Expose codec implementation names in stats.

webrtc/modules/video_coding/main/source/generic_decoder.cc

Index: webrtc/modules/video_coding/main/source/generic_decoder.cc
diff --git a/webrtc/modules/video_coding/main/source/generic_decoder.cc b/webrtc/modules/video_coding/main/source/generic_decoder.cc
index f874e163c83f6ad3a3362cefe32a014f23585059..0e2451402709b5c352e340d5389108bacc2f427a 100644
--- a/webrtc/modules/video_coding/main/source/generic_decoder.cc
+++ b/webrtc/modules/video_coding/main/source/generic_decoder.cc
@@ -18,15 +18,12 @@ namespace webrtc {
 
 VCMDecodedFrameCallback::VCMDecodedFrameCallback(VCMTiming& timing,
                                                  Clock* clock)
-:
-_critSect(CriticalSectionWrapper::CreateCriticalSection()),
-_clock(clock),
-_receiveCallback(NULL),
-_timing(timing),
-_timestampMap(kDecoderFrameMemoryLength),
-_lastReceivedPictureID(0)
-{
-}
+    : _critSect(CriticalSectionWrapper::CreateCriticalSection()),
+      _clock(clock),
+      _receiveCallback(NULL),
+      _timing(timing),
+      _timestampMap(kDecoderFrameMemoryLength),
+      _lastReceivedPictureID(0) {}
 
 VCMDecodedFrameCallback::~VCMDecodedFrameCallback()
 {
@@ -102,6 +99,13 @@ uint64_t VCMDecodedFrameCallback::LastReceivedPictureID() const
     return _lastReceivedPictureID;
 }
 
+void VCMDecodedFrameCallback::OnDecoderImplementationName(
+    const char* implementation_name) {
+  CriticalSectionScoped cs(_critSect);
+  if (_receiveCallback)
+    _receiveCallback->OnDecoderImplementationName(implementation_name);
+}
+
 void VCMDecodedFrameCallback::Map(uint32_t timestamp,
                                   VCMFrameInformation* frameInfo) {
   CriticalSectionScoped cs(_critSect);
@@ -157,6 +161,7 @@ int32_t VCMGenericDecoder::Decode(const VCMEncodedFrame& frame,
                                         frame.CodecSpecific(),
                                         frame.RenderTimeMs());
 
+    _callback->OnDecoderImplementationName(_decoder.ImplementationName());

[stefan-webrtc, 2015/10/16 07:47:03]

Can't we call this only when the implementation actually changes?

[pbos-webrtc, 2015/10/16 13:12:05]

Problem is that the interface doesn't allow us to know when we change
implementation. This might be a fallback and we don't know when that is being
switched to. If you have a good interface idea for that let me know.

[stefan-webrtc, 2015/10/22 09:33:34]

Acknowledged.

[mflodman, 2015/12/18 13:02:43]

I don't understand why we can't know this, let's discuss.

[pbos-webrtc, 2015/12/18 13:07:55]

Software fallback happens silently inside VideoDecoderFallbackWrapper, so the
VCM on the outside doesn't see that. I think we should merge
VideoDecoderFallbackWrapper into VCMGenericDecoder so we can be aware of when
this change occurs. Does that make sense?

     if (ret < WEBRTC_VIDEO_CODEC_OK)
     {
         LOG(LS_WARNING) << "Failed to decode frame with timestamp "