Handle HW decode failures in RTCVideoDecoder

content/renderer/media/rtc_video_decoder.cc

Index: content/renderer/media/rtc_video_decoder.cc
diff --git a/content/renderer/media/rtc_video_decoder.cc b/content/renderer/media/rtc_video_decoder.cc
index 49f64362aa3622623d8b1c55688ebbe5cd6f7c63..c01673f9c5b9b4fe529d06e3af11c248f57e9a40 100644
--- a/content/renderer/media/rtc_video_decoder.cc
+++ b/content/renderer/media/rtc_video_decoder.cc
@@ -28,6 +28,7 @@ namespace content {
 const int32_t RTCVideoDecoder::ID_LAST = 0x3FFFFFFF;
 const int32_t RTCVideoDecoder::ID_HALF = 0x20000000;
 const int32_t RTCVideoDecoder::ID_INVALID = -1;
+const uint32_t kNumVDAErrorsHandled = 5;

[mcasas, 2016/03/28 18:15:20]

micro-pedantic-nit:
s/kNumVDAErrorsHandled/kNumVDAResetsBeforeGivingUp/ ?

[emircan, 2016/03/29 01:50:50]

kNumVDAResetsBeforeSWFallback?

 
 // Maximum number of concurrent VDA::Decode() operations RVD will maintain.
 // Higher values allow better pipelining in the GPU, but also require more
@@ -160,6 +161,16 @@ int32_t RTCVideoDecoder::Decode(
 
   if (state_ == DECODE_ERROR) {
     LOG(ERROR) << "Decoding error occurred.";
+    // Try reseting the session |kNumVDAErrorsHandled| times.
+    if (num_vda_errors_ > kNumVDAErrorsHandled) {
+      DVLOG(1) << num_vda_errors_

[mcasas, 2016/03/28 18:15:20]

nit: s/DVLOG(1)/DLOG(ERROR)/

[emircan, 2016/03/29 01:50:50]

Done.

+               << " errors reported by VDA, falling back to software decode";
+      return WEBRTC_VIDEO_CODEC_FALLBACK_SOFTWARE;
+    }
+    state_ = RESETTING;
+    factories_->GetTaskRunner()->PostTask(
+        FROM_HERE, base::Bind(&RTCVideoDecoder::ResetInternal,
+                              weak_factory_.GetWeakPtr()));
     return WEBRTC_VIDEO_CODEC_ERROR;
   }
 
@@ -476,6 +487,7 @@ void RTCVideoDecoder::NotifyError(media::VideoDecodeAccelerator::Error error) {
 
   base::AutoLock auto_lock(lock_);
   state_ = DECODE_ERROR;
+  num_vda_errors_++;

[mcasas, 2016/03/28 18:15:20]

nit: prefer pre-increment.
I know, I know, we could debate forever
on the effect of idioms on actual real
performance, but humour me... :)

[emircan, 2016/03/29 01:50:50]

Done.

 }
 
 void RTCVideoDecoder::RequestBufferDecode() {
@@ -605,10 +617,14 @@ void RTCVideoDecoder::MovePendingBuffersToDecodeBuffers() {
 }
 
 void RTCVideoDecoder::ResetInternal() {
+  DVLOG(2) << __FUNCTION__;
   DCheckGpuVideoAcceleratorFactoriesTaskRunnerIsCurrent();
-  DVLOG(2) << "ResetInternal";
-  if (vda_)
+
+  if (vda_) {
     vda_->Reset();
+  } else {
+    CreateVDA(vda_codec_profile_, nullptr);
+  }

[mcasas, 2016/03/28 18:15:20]

No {} for one-liners as I replied to pbos@
(this is also pervasive around Chrome code)

[emircan, 2016/03/29 01:50:50]

Done.

 }
 
 // static
@@ -680,9 +696,11 @@ void RTCVideoDecoder::CreateVDA(media::VideoCodecProfile profile,
     media::VideoDecodeAccelerator::Config config(profile);
     if (vda_ && !vda_->Initialize(config, this))
       vda_.release()->Destroy();
+    vda_codec_profile_ = profile;
   }
 
-  waiter->Signal();
+  if (waiter)
+    waiter->Signal();
 }
 
 void RTCVideoDecoder::DestroyTextures() {
@@ -705,7 +723,14 @@ void RTCVideoDecoder::DestroyVDA() {
   if (vda_)
     vda_.release()->Destroy();
   DestroyTextures();
+
   base::AutoLock auto_lock(lock_);
+
+  // Put the buffers back in case we restart the decoder.
+  for (const auto& buffer : bitstream_buffers_in_decoder_)
+    PutSHM_Locked(scoped_ptr<base::SharedMemory>(buffer.second));
+  bitstream_buffers_in_decoder_.clear();
+
   state_ = UNINITIALIZED;
 }