Request keyframes more frequently on stream start/decoding error.

webrtc/modules/video_coding/video_receiver.cc

 /*
  *  Copyright (c) 2013 The WebRTC project authors. All Rights Reserved.
  *
  *  Use of this source code is governed by a BSD-style license
  *  that can be found in the LICENSE file in the root of the source
  *  tree. An additional intellectual property rights grant can be found
  *  in the file PATENTS.  All contributing project authors may
  *  be found in the AUTHORS file in the root of the source tree.
  */
 
@@ skipping 302 matching lines @@
 
 // Must be called from inside the receive side critical section.
 int32_t VideoReceiver::Decode(const VCMEncodedFrame& frame) {
   TRACE_EVENT0("webrtc", "VideoReceiver::Decode");
   // Change decoder if payload type has changed
   VCMGenericDecoder* decoder =
       _codecDataBase.GetDecoder(frame, &_decodedFrameCallback);
   if (decoder == nullptr) {
     return VCM_NO_CODEC_REGISTERED;
   }
-  // Decode a frame
-  int32_t ret = decoder->Decode(frame, clock_->TimeInMilliseconds());
-
-  // Check for failed decoding, run frame type request callback if needed.
-  bool request_key_frame = false;
-  if (ret < 0) {
-    request_key_frame = true;
-  }
-
-  if (!frame.Complete() || frame.MissingFrame()) {

[philipel, 2017/08/07 11:43:34]

I assume this if statement was used when we allowed decoding with artifacts.

[terelius, 2017/08/07 12:00:05]

I don't understand the purpose of this code. It would be good if someone who
does could review the change. 

[stefan-webrtc, 2017/08/07 12:24:53]

I wrote it I think. It's purpose is to request a key frame if we've decoded a
frame which is incomplete or misses references. That should no longer happen.

-    request_key_frame = true;
-    ret = VCM_OK;
-  }
-  if (request_key_frame) {
-    rtc::CritScope cs(&process_crit_);
-    _scheduleKeyRequest = true;

[stefan-webrtc, 2017/08/07 12:24:53]

Would be nice to get rid of this member eventually.

[philipel, 2017/08/07 13:30:11]

Yes, it was still used by other parts of this class, but it should be removed in
some other cleanup CL.

-  }
-  return ret;
+  return decoder->Decode(frame, clock_->TimeInMilliseconds());
 }
 
 // Register possible receive codecs, can be called multiple times
 int32_t VideoReceiver::RegisterReceiveCodec(const VideoCodec* receiveCodec,
                                             int32_t numberOfCores,
                                             bool requireKeyFrame) {
   RTC_DCHECK(construction_thread_.CalledOnValidThread());
   // TODO(tommi): This method must only be called when the decoder thread
   // is not running. Do we need a lock? If not, it looks like we might not need
   // a lock at all for |_codecDataBase|.
@@ skipping 97 matching lines @@
   _receiver.SetNackSettings(max_nack_list_size, max_packet_age_to_nack,
                             max_incomplete_time_ms);
 }
 
 int VideoReceiver::SetMinReceiverDelay(int desired_delay_ms) {
   return _receiver.SetMinReceiverDelay(desired_delay_ms);
 }
 
 }  // namespace vcm
 }  // namespace webrtc