Introduce AudioDecoderConfig to migrate away from GetAVStream().

media/ffmpeg/ffmpeg_common.cc

 // Copyright (c) 2011 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/ffmpeg/ffmpeg_common.h"
 
 #include "base/logging.h"
 
 namespace media {
 
 static const AVRational kMicrosBase = { 1, base::Time::kMicrosecondsPerSecond };
 
 base::TimeDelta ConvertFromTimeBase(const AVRational& time_base,
                                     int64 timestamp) {
   int64 microseconds = av_rescale_q(timestamp, time_base, kMicrosBase);
   return base::TimeDelta::FromMicroseconds(microseconds);
 }
 
 int64 ConvertToTimeBase(const AVRational& time_base,
                         const base::TimeDelta& timestamp) {
   return av_rescale_q(timestamp.InMicroseconds(), kMicrosBase, time_base);
 }
 
+static AudioCodec CodecIDToAudioCodec(CodecID codec_id) {
+  switch (codec_id) {
+    case CODEC_ID_AAC:
+      return kCodecAAC;
+    case CODEC_ID_MP3:
+      return kCodecMP3;
+    case CODEC_ID_VORBIS:
+      return kCodecVorbis;
+    case CODEC_ID_PCM_U8:
+    case CODEC_ID_PCM_S16LE:
+    case CODEC_ID_PCM_S32LE:
+      return kCodecPCM;
+    default:
+      NOTREACHED();
+  }
+  return kUnknownAudioCodec;
+}
+
+static CodecID AudioCodecToCodecID(AudioCodec audio_codec,
+                                   int bits_per_channel) {
+  switch (audio_codec) {
+    case kUnknownAudioCodec:
+      return CODEC_ID_NONE;
+    case kCodecAAC:
+      return CODEC_ID_AAC;
+    case kCodecMP3:
+      return CODEC_ID_MP3;
+    case kCodecPCM:
+      switch (bits_per_channel) {
+        case 8:
+          return CODEC_ID_PCM_U8;
+        case 16:
+          return CODEC_ID_PCM_S16LE;
+        case 32:
+          return CODEC_ID_PCM_S32LE;
+        default:
+          NOTREACHED() << "Unsupported bits_per_channel: " << bits_per_channel;
+      }
+    case kCodecVorbis:
+      return CODEC_ID_VORBIS;
+    default:
+      NOTREACHED();
+  }
+  return CODEC_ID_NONE;
+}
+
+AudioDecoderConfig* AVCodecContextToAudioDecoderConfig(
+    AVCodecContext* codec_context) {
+  DCHECK_EQ(codec_context->codec_type, AVMEDIA_TYPE_AUDIO);
+
+  AudioCodec codec = CodecIDToAudioCodec(codec_context->codec_id);
+  int bits_per_channel = av_get_bits_per_sample_fmt(codec_context->sample_fmt);
+  ChannelLayout channel_layout =
+      ChannelLayoutToChromeChannelLayout(codec_context->channel_layout,
+                                         codec_context->channels);
+  int sample_rate = codec_context->sample_rate;
+
+  return new AudioDecoderConfig(codec,
+                                bits_per_channel,
+                                channel_layout,
+                                sample_rate,
+                                codec_context->extradata,
+                                codec_context->extradata_size);
+}
+
+void AudioDecoderConfigToAVCodecContext(const AudioDecoderConfig* config,
+                                        AVCodecContext* codec_context) {
+  codec_context->codec_type = AVMEDIA_TYPE_AUDIO;
+  codec_context->codec_id = AudioCodecToCodecID(config->codec(),
+                                                config->bits_per_channel());
+
+  switch (config->bits_per_channel()) {
+    case 8:
+      codec_context->sample_fmt = AV_SAMPLE_FMT_U8;
+      break;
+    case 16:
+      codec_context->sample_fmt = AV_SAMPLE_FMT_S16;
+      break;
+    case 32:
+      codec_context->sample_fmt = AV_SAMPLE_FMT_S32;
+      break;
+    default:
+      NOTIMPLEMENTED() << "TODO(scherkus): DO SOMETHING BETTER HERE?";
+      codec_context->sample_fmt = AV_SAMPLE_FMT_NONE;
+  }
+
+  // TODO(scherkus): should we set |channel_layout|? I'm not sure if FFmpeg uses
+  // said information to decode.
+  codec_context->channels =
+      ChannelLayoutToChannelCount(config->channel_layout());
+  codec_context->sample_rate = config->sample_rate();
+
+  if (config->extra_data()) {
+    codec_context->extradata_size = config->extra_data_size();
+    codec_context->extradata = reinterpret_cast<uint8_t*>(
+        av_malloc(config->extra_data_size() + FF_INPUT_BUFFER_PADDING_SIZE));
+    memcpy(codec_context->extradata, config->extra_data(),
+           config->extra_data_size());
+    memset(codec_context->extradata + config->extra_data_size(), '\0',
+           FF_INPUT_BUFFER_PADDING_SIZE);
+  } else {
+    codec_context->extradata = NULL;
+    codec_context->extradata_size = 0;
+  }
+}
+
 VideoCodec CodecIDToVideoCodec(CodecID codec_id) {
   switch (codec_id) {
     case CODEC_ID_VC1:
       return kCodecVC1;
     case CODEC_ID_H264:
       return kCodecH264;
     case CODEC_ID_THEORA:
       return kCodecTheora;
     case CODEC_ID_MPEG2VIDEO:
       return kCodecMPEG2;
     case CODEC_ID_MPEG4:
       return kCodecMPEG4;
     case CODEC_ID_VP8:
       return kCodecVP8;
     default:
       NOTREACHED();
   }
-  return kUnknown;
+  return kUnknownVideoCodec;
 }
 
 CodecID VideoCodecToCodecID(VideoCodec video_codec) {
   switch (video_codec) {
-    case kUnknown:
+    case kUnknownVideoCodec:
       return CODEC_ID_NONE;
     case kCodecVC1:
       return CODEC_ID_VC1;
     case kCodecH264:
       return CODEC_ID_H264;
     case kCodecTheora:
       return CODEC_ID_THEORA;
     case kCodecMPEG2:
       return CODEC_ID_MPEG2VIDEO;
     case kCodecMPEG4:
@@ skipping 171 matching lines @@
         avcodec_close(stream->codec);
       }
     }
   }
 
   // Then finally cleanup the format context.
   av_close_input_file(format_context);
 }
 
 }  // namespace media