Have FFmpeg Decoders handle 0 byte buffers instead of FFmpeg

media/filters/ffmpeg_video_decoder.cc

 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "media/filters/ffmpeg_video_decoder.h"
 
 #include <stddef.h>
 #include <stdint.h>
 
 #include <algorithm>
@@ skipping 331 matching lines @@
   // Due to FFmpeg API changes we no longer have const read-only pointers.
   AVPacket packet;
   av_init_packet(&packet);
   if (buffer->end_of_stream()) {
     packet.data = NULL;
     packet.size = 0;
   } else {
     packet.data = const_cast<uint8_t*>(buffer->data());
     packet.size = buffer->data_size();
 
+    // Starting in M60, avcodec_decode_video2() generates an error if
+    // empty buffer provided. If that is the case signal that more data

[xhwang, 2017/05/15 23:35:17]

"If that is the case" seems to be confusing since we know what will happen?

[jrummell, 2017/05/16 21:54:03]

Done.

+    // is required to produce more frames.

[xhwang, 2017/05/15 23:35:17]

Could you please refer to crbug.com/663438 for context of 0-byte buffers

[jrummell, 2017/05/16 21:54:03]

Done.

+    if (!packet.size)
+      return true;
+
     // Let FFmpeg handle presentation timestamp reordering.
     codec_context_->reordered_opaque = buffer->timestamp().InMicroseconds();
   }
 
   int frame_decoded = 0;
   int result = avcodec_decode_video2(codec_context_.get(),
                                      av_frame_.get(),
                                      &frame_decoded,
                                      &packet);
   // Log the problem if we can't decode a video frame and exit early.
@@ skipping 71 matching lines @@
   if (!codec || avcodec_open2(codec_context_.get(), codec, NULL) < 0) {
     ReleaseFFmpegResources();
     return false;
   }
 
   av_frame_.reset(av_frame_alloc());
   return true;
 }
 
 }  // namespace media