arch/firefox-fourier/0003-ffmpegvideo-v4l2-request-route.patch

@@ -21,13 +21,15 @@ This patch adds a sibling init path, `InitV4L2RequestDecoder`, that:
         the legacy AVCodec-per-hwaccel registration. ALARM, Debian,
         and most distros building with --enable-v4l2-request expose
         this (avcodec_find_decoder_by_name lookup).
-      - **generic codec + AV_HWDEVICE_TYPE_DRM** in `hw_configs`:
+      - **generic codec + hw_configs walk**: the modern hwaccel
-        the modern hwaccel registration on some upstream-only ffmpeg
+        registration. Accepts EITHER AV_HWDEVICE_TYPE_DRM (legacy
-        builds.
+        ffmpeg-v4l2-request-fork output prior to FFmpeg 7.1) OR
+        AV_HWDEVICE_TYPE_V4L2REQUEST (FFmpeg 7.1+ dedicated enum,
+        value 13 on Kwiboo's no-AMF tree, 14 on upstream-AMF tree).
     Probes named-codec first (explicit, portable) and falls back to
-    walking the generic codec's `hw_configs` for the DRM device type;
+    walking the generic codec's `hw_configs` for either device type;
-  * creates an `AV_HWDEVICE_TYPE_DRM` hwdevice context bound to
+  * creates an hwdevice context of the matched type bound to
-    `/dev/dri/renderD128` via the new `av_hwdevice_ctx_create` wrapper
+    `/dev/dri/renderD128` via the `av_hwdevice_ctx_create` wrapper
     (patch 2/4) and attaches it to the codec context;
   * reuses the existing `ChooseV4L2PixelFormat` get-format callback
     (already returns `AV_PIX_FMT_DRM_PRIME`) and the existing
@@ -40,7 +42,7 @@ vendor-MPP-stateful boards neither mechanism is registered for the
 codec, the function bails out, and the existing stateful
 `InitV4L2Decoder` runs as before. No regression of stateful boards.
 
-`mDRMDeviceContext` is unconditionally `av_buffer_unref`'d in
+`mV4L2RequestDeviceContext` is unconditionally `av_buffer_unref`'d in
 `ProcessShutdown` (no-op when null). Gated behind
 `media.ffmpeg.v4l2-request.enabled` from patch 4/4.
 
@@ -49,25 +51,26 @@ Bug 1969297.
 diff --git a/dom/media/platforms/ffmpeg/FFmpegVideoDecoder.h b/dom/media/platforms/ffmpeg/FFmpegVideoDecoder.h
 --- a/dom/media/platforms/ffmpeg/FFmpegVideoDecoder.h	2026-03-18 19:22:14.000000000 +0000
 +++ b/dom/media/platforms/ffmpeg/FFmpegVideoDecoder.h	2026-04-27 20:43:39.347992674 +0000
-@@ -225,7 +225,12 @@
+@@ -225,7 +225,13 @@
    bool IsLinuxHDR() const;
    MediaResult InitVAAPIDecoder();
    MediaResult InitV4L2Decoder();
 +  // firefox-fourier: V4L2 stateless (request API) decode path. Uses
-+  // libavcodec's v4l2_request hwaccel, which it surfaces via
++  // libavcodec's v4l2_request hwaccel, which it surfaces via either
-+  // AV_HWDEVICE_TYPE_DRM rather than a dedicated _V4L2REQUEST type.
++  // AV_HWDEVICE_TYPE_DRM (legacy) or AV_HWDEVICE_TYPE_V4L2REQUEST
++  // (FFmpeg 7.1+ dedicated enum).
 +  MediaResult InitV4L2RequestDecoder();
    bool CreateVAAPIDeviceContext();
-+  bool CreateV4L2RequestDeviceContext();
++  bool CreateV4L2RequestDeviceContext(int aDeviceType);
    bool GetVAAPISurfaceDescriptor(VADRMPRIMESurfaceDescriptor* aVaDesc);
    void AddAcceleratedFormats(nsTArray<AVCodecID>& aCodecList,
                               AVCodecID aCodecID, AVVAAPIHWConfig* hwconfig);
-@@ -239,7 +244,10 @@
+@@ -239,7 +245,10 @@
    void AdjustHWDecodeLogging();
- 
+
    AVBufferRef* mVAAPIDeviceContext = nullptr;
-+  // firefox-fourier: DRM hwdevice ctx for the v4l2_request hwaccel.
++  // firefox-fourier: hwdevice ctx for the v4l2_request hwaccel.
-+  AVBufferRef* mDRMDeviceContext = nullptr;
++  AVBufferRef* mV4L2RequestDeviceContext = nullptr;
    bool mUsingV4L2 = false;
 +  bool mUsingV4L2Request = false;
    // If video overlay is used we want to upload SW decoded frames to
@@ -76,27 +79,33 @@ diff --git a/dom/media/platforms/ffmpeg/FFmpegVideoDecoder.h b/dom/media/platfor
 diff --git a/dom/media/platforms/ffmpeg/FFmpegVideoDecoder.cpp b/dom/media/platforms/ffmpeg/FFmpegVideoDecoder.cpp
 --- a/dom/media/platforms/ffmpeg/FFmpegVideoDecoder.cpp	2026-04-27 16:09:10.000000000 +0200
 +++ b/dom/media/platforms/ffmpeg/FFmpegVideoDecoder.cpp	2026-04-29 00:10:00.098884335 +0200
-@@ -403,6 +403,129 @@
+@@ -403,6 +403,148 @@
    return NS_OK;
  }
- 
+
-+// firefox-fourier: V4L2 stateless (request API) DRM hwdevice context.
++// firefox-fourier: V4L2 stateless (request API) hwdevice context.
-+// libavcodec's v4l2_request hwaccel binds via AV_HWDEVICE_TYPE_DRM —
++// libavcodec's v4l2_request hwaccel binds via either AV_HWDEVICE_TYPE_DRM
-+// no dedicated _V4L2REQUEST type exists upstream.
++// (legacy) or AV_HWDEVICE_TYPE_V4L2REQUEST (FFmpeg 7.1+, enum value 13
-+bool FFmpegVideoDecoder<LIBAV_VER>::CreateV4L2RequestDeviceContext() {
++// on Kwiboo's no-AMF tree, 14 on upstream-AMF tree). Caller passes the
++// matched type as an int (Mozilla's bundled libavutil headers may not
++// have the V4L2REQUEST enumerator).
++bool FFmpegVideoDecoder<LIBAV_VER>::CreateV4L2RequestDeviceContext(
++    int aDeviceType) {
 +  if (!mLib->av_hwdevice_ctx_create) {
 +    FFMPEG_LOG("  av_hwdevice_ctx_create not available (libavutil too old)");
 +    return false;
 +  }
 +  const char* drmDevice = "/dev/dri/renderD128";
-+  if (mLib->av_hwdevice_ctx_create(&mDRMDeviceContext,
++  if (mLib->av_hwdevice_ctx_create(&mV4L2RequestDeviceContext,
-+                                   AV_HWDEVICE_TYPE_DRM, drmDevice,
++                                   (enum AVHWDeviceType)aDeviceType,
-+                                   nullptr, 0) < 0) {
++                                   drmDevice, nullptr, 0) < 0) {
-+    FFMPEG_LOG("  av_hwdevice_ctx_create(DRM, %s) failed", drmDevice);
++    FFMPEG_LOG("  av_hwdevice_ctx_create(type=%d, %s) failed",
++               aDeviceType, drmDevice);
 +    return false;
 +  }
-+  mCodecContext->hw_device_ctx = mLib->av_buffer_ref(mDRMDeviceContext);
++  mCodecContext->hw_device_ctx = mLib->av_buffer_ref(mV4L2RequestDeviceContext);
-+  FFMPEG_LOG("  DRM hwdevice ctx created on %s", drmDevice);
++  FFMPEG_LOG("  v4l2_request hwdevice ctx created (type=%d) on %s",
++             aDeviceType, drmDevice);
 +  return true;
 +}
 +
@@ -113,13 +122,14 @@ diff --git a/dom/media/platforms/ffmpeg/FFmpegVideoDecoder.cpp b/dom/media/platf
 +  // mechanisms depending on the build:
 +  //   (a) Named AVCodec entry (h264_v4l2request, vp8_v4l2request,
 +  //       etc.) — the legacy mechanism. Each hwaccel is a standalone
-+  //       AVCodec, looked up by name. ALARM, Debian, and most distros
++  //       AVCodec, looked up by name. Some forks expose this.
-+  //       building with --enable-v4l2-request expose this.
 +  //   (b) Modern hwaccel registration: the generic codec advertises
-+  //       AV_HWDEVICE_TYPE_DRM in its hw_configs array, and setting
++  //       AV_HWDEVICE_TYPE_DRM (legacy) or AV_HWDEVICE_TYPE_V4L2REQUEST
-+  //       hw_device_ctx on the codec context binds v4l2_request
++  //       (FFmpeg 7.1+ dedicated type, enum value 13 or 14 depending
-+  //       internally. Some upstream-only builds expose this.
++  //       on whether AMF is in the enum) in its hw_configs array, and
-+  // Probe (a) first — it is the explicit, distro-portable lookup.
++  //       setting hw_device_ctx on the codec context binds v4l2_request
++  //       internally.
++  // Probe (a) first — explicit, distro-portable lookup.
 +  // Fall back to (b) when the named entry isn't registered.
 +  const char* requestName = nullptr;
 +  switch (mCodecID) {
@@ -134,8 +144,18 @@ diff --git a/dom/media/platforms/ffmpeg/FFmpegVideoDecoder.cpp b/dom/media/platf
 +      return NS_ERROR_NOT_AVAILABLE;
 +  }
 +
-+  AVCodec* codec = mLib->avcodec_find_decoder_by_name(requestName);
++  // AV_HWDEVICE_TYPE_V4L2REQUEST integer values across known builds.
-+  if (codec) {
++  // Kwiboo's v4l2-request-n7.1.3 tree (no AMF) puts it at 13;
++  // upstream FFmpeg 8.x with AMF puts it at 14.
++  const int V4L2REQUEST_KWIBOO = 13;
++  const int V4L2REQUEST_UPSTREAM = 14;
++
++  AVCodec* codec = nullptr;
++  int matchedType = AV_HWDEVICE_TYPE_DRM;
++
++  AVCodec* named = mLib->avcodec_find_decoder_by_name(requestName);
++  if (named) {
++    codec = named;
 +    FFMPEG_LOG("  using named v4l2_request codec %s", requestName);
 +  } else {
 +    AVCodec* generic = mLib->avcodec_find_decoder(mCodecID);
@@ -143,9 +163,16 @@ diff --git a/dom/media/platforms/ffmpeg/FFmpegVideoDecoder.cpp b/dom/media/platf
 +      for (int i = 0;; i++) {
 +        const AVCodecHWConfig* cfg = mLib->avcodec_get_hw_config(generic, i);
 +        if (!cfg) break;
-+        if (cfg->device_type == AV_HWDEVICE_TYPE_DRM) {
++        if (!(cfg->methods & AV_CODEC_HW_CONFIG_METHOD_HW_DEVICE_CTX)) {
++          continue;
++        }
++        if (cfg->device_type == AV_HWDEVICE_TYPE_DRM ||
++            (int)cfg->device_type == V4L2REQUEST_KWIBOO ||
++            (int)cfg->device_type == V4L2REQUEST_UPSTREAM) {
 +          codec = generic;
-+          FFMPEG_LOG("  using generic codec %s with DRM hwaccel", codec->name);
++          matchedType = (int)cfg->device_type;
++          FFMPEG_LOG("  using generic codec %s with v4l2_request hwaccel "
++                     "(device_type=%d)", codec->name, matchedType);
 +          break;
 +        }
 +      }
@@ -153,9 +180,9 @@ diff --git a/dom/media/platforms/ffmpeg/FFmpegVideoDecoder.cpp b/dom/media/platf
 +  }
 +
 +  if (!codec) {
-+    FFMPEG_LOG("  no v4l2_request path for codec ID %d \u2014 neither named "
++    FFMPEG_LOG("  no v4l2_request path for codec ID %d — neither named "
-+               "codec %s nor generic codec with DRM hwaccel available "
++               "codec %s nor generic codec with DRM/V4L2REQUEST hwaccel "
-+               "(libavcodec built without --enable-v4l2-request?)",
++               "available (libavcodec built without --enable-v4l2-request?)",
 +               mCodecID, requestName);
 +    return NS_ERROR_NOT_AVAILABLE;
 +  }
@@ -176,7 +203,7 @@ diff --git a/dom/media/platforms/ffmpeg/FFmpegVideoDecoder.cpp b/dom/media/platf
 +  auto releaseDecoder = MakeScopeExit(
 +      [&]() MOZ_NO_THREAD_SAFETY_ANALYSIS { ReleaseCodecContext(); });
 +
-+  if (!CreateV4L2RequestDeviceContext()) {
++  if (!CreateV4L2RequestDeviceContext(matchedType)) {
 +    return NS_ERROR_NOT_AVAILABLE;
 +  }
 +
@@ -205,10 +232,10 @@ diff --git a/dom/media/platforms/ffmpeg/FFmpegVideoDecoder.cpp b/dom/media/platf
 +
  MediaResult FFmpegVideoDecoder<LIBAV_VER>::InitV4L2Decoder() {
    FFMPEG_LOG("Initialising V4L2-DRM FFmpeg decoder");
- 
+
-@@ -656,6 +779,16 @@
+@@ -656,6 +798,16 @@
  #  endif  // MOZ_ENABLE_VAAPI
- 
+
  #  ifdef MOZ_ENABLE_V4L2
 +  // firefox-fourier: try V4L2 stateless (request API) first. On
 +  // mainline-Linux Rockchip boards (RK3399 rkvdec, RK3566/RK3588
@@ -223,14 +250,14 @@ diff --git a/dom/media/platforms/ffmpeg/FFmpegVideoDecoder.cpp b/dom/media/platf
    // VAAPI didn't work or is disabled, so try V4L2 with DRM
    if (NS_SUCCEEDED(InitV4L2Decoder())) {
      return;
-@@ -2046,6 +2179,11 @@
+@@ -2046,6 +2198,11 @@
    if (IsHardwareAccelerated()) {
      mLib->av_buffer_unref(&mVAAPIDeviceContext);
    }
-+  // firefox-fourier: release the DRM hwdevice ctx for the v4l2_request
++  // firefox-fourier: release the hwdevice ctx for the v4l2_request
 +  // hwaccel. Always safe — av_buffer_unref no-ops on a null pointer.
-+  if (mDRMDeviceContext) {
++  if (mV4L2RequestDeviceContext) {
-+    mLib->av_buffer_unref(&mDRMDeviceContext);
++    mLib->av_buffer_unref(&mV4L2RequestDeviceContext);
 +  }
  #endif
  #ifdef MOZ_ENABLE_D3D11VA