diff options
Diffstat (limited to 'media')
| -rw-r--r-- | media/base/video_frame.cc | 11 |
1 files changed, 9 insertions, 2 deletions
diff --git a/media/base/video_frame.cc b/media/base/video_frame.cc index 8dab6fd..2d152f1 100644 --- a/media/base/video_frame.cc +++ b/media/base/video_frame.cc @@ -135,7 +135,10 @@ void VideoFrame::AllocateYUV() { kFrameSizeAlignment); size_t uv_stride = RoundUp(row_bytes(VideoFrame::kUPlane), kFrameSizeAlignment); - size_t y_height = RoundUp(height_, kFrameSizeAlignment); + // The *2 here is because some formats (e.g. h264) allow interlaced coding, + // and then the size needs to be a multiple of two macroblocks (vertically). + // See libavcodec/utils.c:avcodec_align_dimensions2(). + size_t y_height = RoundUp(height_, kFrameSizeAlignment * 2); size_t uv_height = format_ == VideoFrame::YV12 ? y_height / 2 : y_height; size_t y_bytes = y_height * y_stride; size_t uv_bytes = uv_height * uv_stride; @@ -143,8 +146,12 @@ void VideoFrame::AllocateYUV() { #if !defined(OS_ANDROID) // TODO(dalecurtis): use DataAligned or so, so this #ifdef hackery // doesn't need to be repeated in every single user of aligned data. + // The extra line of UV being allocated is because h264 chroma MC + // overreads by one line in some cases, see libavcodec/utils.c: + // avcodec_align_dimensions2() and libavcodec/x86/h264_chromamc.asm: + // put_h264_chroma_mc4_ssse3(). uint8* data = reinterpret_cast<uint8*>( - av_malloc(y_bytes + (uv_bytes * 2) + kFramePadBytes)); + av_malloc(y_bytes + (uv_bytes * 2 + uv_stride) + kFramePadBytes)); #else uint8* data = new uint8_t[y_bytes + (uv_bytes * 2)]; #endif |