Add support for writing raw encoder output to .ivf files.

webrtc/video/vie_encoder.cc

 /*
  *  Copyright (c) 2012 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 409 matching lines @@
   }
 
   if (stats_proxy_)
     stats_proxy_->OnSendEncodedImage(encoded_image, rtp_video_hdr);
 
   bool success = send_payload_router_->RoutePayload(
       encoded_image._frameType, payload_type, encoded_image._timeStamp,
       encoded_image.capture_time_ms_, encoded_image._buffer,
       encoded_image._length, fragmentation_header, rtp_video_hdr);
   overuse_detector_->FrameSent(encoded_image._timeStamp);
+
+  if (kEnableFrameRecording) {

[pbos-webrtc, 2016/04/05 13:31:28]

This isn't done on a known thread, for simulcast with hardware encoders you have
data races here (all hardware encoders use separate threads for callbacks).

[sprang_webrtc, 2016/04/05 16:00:53]

Ah. I'm assuming now that callbacks are at least not overlapping per simulcast
stream? Otherwise we could have reordering even before packetization?

+    int layer = rtp_video_hdr->simulcastIdx;
+    if (file_writers_[layer] == nullptr) {
+      uint64_t instance_id = reinterpret_cast<uint64_t>(this);
+      std::ostringstream oss;
+      oss << "bitstream_" << instance_id << "_" << layer << ".ivf";
+      file_writers_[layer] =
+          IvfFileWriter::Open(oss.str().c_str(), rtp_video_hdr->codec);
+    }
+    if (file_writers_[layer].get() != nullptr) {
+      bool ok = file_writers_[layer]->WriteFrame(encoded_image);
+      RTC_DCHECK(ok);
+    }
+  }
+
   return success ? 0 : -1;
 }
 
 void ViEEncoder::OnEncoderImplementationName(
     const char* implementation_name) {
   if (stats_proxy_)
     stats_proxy_->OnEncoderImplementationName(implementation_name);
 }
 
 int32_t ViEEncoder::SendStatistics(const uint32_t bit_rate,
@@ skipping 90 matching lines @@
     const uint32_t width,
     const uint32_t height) {
   return vp_->SetTargetResolution(width, height, frame_rate);
 }
 
 void QMVideoSettingsCallback::SetTargetFramerate(int frame_rate) {
   vp_->SetTargetFramerate(frame_rate);
 }
 
 }  // namespace webrtc