changeset:   544864:a8603f131703
tag:         tip
parent:      544861:161920b70ae4
user:        Martin Stransky <stransky@redhat.com>
date:        Fri Jul 31 13:39:48 2020 +0200
files:       dom/media/platforms/ffmpeg/FFmpegVideoDecoder.cpp dom/media/platforms/ffmpeg/FFmpegVideoDecoder.h
description:
Bug 1645671 [Linux/VA-API] Create DMABufSurfaceWrapper directly at nsTAttay and disable DMABufSurfaceWrapper class copy and assignment constructors, r?jya

When DMABufSurfaceWrapper is added to nsTArray, a temporary local DMABufSurfaceWrapper object is created. When the temporary
object is deleted after the adding, associated dmabuf data is released which leads to rendering artifact during VA-API video playback.

As a fix in this patch we create DMABufSurfaceWrapper 'in-place' at nsTAttay.
We also disable DMABufSurfaceWrapper class copy and assignment constructors to avoid similar potential issues.

Differential Revision: https://phabricator.services.mozilla.com/D85152


diff --git a/dom/media/platforms/ffmpeg/FFmpegVideoDecoder.cpp b/dom/media/platforms/ffmpeg/FFmpegVideoDecoder.cpp
--- a/dom/media/platforms/ffmpeg/FFmpegVideoDecoder.cpp
+++ b/dom/media/platforms/ffmpeg/FFmpegVideoDecoder.cpp
@@ -777,17 +777,17 @@ MediaResult FFmpegVideoDecoder<LIBAV_VER
                          RESULT_DETAIL("Unable to get DMABufSurfaceYUV"));
     }
 
 #  ifdef MOZ_LOGGING
     static int uid = 0;
     surface->SetUID(++uid);
     FFMPEG_LOG("Created new DMABufSurface UID = %d", uid);
 #  endif
-    mDMABufSurfaces.AppendElement(DMABufSurfaceWrapper(surface, mLib));
+    mDMABufSurfaces.EmplaceBack(surface, mLib);
     surfaceWrapper = &(mDMABufSurfaces[mDMABufSurfaces.Length() - 1]);
   } else {
     surface = surfaceWrapper->GetDMABufSurface();
     bool ret;
 
     if (mVAAPIDeviceContext) {
       ret = surface->UpdateYUVData(vaDesc);
     } else {
diff --git a/dom/media/platforms/ffmpeg/FFmpegVideoDecoder.h b/dom/media/platforms/ffmpeg/FFmpegVideoDecoder.h
--- a/dom/media/platforms/ffmpeg/FFmpegVideoDecoder.h
+++ b/dom/media/platforms/ffmpeg/FFmpegVideoDecoder.h
@@ -70,16 +70,22 @@ class DMABufSurfaceWrapper final {
   // Check if DMABufSurface is used by any gecko rendering process
   // (WebRender or GL compositor) or by DMABUFSurfaceImage/VideoData.
   bool IsUsed() const { return mSurface->IsGlobalRefSet(); }
 
   RefPtr<DMABufSurfaceYUV> GetDMABufSurface() const {
     return mSurface->GetAsDMABufSurfaceYUV();
   }
 
+  // Don't allow DMABufSurfaceWrapper plain copy as it leads to
+  // enexpected DMABufSurface/HW buffer releases and we don't want to
+  // deep copy them.
+  DMABufSurfaceWrapper(const DMABufSurfaceWrapper&) = delete;
+  const DMABufSurfaceWrapper& operator=(DMABufSurfaceWrapper const&) = delete;
+
  private:
   const RefPtr<DMABufSurface> mSurface;
   const FFmpegLibWrapper* mLib;
   AVBufferRef* mAVHWFramesContext;
   AVBufferRef* mHWAVBuffer;
 };
 #endif