Index: content/common/gpu/media/dxva_video_decode_accelerator.cc |
=================================================================== |
--- content/common/gpu/media/dxva_video_decode_accelerator.cc (revision 168333) |
+++ content/common/gpu/media/dxva_video_decode_accelerator.cc (working copy) |
@@ -73,6 +73,11 @@ |
log << ", HRESULT: 0x" << std::hex << result, \ |
error_code, ret); |
+// Maximum number of iterations we allow before aborting the attempt to flush |
+// the batched queries to the driver and allow torn/corrupt frames to be |
+// rendered. |
+enum { kMaxIterationsForD3DFlush = 10 }; |
+ |
static IMFSample* CreateEmptySample() { |
base::win::ScopedComPtr<IMFSample> sample; |
HRESULT hr = MFCreateSample(sample.Receive()); |
@@ -312,6 +317,7 @@ |
D3DPOOL_DEFAULT, |
picture_buffer->decoding_texture_.Receive(), |
&share_handle); |
+ |
RETURN_ON_HR_FAILURE(hr, "Failed to create texture", |
linked_ptr<DXVAPictureBuffer>(NULL)); |
return picture_buffer; |
@@ -392,15 +398,30 @@ |
D3DTEXF_NONE); |
RETURN_ON_HR_FAILURE(hr, "Colorspace conversion via StretchRect failed", |
false); |
+ |
// Ideally, this should be done immediately before the draw call that uses |
// the texture. Flush it once here though. |
hr = query_->Issue(D3DISSUE_END); |
RETURN_ON_HR_FAILURE(hr, "Failed to issue END", false); |
- do { |
- hr = query_->GetData(NULL, 0, D3DGETDATA_FLUSH); |
- if (hr == S_FALSE) |
- Sleep(1); // Poor-man's Yield(). |
- } while (hr == S_FALSE); |
+ |
+ // The DXVA decoder has its own device which it uses for decoding. ANGLE |
+ // has its own device which we don't have access to. |
+ // The above code attempts to copy the decoded picture into a surface |
+ // which is owned by ANGLE. As there are multiple devices involved in |
+ // this, the StretchRect call above is not synchronous. |
+ // We attempt to flush the batched operations to ensure that the picture is |
+ // copied to the surface owned by ANGLE. |
+ // We need to do this in a loop and call flush multiple times. |
+ // We have seen the GetData call for flushing the command buffer fail to |
+ // return success occassionally on multi core machines, leading to an |
+ // infinite loop. |
+ // Workaround is to have an upper limit of 10 on the number of iterations to |
+ // wait for the Flush to finish. |
+ int iterations = 0; |
+ while ((query_->GetData(NULL, 0, D3DGETDATA_FLUSH) == S_FALSE) && |
+ ++iterations < kMaxIterationsForD3DFlush) { |
+ Sleep(1); // Poor-man's Yield(). |
+ } |
eglBindTexImage( |
static_cast<EGLDisplay*>(eglGetDisplay(EGL_DEFAULT_DISPLAY)), |
decoding_surface_, |
@@ -497,7 +518,6 @@ |
// CopyOutputSampleDataToPictureBuffer). |
hr = query_->Issue(D3DISSUE_END); |
RETURN_ON_HR_FAILURE(hr, "Failed to issue END test query", false); |
- |
return true; |
} |