From 7905911bfde90df5f9d7b9ddce2dbc553bf29479 Mon Sep 17 00:00:00 2001
From: Anthony Jones <ajones@mozilla.com>
Date: Thu, 3 Jul 2014 14:43:17 +1200
Subject: [PATCH] Bug 1033137 - Fix image lifetime issues in libav backend;
 r=edwin

---
 content/media/fmp4/ffmpeg/FFmpegDataDecoder.cpp |  5 +++++
 content/media/fmp4/ffmpeg/FFmpegH264Decoder.cpp | 14 +++++++++++---
 content/media/fmp4/ffmpeg/FFmpegH264Decoder.h   | 14 +-------------
 3 files changed, 17 insertions(+), 16 deletions(-)

diff --git a/content/media/fmp4/ffmpeg/FFmpegDataDecoder.cpp b/content/media/fmp4/ffmpeg/FFmpegDataDecoder.cpp
index c6ba598f17b0..15773a1fa5d0 100644
--- a/content/media/fmp4/ffmpeg/FFmpegDataDecoder.cpp
+++ b/content/media/fmp4/ffmpeg/FFmpegDataDecoder.cpp
@@ -12,6 +12,7 @@
 #include "FFmpegLibs.h"
 #include "FFmpegLog.h"
 #include "FFmpegDataDecoder.h"
+#include "prsystem.h"
 
 namespace mozilla
 {
@@ -83,6 +84,10 @@ FFmpegDataDecoder<LIBAV_VER>::Init()
   // FFmpeg will call back to this to negotiate a video pixel format.
   mCodecContext.get_format = ChoosePixelFormat;
 
+  mCodecContext.thread_count = PR_GetNumberOfProcessors();
+  mCodecContext.thread_type = FF_THREAD_FRAME;
+  mCodecContext.thread_safe_callbacks = false;
+
   mCodecContext.extradata = mExtraData.begin();
   mCodecContext.extradata_size = mExtraData.length();
 
diff --git a/content/media/fmp4/ffmpeg/FFmpegH264Decoder.cpp b/content/media/fmp4/ffmpeg/FFmpegH264Decoder.cpp
index 2fe03703eb8a..781764419a89 100644
--- a/content/media/fmp4/ffmpeg/FFmpegH264Decoder.cpp
+++ b/content/media/fmp4/ffmpeg/FFmpegH264Decoder.cpp
@@ -42,6 +42,7 @@ FFmpegH264Decoder<LIBAV_VER>::Init()
   NS_ENSURE_SUCCESS(rv, rv);
 
   mCodecContext.get_buffer = AllocateBufferCb;
+  mCodecContext.release_buffer = ReleaseBufferCb;
 
   return NS_OK;
 }
@@ -82,8 +83,8 @@ FFmpegH264Decoder<LIBAV_VER>::DecodeFrame(mp4_demuxer::MP4Sample* aSample)
 
     data = VideoData::CreateFromImage(
       info, mImageContainer, aSample->byte_offset,
-      aSample->composition_timestamp, aSample->duration, mCurrentImage,
-      aSample->is_sync_point, -1,
+      aSample->composition_timestamp, aSample->duration,
+      reinterpret_cast<Image*>(frame->opaque), aSample->is_sync_point, -1,
       gfx::IntRect(0, 0, mCodecContext.width, mCodecContext.height));
 
     mCallback->Output(data.forget());
@@ -132,6 +133,13 @@ FFmpegH264Decoder<LIBAV_VER>::AllocateBufferCb(AVCodecContext* aCodecContext,
   }
 }
 
+/* static */ void
+FFmpegH264Decoder<LIBAV_VER>::ReleaseBufferCb(AVCodecContext* aCodecContext,
+                                              AVFrame* aFrame)
+{
+  reinterpret_cast<Image*>(aFrame->opaque)->Release();
+}
+
 int
 FFmpegH264Decoder<LIBAV_VER>::AllocateYUV420PVideoBuffer(
   AVCodecContext* aCodecContext, AVFrame* aFrame)
@@ -194,7 +202,7 @@ FFmpegH264Decoder<LIBAV_VER>::AllocateYUV420PVideoBuffer(
   PlanarYCbCrDataFromAVFrame(data, aFrame);
   ycbcr->SetDataNoCopy(data);
 
-  mCurrentImage.swap(image);
+  aFrame->opaque = reinterpret_cast<void*>(image.forget().take());
 
   return 0;
 }
diff --git a/content/media/fmp4/ffmpeg/FFmpegH264Decoder.h b/content/media/fmp4/ffmpeg/FFmpegH264Decoder.h
index 9947b8ab30a5..f81aa89218bf 100644
--- a/content/media/fmp4/ffmpeg/FFmpegH264Decoder.h
+++ b/content/media/fmp4/ffmpeg/FFmpegH264Decoder.h
@@ -49,22 +49,10 @@ private:
                                  AVFrame* aFrame);
 
   static int AllocateBufferCb(AVCodecContext* aCodecContext, AVFrame* aFrame);
+  static void ReleaseBufferCb(AVCodecContext* aCodecContext, AVFrame* aFrame);
 
   MediaDataDecoderCallback* mCallback;
   nsRefPtr<ImageContainer> mImageContainer;
-
-  /**
-   * Pass Image back from the allocator to our DoDecode method.
-   * We *should* return the image back through ffmpeg wrapped in an AVFrame like
-   * we're meant to. However, if avcodec_decode_video2 fails, it returns a
-   * completely different frame from the one holding our image and it will be
-   * leaked.
-   * This could be handled in the future by wrapping our Image in a reference
-   * counted AVBuffer and letting ffmpeg hold the nsAutoPtr<Image>, but
-   * currently we have to support older versions of ffmpeg which lack
-   * refcounting.
-   */
-  nsRefPtr<Image> mCurrentImage;
 };
 
 } // namespace mozilla