&drmDesc{}`。
|
||
// SAFETY 后续不再赘述——这是 `unsafe fn` 内部，调用契约由函数签名保证。
|
||
let mut desc: ffi::AVDRMFrameDescriptor = mem::zeroed();
|
||
desc.nb_objects = 1;
|
||
desc.objects[0].fd = duped_fd;
|
||
desc.objects[0].size = (height as usize) * (stride as usize);
|
||
desc.objects[0].format_modifier = modifier;
|
||
desc.nb_layers = 1;
|
||
desc.layers[0].format = drm_format;
|
||
desc.layers[0].nb_planes = 1;
|
||
desc.layers[0].planes[0].object_index = 0;
|
||
desc.layers[0].planes[0].offset = offset as isize;
|
||
desc.layers[0].planes[0].pitch = stride as isize;
|
||
|
||
// `Box::new(desc)` 把栈上的 descriptor 移到堆上；`Box::into_raw` 交出所有权给 FFmpeg。
|
||
// `av_buffer_create` 会接管这块内存：当 AVBufferRef refcount 归零时调用
|
||
// `cleanup_drm_descriptor`（自定义 free 回调）→ close fd + Box::from_raw 释放堆内存。
|
||
let desc_box = Box::new(desc);
|
||
let desc_ptr = Box::into_raw(desc_box);
|
||
|
||
// 创建 FFmpeg 自定义 AVBufferRef：data 指向 descriptor，free 回调为 cleanup_drm_descriptor。
|
||
// 失败时（极少）需要手动恢复 Box 并 close fd，否则泄漏。
|
||
let buf_ref = ffi::av_buffer_create(
|
||
desc_ptr as *mut u8,
|
||
std::mem::size_of::<ffi::AVDRMFrameDescriptor>(),
|
||
Some(cleanup_drm_descriptor),
|
||
ptr::null_mut(),
|
||
0,
|
||
);
|
||
if buf_ref.is_null() {
|
||
let desc_box = Box::from_raw(desc_ptr);
|
||
libc::close(desc_box.objects[0].fd);
|
||
bail!("av_buffer_create returned null for DRM descriptor");
|
||
}
|
||
|
||
// 构造 src AVFrame：格式为 `AV_PIX_FMT_DRM_PRIME`（FFmpeg 的 DMA-BUF 包装格式），
|
||
// `data[0]` 指向 AVBufferRef 的 data（即 descriptor），`buf[0]` 持有 ref 防止提前释放。
|
||
let mut src = ff::frame::Video::empty();
|
||
{
|
||
let sp = src.as_mut_ptr();
|
||
(*sp).format = ffi::AVPixelFormat::AV_PIX_FMT_DRM_PRIME as i32;
|
||
(*sp).width = width as i32;
|
||
(*sp).height = height as i32;
|
||
(*sp).data[0] = (*buf_ref).data;
|
||
(*sp).buf[0] = buf_ref;
|
||
}
|
||
|
||
// 构造 dst AVFrame：格式为 `AV_PIX_FMT_VAAPI`，挂上 `hw_frames_ctx` 让 FFmpeg 知道用哪个池。
|
||
let mut dst = ff::frame::Video::empty();
|
||
// 中文概述：把 dst 的 format 设为 VAAPI、`hw_frames_ctx` 设为新的 ref。
|
||
// `av_buffer_ref(frames_ctx)` 必须成功，否则 av_hwframe_map 无法定位帧池。
|
||
// SAFETY: frames_ctx is guaranteed by this unsafe function's contract to be a
|
||
// valid initialized VAAPI frames context; we set format/hw_frames_ctx on a
|
||
// freshly allocated dst frame.
|
||
unsafe {
|
||
let dp = dst.as_mut_ptr();
|
||
(*dp).format = ffi::AVPixelFormat::AV_PIX_FMT_VAAPI as i32;
|
||
(*dp).hw_frames_ctx = ffi::av_buffer_ref(frames_ctx);
|
||
if (*dp).hw_frames_ctx.is_null() {
|
||
bail!("av_buffer_ref(frames_ctx) returned null");
|
||
}
|
||
}
|
||
// 中文概述：核心 FFI 调用——FFmpeg 在内部调用 VAAPI `vaCreateSurfaces`+`vaMapBuffer`
|
||
// 把 DMA-BUF 映射到 GPU 表面，写入 dst。零 CPU 拷贝。
|
||
// SAFETY: src and dst are initialized AVFrames; dst has a valid hw_frames_ctx
|
||
// ref and av_hwframe_map fills dst from src.
|
||
let ret = unsafe {
|
||
ffi::av_hwframe_map(
|
||
dst.as_mut_ptr(),
|
||
src.as_ptr(),
|
||
ffi::AV_HWFRAME_MAP_READ as i32,
|
||
)
|
||
};
|
||
if ret < 0 {
|
||
bail!("av_hwframe_map failed: {}", ff_err(ret));
|
||
}
|
||
|
||
Ok(dst)
|
||
}
|
||
|
||
// `av_buffer_create` 的 free 回调：当自定义 AVBufferRef 的 refcount 归零时被 FFmpeg 调用。
|
||
// `unsafe extern "C" fn` 是因为 FFmpeg 通过 C 函数指针调用它（C ABI 兼容）。
|
||
// 职责：(1) close DMA-BUF 的 dup'd fd；(2) `Box::from_raw` 恢复堆内存所有权并立即 drop。
|
||
// `_opaque`：FFmpeg 的 AVBufferRef 允许附带 opaque 数据（本例未用，故 `_` 前缀）。
|
||
// 类比 Go：相当于 `runtime.SetFinalizer` 的回调，但是 FFmpeg 主动调用的（确定性）。
|
||
unsafe extern "C" fn cleanup_drm_descriptor(_opaque: *mut c_void, data: *mut u8) {
|
||
let desc = data as *mut ffi::AVDRMFrameDescriptor;
|
||
if !desc.is_null() && (*desc).nb_objects > 0 && (*desc).objects[0].fd >= 0 {
|
||
libc::close((*desc).objects[0].fd);
|
||
}
|
||
let _ = Box::from_raw(data as *mut ffi::AVDRMFrameDescriptor);
|
||
}
|
||
|
||
// 把 FFmpeg 的负数错误码（AVERROR）转成人类可读字符串。
|
||
// `av_strerror` 是 FFmpeg 的线程安全 strerror 等价物，写入调用方提供的缓冲区。
|
||
// `pub(crate)` 可见性：仅供本 crate 内部错误格式化使用（不暴露给外部）。
|
||
/// Convert an FFmpeg error code to a human-readable string.
|
||
pub(crate) fn av_err_to_string(err: i32) -> String {
|
||
// 128 字节足够 AVERROR 描述（FFmpeg 内部字符串都很短）。
|
||
let mut buf = vec![0u8; 128];
|
||
// 中文概述：调用 FFmpeg `av_strerror`，把错误码描述写入 buf。
|
||
// 失败（无效错误码）时 buf 仍为全 0，trim 后为空字符串。
|
||
// SAFETY: buf points to 128 writable bytes and lives for the duration of
|
||
// av_strerror.
|
||
unsafe {
|
||
ffi::av_strerror(err, buf.as_mut_ptr() as *mut i8, buf.len());
|
||
}
|
||
// `from_utf8_lossy` 容忍非 UTF-8 字节；`trim_end_matches('\0')` 去掉 C 字符串结尾的 NUL。
|
||
String::from_utf8_lossy(&buf)
|
||
.trim_end_matches('\0')
|
||
.to_string()
|
||
}
|
||
|
||
// 带数字码的错误格式化：`"error -22 (Invalid argument)"`。
|
||
// 数字码很重要——AVERROR 是负数，但有些 FFmpeg 错误是宏（如 AVERROR(EAGAIN)），
|
||
// 看数字能区分底层 errno 还是 FFmpeg 自定义错误。
|
||
/// Format an FFmpeg error code with both numeric value and description.
|
||
/// Example output: "error -22 (Invalid argument)"
|
||
pub(crate) fn ff_err(ret: i32) -> String {
|
||
format!("error {ret} ({})", av_err_to_string(ret))
|
||
}
|
||
// ---------------------------------------------------------------------------
|
||
// EncState
|
||
// ---------------------------------------------------------------------------
|
||
|
||
// 编码状态机：把 VAAPI 硬件帧 → H.264 ES 流 → MP4 文件的"主循环编排者"。
|
||
//
|
||
// 字段角色（按数据流顺序）：
|
||
// - enc_video : 已打开的 h264_vaapi 编码器句柄（FFmpeg AVCodecContext 包装）
|
||
// - video_filter : scale/crop/format 过滤图（BGRA→NV12 + VAAPI 像素格式上传）
|
||
// - frames_rgb : 捕获侧 hw frames 池（与 import_dma_buf_to_vaapi 共享）
|
||
// - hw_device_ctx : VAAPI 设备上下文（DRM render node 句柄）
|
||
// - octx : 输出 muxer 上下文（MP4 文件）
|
||
// - starting_timestamp : 首帧 PTS 锚点，用于把绝对时间戳归零（避免 MP4 起始时间漂移）
|
||
// - frames_written : 是否已写出过帧（用于决定 flush 时是否写 trailer）
|
||
//
|
||
// 跨线程约束：state.rs/state_portal.rs 的设计是"单线程驱动"——`&mut EncState`
|
||
// 由外层 main 串行化访问，因此 `enc_video` / `octx` 等 FFmpeg 上下文不需要锁。
|
||
// `unsafe impl Send` 仅表达"类型上可以跨线程移动"，不代表"可以并发访问"。
|
||
pub struct EncState {
|
||
enc_video: ff::codec::encoder::video::Video,
|
||
frames_rgb: AvHwFrameCtx,
|
||
video_filter: ff::filter::Graph,
|
||
hw_device_ctx: AvHwDevCtx,
|
||
octx: ff::format::context::Output,
|
||
starting_timestamp: Option<i64>,
|
||
frames_written: bool,
|
||
}
|
||
|
||
// 安全说明：FFmpeg 的 AVCodecContext/AVFormatContext 等 C 对象不是自动 Sync 的，
|
||
// 但本工程的并发模型保证 EncState 只在单一编码线程内被 `&mut` 访问，因此标记
|
||
// Send（跨线程移动）是安全的；若未来引入并发编码必须重新审视（参见 AGENTS.md
|
||
// 关于 avhw.rs 显式 `unsafe impl Send` 与独占性假设的说明）。
|
||
unsafe impl Send for EncState {}
|
||
|
||
// impl EncState：编码主循环对外暴露的方法集合。
|
||
//
|
||
// 方法职责（按数据流顺序）：
|
||
// - new : 构造 VAAPI 设备/帧池/filter 图/编码器/muxer 6 步流水线（FFmpeg 严格顺序）
|
||
// - frames_rgb : 暴露内部 hw frames 池给捕获侧 import_dma_buf_to_vaapi 共享
|
||
// - encode_frame : 单帧驱动：送入 filter → 拉过滤后帧 → avcodec_send_frame → drain_encoder
|
||
// - flush : EOF 处理：filter drain + 空帧 avcodec_send_frame 触发 encoder flush + write_trailer
|
||
// - drain_encoder: 内部辅助：循环 avcodec_receive_packet 直到 EAGAIN/EOF，重缩放 PTS 并写 muxer
|
||
impl EncState {
|
||
// 抑制 clippy::too_many_arguments：构造函数需要 11 个参数（捕获尺寸/编码尺寸/码率/GOP/帧率/变换/共享 hw ctx），
|
||
// 拆分为 builder 模式反而会增加 FFI 调用顺序出错的风险（FFmpeg 各步骤有严格依赖关系）。
|
||
#[allow(clippy::too_many_arguments)]
|
||
// 构造编码器：类比 Go `func NewEncState(...) (*EncState, error)`，11 个参数对应 6 步流水线配置。
|
||
// 返回 `Result<Self>` 用 `?` 把任何 FFI/IO 错误传播给调用方（state.rs/state_portal.rs）。
|
||
pub fn new(
|
||
drm_device: &Path,
|
||
output_path: &Path,
|
||
width: u32,
|
||
height: u32,
|
||
enc_width: u32,
|
||
enc_height: u32,
|
||
bitrate: u64,
|
||
gop_size: u32,
|
||
fps: u32,
|
||
transform: Transform,
|
||
existing_hw_ctx: Option<AvHwDevCtx>,
|
||
) -> Result<Self> {
|
||
tracing::info!(
|
||
"EncState::new: {width}x{height} enc={enc_width}x{enc_height} transform={transform:?}"
|
||
);
|
||
// 1. VAAPI device — reuse existing context if provided
|
||
// `match` 是 Rust 的 exhaustive 模式匹配（类似 Go `switch` 但更强：编译器强制覆盖所有分支）。
|
||
// `Option<AvHwDevCtx>` 等价于 Go `*AvHwDevCtx`（Some=value，None=nil），但类型系统强制处理 nil 情况。
|
||
let hw_device_ctx = match existing_hw_ctx {
|
||
Some(ctx) => ctx,
|
||
None => AvHwDevCtx::new_vaapi(drm_device)?,
|
||
};
|
||
|
||
let frames_rgb =
|
||
AvHwFrameCtx::for_capture(&hw_device_ctx, width, height, ff::format::Pixel::BGRA)?;
|
||
|
||
// 3. Filter graph — must be built BEFORE encoder config so we can derive
|
||
// hw_frames_ctx from the buffersink output (correct surface pool dimensions).
|
||
let mut video_filter = build_filter_graph(
|
||
&hw_device_ctx,
|
||
&frames_rgb,
|
||
width,
|
||
height,
|
||
enc_width,
|
||
enc_height,
|
||
fps,
|
||
transform,
|
||
)?;
|
||
|
||
let mut sink_ctx = video_filter
|
||
.get("out")
|
||
// `ok_or_else(|| ...)` 把 `Option<T>` 转为 `Result<T, E>`：None 时执行闭包构造错误。
|
||
// 闭包 `|| ...` 延迟构造（类比 Go `if x == nil { return fmt.Errorf(...) }`）；
|
||
// 末尾 `?` 把 Err 传播给调用方，Ok(t) 则解包继续。
|
||
.ok_or_else(|| anyhow::anyhow!("filter 'out' not found"))?;
|
||
// 中文概述：从 buffersink 取出硬件帧上下文并 `av_buffer_ref` 提升为拥有引用。
|
||
// SAFETY: sink_ctx is a live buffersink; the returned hw_frames_ctx is
|
||
// borrowed, so av_buffer_ref creates an owned reference.
|
||
let sink_hw_frames = unsafe {
|
||
let raw = ffi::av_buffersink_get_hw_frames_ctx(sink_ctx.as_mut_ptr());
|
||
if raw.is_null() {
|
||
bail!("buffersink has no hw_frames_ctx — filter graph may not be configured for hardware output");
|
||
}
|
||
let hw_ref = ffi::av_buffer_ref(raw);
|
||
if hw_ref.is_null() {
|
||
bail!("av_buffer_ref failed for buffersink hw_frames_ctx — likely out of memory");
|
||
}
|
||
hw_ref
|
||
};
|
||
|
||
// 中文概述：解引用 sink_hw_frames 检查 filter graph 输出尺寸与编码器期望尺寸是否一致；
|
||
// 不一致仅 warn（filter 可能做隐式 scale），不视为硬错误。
|
||
// SAFETY: sink_hw_frames is an owned AVBufferRef to an AVHWFramesContext
|
||
// returned by the validated filter graph.
|
||
unsafe {
|
||
let fc = (*sink_hw_frames).data as *mut ffi::AVHWFramesContext;
|
||
let actual_w = (*fc).width as u32;
|
||
let actual_h = (*fc).height as u32;
|
||
if actual_w != enc_width || actual_h != enc_height {
|
||
tracing::warn!(
|
||
"Filter output dimensions {actual_w}x{actual_h} differ from encoder dimensions {enc_width}x{enc_height}"
|
||
);
|
||
}
|
||
}
|
||
|
||
// 4. Find h264_vaapi encoder
|
||
// `ff::encoder::find_by_name("h264_vaapi")` 返回 `Option<Codec>`：FFmpeg 未编译 VAAPI 时为 None。
|
||
// `.ok_or_else(...)?` 链式：Option → Result → 自动传播。
|
||
let codec = ff::encoder::find_by_name("h264_vaapi")
|
||
.ok_or_else(|| anyhow::anyhow!("h264_vaapi encoder not found"))?;
|
||
|
||
// 块表达式 `{ ... }` 求值为最后一个表达式（无分号）的值：这里 `ctx.encoder().video()?`
|
||
// 返回 `Result<Encoder<Video>>`，`?` 解开为 `Encoder<Video>`，作为整个块的值赋给 `enc`。
|
||
// 类比 Go 的 `enc := func() *Encoder { ... return x }()` 但 Rust 的块是表达式级。
|
||
let mut enc = {
|
||
let ctx = ff::codec::Context::new_with_codec(codec);
|
||
ctx.encoder().video()?
|
||
};
|
||
|
||
enc.set_width(enc_width);
|
||
enc.set_height(enc_height);
|
||
enc.set_format(ff::format::Pixel::VAAPI);
|
||
enc.set_bit_rate(bitrate as usize);
|
||
enc.set_gop(gop_size);
|
||
enc.set_time_base(ff::Rational::new(1, fps as i32));
|
||
enc.set_max_b_frames(0);
|
||
|
||
// VBV rate limiting: caps IDR burst size for WebRTC. Without this a 4K
|
||
// scene change can produce a 256KB keyframe that overflows the UDP send
|
||
// buffer. bufsize=bitrate/4 ≈ 250ms of video at the target bitrate.
|
||
// 中文概述：直接写裸指针字段 rc_max_rate/rc_buffer_size 设置 VBV 上限，避免 4K IDR 帧击爆 UDP 缓冲。
|
||
unsafe {
|
||
let ctx_ptr = enc.as_mut_ptr();
|
||
(*ctx_ptr).rc_max_rate = bitrate as i64;
|
||
(*ctx_ptr).rc_buffer_size = (bitrate / 4) as i32;
|
||
}
|
||
|
||
// 中文概述：AV_CODEC_FLAG_GLOBAL_HEADER 必须在 open 之前设置，触发 SPS/PPS extradata 生成（muxer 做 Annex B → AVCC 转换时需要）。
|
||
// SAFETY: AV_CODEC_FLAG_GLOBAL_HEADER must be set BEFORE opening the encoder.
|
||
// It triggers SPS/PPS extradata generation needed by the muxer for
|
||
// Annex B to AVCC conversion.
|
||
unsafe {
|
||
(*enc.as_mut_ptr()).flags |= ffi::AV_CODEC_FLAG_GLOBAL_HEADER as i32;
|
||
}
|
||
// 中文概述：把 hw_device_ctx 与 sink_hw_frames（filter 输出帧池）引用赋给编码器，编码器从该池分配 VAAPI surface。
|
||
// SAFETY: Assign hw device and frames ctx to the encoder.
|
||
unsafe {
|
||
(*enc.as_mut_ptr()).hw_device_ctx = hw_device_ctx.ref_clone();
|
||
(*enc.as_mut_ptr()).hw_frames_ctx = sink_hw_frames;
|
||
}
|
||
|
||
// SAFETY: Set repeat_pps=1 on the encoder so PPS is inserted in every encoded frame.
|
||
// This ensures decoders can start decoding from any frame (important for WebRTC).
|
||
// Note: repeat_pps is only available in FFmpeg 7.0+ (not in 6.x). On older FFmpeg,
|
||
// IDR frames carry SPS by default; PPS repetition depends on the driver.
|
||
// For SPS repetition: IDR frames carry SPS by default, controlled by gop_size/idr_interval.
|
||
{
|
||
let key = CString::new("repeat_pps").unwrap();
|
||
let val = CString::new("1").unwrap();
|
||
let ret = unsafe {
|
||
ffi::av_opt_set((*enc.as_mut_ptr()).priv_data, key.as_ptr(), val.as_ptr(), 0)
|
||
};
|
||
if ret < 0 {
|
||
tracing::warn!("av_opt_set repeat_pps failed ({}), likely FFmpeg < 7.0; continuing without per-frame PPS", ff_err(ret));
|
||
}
|
||
}
|
||
|
||
// 5. Open encoder. Video::open() returns Encoder(Video); .0 extracts the Video.
|
||
// `.map_err(|e| ...)?` 用闭包包装错误上下文（保留原始 ffmpeg::Error，附加上下文消息），
|
||
// `?` 自动传播。元组解构 `opened.0`：`Encoder(Video)` 是 newtype 包装，`.0` 取内部 Video。
|
||
let opened = enc
|
||
.open()
|
||
.map_err(|e| anyhow::anyhow!("Failed to open h264_vaapi encoder: {e}"))?;
|
||
let enc_video = opened.0;
|
||
|
||
// 6. Muxer setup (strict order)
|
||
// `CString` 是 Rust ↔ C FFI 的桥梁：FFmpeg C API 需要以 `\0` 结尾的字符串，
|
||
// Rust `String`/`&str` 不带终止符，必须用 `CString::new` 包装。
|
||
// `output_path.to_str().unwrap()` 把 `Path` 转 UTF-8 字符串切片（非 UTF-8 路径会 panic）。
|
||
let output_cstr = CString::new(output_path.to_str().unwrap())?;
|
||
// 裸指针声明：`*mut ffi::AVFormatContext` 是 C 指针（FFI 类型），Rust 中默认不可解引用。
|
||
// `ptr::null_mut()` 等价于 C 的 `NULL`；FFmpeg C API 接收 `**` 时会重新分配并写回。
|
||
let mut fmt_ctx_ptr: *mut ffi::AVFormatContext = ptr::null_mut();
|
||
|
||
// 中文概述：根据文件扩展名（.mp4/.mkv/...）分配输出 format context，但不打开文件。
|
||
// SAFETY: avformat_alloc_output_context2 creates format context from
|
||
// the file extension. Does NOT open the file.
|
||
let ret = unsafe {
|
||
ffi::avformat_alloc_output_context2(
|
||
&mut fmt_ctx_ptr,
|
||
ptr::null_mut(),
|
||
ptr::null(),
|
||
output_cstr.as_ptr(),
|
||
)
|
||
};
|
||
if ret < 0 || fmt_ctx_ptr.is_null() {
|
||
bail!("Failed to allocate output format context: {}", ff_err(ret));
|
||
}
|
||
|
||
// 中文概述：检查编码器 codec_id 与 muxer oformat 是否兼容（H.264 + MP4 应返回 ≥0）。
|
||
// SAFETY: avformat_query_codec checks codec+format compatibility.
|
||
let codec_id = unsafe { (*enc_video.as_ptr()).codec_id };
|
||
let oformat = unsafe { (*fmt_ctx_ptr).oformat };
|
||
let compat = unsafe {
|
||
ffi::avformat_query_codec(oformat, codec_id, ffi::FF_COMPLIANCE_NORMAL as i32)
|
||
};
|
||
if compat < 0 {
|
||
bail!("H.264 codec not supported by output container format");
|
||
}
|
||
|
||
// 中文概述：在 format context 中新建一条 stream（视频流），返回的指针由 fmt_ctx 拥有，无需手动释放。
|
||
// SAFETY: avformat_new_stream creates a new stream in the format context.
|
||
let stream_ptr = unsafe { ffi::avformat_new_stream(fmt_ctx_ptr, ptr::null()) };
|
||
if stream_ptr.is_null() {
|
||
bail!("Failed to create new stream in output context");
|
||
}
|
||
|
||
// 中文概述：从 encoder 拷贝参数（含 SPS/PPS extradata）到 stream->codecpar，供 demuxer 解析。
|
||
// SAFETY: avcodec_parameters_from_context copies encoder params + extradata.
|
||
let ret = unsafe {
|
||
ffi::avcodec_parameters_from_context((*stream_ptr).codecpar, enc_video.as_ptr())
|
||
};
|
||
if ret < 0 {
|
||
bail!(
|
||
"Failed to copy encoder parameters to stream: {}",
|
||
ff_err(ret)
|
||
);
|
||
}
|
||
|
||
// 中文概述：把 encoder 的 time_base（1/fps）拷贝到 stream，muxer 写头部时按此时基打时间戳。
|
||
// SAFETY: Copy encoder time_base to stream.
|
||
unsafe {
|
||
(*stream_ptr).time_base = (*enc_video.as_ptr()).time_base;
|
||
}
|
||
|
||
// 中文概述：打开输出文件 IO 上下文（AVIO），把 pb（AVIOContext*）挂到 fmt_ctx。
|
||
// SAFETY: avio_open opens the output file for writing.
|
||
let ret = unsafe {
|
||
ffi::avio_open(
|
||
&mut (*fmt_ctx_ptr).pb,
|
||
output_cstr.as_ptr(),
|
||
ffi::AVIO_FLAG_WRITE,
|
||
)
|
||
};
|
||
if ret < 0 {
|
||
bail!(
|
||
"Failed to open output file '{}': {}",
|
||
output_path.display(),
|
||
ff_err(ret)
|
||
);
|
||
}
|
||
|
||
// 中文概述：写入容器头部（MP4 ftyp box 等），失败需关闭 IO 释放资源（此处简化为直接 bail）。
|
||
// SAFETY: avformat_write_header writes the container header.
|
||
let ret = unsafe { ffi::avformat_write_header(fmt_ctx_ptr, ptr::null_mut()) };
|
||
if ret < 0 {
|
||
bail!("Failed to write output header: {}", ff_err(ret));
|
||
}
|
||
|
||
// 中文概述：把裸 fmt_ctx_ptr 包装回 safe Rust 的 Output 类型，由 octx 的 Drop 负责最终释放。
|
||
// SAFETY: We created fmt_ctx_ptr above and it's valid.
|
||
let octx = unsafe { ff::format::context::Output::wrap(fmt_ctx_ptr) };
|
||
|
||
// `Ok(Self { ... })` 是 Rust 构造语法：struct literal 字段简写（`enc_video` 等价于 `enc_video: enc_video`）。
|
||
// 类比 Go `return &EncState{enc_video: ..., ...}, nil`，但 Rust 的 `Self` 是类型别名。
|
||
Ok(Self {
|
||
enc_video,
|
||
frames_rgb,
|
||
video_filter,
|
||
hw_device_ctx,
|
||
octx,
|
||
starting_timestamp: None,
|
||
frames_written: false,
|
||
})
|
||
}
|
||
|
||
// 共享访问器：返回内部 hw frames 池的引用，捕获侧（state.rs/state_portal.rs）用它
|
||
// 给 `import_dma_buf_to_vaapi` 分配目标 VAAPI surface。借用检查器保证调用方不能
|
||
// 在持有 `&AvHwFrameCtx` 期间 `&mut self`（例如调用 `encode_frame`）。
|
||
pub fn frames_rgb(&self) -> &AvHwFrameCtx {
|
||
&self.frames_rgb
|
||
}
|
||
|
||
// 单帧驱动主循环：`&mut self` 表示独占借用（类比 Go `*receiver` + 单线程保证）。
|
||
// 接收一个 VAAPI 硬件帧，通过 filter 图（BGRA→NV12 + scale/crop）后送给编码器。
|
||
pub fn encode_frame(&mut self, hw_frame: &ff::frame::Video) -> Result<()> {
|
||
let mut filter_src_ctx = self
|
||
.video_filter
|
||
.get("in")
|
||
.ok_or_else(|| anyhow::anyhow!("filter 'in' not found"))?;
|
||
let mut filter_src = filter_src_ctx.source();
|
||
let mut filter_sink_ctx = self
|
||
.video_filter
|
||
.get("out")
|
||
.ok_or_else(|| anyhow::anyhow!("filter 'out' not found"))?;
|
||
let mut filter_sink = filter_sink_ctx.sink();
|
||
|
||
// SAFETY: hw_frame is a valid VAAPI hardware frame from capture.
|
||
filter_src
|
||
.add(hw_frame)
|
||
.map_err(|e| anyhow::anyhow!("Filter source add failed: {e}"))?;
|
||
|
||
// 持续从 sink 拉过滤后帧，直到 EAGAIN（filter 缓冲空）。
|
||
// `loop {}` 是 Rust 无限循环（类比 Go `for {}`），靠 `break` 退出。
|
||
loop {
|
||
// `ff::frame::Video::empty()` 分配零值帧（无数据），filter_sink.frame() 填充它。
|
||
// `&mut filtered` 把可变借用传给 ffmpeg-next，类比 Go `&filtered`。
|
||
let mut filtered = ff::frame::Video::empty();
|
||
// 多路 match：Ok 表示成功；带 guard 的 `Err(ff::Error::Other { errno }) if errno == ffi::EAGAIN`
|
||
// 是 pattern guard（类比 Go `switch v := err.(type); ...`）；通配 `Err(e)` 兜底。
|
||
match filter_sink.frame(&mut filtered) {
|
||
Ok(()) => {
|
||
// 若 filter 没设 PTS（pts()==None），用输入 hw_frame 的 PTS 兜底。
|
||
if filtered.pts().is_none() {
|
||
filtered.set_pts(hw_frame.pts());
|
||
}
|
||
}
|
||
Err(ff::Error::Other { errno }) if errno == ffi::EAGAIN => break,
|
||
Err(e) => bail!("Filter sink get frame failed: {e}"),
|
||
}
|
||
|
||
let pts = filtered.pts().unwrap_or(0);
|
||
if self.starting_timestamp.is_none() {
|
||
self.starting_timestamp = Some(pts);
|
||
}
|
||
let start_ts = self.starting_timestamp.unwrap();
|
||
|
||
// 中文概述：把过滤后的 NV12 VAAPI surface 发送给编码器输入队列；<0 表示 FFI 失败。
|
||
// SAFETY: avcodec_send_frame sends a valid NV12 VAAPI surface to the encoder.
|
||
let ret =
|
||
unsafe { ffi::avcodec_send_frame(self.enc_video.as_mut_ptr(), filtered.as_ptr()) };
|
||
if ret < 0 {
|
||
bail!("avcodec_send_frame failed: {}", ff_err(ret));
|
||
}
|
||
// 立即 drain 编码器输出队列：FFmpeg 编码可能延迟一帧或多帧才产出 packet，
|
||
// send_frame 后必须 receive_packet 直到 EAGAIN，否则编码器内部缓冲溢出。
|
||
self.drain_encoder(start_ts)?;
|
||
}
|
||
|
||
Ok(())
|
||
}
|
||
|
||
// EOF 处理：在调用方（state.rs/state_portal.rs）完成所有 `encode_frame` 后调用，
|
||
// 负责把 filter 图残余帧排空 + 触发编码器 EOS + 写 muxer trailer（moov box 等）。
|
||
pub fn flush(&mut self) -> Result<()> {
|
||
// Flush filter graph
|
||
let mut filter_src_ctx = self
|
||
.video_filter
|
||
.get("in")
|
||
.ok_or_else(|| anyhow::anyhow!("filter 'in' not found"))?;
|
||
let mut filter_src = filter_src_ctx.source();
|
||
// `if let Err(e) = ...` 模式匹配：只关心 Err 分支，Ok 丢弃。类比 Go `if err := ...; err != nil {}`。
|
||
if let Err(e) = filter_src.flush() {
|
||
tracing::debug!("filter source flush error: {e}");
|
||
}
|
||
|
||
// Drain filter
|
||
let mut filter_sink_ctx = self
|
||
.video_filter
|
||
.get("out")
|
||
.ok_or_else(|| anyhow::anyhow!("filter 'out' not found"))?;
|
||
// Drain filter：循环拉 sink，把 filter 图中残余的帧全部送入编码器。
|
||
// 与 encode_frame 不同：这里 Err 通配 `Err(_) => break`（任何错误都视为 drain 完毕），
|
||
// 因为 flush 是收尾阶段，不再传播错误。
|
||
let mut filter_sink = filter_sink_ctx.sink();
|
||
loop {
|
||
let mut filtered = ff::frame::Video::empty();
|
||
match filter_sink.frame(&mut filtered) {
|
||
Ok(()) => {
|
||
// `unwrap_or(0)` 是 Option 的兜底方法：None 返回 0，Some(v) 返回 v。
|
||
// flush 时若从未编码过帧（starting_timestamp=None），用 0 作为 PTS 基线。
|
||
let start_ts = self.starting_timestamp.unwrap_or(0);
|
||
// 中文概述：把 drain 出的帧送编码器；flush 路径失败也 bail（停止 flush）。
|
||
// SAFETY: filtered is a valid VAAPI frame drained from the
|
||
// filter graph; enc_video is an opened encoder.
|
||
let ret = unsafe {
|
||
ffi::avcodec_send_frame(self.enc_video.as_mut_ptr(), filtered.as_ptr())
|
||
};
|
||
if ret < 0 {
|
||
bail!("avcodec_send_frame failed during flush: {}", ff_err(ret));
|
||
}
|
||
self.drain_encoder(start_ts)?;
|
||
}
|
||
Err(_) => break,
|
||
}
|
||
}
|
||
|
||
// 中文概述：发送 NULL 帧给编码器，触发 EOS（End Of Stream），编码器内部缓冲的帧会被强制输出。
|
||
// SAFETY: Sending null frame signals end of stream to encoder.
|
||
unsafe {
|
||
ffi::avcodec_send_frame(self.enc_video.as_mut_ptr(), ptr::null());
|
||
}
|
||
|
||
let start_ts = self.starting_timestamp.unwrap_or(0);
|
||
// 最后一次 drain：取出 EOS 触发后所有剩余 packet。
|
||
self.drain_encoder(start_ts)?;
|
||
|
||
// Write trailer only if at least one frame was encoded.
|
||
// 写 trailer 条件：若全程 0 帧编码，写 trailer 会让 muxer 生成空 moov（损坏文件），所以用 frames_written 守卫。
|
||
if self.frames_written {
|
||
self.octx
|
||
.write_trailer()
|
||
.map_err(|e| anyhow::anyhow!("Failed to write trailer: {e}"))?;
|
||
}
|
||
|
||
Ok(())
|
||
}
|
||
|
||
// 内部辅助方法（无 pub）：每次 send_frame 后调用，循环 receive_packet 直到 EAGAIN/EOF。
|
||
// `start_ts: i64` 是首帧 PTS，用于把所有 packet 的 PTS/DTS 减去首帧 PTS（归零起点）。
|
||
fn drain_encoder(&mut self, start_ts: i64) -> Result<()> {
|
||
loop {
|
||
let mut pkt = ff::Packet::empty();
|
||
// 中文概述：从编码器拉一个已编码 packet；返回 <0 时区分 EAGAIN（暂时无）和 EOF（流结束）。
|
||
// SAFETY: avcodec_receive_packet retrieves an encoded packet.
|
||
let ret = unsafe {
|
||
ffi::avcodec_receive_packet(self.enc_video.as_mut_ptr(), pkt.as_mut_ptr())
|
||
};
|
||
if ret < 0 {
|
||
// 嵌套 if：先判 ret<0（FFI 错误），再判具体码（EAGAIN/EOF）。
|
||
// `ffi::AVERROR(ffi::EAGAIN)` 是 FFmpeg 的 errno 包装宏（负数）。
|
||
if ret == ffi::AVERROR(ffi::EAGAIN) || ret == ffi::AVERROR_EOF {
|
||
break;
|
||
}
|
||
bail!("avcodec_receive_packet failed: {}", ff_err(ret));
|
||
}
|
||
|
||
// Rescale timestamps from encoder time_base to stream time_base
|
||
// 时间基重缩放：encoder 用 1/fps，stream 可能用 1/1000 等不同基。
|
||
// rescale_ts 用有理数运算，避免浮点误差累积。
|
||
let enc_tb = self.enc_video.time_base();
|
||
// 中文概述：通过裸指针读 octx.streams[0].time_base，得到 stream 的时间基（由 muxer 决定）。
|
||
// SAFETY: octx was created with stream 0 during muxer setup; streams
|
||
// is non-null and stream 0 remains owned by the format context.
|
||
let stream_tb = unsafe {
|
||
let fmt = *self.octx.as_ptr();
|
||
if fmt.nb_streams == 0 || fmt.streams.is_null() {
|
||
bail!("no streams in output context");
|
||
}
|
||
// `fmt.streams.add(0)` 是裸指针算术： streams 是 `*mut *mut AVStream`，
|
||
// `.add(0)` 取首元素地址，外层 `*` 解引用得到 `*mut AVStream`。
|
||
let st = *fmt.streams.add(0);
|
||
ff::Rational::from((*st).time_base)
|
||
};
|
||
pkt.rescale_ts(enc_tb, stream_tb);
|
||
|
||
// Offset timestamps so first frame starts at 0
|
||
// PTS/DTS 归零：把首帧 PTS 减去自身得到 0，后续帧相对首帧的偏移。`if let Some(pts) = ...`
|
||
// 模式匹配：只有当 PTS 存在时才改写（部分 packet 可能没有 PTS）。
|
||
if let Some(pts) = pkt.pts() {
|
||
pkt.set_pts(Some(pts - start_ts));
|
||
}
|
||
if let Some(dts) = pkt.dts() {
|
||
pkt.set_dts(Some(dts - start_ts));
|
||
}
|
||
|
||
// 标记 packet 属于 stream 0（视频流）。
|
||
pkt.set_stream(0);
|
||
// 交错写入：muxer 内部会按 DTS 排序后写出，类比 Go `mp4Writer.WriteInterleaved(pkt)`。
|
||
pkt.write_interleaved(&mut self.octx)
|
||
.map_err(|e| anyhow::anyhow!("Failed to write packet: {e}"))?;
|
||
|
||
// 标记：至少一帧已写入 muxer（flush 时用此守卫决定是否写 trailer）。
|
||
self.frames_written = true;
|
||
}
|
||
Ok(())
|
||
}
|
||
}
|
||
|
||
// ---------------------------------------------------------------------------
|
||
// SwEncState - VAAPI GPU downscale + software H.264 encode
|
||
// ---------------------------------------------------------------------------
|
||
|
||
// 编码完成的 H.264 帧载体，是软件编码路径（SwEncEncode → WebRTC 通道）的输出单元。
|
||
// 与硬件路径 EncState 不同：硬件路径直接对接 avformat muxer，PTS 由 muxer 内部维护；
|
||
// 软件路径通过 crossbeam channel 把帧送到 webrtc 线程，必须显式携带 PTS 与捕获时间戳。
|
||
//
|
||
// 字段语义：
|
||
// - data：H.264 NAL 字节流（Annex B 或 AVCC，取决于 encoder 配置；本工程用 libx264 默认 Annex B）
|
||
// - pts_ticks：编码器 time_base 单位下的 PTS（WebRTC 模式下 time_base=1/90000，
|
||
// 直接对应 RTP 时间戳，90kHz 精度）
|
||
// - capture_time：墙上时钟捕获时刻，从 CpuNv12Frame 透传，用于 stats 的 frame_age 指标
|
||
//
|
||
// issue #24 背景：Wayland damage-driven 帧率波动大，若 PTS 用帧计数 * (1/fps) 估算，
|
||
// 浏览器 jitter buffer 会膨胀到秒级；必须用真实捕获时刻换算 PTS。
|
||
//
|
||
// 与 Go 对照：类似 Go 视频包结构体 `type Frame struct { Data []byte; PTSTicks int64; CaptureTime time.Time }`。
|
||
/// Encoded H.264 frame with timing metadata for WebRTC output.
|
||
///
|
||
/// MP4 file output (FrameOutput::Muxer) does NOT use this - it writes via
|
||
/// avformat which preserves PTS internally. WebRTC output (FrameOutput::Channel)
|
||
/// requires explicit PTS propagation so RTP timestamps reflect real capture time.
|
||
/// Without this, WebRTC clients' jitter buffers grow to seconds under
|
||
/// damage-driven variable frame rate. See issue #24.
|
||
#[derive(Debug)]
|
||
pub struct EncodedH264Frame {
|
||
/// H.264 NAL byte stream (Annex B or AVCC depending on encoder configuration)
|
||
pub data: Vec<u8>,
|
||
/// PTS in encoder time_base units (1/fps seconds), normalized so first frame = 0.
|
||
/// Derived from real capture time, NOT frame counter.
|
||
pub pts_ticks: i64,
|
||
/// Wall-clock capture time, propagated from CpuNv12Frame for frame_age stat.
|
||
pub capture_time: std::time::Instant,
|
||
}
|
||
|
||
// 编码器输出目的地二选一枚举：
|
||
// - Muxer：直接对接 FFmpeg avformat 写 MP4 文件（自包含 PTS，硬编码路径 EncState 风格）
|
||
// - Channel：crossbeam Sender<EncodedH264Frame>，把帧送 WebRTC 信令线程（必须显式带 PTS）
|
||
// 类比 Go：`type FrameOutput interface { Write(Frame) error }` 的两种实现。
|
||
// 该枚举让 SwEncEncode 在 new_muxer / new_webrtc 两个构造函数间共享同一 drain_encoder 主循环。
|
||
pub enum FrameOutput {
|
||
Muxer(ff::format::context::Output),
|
||
Channel(crossbeam_channel::Sender<EncodedH264Frame>),
|
||
}
|
||
|
||
// 主线程持有：完成 VAAPI GPU 下采样 + av_hwframe_transfer_data 回到 CPU 的 NV12 帧缓冲。
|
||
// 数据流：PipeWire/wlr 帧通过 import_and_scale 进入 → VAAPI scale_vaapi 转 NV12 →
|
||
// transfer_filtered_to_cpu 拷贝到 Vec<u8> → 通过 channel 跨线程送 SwEncEncode 编码线程。
|
||
// NV12 格式：Y 平面满分辨率，UV 交错平面半高（chroma 高度减半）；stride 可能 > width
|
||
// （对齐到 GPU 要求）。字段不带 GPU 资源（纯 CPU 内存），自动 Send。
|
||
/// Owned CPU NV12 frame data for cross-thread transfer.
|
||
/// Produced by main thread (VAAPI import + GPU scale + transfer), consumed by encode thread.
|
||
pub struct CpuNv12Frame {
|
||
pub y_data: Vec<u8>,
|
||
pub uv_data: Vec<u8>,
|
||
pub y_stride: usize,
|
||
pub uv_stride: usize,
|
||
pub pts: i64,
|
||
/// Wall-clock time when this frame was captured (PipeWire delivery).
|
||
/// Used for frame_age stat: time from capture to WebRTC send.
|
||
pub capture_time: std::time::Instant,
|
||
}
|
||
|
||
// 软件编码路径的"导入 + GPU 缩放"半部：负责把外部 DMA-BUF 帧（PipeWire/wlr）经
|
||
// VAAPI 硬件零拷贝导入 → scale_vaapi GPU 下采样 → av_hwframe_transfer_data 回传 CPU NV12，
|
||
// 最后封装为 CpuNv12Frame 喂给 SwEncEncode（libx264 软编）。
|
||
//
|
||
// 与 EncState（硬编直连）的区别：本结构仅做 GPU 辅助的导入/缩放，H.264 编码由 CPU 完成；
|
||
// 因此自始至终只在导入线程访问，跨线程边界是 channel（CpuNv12Frame）。
|
||
//
|
||
// 字段：
|
||
// - hw_dev / frames_rgb：VAAPI 设备 + BGRA 硬件帧上下文（DMA-BUF 导入目的地）
|
||
// - filter_graph：FFmpeg 滤镜图（scale_vaapi=M,w=enc:h=enc,format=nv12）
|
||
// - width/height：源帧尺寸；enc_width/enc_height：目标缩放后尺寸
|
||
// - resolution_rx / encoder_resolution_tx：可选的动态分辨率控制通道对
|
||
pub struct SwEncImport {
|
||
hw_dev: AvHwDevCtx,
|
||
frames_rgb: AvHwFrameCtx,
|
||
filter_graph: ff::filter::Graph,
|
||
width: u32,
|
||
height: u32,
|
||
enc_width: u32,
|
||
enc_height: u32,
|
||
fps: u32,
|
||
resolution_rx: Option<crossbeam_channel::Receiver<BitrateCommand>>,
|
||
encoder_resolution_tx: Option<crossbeam_channel::Sender<ResolutionChange>>,
|
||
}
|
||
|
||
// impl SwEncImport：5 个方法按数据流顺序
|
||
// (1) new / new_with_resolution_control：构造函数（建立 VAAPI + filter graph）
|
||
// (2) frames_rgb：访问器（暴露硬件帧上下文给外部 DMA-BUF 导入）
|
||
// (3) import_and_scale：单帧主流程（filter_src.add → filter_sink.frame 循环 → transfer_to_cpu）
|
||
// (4) flush_import：EOS 时排空 filter graph 缓冲
|
||
// (5) poll_resolution_commands + transfer_filtered_to_cpu：私有辅助
|
||
impl SwEncImport {
|
||
#[allow(clippy::too_many_arguments)]
|
||
pub fn new(
|
||
drm_device: &Path,
|
||
width: u32,
|
||
height: u32,
|
||
enc_width: u32,
|
||
enc_height: u32,
|
||
fps: u32,
|
||
) -> Result<Self> {
|
||
// drm_device 形如 /dev/dri/renderD128；AvHwDevCtx::new_vaapi 内部打开 DRM fd 并
|
||
// 调 vaGetDisplayDRM / vaInitialize 建立 VAAPI 连接（FFmpeg hwcontext_vaapi）。
|
||
// ? 自动传播 Result（类比 Go `if err != nil { return err }`）。
|
||
let hw_dev = AvHwDevCtx::new_vaapi(drm_device)?;
|
||
// 硬件帧上下文：调用 vaCreateSurfaces 申请 BGRA surface 池供 DMA-BUF 导入使用；
|
||
// AV_PIX_FMT_BGRA 对应 PipeWire/wlr 帧的常见 RGB 格式。返回的 AvHwFrameCtx 持有
|
||
// AVHWFramesContext，surface 池大小由 FFmpeg 默认（通常 4-8 帧）。
|
||
let frames_rgb =
|
||
AvHwFrameCtx::for_capture(&hw_dev, width, height, ff::format::Pixel::BGRA)?;
|
||
// 建立 scale_vaapi 滤镜图：源=BGRA/VAAPI，scale=enc_width×enc_height，format=nv12。
|
||
// 滤镜图绑定的 hw_dev 与 frames_rgb 必须同属一个 VAAPI 设备，否则 vaCreateSurfaces
|
||
// 在不同 display 上会失败。
|
||
let filter_graph = build_swenc_filter_graph(
|
||
&hw_dev,
|
||
&frames_rgb,
|
||
width,
|
||
height,
|
||
enc_width,
|
||
enc_height,
|
||
fps,
|
||
)?;
|
||
|
||
// Self 是返回类型的别名（Rust 构造器惯用法，类比 Go `return &Foo{...}` 中的 Foo）。
|
||
// 字段简写：当局部变量名与字段名相同时可省略 `field: value`，等价于 Go 结构体字面量简写。
|
||
// resolution_rx / encoder_resolution_tx 留 None，由 new_with_resolution_control 后续填充。
|
||
Ok(Self {
|
||
hw_dev,
|
||
frames_rgb,
|
||
filter_graph,
|
||
width,
|
||
height,
|
||
enc_width,
|
||
enc_height,
|
||
fps,
|
||
resolution_rx: None,
|
||
encoder_resolution_tx: None,
|
||
})
|
||
}
|
||
|
||
#[allow(clippy::too_many_arguments)]
|
||
pub fn new_with_resolution_control(
|
||
drm_device: &Path,
|
||
width: u32,
|
||
height: u32,
|
||
enc_width: u32,
|
||
enc_height: u32,
|
||
fps: u32,
|
||
resolution_rx: crossbeam_channel::Receiver<BitrateCommand>,
|
||
encoder_resolution_tx: crossbeam_channel::Sender<ResolutionChange>,
|
||
) -> Result<Self> {
|
||
let mut this = Self::new(drm_device, width, height, enc_width, enc_height, fps)?;
|
||
this.resolution_rx = Some(resolution_rx);
|
||
this.encoder_resolution_tx = Some(encoder_resolution_tx);
|
||
Ok(this)
|
||
}
|
||
|
||
pub fn frames_rgb(&self) -> &AvHwFrameCtx {
|
||
let _ = self.hw_dev.as_ptr();
|
||
&self.frames_rgb
|
||
}
|
||
|
||
pub fn import_and_scale(&mut self, hw_frame: &ff::frame::Video) -> Result<CpuNv12Frame> {
|
||
// 先消费 ResolutionChange 命令：若分辨率改变，本函数后续的 filter graph 已是新图。
|
||
self.poll_resolution_commands()?;
|
||
|
||
// 拿到滤镜图的输入/输出端点（"in"/"out" 是 build_swenc_filter_graph 中注册的名称）。
|
||
// ok_or_else 把 Option<Result> 转 Result（延迟构造错误，类比 Go `if x == nil { return err }`）。
|
||
// ? 自动传播 Result；mut 因为 source()/sink() 返回 &mut 借用。
|
||
let mut filter_src_ctx = self
|
||
.filter_graph
|
||
.get("in")
|
||
.ok_or_else(|| anyhow::anyhow!("filter 'in' not found"))?;
|
||
let mut filter_src = filter_src_ctx.source();
|
||
let mut filter_sink_ctx = self
|
||
.filter_graph
|
||
.get("out")
|
||
.ok_or_else(|| anyhow::anyhow!("filter 'out' not found"))?;
|
||
let mut filter_sink = filter_sink_ctx.sink();
|
||
|
||
// 把外部导入的硬件帧（hw_frame 是 AV_PIX_FMT_DRM_PRIME/VAAPI，VASurfaceID 在 data[3]）
|
||
// 送入滤镜图入口。滤镜图内部 scale_vaapi 执行 GPU 下采样 + 格式转换。
|
||
// map_err 把 ffmpeg::Error 包装成 anyhow::Error 加上下文。
|
||
filter_src
|
||
.add(hw_frame)
|
||
.map_err(|e| anyhow::anyhow!("software pipeline filter source add failed: {e}"))?;
|
||
|
||
// filter graph 可能产生多帧（理论上 scale_vaapi 1:1，但 deinterlace/ fps 滤镜可能 1:N）。
|
||
// 这里只取第一帧；额外帧计数后丢并 warn。EAGAIN 表示滤镜图已 drain 完毕。
|
||
let mut first = None;
|
||
let mut extra_count = 0usize;
|
||
loop {
|
||
let mut filtered = ff::frame::Video::empty();
|
||
match filter_sink.frame(&mut filtered) {
|
||
Ok(()) => {
|
||
// 若 filter 没有显式设置 PTS（罕见），用源帧 PTS 兜底。
|
||
if filtered.pts().is_none() {
|
||
filtered.set_pts(hw_frame.pts());
|
||
}
|
||
let cpu_frame = self.transfer_filtered_to_cpu(&filtered)?;
|
||
if first.is_none() {
|
||
first = Some(cpu_frame);
|
||
} else {
|
||
extra_count += 1;
|
||
}
|
||
}
|
||
// ffi::EAGAIN：滤镜图当前没有输出可取；这是正常的"等下一帧"信号，break 主循环。
|
||
// 类比 Go 中 io.Read 返回 EAGAIN。
|
||
Err(ff::Error::Other { errno }) if errno == ffi::EAGAIN => break,
|
||
Err(e) => bail!("software pipeline filter sink get frame failed: {e}"),
|
||
}
|
||
}
|
||
|
||
if extra_count > 0 {
|
||
tracing::warn!(
|
||
"software import filter produced {extra_count} extra frame(s); dropping extras"
|
||
);
|
||
}
|
||
|
||
// first 一定存在：filter_src.add 成功后 scale_vaapi 至少产出一帧；
|
||
// 若不产出说明上游 filter graph 配置错误或 hw_frame 无效，返回错误。
|
||
first.ok_or_else(|| anyhow::anyhow!("software pipeline produced no scaled frame"))
|
||
}
|
||
|
||
pub fn flush_import(&mut self) -> Result<Vec<CpuNv12Frame>> {
|
||
let mut filter_src_ctx = self
|
||
.filter_graph
|
||
.get("in")
|
||
.ok_or_else(|| anyhow::anyhow!("filter 'in' not found"))?;
|
||
let mut filter_src = filter_src_ctx.source();
|
||
if let Err(e) = filter_src.flush() {
|
||
tracing::debug!("filter source flush error: {e}");
|
||
}
|
||
|
||
let mut filter_sink_ctx = self
|
||
.filter_graph
|
||
.get("out")
|
||
.ok_or_else(|| anyhow::anyhow!("filter 'out' not found"))?;
|
||
let mut filter_sink = filter_sink_ctx.sink();
|
||
let mut frames = Vec::new();
|
||
loop {
|
||
let mut filtered = ff::frame::Video::empty();
|
||
match filter_sink.frame(&mut filtered) {
|
||
Ok(()) => frames.push(self.transfer_filtered_to_cpu(&filtered)?),
|
||
Err(_) => break,
|
||
}
|
||
}
|
||
|
||
Ok(frames)
|
||
}
|
||
|
||
fn poll_resolution_commands(&mut self) -> Result<()> {
|
||
let Some(rx) = self.resolution_rx.as_ref().cloned() else {
|
||
return Ok(());
|
||
};
|
||
|
||
let mut requested = None;
|
||
while let Ok(cmd) = rx.try_recv() {
|
||
match cmd {
|
||
BitrateCommand::UpdateResolution { width, height } => {
|
||
requested = Some((width & !1, height & !1));
|
||
}
|
||
BitrateCommand::UpdateBitrate { .. } => {}
|
||
BitrateCommand::ForceKeyframe => {}
|
||
}
|
||
}
|
||
|
||
let Some((width, height)) = requested else {
|
||
return Ok(());
|
||
};
|
||
if width == self.enc_width && height == self.enc_height {
|
||
return Ok(());
|
||
}
|
||
|
||
tracing::info!(
|
||
from = format_args!("{}x{}", self.enc_width, self.enc_height),
|
||
to = format_args!("{}x{}", width, height),
|
||
"rebuilding software import filter graph for resolution change"
|
||
);
|
||
let _ = self.flush_import();
|
||
self.filter_graph = build_swenc_filter_graph(
|
||
&self.hw_dev,
|
||
&self.frames_rgb,
|
||
self.width,
|
||
self.height,
|
||
width,
|
||
height,
|
||
self.fps,
|
||
)?;
|
||
self.enc_width = width;
|
||
self.enc_height = height;
|
||
|
||
if let Some(tx) = &self.encoder_resolution_tx {
|
||
tx.send(ResolutionChange { width, height })
|
||
.map_err(|_| anyhow::anyhow!("encoder resolution channel disconnected"))?;
|
||
}
|
||
|
||
Ok(())
|
||
}
|
||
|
||
fn transfer_filtered_to_cpu(&self, filtered: &ff::frame::Video) -> Result<CpuNv12Frame> {
|
||
// 中文概述：分配一个 CPU 侧的 AVFrame 作为 av_hwframe_transfer_data 的目标。
|
||
// 英文 SAFETY 详细论证见下方。
|
||
// SAFETY: av_frame_alloc returns a newly allocated AVFrame or null,
|
||
// which is checked below.
|
||
let mut sw_nv12 = unsafe { ffi::av_frame_alloc() };
|
||
if sw_nv12.is_null() {
|
||
bail!("av_frame_alloc failed for NV12 transfer frame");
|
||
}
|
||
|
||
// 中文概述：GPU→CPU 数据回传。filtered 指向 VAAPI NV12 surface，
|
||
// av_hwframe_transfer_data 内部调用 vaGetImage 等同步原语把 GPU 显存拷贝到 sw_nv12。
|
||
// 英文 SAFETY 论证下方。
|
||
// SAFETY: sw_nv12 is an allocated destination frame; filtered is a valid VAAPI NV12
|
||
// surface produced by scale_vaapi at encoder dimensions.
|
||
let transfer_ret = unsafe { ffi::av_hwframe_transfer_data(sw_nv12, filtered.as_ptr(), 0) };
|
||
if transfer_ret < 0 {
|
||
// 中文概述：transfer 失败时必须释放 sw_nv12 防止泄漏；FFmpeg C API 无 RAII。
|
||
// SAFETY: sw_nv12 was allocated above and has not been freed yet.
|
||
unsafe { ffi::av_frame_free(&mut sw_nv12) };
|
||
bail!(
|
||
"av_hwframe_transfer_data failed for GPU-downscaled frame: {}",
|
||
ff_err(transfer_ret)
|
||
);
|
||
}
|
||
|
||
// 中文概述：从 AVFrame 字段读 Y/UV 平面指针、linesize、尺寸，校验后拷贝到 Vec<u8>。
|
||
// 错误路径同样调用 av_frame_free 释放。最后再次 av_frame_free 释放 sw_nv12 自身。
|
||
// 英文 SAFETY 详细论证见下方。
|
||
// SAFETY: sw_nv12 was filled by av_hwframe_transfer_data. NV12 planes 0 and 1 are
|
||
// initialized for enc_width x enc_height; linesize values define each row's byte span.
|
||
let frame = unsafe {
|
||
let y_ptr = (*sw_nv12).data[0];
|
||
let uv_ptr = (*sw_nv12).data[1];
|
||
if y_ptr.is_null() || uv_ptr.is_null() {
|
||
ffi::av_frame_free(&mut sw_nv12);
|
||
bail!("NV12 transfer frame missing Y/UV plane data");
|
||
}
|
||
let y_stride = (*sw_nv12).linesize[0] as usize;
|
||
let uv_stride = (*sw_nv12).linesize[1] as usize;
|
||
if (*sw_nv12).width != self.enc_width as i32
|
||
|| (*sw_nv12).height != self.enc_height as i32
|
||
{
|
||
ffi::av_frame_free(&mut sw_nv12);
|
||
bail!("NV12 transfer frame has unexpected dimensions");
|
||
}
|
||
let y_len = y_stride * self.enc_height as usize;
|
||
let uv_len = uv_stride * (self.enc_height as usize / 2);
|
||
// slice::from_raw_parts：把 C 的裸指针 + 长度变成 Rust 切片（零拷贝）。
|
||
// 紧接着 .to_vec() 立即深拷贝，避免 sw_nv12 释放后切片悬空。
|
||
let y_data = slice::from_raw_parts(y_ptr, y_len).to_vec();
|
||
let uv_data = slice::from_raw_parts(uv_ptr, uv_len).to_vec();
|
||
let pts = filtered.pts().unwrap_or(0);
|
||
ffi::av_frame_free(&mut sw_nv12);
|
||
CpuNv12Frame {
|
||
y_data,
|
||
uv_data,
|
||
y_stride,
|
||
uv_stride,
|
||
pts,
|
||
capture_time: std::time::Instant::now(),
|
||
}
|
||
};
|
||
|
||
Ok(frame)
|
||
}
|
||
}
|
||
|
||
// 软件编码路径的"CPU 编码"半部：消费 CpuNv12Frame（NV12），用 sws_scale 转 YUV420P，
|
||
// 喂 libx264 软件 H.264 编码器，输出 EncodedH264Frame。与 SwEncImport 配对使用：
|
||
// SwEncImport 负责 GPU 辅助导入/缩放，SwEncEncode 负责 CPU 编码；两者通过 channel 通信。
|
||
//
|
||
// 持有的 C 资源（裸指针，非 Send/Sync 自动，需手写 unsafe impl Send 见下）：
|
||
// - sws_ctx：FFmpeg SwsContext（NV12 → YUV420P 颜色空间转换器，无 resize）
|
||
// - yuv_frame：可复用的 AVFrame（YUV420P，尺寸 = enc_width × enc_height）
|
||
// - enc_video：打开的 libx264 AVCodecContext
|
||
//
|
||
// 其他字段是控制状态（动态码率/分辨率/关键帧请求、去重哈希、计时统计、WebRTC 暂停/断开）。
|
||
// 详见每个字段上方英文 ///（保留）。
|
||
pub struct SwEncEncode {
|
||
sws_ctx: *mut ffi::SwsContext,
|
||
enc_video: ff::codec::encoder::video::Video,
|
||
output: Option<FrameOutput>,
|
||
yuv_frame: *mut ffi::AVFrame,
|
||
last_frame_hash: u64,
|
||
frame_count: u64,
|
||
starting_timestamp: Option<i64>,
|
||
frames_written: bool,
|
||
webrtc_disconnected: bool,
|
||
webrtc_paused: Option<Arc<AtomicBool>>,
|
||
bitrate_rx: crossbeam_channel::Receiver<BitrateCommand>,
|
||
resolution_rx: crossbeam_channel::Receiver<ResolutionChange>,
|
||
enc_width: u32,
|
||
enc_height: u32,
|
||
fps: u32,
|
||
bitrate: u64,
|
||
gop_size: u32,
|
||
/// Set true when WebRTC requests a keyframe. Forces the next frame to
|
||
/// `AV_PICTURE_TYPE_I` and bypasses the dedup hash check. Cleared only
|
||
/// after `avcodec_send_frame` accepts the forced frame.
|
||
force_keyframe_pending: bool,
|
||
/// Last per-frame timing snapshot. Reset to `Default` at the start of
|
||
/// every `encode_cpu_frame` call (even on early returns) so stale values
|
||
/// from a previous frame can never leak out.
|
||
last_timing: SwEncodeTiming,
|
||
/// Capture time of the frame currently being encoded. Saved from the
|
||
/// input `CpuNv12Frame` so `drain_encoder` can propagate it into the
|
||
/// emitted `EncodedH264Frame` for the frame_age stat (issue #20).
|
||
last_capture_time: Option<Instant>,
|
||
}
|
||
|
||
// FNV-1a 64 位哈希常量，用于帧去重（见 encode_cpu_frame 调用 hash_sampled_y_plane）：
|
||
// - FNV1A_OFFSET_BASIS：初始哈希值（FNV 论文推荐的 64 位 offset basis）
|
||
// - FNV1A_PRIME：每字节乘法因子（64 位素数）
|
||
// - Y_PLANE_HASH_ROW_STEP：Y 平面采样步长（仅哈希每 8 行，性能与碰撞率权衡）
|
||
// 算法：hash = (hash XOR byte) * PRIME，每字节迭代；XOR + 乘法双混淆，分布均匀。
|
||
// 选择 FNV-1a 而非 CRC32：性能相当但无查表依赖，纯整数运算适合帧级 hot path。
|
||
// 64 位宽：1080p60 一帧 1920*1080*0.125 字节 ≈ 260KB 采样数据，32 位易碰撞。
|
||
const FNV1A_OFFSET_BASIS: u64 = 0xcbf29ce484222325;
|
||
const FNV1A_PRIME: u64 = 0x100000001b3;
|
||
const Y_PLANE_HASH_ROW_STEP: usize = 8;
|
||
|
||
// WebRTC 模式下的编码器 time_base 分母（90kHz）。匹配 RTP 视频时钟频率（RFC 3551）。
|
||
// 这样编码器输出的 PTS 直接就是 RTP 时间戳，无需二次换算（microsecond 精度足够）。
|
||
// MP4 模式保留 1/fps time_base 以简化文件写入。
|
||
/// WebRTC media clock frequency in Hz. Matches RTP clock for video (RFC 3551).
|
||
/// Used as encoder time_base denominator for WebRTC mode (1/90000) so that
|
||
/// PTS values directly become RTP timestamps with microsecond precision.
|
||
/// MP4 mode keeps 1/fps time_base for file output simplicity.
|
||
pub const WEBRTC_RTP_CLOCK_HZ: i128 = 90_000;
|
||
|
||
// 计算 NV12 Y 平面的 FNV-1a 采样哈希，用于检测连续帧是否像素相同（静帧去重）。
|
||
// 步长 Y_PLANE_HASH_ROW_STEP=8：仅哈希每 8 行的全部像素，跳过中间 7 行。
|
||
// 这是性能优化：1080p60 全量哈希 ~10MB/帧 * 60fps = 600MB/s 内存带宽；
|
||
// 采样到 ~1.3MB/帧仍能可靠检测桌面静止（多数静止帧大面积像素相同）。
|
||
//
|
||
// 等价 Go：
|
||
// hash := uint64(0xcbf29ce484222325)
|
||
// for row := 0; row < height; row += 8 {
|
||
// off := row * stride
|
||
// for _, b := range y_data[off:off+width] {
|
||
// hash ^= uint64(b); hash *= 0x100000001b3
|
||
// }
|
||
// }
|
||
// wrapping_mul：故意允许溢出回绕（u64 取模 2^64），等价于 Go 无符号溢出语义。
|
||
fn hash_sampled_y_plane(y_data: &[u8], width: usize, height: usize, stride: usize) -> u64 {
|
||
let mut hash = FNV1A_OFFSET_BASIS;
|
||
|
||
for row in (0..height).step_by(Y_PLANE_HASH_ROW_STEP) {
|
||
let row_start = row * stride;
|
||
let row_end = row_start + width;
|
||
for &byte in &y_data[row_start..row_end] {
|
||
hash ^= u64::from(byte);
|
||
hash = hash.wrapping_mul(FNV1A_PRIME);
|
||
}
|
||
}
|
||
|
||
hash
|
||
}
|
||
|
||
// unsafe impl Send 中文概述：SwEncEncode 含裸指针（sws_ctx / yuv_frame / enc_video），
|
||
// Rust 默认认为裸指针非 Send（防止跨线程共享 C 资源）。这里手写 unsafe impl Send 表示：
|
||
// 本类型在构造完成后只被 move 到一个编码线程，所有访问通过 &mut self 独占借用，
|
||
// 满足"单线程独占"模型。AGENTS.md 明确警告：跨线程移动这些 wrapper 前必须重审 exclusivity 假设。
|
||
// 英文 SAFETY 详细论证下方保留不动。
|
||
// SAFETY: SwEncEncode owns sws_ctx/yuv_frame/enc_video exclusively after construction.
|
||
// It is moved to a single encode thread and only accessed through &mut self there.
|
||
unsafe impl Send for SwEncEncode {}
|
||
|
||
// impl SwEncEncode：6 个方法按数据流顺序
|
||
// (1) new_muxer：构造函数，输出到 MP4 文件（new_with_resolution_control 调用）
|
||
// (2) new_webrtc：构造函数，输出到 crossbeam Sender<EncodedH264Frame>
|
||
// (3) flush：EOS 时排空编码器（send null frame + drain）
|
||
// (4) take_timing：取出最近一帧的 sws/encode 耗时统计
|
||
// (5) encode_cpu_frame：单帧主循环（NV12 → YUV420P → libx264 → drain → channel/muxer）
|
||
// (6) recreate_encoder / write_trailer_if_needed / drain_encoder：私有辅助
|
||
impl SwEncEncode {
|
||
#[allow(clippy::too_many_arguments)]
|
||
fn new_muxer(
|
||
output_path: &Path,
|
||
enc_width: u32,
|
||
enc_height: u32,
|
||
fps: u32,
|
||
bitrate: u64,
|
||
gop_size: u32,
|
||
) -> Result<Self> {
|
||
// MP4 muxer 模式构造函数：用 avformat 写文件，不接 WebRTC。
|
||
// 调用专用工厂函数（create_software_h264_muxer 内部完成 avformat_alloc_output +
|
||
// libx264 encoder + avio_open + write_header）。
|
||
let sws_ctx = create_nv12_to_yuv420p_sws(enc_width, enc_height)?;
|
||
let (enc_video, octx) =
|
||
create_software_h264_muxer(output_path, enc_width, enc_height, fps, bitrate, gop_size)?;
|
||
let yuv_frame = alloc_yuv420p_frame(enc_width, enc_height)?;
|
||
// 创建后立即 drop 发送端的 dummy channel idiom：构造一个容量 1 的 channel，
|
||
// 拿到接收端后立刻丢弃发送端（drop(dummy_tx)），使接收端永远 recv 到 Disconnected。
|
||
// encode_cpu_frame 中的 try_recv 循环因此立即结束，等效"无分辨率控制"。
|
||
// 比用 Option<Receiver> 更优雅：避免每个调用点都 match Option。
|
||
let (dummy_tx, bitrate_rx) = crossbeam_channel::bounded(1);
|
||
drop(dummy_tx);
|
||
let (dummy_resolution_tx, resolution_rx) = crossbeam_channel::bounded(1);
|
||
drop(dummy_resolution_tx);
|
||
|
||
Ok(Self {
|
||
sws_ctx,
|
||
enc_video,
|
||
output: Some(FrameOutput::Muxer(octx)),
|
||
yuv_frame,
|
||
last_frame_hash: 0,
|
||
frame_count: 0,
|
||
starting_timestamp: None,
|
||
frames_written: false,
|
||
webrtc_disconnected: false,
|
||
webrtc_paused: None,
|
||
bitrate_rx,
|
||
resolution_rx,
|
||
enc_width,
|
||
enc_height,
|
||
fps,
|
||
bitrate,
|
||
gop_size,
|
||
force_keyframe_pending: false,
|
||
last_timing: SwEncodeTiming::default(),
|
||
last_capture_time: None,
|
||
})
|
||
}
|
||
|
||
#[allow(clippy::too_many_arguments)]
|
||
pub fn new_webrtc(
|
||
enc_width: u32,
|
||
enc_height: u32,
|
||
fps: u32,
|
||
bitrate: u64,
|
||
gop_size: u32,
|
||
tx: crossbeam_channel::Sender<EncodedH264Frame>,
|
||
webrtc_paused: Arc<AtomicBool>,
|
||
bitrate_rx: crossbeam_channel::Receiver<BitrateCommand>,
|
||
resolution_rx: crossbeam_channel::Receiver<ResolutionChange>,
|
||
) -> Result<Self> {
|
||
let sws_ctx = create_nv12_to_yuv420p_sws(enc_width, enc_height)?;
|
||
let enc_video =
|
||
create_software_h264_encoder(enc_width, enc_height, fps, bitrate, gop_size)?;
|
||
let yuv_frame = alloc_yuv420p_frame(enc_width, enc_height)?;
|
||
|
||
Ok(Self {
|
||
sws_ctx,
|
||
enc_video,
|
||
output: Some(FrameOutput::Channel(tx)),
|
||
yuv_frame,
|
||
last_frame_hash: 0,
|
||
frame_count: 0,
|
||
starting_timestamp: None,
|
||
frames_written: false,
|
||
webrtc_disconnected: false,
|
||
webrtc_paused: Some(webrtc_paused),
|
||
bitrate_rx,
|
||
resolution_rx,
|
||
enc_width,
|
||
enc_height,
|
||
fps,
|
||
bitrate,
|
||
gop_size,
|
||
force_keyframe_pending: false,
|
||
last_timing: SwEncodeTiming::default(),
|
||
last_capture_time: None,
|
||
})
|
||
}
|
||
|
||
pub fn flush(&mut self) -> Result<()> {
|
||
// 中文概述：flush 阶段，向打开的 libx264 编码器发送 NULL frame 触发 drain 模式。
|
||
// FFmpeg 契约：send_frame(NULL) 表示输入 EOS，后续 receive_packet 直到返回 AVERROR_EOF。
|
||
// AVERROR_EOF 在内部被忽略（已 drain 完毕），其他错误传播。
|
||
// 英文 SAFETY 见下方。
|
||
// SAFETY: Sending a null frame flushes the opened software encoder;
|
||
// no frame data is dereferenced. enc_video is exclusively borrowed via &mut self.
|
||
unsafe {
|
||
let ret = ffi::avcodec_send_frame(self.enc_video.as_mut_ptr(), ptr::null());
|
||
if ret < 0 && ret != ffi::AVERROR_EOF {
|
||
bail!("software encoder flush send failed: {}", ff_err(ret));
|
||
}
|
||
}
|
||
let start_ts = self.starting_timestamp.unwrap_or(0);
|
||
let _ = self.drain_encoder(start_ts)?;
|
||
|
||
Ok(())
|
||
}
|
||
|
||
pub fn take_timing(&mut self) -> SwEncodeTiming {
|
||
mem::take(&mut self.last_timing)
|
||
}
|
||
|
||
pub fn encode_cpu_frame(&mut self, frame: &CpuNv12Frame) -> Result<EncodeOutcome> {
|
||
// 每帧开始：把计时统计置零，避免上一帧的 stale 值泄漏（last_timing 字段注释见 struct）。
|
||
self.last_timing = SwEncodeTiming::default();
|
||
// Save capture_time so drain_encoder can propagate it into the
|
||
// EncodedH264Frame emitted via the WebRTC channel (issue #20).
|
||
self.last_capture_time = Some(frame.capture_time);
|
||
|
||
// WebRTC 通道已断开（之前 drain_encoder 检测到 Disconnected）→ 后续帧直接跳过。
|
||
if self.webrtc_disconnected {
|
||
return Ok(EncodeOutcome::SkippedDisconnected);
|
||
}
|
||
|
||
// 必须先 drain bitrate 命令再做 stride 检查：导入线程在 emit ResolutionChange 后
|
||
// 才送来新的（更小 stride 的）帧；若先检查 stride 会因旧 stride 与新帧不匹配误报。
|
||
// Must drain before the stride check: the import thread emits
|
||
// ResolutionChange before the new (smaller-stride) frame arrives.
|
||
while let Ok(cmd) = self.bitrate_rx.try_recv() {
|
||
match cmd {
|
||
BitrateCommand::UpdateBitrate { target_bps } => {
|
||
// #23 defensive guardrail: clamp to reasonable max even if policy layer
|
||
// is bypassed. 50 Mbps is a hard ceiling; primary cap is enforced in
|
||
// state_portal.rs webrtc_thread_loop via --max-bitrate flag.
|
||
const ENCODER_BITRATE_HARD_CAP: u64 = 50_000_000;
|
||
let target_bps = target_bps.min(ENCODER_BITRATE_HARD_CAP);
|
||
tracing::info!(target_bps, "updating encoder bitrate from BWE feedback");
|
||
self.bitrate = target_bps;
|
||
// 中文概述：直接写 libx264 AVCodecContext 的 bit_rate 字段（i64），
|
||
// 实时调整编码器输出码率（BWE 反馈驱动）。英文 SAFETY 见下方。
|
||
// SAFETY: enc_video is an opened AVCodecContext exclusively owned by &mut self.
|
||
unsafe {
|
||
let ctx = self.enc_video.as_mut_ptr();
|
||
(*ctx).bit_rate = target_bps as i64;
|
||
}
|
||
}
|
||
BitrateCommand::UpdateResolution { .. } => {}
|
||
BitrateCommand::ForceKeyframe => {
|
||
self.force_keyframe_pending = true;
|
||
tracing::debug!("encode thread: ForceKeyframe requested");
|
||
}
|
||
}
|
||
}
|
||
|
||
// 暂存 keyframe 请求状态：实际使用在本函数后段（pict_type 设置处），中间可能被覆盖。
|
||
let force_this_frame = self.force_keyframe_pending;
|
||
|
||
// drain ResolutionChange 通道：若分辨率变化，调用 recreate_encoder 重建 libx264 +
|
||
// sws_ctx + yuv_frame（避免在帧处理中途重建，确保后续 unsafe 块看到的字段一致）。
|
||
while let Ok(change) = self.resolution_rx.try_recv() {
|
||
self.recreate_encoder(change.width, change.height)?;
|
||
}
|
||
|
||
if frame.y_stride < self.enc_width as usize || frame.uv_stride < self.enc_width as usize {
|
||
bail!("CPU NV12 frame stride is smaller than encoder width");
|
||
}
|
||
// 暂停检查：webrtc_paused 是 Arc<AtomicBool>（跨线程共享），Relaxed 内存序足够
|
||
// （单字段读，不参与 happens-before 协调；类比 Go atomic.LoadInt32）。
|
||
if let Some(ref paused) = self.webrtc_paused {
|
||
if paused.load(Ordering::Relaxed) {
|
||
return Ok(EncodeOutcome::SkippedPaused);
|
||
}
|
||
}
|
||
|
||
let width = self.enc_width as usize;
|
||
let height = self.enc_height as usize;
|
||
// required_y_len：Y 平面所需最小字节数 = (height-1) 行完整 stride + 末行 width 字节。
|
||
// 用于校验源帧尺寸合法（防御式编程，避免 from_raw_parts 越界）。
|
||
let required_y_len = frame.y_stride * height.saturating_sub(1) + width;
|
||
if frame.y_data.len() < required_y_len {
|
||
bail!("CPU NV12 frame Y plane is smaller than encoder dimensions");
|
||
}
|
||
|
||
let frame_index = self.frame_count;
|
||
self.frame_count = self.frame_count.saturating_add(1);
|
||
// 帧去重：FNV-1a 哈希 Y 平面采样点，与上一帧相同则丢帧（静帧优化）。
|
||
let current_hash = hash_sampled_y_plane(&frame.y_data, width, height, frame.y_stride);
|
||
// GOP 强制关键帧：每 gop_size 帧一个 I-frame（libx264 也可由 keyint 控制，但这里
|
||
// 用 force_gop_frame 显式触发）。
|
||
let force_gop_frame = self.gop_size > 0 && frame_index % u64::from(self.gop_size) == 0;
|
||
if frame_index > 0 && !force_gop_frame && !force_this_frame && current_hash == self.last_frame_hash {
|
||
tracing::debug!(frame_index, "skipping duplicate frame");
|
||
self.last_frame_hash = current_hash;
|
||
return Ok(EncodeOutcome::SkippedDuplicate);
|
||
}
|
||
self.last_frame_hash = current_hash;
|
||
|
||
let sws_start = Instant::now();
|
||
// 中文概述：sws_scale 把 NV12（含交错的 UV 半高平面）转 YUV420P（Y + U + V 三平面）。
|
||
// yuv_frame 是预分配的可复用 AVFrame，av_frame_make_writable 确保独占写权限。
|
||
// src_slices/src_strides 是 4 元素数组（FFmpeg 固定 API），后两个填 null/0。
|
||
// 英文 SAFETY 见下方。
|
||
// SAFETY: yuv_frame is an owned reusable YUV420P frame at the same dimensions as sw_nv12;
|
||
// sws_ctx was created for NV12 -> YUV420P with no resize, so sws_scale only converts format.
|
||
unsafe {
|
||
let ret = ffi::av_frame_make_writable(self.yuv_frame);
|
||
if ret < 0 {
|
||
bail!("av_frame_make_writable failed: {}", ff_err(ret));
|
||
}
|
||
let src_slices = [
|
||
frame.y_data.as_ptr(),
|
||
frame.uv_data.as_ptr(),
|
||
ptr::null(),
|
||
ptr::null(),
|
||
];
|
||
let src_strides = [frame.y_stride as i32, frame.uv_stride as i32, 0, 0];
|
||
let scaled = ffi::sws_scale(
|
||
self.sws_ctx,
|
||
src_slices.as_ptr(),
|
||
src_strides.as_ptr(),
|
||
0,
|
||
self.enc_height as i32,
|
||
(*self.yuv_frame).data.as_ptr() as *mut *mut u8,
|
||
(*self.yuv_frame).linesize.as_ptr() as *const i32,
|
||
);
|
||
if scaled < 0 {
|
||
bail!("sws_scale failed for software encoder: {scaled}");
|
||
}
|
||
}
|
||
let sws_us = sws_start.elapsed().as_micros() as u64;
|
||
|
||
let pts = frame.pts;
|
||
if self.starting_timestamp.is_none() {
|
||
self.starting_timestamp = Some(pts);
|
||
}
|
||
let start_ts = self.starting_timestamp.unwrap_or(0);
|
||
|
||
let enc_start = Instant::now();
|
||
// 中文概述：把 YUV420P 帧送入 libx264。pict_type 重置为 NONE（除非 force_this_frame
|
||
// 强制 I-frame）—— yuv_frame 复用，若不重置上一帧的 I-type 会泄漏到当前 P-frame。
|
||
// forced-idr=1 编码器选项让 AV_PICTURE_TYPE_I 触发真正的 IDR NALU（不是普通 I-frame）。
|
||
// 英文 SAFETY 详细论证下方。
|
||
// SAFETY: yuv_frame is initialized, writable, and matches the opened encoder format.
|
||
// pict_type is reset every frame: the AVFrame is reused, so without resetting to NONE
|
||
// a previously-forced I-type would leak into subsequent P-frames. With forced-idr=1
|
||
// set on the encoder, AV_PICTURE_TYPE_I produces a true IDR NALU.
|
||
unsafe {
|
||
(*self.yuv_frame).pts = pts;
|
||
(*self.yuv_frame).pict_type = if force_this_frame {
|
||
ffi::AVPictureType::AV_PICTURE_TYPE_I
|
||
} else {
|
||
ffi::AVPictureType::AV_PICTURE_TYPE_NONE
|
||
};
|
||
let ret = ffi::avcodec_send_frame(self.enc_video.as_mut_ptr(), self.yuv_frame);
|
||
if ret < 0 {
|
||
bail!(
|
||
"avcodec_send_frame failed for software encoder: {}",
|
||
ff_err(ret)
|
||
);
|
||
}
|
||
}
|
||
|
||
if force_this_frame {
|
||
self.force_keyframe_pending = false;
|
||
}
|
||
|
||
// drain_encoder 内部循环 avcodec_receive_packet，把所有编码好的 packet 写 muxer 或 channel。
|
||
let output_bytes = self.drain_encoder(start_ts)?;
|
||
let encode_us = enc_start.elapsed().as_micros() as u64;
|
||
|
||
self.last_timing = SwEncodeTiming {
|
||
sws_us,
|
||
encode_us,
|
||
output_bytes,
|
||
};
|
||
|
||
Ok(EncodeOutcome::Encoded)
|
||
}
|
||
|
||
fn recreate_encoder(&mut self, width: u32, height: u32) -> Result<()> {
|
||
if width == self.enc_width && height == self.enc_height {
|
||
return Ok(());
|
||
}
|
||
|
||
tracing::info!(
|
||
from = format_args!("{}x{}", self.enc_width, self.enc_height),
|
||
to = format_args!("{}x{}", width, height),
|
||
"recreating WebRTC software encoder for resolution change"
|
||
);
|
||
|
||
if !self.sws_ctx.is_null() {
|
||
// 中文概述：分辨率变化前先释放旧 sws_ctx（NV12→YUV420P 转换器），
|
||
// 紧接着把字段置 null 防止二次释放。英文 SAFETY 见下方。
|
||
// SAFETY: sws_ctx is owned exclusively by self and will be replaced below.
|
||
unsafe { ffi::sws_freeContext(self.sws_ctx) };
|
||
self.sws_ctx = ptr::null_mut();
|
||
}
|
||
if !self.yuv_frame.is_null() {
|
||
// 中文概述：同步释放旧 yuv_frame，av_frame_free 内部清空 data/extended_data。
|
||
// SAFETY: yuv_frame is owned exclusively by self and will be replaced below.
|
||
unsafe { ffi::av_frame_free(&mut self.yuv_frame) };
|
||
}
|
||
|
||
self.sws_ctx = create_nv12_to_yuv420p_sws(width, height)?;
|
||
self.enc_video =
|
||
create_software_h264_encoder(width, height, self.fps, self.bitrate, self.gop_size)?;
|
||
self.yuv_frame = alloc_yuv420p_frame(width, height)?;
|
||
self.enc_width = width;
|
||
self.enc_height = height;
|
||
self.last_frame_hash = 0;
|
||
self.frame_count = 0;
|
||
self.force_keyframe_pending = true;
|
||
|
||
Ok(())
|
||
}
|
||
|
||
fn write_trailer_if_needed(&mut self) -> Result<()> {
|
||
if self.frames_written {
|
||
if let Some(FrameOutput::Muxer(ref mut octx)) = self.output {
|
||
octx.write_trailer()
|
||
.map_err(|e| anyhow::anyhow!("Failed to write trailer: {e}"))?;
|
||
}
|
||
}
|
||
Ok(())
|
||
}
|
||
|
||
fn drain_encoder(&mut self, start_ts: i64) -> Result<usize> {
|
||
let mut total_bytes = 0usize;
|
||
// drain 循环：avcodec_send_frame 之后，必须反复调用 avcodec_receive_packet 直到 EAGAIN/EOF。
|
||
// FFmpeg 编码 API 是异步的：send_frame 立即返回，packet 通过 receive_packet 取出。
|
||
// 类比 Go 的 chan: send_frame=send, receive_packet=recv, EAGAIN=chan 空。
|
||
loop {
|
||
let mut pkt = ff::Packet::empty();
|
||
// 中文概述：从打开的 libx264 编码器取出一个已编码 packet。
|
||
// 英文 SAFETY 见下方。
|
||
// SAFETY: enc_video is an open encoder; pkt is writable packet storage.
|
||
let ret = unsafe {
|
||
ffi::avcodec_receive_packet(self.enc_video.as_mut_ptr(), pkt.as_mut_ptr())
|
||
};
|
||
if ret < 0 {
|
||
if ret == ffi::AVERROR(ffi::EAGAIN) || ret == ffi::AVERROR_EOF {
|
||
break;
|
||
}
|
||
bail!("avcodec_receive_packet failed: {}", ff_err(ret));
|
||
}
|
||
|
||
// Count encoded bytes produced before the Muxer/Channel match to
|
||
// avoid branch duplication and handle multi-packet drain correctly.
|
||
// 中文概述：从 AVPacket.size 读字节数累加，避免在 Muxer/Channel 分支里重复统计。
|
||
// 英文 SAFETY 见下方。
|
||
// SAFETY: pkt was just filled by a successful avcodec_receive_packet;
|
||
// the size field is valid and initialized.
|
||
let pkt_size = unsafe { (*pkt.as_mut_ptr()).size };
|
||
if pkt_size > 0 {
|
||
total_bytes += pkt_size as usize;
|
||
}
|
||
|
||
// 输出目的地二选一：Muxer 写文件，Channel 送 WebRTC 线程。
|
||
match self.output {
|
||
Some(FrameOutput::Muxer(ref mut octx)) => {
|
||
let enc_tb = self.enc_video.time_base();
|
||
// 中文概述：从 AVFormatContext 读 stream 0 的 time_base（muxer 写入时用）。
|
||
// 必须校验 nb_streams > 0 && streams 非空，防止空 muxer 触发 UB。
|
||
// 英文 SAFETY 见下方。
|
||
// SAFETY: muxer output was created with stream 0 during setup;
|
||
// streams is non-null and stream 0 remains owned by the format context.
|
||
let stream_tb = unsafe {
|
||
let fmt = *octx.as_ptr();
|
||
if fmt.nb_streams == 0 || fmt.streams.is_null() {
|
||
bail!("no streams in output context");
|
||
}
|
||
let st = *fmt.streams.add(0);
|
||
ff::Rational::from((*st).time_base)
|
||
};
|
||
// rescale_ts：编码器 time_base → 容器 time_base 的有理数换算。
|
||
pkt.rescale_ts(enc_tb, stream_tb);
|
||
|
||
// 减去起始 PTS 让首帧 PTS=0；Muxer 模式下 AVFormatContext 自己管 DTS。
|
||
if let Some(pts) = pkt.pts() {
|
||
pkt.set_pts(Some(pts - start_ts));
|
||
}
|
||
if let Some(dts) = pkt.dts() {
|
||
pkt.set_dts(Some(dts - start_ts));
|
||
}
|
||
|
||
pkt.set_stream(0);
|
||
pkt.write_interleaved(octx)
|
||
.map_err(|e| anyhow::anyhow!("Failed to write packet: {e}"))?;
|
||
self.frames_written = true;
|
||
}
|
||
Some(FrameOutput::Channel(ref tx)) => {
|
||
// 中文概述：把 AVPacket 字段读出到栈上 raw 结构体，用于检查 size/data。
|
||
// 英文 SAFETY 见下方。
|
||
// SAFETY: pkt is a valid AVPacket just filled by
|
||
// avcodec_receive_packet; this copies fields for
|
||
// read-only inspection before pkt is dropped.
|
||
let raw = unsafe { *pkt.as_mut_ptr() };
|
||
if raw.size > 0 && !raw.data.is_null() {
|
||
// 中文概述：从 raw.data 裸指针构造临时切片（零拷贝），随即 .to_vec() 深拷贝。
|
||
// 类比 Go 的 unsafe Slice((*byte)(data), size) → append(nil, slice...)。
|
||
// SAFETY: `pkt` is a valid AVPacket just filled by a successful
|
||
// `avcodec_receive_packet` call. We checked `size > 0` and
|
||
// `data` is non-null, so `data` points to `size` initialized
|
||
// bytes owned by the packet. `u8` has alignment 1, and the
|
||
// slice is copied into a Vec before the packet is unreffed.
|
||
let data: &[u8] =
|
||
unsafe { std::slice::from_raw_parts(raw.data, raw.size as usize) };
|
||
// Normalize PTS: subtract starting_timestamp so first frame = 0.
|
||
// Mirrors the Muxer branch normalization above. `start_ts` is
|
||
// self.starting_timestamp.unwrap_or(0) (passed by caller), so
|
||
// when no origin is recorded yet the subtraction is a no-op.
|
||
let pts_ticks = match pkt.pts() {
|
||
Some(p) => p - start_ts,
|
||
None => {
|
||
// libx264 should always set PTS; emitting RTP ts=0
|
||
// here would recreate issue #24. Drop the packet.
|
||
tracing::warn!(
|
||
"encoder produced packet without PTS, dropping"
|
||
);
|
||
continue;
|
||
}
|
||
};
|
||
// try_send 非阻塞：通道满或断开都立即返回（不阻塞 encode 线程）。
|
||
// 类比 Go 的 `select { case ch <- frame: default: drop }`。
|
||
match tx.try_send(EncodedH264Frame {
|
||
data: data.to_vec(),
|
||
pts_ticks,
|
||
capture_time: self
|
||
.last_capture_time
|
||
.unwrap_or_else(Instant::now),
|
||
}) {
|
||
Ok(()) => {}
|
||
Err(crossbeam_channel::TrySendError::Full(frame)) => {
|
||
tracing::warn!(
|
||
"WebRTC channel full, dropping frame: {} bytes lost",
|
||
frame.data.len()
|
||
);
|
||
}
|
||
Err(crossbeam_channel::TrySendError::Disconnected(frame)) => {
|
||
tracing::warn!(
|
||
"WebRTC channel disconnected: {} bytes lost",
|
||
frame.data.len()
|
||
);
|
||
// 设置断开标志，后续 encode_cpu_frame 调用立即 SkippedDisconnected，
|
||
// 避免每帧都重复走 sws_scale + encode + drain 的浪费路径。
|
||
self.webrtc_disconnected = true;
|
||
break;
|
||
}
|
||
}
|
||
}
|
||
}
|
||
None => {}
|
||
}
|
||
}
|
||
Ok(total_bytes)
|
||
}
|
||
}
|
||
|
||
// impl Drop for SwEncEncode：C 资源释放。enc_video 由 ff::codec::encoder::video::Video
|
||
// 包装，Drop 会自动调用 avcodec_close；sws_ctx 和 yuv_frame 是裸指针，必须在此手动释放。
|
||
// 类比 Go 的 `defer ffi.sws_freeContext(sws_ctx)`——Rust 没有原生 defer，但 Drop trait 等价。
|
||
impl Drop for SwEncEncode {
|
||
fn drop(&mut self) {
|
||
if !self.sws_ctx.is_null() {
|
||
// 中文概述：释放 sws_ctx。释放后置 null 防止二次释放（虽然 drop 后 self 立即销毁，
|
||
// 但这是防御式编程惯例，与 recreate_encoder 中的释放路径保持一致）。
|
||
// 英文 SAFETY 见下方。
|
||
// SAFETY: sws_ctx is owned by this state and was returned by sws_getContext.
|
||
unsafe { ffi::sws_freeContext(self.sws_ctx) };
|
||
self.sws_ctx = ptr::null_mut();
|
||
}
|
||
if !self.yuv_frame.is_null() {
|
||
// 中文概述：释放 yuv_frame。av_frame_free 接收 **mut 并内部置 null，无需手动置空。
|
||
// 英文 SAFETY 见下方。
|
||
// SAFETY: yuv_frame is owned by this state and was allocated by av_frame_alloc.
|
||
unsafe { ffi::av_frame_free(&mut self.yuv_frame) };
|
||
}
|
||
}
|
||
}
|
||
|
||
pub struct SwEncState {
|
||
import: SwEncImport,
|
||
encode: SwEncEncode,
|
||
}
|
||
|
||
// SAFETY: SwEncState owns import and encode state exclusively and existing sync callers move it
|
||
// between threads only with external serialization; all FFI handles are accessed through &mut self.
|
||
unsafe impl Send for SwEncState {}
|
||
|
||
impl SwEncState {
|
||
#[allow(clippy::too_many_arguments)]
|
||
pub fn new(
|
||
drm_device: &Path,
|
||
output_path: &Path,
|
||
width: u32,
|
||
height: u32,
|
||
enc_width: u32,
|
||
enc_height: u32,
|
||
fps: u32,
|
||
bitrate: u64,
|
||
gop_size: u32,
|
||
) -> Result<Self> {
|
||
tracing::info!(
|
||
"SwEncState::new: GPU downscale {width}x{height} BGRA -> {enc_width}x{enc_height} NV12, software H.264"
|
||
);
|
||
let import = SwEncImport::new(drm_device, width, height, enc_width, enc_height, fps)?;
|
||
let encode =
|
||
SwEncEncode::new_muxer(output_path, enc_width, enc_height, fps, bitrate, gop_size)?;
|
||
Ok(Self { import, encode })
|
||
}
|
||
|
||
#[allow(clippy::too_many_arguments)]
|
||
pub fn new_webrtc(
|
||
drm_device: &Path,
|
||
width: u32,
|
||
height: u32,
|
||
enc_width: u32,
|
||
enc_height: u32,
|
||
fps: u32,
|
||
bitrate: u64,
|
||
gop_size: u32,
|
||
tx: crossbeam_channel::Sender<EncodedH264Frame>,
|
||
webrtc_paused: Arc<AtomicBool>,
|
||
) -> Result<Self> {
|
||
tracing::info!(
|
||
"SwEncState::new_webrtc: GPU downscale {width}x{height} BGRA -> {enc_width}x{enc_height} NV12, software H.264 -> WebRTC"
|
||
);
|
||
let import = SwEncImport::new(drm_device, width, height, enc_width, enc_height, fps)?;
|
||
let (dummy_tx, bitrate_rx) = crossbeam_channel::bounded(1);
|
||
drop(dummy_tx);
|
||
let (dummy_resolution_tx, resolution_rx) = crossbeam_channel::bounded(1);
|
||
drop(dummy_resolution_tx);
|
||
let encode = SwEncEncode::new_webrtc(
|
||
enc_width,
|
||
enc_height,
|
||
fps,
|
||
bitrate,
|
||
gop_size,
|
||
tx,
|
||
webrtc_paused,
|
||
bitrate_rx,
|
||
resolution_rx,
|
||
)?;
|
||
Ok(Self { import, encode })
|
||
}
|
||
|
||
pub fn frames_rgb(&self) -> &AvHwFrameCtx {
|
||
self.import.frames_rgb()
|
||
}
|
||
|
||
pub fn encode_frame(&mut self, hw_frame: &ff::frame::Video) -> Result<()> {
|
||
let cpu_frame = self.import.import_and_scale(hw_frame)?;
|
||
self.encode.encode_cpu_frame(&cpu_frame).map(|_| ())
|
||
}
|
||
|
||
pub fn flush(&mut self) -> Result<()> {
|
||
for frame in self.import.flush_import()? {
|
||
self.encode.encode_cpu_frame(&frame)?;
|
||
}
|
||
self.encode.flush()?;
|
||
self.encode.write_trailer_if_needed()
|
||
}
|
||
}
|
||
|
||
// ---------------------------------------------------------------------------
|
||
// Shared encoder creation (used by both wlr-screencopy and portal paths)
|
||
// ---------------------------------------------------------------------------
|
||
|
||
/// Create a fully configured encoder with VAAPI hardware acceleration.
|
||
///
|
||
/// Convenience wrapper around [`EncState::new`] that computes default values
|
||
/// for `bitrate` and `gop_size` when not provided, and handles encoder dimension
|
||
/// transposition for rotated/transformed outputs.
|
||
#[allow(clippy::too_many_arguments)]
|
||
pub fn create_encoder(
|
||
drm_device: &Path,
|
||
output_path: &Path,
|
||
width: u32,
|
||
height: u32,
|
||
fps: u32,
|
||
transform: Transform,
|
||
bitrate: Option<u64>,
|
||
gop_size: Option<u32>,
|
||
existing_hw_ctx: Option<AvHwDevCtx>,
|
||
) -> Result<EncState> {
|
||
let (enc_w, enc_h) = transpose_if_transform_transposed(transform, width as i32, height as i32);
|
||
let actual_bitrate =
|
||
bitrate.unwrap_or_else(|| 2 * (width as u64) * (height as u64) * (fps as u64) / 100);
|
||
let actual_gop_size = gop_size.unwrap_or(fps);
|
||
EncState::new(
|
||
drm_device,
|
||
output_path,
|
||
width,
|
||
height,
|
||
enc_w as u32,
|
||
enc_h as u32,
|
||
actual_bitrate,
|
||
actual_gop_size,
|
||
fps,
|
||
transform,
|
||
existing_hw_ctx,
|
||
)
|
||
}
|
||
|
||
// ---------------------------------------------------------------------------
|
||
// Software-encode GPU-downscale helpers
|
||
// ---------------------------------------------------------------------------
|
||
|
||
#[allow(clippy::too_many_arguments)]
|
||
fn build_swenc_filter_graph(
|
||
hw_dev: &AvHwDevCtx,
|
||
frames_rgb: &AvHwFrameCtx,
|
||
width: u32,
|
||
height: u32,
|
||
enc_width: u32,
|
||
enc_height: u32,
|
||
fps: u32,
|
||
) -> Result<ff::filter::Graph> {
|
||
let mut graph = ff::filter::Graph::new();
|
||
let buffersrc =
|
||
ff::filter::find("buffer").ok_or_else(|| anyhow::anyhow!("filter 'buffer' not found"))?;
|
||
let buffersink = ff::filter::find("buffersink")
|
||
.ok_or_else(|| anyhow::anyhow!("filter 'buffersink' not found"))?;
|
||
let scale_vaapi = ff::filter::find("scale_vaapi")
|
||
.ok_or_else(|| anyhow::anyhow!("filter 'scale_vaapi' not found"))?;
|
||
|
||
// FFmpeg 8.0+ rejects VAAPI pix_fmt in buffer args before hw_frames_ctx is attached.
|
||
// Use a SW placeholder, then override format/hw_frames_ctx with av_buffersrc_parameters_set.
|
||
let args = format!(
|
||
"video_size={}x{}:pix_fmt=bgra:time_base=1/{fps}:pixel_aspect=1/1",
|
||
width, height,
|
||
);
|
||
let mut src_ctx = graph.add(&buffersrc, "in", &args)?;
|
||
|
||
// SAFETY: av_buffersrc_parameters_alloc returns newly allocated parameters
|
||
// or null, which is checked below.
|
||
let par = unsafe { ffi::av_buffersrc_parameters_alloc() };
|
||
if par.is_null() {
|
||
bail!("av_buffersrc_parameters_alloc returned null");
|
||
}
|
||
// SAFETY: par and src_ctx are valid; frames_rgb.ref_clone returns an owned hw_frames_ctx ref
|
||
// that buffersrc consumes on successful parameter set.
|
||
unsafe {
|
||
(*par).format = Into::<ffi::AVPixelFormat>::into(ff::format::Pixel::VAAPI) as i32;
|
||
(*par).width = width as i32;
|
||
(*par).height = height as i32;
|
||
(*par).time_base = ffi::AVRational {
|
||
num: 1,
|
||
den: fps as i32,
|
||
};
|
||
(*par).hw_frames_ctx = frames_rgb.ref_clone();
|
||
let ret = ffi::av_buffersrc_parameters_set(src_ctx.as_mut_ptr(), par);
|
||
ffi::av_free(par as *mut _);
|
||
if ret < 0 {
|
||
bail!("av_buffersrc_parameters_set failed: {}", ff_err(ret));
|
||
}
|
||
}
|
||
|
||
let mut scale_ctx = graph.add(
|
||
&scale_vaapi,
|
||
"scale",
|
||
&format!("{enc_width}:{enc_height}:format=nv12"),
|
||
)?;
|
||
// SAFETY: scale_vaapi keeps a ref-counted device context while the graph is alive.
|
||
unsafe {
|
||
(*scale_ctx.as_mut_ptr()).hw_device_ctx = hw_dev.ref_clone();
|
||
}
|
||
|
||
let mut sink_ctx = graph.add(&buffersink, "out", "")?;
|
||
src_ctx.link(0, &mut scale_ctx, 0);
|
||
scale_ctx.link(0, &mut sink_ctx, 0);
|
||
graph
|
||
.validate()
|
||
.map_err(|e| anyhow::anyhow!("software GPU filter graph validation failed: {e}"))?;
|
||
|
||
Ok(graph)
|
||
}
|
||
|
||
fn create_nv12_to_yuv420p_sws(width: u32, height: u32) -> Result<*mut ffi::SwsContext> {
|
||
// SAFETY: sws_getContext creates an owned scaler context for same-size NV12 -> YUV420P.
|
||
let ctx = unsafe {
|
||
ffi::sws_getContext(
|
||
width as i32,
|
||
height as i32,
|
||
ffi::AVPixelFormat::AV_PIX_FMT_NV12,
|
||
width as i32,
|
||
height as i32,
|
||
ffi::AVPixelFormat::AV_PIX_FMT_YUV420P,
|
||
2,
|
||
ptr::null_mut(),
|
||
ptr::null_mut(),
|
||
ptr::null_mut(),
|
||
)
|
||
};
|
||
if ctx.is_null() {
|
||
bail!("Failed to create NV12 -> YUV420P sws_scale context");
|
||
}
|
||
Ok(ctx)
|
||
}
|
||
|
||
fn alloc_yuv420p_frame(width: u32, height: u32) -> Result<*mut ffi::AVFrame> {
|
||
// SAFETY: Allocate an AVFrame, configure format/dimensions, then allocate writable buffers.
|
||
unsafe {
|
||
let mut frame = ffi::av_frame_alloc();
|
||
if frame.is_null() {
|
||
bail!("av_frame_alloc failed");
|
||
}
|
||
(*frame).width = width as i32;
|
||
(*frame).height = height as i32;
|
||
(*frame).format = ffi::AVPixelFormat::AV_PIX_FMT_YUV420P as i32;
|
||
let ret = ffi::av_frame_get_buffer(frame, 0);
|
||
if ret < 0 {
|
||
ffi::av_frame_free(&mut frame);
|
||
bail!("av_frame_get_buffer failed: {}", ff_err(ret));
|
||
}
|
||
Ok(frame)
|
||
}
|
||
}
|
||
|
||
fn create_software_h264_muxer(
|
||
output_path: &Path,
|
||
width: u32,
|
||
height: u32,
|
||
fps: u32,
|
||
bitrate: u64,
|
||
gop_size: u32,
|
||
) -> Result<(
|
||
ff::codec::encoder::video::Video,
|
||
ff::format::context::Output,
|
||
)> {
|
||
let output_cstr = CString::new(output_path.to_str().unwrap())?;
|
||
let codec = ff::encoder::find_by_name("libx264")
|
||
.or_else(|| ff::encoder::find_by_name("libopenh264"))
|
||
.ok_or_else(|| {
|
||
anyhow::anyhow!("No H.264 software encoder found (tried libx264, libopenh264)")
|
||
})?;
|
||
let codec_name = codec.name().to_string();
|
||
|
||
let mut enc = {
|
||
let ctx = ff::codec::Context::new_with_codec(codec);
|
||
ctx.encoder().video()?
|
||
};
|
||
enc.set_width(width);
|
||
enc.set_height(height);
|
||
enc.set_format(ff::format::Pixel::YUV420P);
|
||
enc.set_bit_rate(bitrate as usize);
|
||
enc.set_gop(gop_size);
|
||
enc.set_time_base(ff::Rational::new(1, fps as i32));
|
||
enc.set_max_b_frames(3);
|
||
|
||
// SAFETY: global headers are needed by MP4 and harmless for other common muxers.
|
||
unsafe {
|
||
(*enc.as_mut_ptr()).flags |= ffi::AV_CODEC_FLAG_GLOBAL_HEADER as i32;
|
||
}
|
||
|
||
if codec_name == "libx264" {
|
||
// SAFETY: priv_data and codec context belong to the unopened encoder;
|
||
// strings live for each av_opt_set call.
|
||
unsafe {
|
||
let key = CString::new("preset").unwrap();
|
||
let val = CString::new("fast").unwrap();
|
||
ffi::av_opt_set((*enc.as_mut_ptr()).priv_data, key.as_ptr(), val.as_ptr(), 0);
|
||
let key = CString::new("threads").unwrap();
|
||
let val = CString::new("6").unwrap();
|
||
ffi::av_opt_set((*enc.as_mut_ptr()).priv_data, key.as_ptr(), val.as_ptr(), 0);
|
||
(*enc.as_mut_ptr()).profile = ffi::AV_PROFILE_H264_HIGH as i32;
|
||
// SAFETY: enc is a valid, initialized AVCodecContext from
|
||
// avcodec_alloc_context3. Setting level is a simple i32 field
|
||
// assignment on a properly aligned struct.
|
||
(*enc.as_mut_ptr()).level = 40; // H.264 Level 4.0 (up to 1080p@30)
|
||
}
|
||
}
|
||
|
||
let opened = enc
|
||
.open()
|
||
.map_err(|e| anyhow::anyhow!("Failed to open {codec_name} encoder: {e}"))?;
|
||
let enc_video = opened.0;
|
||
|
||
let use_null = output_path
|
||
.to_str()
|
||
.map(|s| s.contains("null"))
|
||
.unwrap_or(false);
|
||
let fmt_name = if use_null {
|
||
CString::new("null").unwrap()
|
||
} else {
|
||
CString::new("").unwrap()
|
||
};
|
||
let fmt_name_ptr = if use_null {
|
||
fmt_name.as_ptr()
|
||
} else {
|
||
ptr::null()
|
||
};
|
||
|
||
let mut fmt_ctx_ptr: *mut ffi::AVFormatContext = ptr::null_mut();
|
||
// SAFETY: fmt_ctx_ptr is initialized by FFmpeg; C strings live across the call.
|
||
let ret = unsafe {
|
||
ffi::avformat_alloc_output_context2(
|
||
&mut fmt_ctx_ptr,
|
||
ptr::null_mut(),
|
||
fmt_name_ptr,
|
||
output_cstr.as_ptr(),
|
||
)
|
||
};
|
||
if ret < 0 || fmt_ctx_ptr.is_null() {
|
||
bail!("Failed to allocate output format context: {}", ff_err(ret));
|
||
}
|
||
|
||
// SAFETY: fmt_ctx_ptr is valid; stream and codec parameters are owned by the format context.
|
||
let stream_ptr = unsafe { ffi::avformat_new_stream(fmt_ctx_ptr, ptr::null()) };
|
||
if stream_ptr.is_null() {
|
||
bail!("Failed to create output stream");
|
||
}
|
||
|
||
// SAFETY: stream_ptr and encoder context are valid; parameters are copied into stream.
|
||
let ret =
|
||
unsafe { ffi::avcodec_parameters_from_context((*stream_ptr).codecpar, enc_video.as_ptr()) };
|
||
if ret < 0 {
|
||
bail!("Failed to copy codec parameters to stream: {}", ff_err(ret));
|
||
}
|
||
// SAFETY: stream_ptr is valid and writable during muxer setup.
|
||
unsafe {
|
||
(*stream_ptr).time_base = (*enc_video.as_ptr()).time_base;
|
||
}
|
||
|
||
// SAFETY: open an AVIO only for muxers that require files; null muxer advertises NOFILE.
|
||
unsafe {
|
||
if (*(*fmt_ctx_ptr).oformat).flags & ffi::AVFMT_NOFILE == 0 {
|
||
let ret = ffi::avio_open(
|
||
&mut (*fmt_ctx_ptr).pb,
|
||
output_cstr.as_ptr(),
|
||
ffi::AVIO_FLAG_WRITE,
|
||
);
|
||
if ret < 0 {
|
||
bail!(
|
||
"Failed to open output file '{}': {}",
|
||
output_path.display(),
|
||
ff_err(ret)
|
||
);
|
||
}
|
||
}
|
||
}
|
||
|
||
// SAFETY: fmt_ctx_ptr is fully configured.
|
||
let ret = unsafe { ffi::avformat_write_header(fmt_ctx_ptr, ptr::null_mut()) };
|
||
if ret < 0 {
|
||
bail!("Failed to write output header: {}", ff_err(ret));
|
||
}
|
||
|
||
// SAFETY: ownership of fmt_ctx_ptr transfers to ffmpeg-next Output wrapper.
|
||
let octx = unsafe { ff::format::context::Output::wrap(fmt_ctx_ptr) };
|
||
tracing::info!("Using software H.264 encoder: {codec_name}");
|
||
Ok((enc_video, octx))
|
||
}
|
||
|
||
fn create_software_h264_encoder(
|
||
width: u32,
|
||
height: u32,
|
||
fps: u32,
|
||
bitrate: u64,
|
||
gop_size: u32,
|
||
) -> Result<ff::codec::encoder::video::Video> {
|
||
let codec = ff::encoder::find_by_name("libx264")
|
||
.or_else(|| ff::encoder::find_by_name("libopenh264"))
|
||
.ok_or_else(|| anyhow::anyhow!("No H.264 software encoder found"))?;
|
||
let codec_name = codec.name().to_string();
|
||
|
||
let mut enc = {
|
||
let ctx = ff::codec::Context::new_with_codec(codec);
|
||
ctx.encoder().video()?
|
||
};
|
||
enc.set_width(width);
|
||
enc.set_height(height);
|
||
enc.set_format(ff::format::Pixel::YUV420P);
|
||
enc.set_bit_rate(bitrate as usize);
|
||
enc.set_gop(gop_size);
|
||
// 90kHz media clock matches RTP directly. Eliminates 1/fps quantization
|
||
// that previously caused sequential RTP timestamps during 60fps capture,
|
||
// leading to 2x RTP time inflation and 10s+ browser jitter buffer growth.
|
||
// See issue #25.
|
||
enc.set_time_base(ff::Rational::new(1, 90_000));
|
||
// Explicit framerate is REQUIRED when time_base is not 1/fps, otherwise
|
||
// libx264 infers wrong fps from the 90kHz time_base and VBV rate control
|
||
// breaks. Per Oracle review round for #25.
|
||
enc.set_frame_rate(Some(ff::Rational::new(fps as i32, 1)));
|
||
enc.set_max_b_frames(0);
|
||
|
||
if codec_name == "libx264" {
|
||
// SAFETY: priv_data and codec context belong to the unopened encoder;
|
||
// each CString lives for the duration of its av_opt_set call.
|
||
unsafe {
|
||
let key = CString::new("preset").unwrap();
|
||
let val = CString::new("veryfast").unwrap();
|
||
ffi::av_opt_set((*enc.as_mut_ptr()).priv_data, key.as_ptr(), val.as_ptr(), 0);
|
||
let key = CString::new("tune").unwrap();
|
||
let val = CString::new("zerolatency").unwrap();
|
||
ffi::av_opt_set((*enc.as_mut_ptr()).priv_data, key.as_ptr(), val.as_ptr(), 0);
|
||
let key = CString::new("threads").unwrap();
|
||
let val = CString::new("6").unwrap();
|
||
ffi::av_opt_set((*enc.as_mut_ptr()).priv_data, key.as_ptr(), val.as_ptr(), 0);
|
||
// High profile via AVCodecContext.profile (not x264opts — x264 rejects it there).
|
||
// High enables CABAC + 8x8dct automatically.
|
||
(*enc.as_mut_ptr()).profile = ffi::AV_PROFILE_H264_HIGH as i32;
|
||
// SAFETY: enc is a valid, initialized AVCodecContext from
|
||
// avcodec_alloc_context3. Setting level is a simple i32 field
|
||
// assignment on a properly aligned struct.
|
||
(*enc.as_mut_ptr()).level = 42; // H.264 Level 4.2 (up to 1440p@30)
|
||
// SAFETY: priv_data belongs to the unopened libx264 encoder context.
|
||
// `forced-idr` is an FFmpeg-level private option (not x264-native),
|
||
// so it must be set via av_opt_set, NOT via the x264opts string.
|
||
// With forced-idr=1, setting AV_PICTURE_TYPE_I on an input frame
|
||
// produces a true IDR NALU with inline SPS/PPS (repeat_headers=1).
|
||
let key = CString::new("forced-idr").unwrap();
|
||
let val = CString::new("1").unwrap();
|
||
ffi::av_opt_set((*enc.as_mut_ptr()).priv_data, key.as_ptr(), val.as_ptr(), 0);
|
||
let key = CString::new("x264opts").unwrap();
|
||
// x264's vbv-maxrate unit is kbit/s and vbv-bufsize is kbit (NOT bps).
|
||
// Confirmed via x264 source encoder/ratecontrol.c:658-661 which multiplies
|
||
// these values by 1000 to convert kbit → bit at use site. Passing bps makes
|
||
// VBV effectively unbounded (5.5 Mbps becomes 5.5 Gbps, clipped to 2 Gbps).
|
||
// See https://github.com/mirror/x264/blob/c24e06c2e184345ceb33eb20a15d1024d9fd3497/encoder/ratecontrol.c#L658-L661
|
||
let vbv_maxrate_kbps = bitrate / 1000;
|
||
let vbv_bufsize_kbps = (bitrate / 4) / 1000;
|
||
let val = CString::new(format!(
|
||
"repeat_headers=1:vbv-maxrate={vbv_maxrate_kbps}:vbv-bufsize={vbv_bufsize_kbps}"
|
||
))
|
||
.unwrap();
|
||
ffi::av_opt_set((*enc.as_mut_ptr()).priv_data, key.as_ptr(), val.as_ptr(), 0);
|
||
}
|
||
}
|
||
|
||
let opened = enc
|
||
.open()
|
||
.map_err(|e| anyhow::anyhow!("Failed to open {codec_name} encoder: {e}"))?;
|
||
tracing::info!("WebRTC encoder: {codec_name} {width}x{height} @ {fps}fps {bitrate}bps (profile High, preset veryfast)");
|
||
Ok(opened.0)
|
||
}
|
||
|
||
// ---------------------------------------------------------------------------
|
||
// Filter graph (inline)
|
||
// ---------------------------------------------------------------------------
|
||
|
||
fn build_filter_graph(
|
||
hw_dev: &AvHwDevCtx,
|
||
frames_rgb: &AvHwFrameCtx,
|
||
width: u32,
|
||
height: u32,
|
||
_enc_width: u32,
|
||
_enc_height: u32,
|
||
fps: u32,
|
||
transform: Transform,
|
||
) -> Result<ff::filter::Graph> {
|
||
let mut graph = ff::filter::Graph::new();
|
||
|
||
let buffersrc =
|
||
ff::filter::find("buffer").ok_or_else(|| anyhow::anyhow!("filter 'buffer' not found"))?;
|
||
let buffersink = ff::filter::find("buffersink")
|
||
.ok_or_else(|| anyhow::anyhow!("filter 'buffersink' not found"))?;
|
||
let scale_vaapi = ff::filter::find("scale_vaapi")
|
||
.ok_or_else(|| anyhow::anyhow!("filter 'scale_vaapi' not found"))?;
|
||
|
||
// buffersrc — use AVBufferSrcParameters to set hw_frames_ctx properly
|
||
let args = format!(
|
||
"video_size={}x{}:pix_fmt={}:time_base=1/{fps}:pixel_aspect=1/1",
|
||
width,
|
||
height,
|
||
Into::<ffi::AVPixelFormat>::into(ff::format::Pixel::VAAPI) as i32,
|
||
);
|
||
let mut src_ctx = graph.add(&buffersrc, "in", &args)?;
|
||
|
||
// SAFETY: av_buffersrc_parameters_alloc allocates params for the buffersrc.
|
||
let par = unsafe { ffi::av_buffersrc_parameters_alloc() };
|
||
if par.is_null() {
|
||
bail!("av_buffersrc_parameters_alloc returned null");
|
||
}
|
||
// SAFETY: Set hw_frames_ctx on the buffersrc parameters, then apply.
|
||
unsafe {
|
||
(*par).format = Into::<ffi::AVPixelFormat>::into(ff::format::Pixel::VAAPI) as i32;
|
||
(*par).width = width as i32;
|
||
(*par).height = height as i32;
|
||
(*par).time_base = ffi::AVRational {
|
||
num: 1,
|
||
den: fps as i32,
|
||
};
|
||
(*par).hw_frames_ctx = frames_rgb.ref_clone();
|
||
let ret = ffi::av_buffersrc_parameters_set(src_ctx.as_mut_ptr(), par);
|
||
ffi::av_free(par as *mut _);
|
||
if ret < 0 {
|
||
bail!("av_buffersrc_parameters_set failed: {}", ff_err(ret));
|
||
}
|
||
}
|
||
|
||
// scale_vaapi: hardware scaling and colourspace conversion (keeps original dimensions)
|
||
let mut scale_ctx = graph.add(
|
||
&scale_vaapi,
|
||
"scale",
|
||
&format!("{width}:{height}:format=nv12"),
|
||
)?;
|
||
// SAFETY: scale_vaapi needs hw_device_ctx for VAAPI device access.
|
||
unsafe {
|
||
(*scale_ctx.as_mut_ptr()).hw_device_ctx = hw_dev.ref_clone();
|
||
}
|
||
|
||
// buffersink
|
||
let mut sink_ctx = graph.add(&buffersink, "out", "")?;
|
||
|
||
// Build filter chain: src -> scale -> [transpose] -> sink
|
||
src_ctx.link(0, &mut scale_ctx, 0);
|
||
|
||
match transform {
|
||
Transform::Normal => {
|
||
scale_ctx.link(0, &mut sink_ctx, 0);
|
||
}
|
||
other => {
|
||
let transpose = ff::filter::find("transpose_vaapi")
|
||
.ok_or_else(|| anyhow::anyhow!("filter 'transpose_vaapi' not found"))?;
|
||
let dir_val = match other {
|
||
Transform::Normal90 => "1",
|
||
Transform::Normal180 => "4",
|
||
Transform::Normal270 => "2",
|
||
Transform::Flipped => "5",
|
||
Transform::Flipped90 => "3",
|
||
Transform::Flipped180 => "6",
|
||
Transform::Flipped270 => "0",
|
||
Transform::Normal => unreachable!(),
|
||
};
|
||
let mut trans_ctx = graph.add(&transpose, "transpose", &format!("dir={dir_val}"))?;
|
||
// SAFETY: trans_ctx is a live transpose_vaapi filter context;
|
||
// scale_vaapi/transpose_vaapi keep a ref-counted device context.
|
||
unsafe {
|
||
(*trans_ctx.as_mut_ptr()).hw_device_ctx = hw_dev.ref_clone();
|
||
}
|
||
scale_ctx.link(0, &mut trans_ctx, 0);
|
||
trans_ctx.link(0, &mut sink_ctx, 0);
|
||
}
|
||
}
|
||
|
||
graph
|
||
.validate()
|
||
.map_err(|e| anyhow::anyhow!("Filter graph validation failed: {e}"))?;
|
||
|
||
Ok(graph)
|
||
}
|
||
|
||
#[cfg(test)]
|
||
mod tests {
|
||
use super::*;
|
||
|
||
// ── Task 1: VBV x264opts formatting ──
|
||
|
||
#[test]
|
||
fn vbv_x264opts_format() {
|
||
let bitrate: u64 = 5_000_000;
|
||
// x264 expects kbit/s and kbit, not bps
|
||
let vbv_maxrate_kbps = bitrate / 1000;
|
||
let vbv_bufsize_kbps = (bitrate / 4) / 1000;
|
||
let opts = format!("repeat_headers=1:vbv-maxrate={vbv_maxrate_kbps}:vbv-bufsize={vbv_bufsize_kbps}");
|
||
assert_eq!(vbv_maxrate_kbps, 5000);
|
||
assert_eq!(vbv_bufsize_kbps, 1250);
|
||
assert!(opts.contains("vbv-maxrate=5000"));
|
||
assert!(opts.contains("vbv-bufsize=1250"));
|
||
}
|
||
|
||
#[test]
|
||
fn vbv_bufsize_is_quarter_of_maxrate() {
|
||
for bitrate in [1_000_000, 5_000_000, 10_000_000] {
|
||
// x264 expects kbit/s and kbit; both scaled by /1000, ratio preserved
|
||
let maxrate_kbps = bitrate / 1000;
|
||
let bufsize_kbps = (bitrate / 4) / 1000;
|
||
assert_eq!(bufsize_kbps * 4, maxrate_kbps, "bufsize should be maxrate/4");
|
||
}
|
||
}
|
||
|
||
// ── Task 3: GOP formula ──
|
||
|
||
#[test]
|
||
fn webrtc_gop_formula() {
|
||
assert_eq!((15u32 * 2).max(20), 30); // 15fps -> 30
|
||
assert_eq!((30u32 * 2).max(20), 60); // 30fps -> 60
|
||
assert_eq!((60u32 * 2).max(20), 120); // 60fps -> 120
|
||
assert_eq!((5u32 * 2).max(20), 20); // 5fps -> 20 (floor)
|
||
}
|
||
|
||
#[test]
|
||
fn h264_level_values() {
|
||
// Level 4.0 supports up to 1080p@30fps (used for file muxer)
|
||
assert_eq!(40i32, 40);
|
||
// Level 4.2 supports up to 1440p@30fps (used for WebRTC low-latency encoder)
|
||
assert_eq!(42i32, 42);
|
||
}
|
||
|
||
// ── Task 4: Duplicate frame hash detection ──
|
||
|
||
#[test]
|
||
fn hash_sampled_y_plane_first_frame_consistent() {
|
||
let width = 64;
|
||
let height = 64;
|
||
let stride = 64;
|
||
let y_data = vec![0u8; stride * height];
|
||
let hash1 = hash_sampled_y_plane(&y_data, width, height, stride);
|
||
let hash2 = hash_sampled_y_plane(&y_data, width, height, stride);
|
||
assert_eq!(hash1, hash2, "same input should produce same hash");
|
||
}
|
||
|
||
#[test]
|
||
fn hash_sampled_y_plane_detects_different_frames() {
|
||
let width = 64;
|
||
let height = 64;
|
||
let stride = 64;
|
||
let y_data1 = vec![0u8; stride * height];
|
||
let y_data2 = vec![128u8; stride * height];
|
||
let hash1 = hash_sampled_y_plane(&y_data1, width, height, stride);
|
||
let hash2 = hash_sampled_y_plane(&y_data2, width, height, stride);
|
||
assert_ne!(
|
||
hash1, hash2,
|
||
"different frame data should produce different hashes"
|
||
);
|
||
}
|
||
|
||
#[test]
|
||
fn hash_sampled_y_plane_samples_every_8th_row() {
|
||
// Changing a non-sampled row (e.g., row 1) should NOT change the hash
|
||
let width = 64;
|
||
let height = 64;
|
||
let stride = 64;
|
||
let y_data1 = vec![0u8; stride * height];
|
||
let mut y_data2 = vec![0u8; stride * height];
|
||
// Row 1 is NOT sampled (sampling is every 8th row: 0, 8, 16, ...)
|
||
y_data2[stride * 1..stride * 1 + width].fill(255);
|
||
let hash1 = hash_sampled_y_plane(&y_data1, width, height, stride);
|
||
let hash2 = hash_sampled_y_plane(&y_data2, width, height, stride);
|
||
assert_eq!(
|
||
hash1, hash2,
|
||
"non-sampled row change should not affect hash"
|
||
);
|
||
}
|
||
|
||
#[test]
|
||
fn hash_sampled_y_plane_sensitive_to_sampled_row() {
|
||
// Changing a sampled row (row 0) SHOULD change the hash
|
||
let width = 64;
|
||
let height = 64;
|
||
let stride = 64;
|
||
let y_data1 = vec![0u8; stride * height];
|
||
let mut y_data2 = vec![0u8; stride * height];
|
||
// Row 0 IS sampled (every 8th row starting from 0)
|
||
y_data2[stride * 0..stride * 0 + width].fill(255);
|
||
let hash1 = hash_sampled_y_plane(&y_data1, width, height, stride);
|
||
let hash2 = hash_sampled_y_plane(&y_data2, width, height, stride);
|
||
assert_ne!(
|
||
hash1, hash2,
|
||
"sampled row change should produce different hash"
|
||
);
|
||
}
|
||
|
||
#[test]
|
||
fn hash_sampled_y_plane_handles_stride_greater_than_width() {
|
||
// Stride can be larger than width due to alignment; unused padding should not affect hash
|
||
let width = 32;
|
||
let height = 16;
|
||
let stride = 64; // padded stride
|
||
let y_data1 = vec![0u8; stride * height];
|
||
let mut y_data2 = vec![0u8; stride * height];
|
||
// Fill the padding area (columns 32..63) of row 0 with garbage
|
||
y_data2[width..stride].fill(0xFF);
|
||
let hash1 = hash_sampled_y_plane(&y_data1, width, height, stride);
|
||
let hash2 = hash_sampled_y_plane(&y_data2, width, height, stride);
|
||
assert_eq!(
|
||
hash1, hash2,
|
||
"padding bytes beyond width should not affect hash"
|
||
);
|
||
}
|
||
}
|