Support for parsing encrypted WebM streams by src.

media/ffmpeg/ffmpeg_common.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/ffmpeg/ffmpeg_common.h"
 
 #include "base/basictypes.h"
 #include "base/logging.h"
 #include "media/base/decoder_buffer.h"
 #include "media/base/video_frame.h"
@@ skipping 277 matching lines @@
     case 7:
       return CHANNEL_LAYOUT_6_1;
     case 8:
       return CHANNEL_LAYOUT_7_1;
     default:
       DVLOG(1) << "Unsupported channel count: " << channels;
   }
   return CHANNEL_LAYOUT_UNSUPPORTED;
 }
 
-void AVCodecContextToAudioDecoderConfig(
+static void AVCodecContextToAudioDecoderConfig(
     const AVCodecContext* codec_context,
+    bool is_encrypted,
     AudioDecoderConfig* config) {
   DCHECK_EQ(codec_context->codec_type, AVMEDIA_TYPE_AUDIO);
 
   AudioCodec codec = CodecIDToAudioCodec(codec_context->codec_id);
 
   SampleFormat sample_format =
       AVSampleFormatToSampleFormat(codec_context->sample_fmt);
 
   ChannelLayout channel_layout = ChannelLayoutToChromeChannelLayout(
       codec_context->channel_layout, codec_context->channels);
 
   if (codec == kCodecOpus) {
     // |codec_context->sample_fmt| is not set by FFmpeg because Opus decoding is
     // not enabled in FFmpeg, so we need to manually set the sample format.
     sample_format = kSampleFormatS16;
   }
 
   config->Initialize(codec,
                      sample_format,
                      channel_layout,
                      codec_context->sample_rate,
                      codec_context->extradata,
                      codec_context->extradata_size,
-                     false,  // Not encrypted.
+                     is_encrypted,
                      true);
   if (codec != kCodecOpus) {
     DCHECK_EQ(av_get_bytes_per_sample(codec_context->sample_fmt) * 8,
               config->bits_per_channel());
   }
 }
 
+void AVStreamToAudioDecoderConfig(
+    const AVStream* stream,
+    AudioDecoderConfig* config) {
+  bool is_encrypted = false;
+  AVDictionaryEntry* key = av_dict_get(stream->metadata, "enc_key_id", NULL, 0);
+  if (key)
+    is_encrypted = true;
+  return AVCodecContextToAudioDecoderConfig(stream->codec,
+                                            is_encrypted, config);
+}
+
 void AudioDecoderConfigToAVCodecContext(const AudioDecoderConfig& config,
                                         AVCodecContext* codec_context) {
   codec_context->codec_type = AVMEDIA_TYPE_AUDIO;
   codec_context->codec_id = AudioCodecToCodecID(config.codec(),
                                                 config.sample_format());
   codec_context->sample_fmt = SampleFormatToAVSampleFormat(
       config.sample_format());
 
   // TODO(scherkus): should we set |channel_layout|? I'm not sure if FFmpeg uses
   // said information to decode.
@@ skipping 43 matching lines @@
   gfx::Size natural_size = GetNaturalSize(
       visible_rect.size(), aspect_ratio.num, aspect_ratio.den);
 
   VideoFrame::Format format = PixelFormatToVideoFormat(stream->codec->pix_fmt);
   if (codec == kCodecVP9) {
     // TODO(tomfinegan): libavcodec doesn't know about VP9.
     format = VideoFrame::YV12;
     coded_size = natural_size;
   }
 
+  bool is_encrypted = false;
+  AVDictionaryEntry* key = av_dict_get(stream->metadata, "enc_key_id", NULL, 0);
+  if (key)
+    is_encrypted = true;
+
   config->Initialize(codec,
                      profile,
                      format,
                      coded_size, visible_rect, natural_size,
                      stream->codec->extradata, stream->codec->extradata_size,
-                     false,  // Not encrypted.
+                     is_encrypted,
                      true);
 }
 
 void VideoDecoderConfigToAVCodecContext(
     const VideoDecoderConfig& config,
     AVCodecContext* codec_context) {
   codec_context->codec_type = AVMEDIA_TYPE_VIDEO;
   codec_context->codec_id = VideoCodecToCodecID(config.codec());
   codec_context->profile = VideoCodecProfileToProfileID(config.profile());
   codec_context->coded_width = config.coded_size().width();
@@ skipping 101 matching lines @@
       return PIX_FMT_YUV422P;
     case VideoFrame::YV12:
       return PIX_FMT_YUV420P;
     default:
       DVLOG(1) << "Unsupported VideoFrame::Format: " << video_format;
   }
   return PIX_FMT_NONE;
 }
 
 }  // namespace media