Linux: make it possible to compile against libav when use_system_ffmpeg==1

media/filters/ffmpeg_audio_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_audio_decoder.h"
 
 #include "base/bind.h"
 #include "base/callback_helpers.h"
 #include "base/location.h"
 #include "base/message_loop_proxy.h"
@@ skipping 378 matching lines @@
         // Currently Vorbis is the only codec that causes us to drop samples.
         // If we have to drop samples it always means the timeline starts at 0.
         DCHECK_EQ(codec_context_->codec_id, AV_CODEC_ID_VORBIS);
         output_timestamp_helper_->SetBaseTimestamp(base::TimeDelta());
       } else {
         output_timestamp_helper_->SetBaseTimestamp(input->GetTimestamp());
       }
     }
 
     int decoded_audio_size = 0;
+#ifdef CHROMIUM_NO_AVFRAME_CHANNELS
+    int channels = av_get_channel_layout_nb_channels(
+        av_frame_->channel_layout);
+#else
+    int channels = av_frame_->channels;
+#endif
     if (frame_decoded) {
       if (av_frame_->sample_rate != samples_per_second_ ||
-          av_frame_->channels != channels_ ||
+          channels != channels_ ||
           av_frame_->format != av_sample_format_) {
         DLOG(ERROR) << "Unsupported midstream configuration change!"
                     << " Sample Rate: " << av_frame_->sample_rate << " vs "
                     << samples_per_second_
-                    << ", Channels: " << av_frame_->channels << " vs "
+                    << ", Channels: " << channels << " vs "
                     << channels_
                     << ", Sample Format: " << av_frame_->format << " vs "
                     << av_sample_format_;
 
         // This is an unrecoverable error, so bail out.
         QueuedAudioBuffer queue_entry = { kDecodeError, NULL };
         queued_audio_.push_back(queue_entry);
         break;
       }
 
@@ skipping 74 matching lines @@
     // Decoding finished successfully, update statistics.
     if (result > 0) {
       PipelineStatistics statistics;
       statistics.audio_bytes_decoded = result;
       statistics_cb_.Run(statistics);
     }
   } while (packet.size > 0);
 }
 
 }  // namespace media