From e876248ed8d704fc22a58e0b77fb96e01467558b Mon Sep 17 00:00:00 2001
From: "dalecurtis@chromium.org"
 <dalecurtis@chromium.org@0039d316-1c4b-4281-b951-d872f2087c98>
Date: Thu, 7 Feb 2013 00:54:09 +0000
Subject: Attempt to guess channel layout if not specified.

BUG=174502
TEST=Unit test.


Review URL: https://chromiumcodereview.appspot.com/12210026

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@181125 0039d316-1c4b-4281-b951-d872f2087c98
---
 media/ffmpeg/ffmpeg_common.cc               | 46 +++++++++++------------------
 media/filters/audio_file_reader_unittest.cc |  5 ++++
 2 files changed, 23 insertions(+), 28 deletions(-)

(limited to 'media')

diff --git a/media/ffmpeg/ffmpeg_common.cc b/media/ffmpeg/ffmpeg_common.cc
index b5e4100..26953ef 100644
--- a/media/ffmpeg/ffmpeg_common.cc
+++ b/media/ffmpeg/ffmpeg_common.cc
@@ -261,27 +261,28 @@ static AVSampleFormat SampleFormatToAVSampleFormat(SampleFormat sample_format) {
   return AV_SAMPLE_FMT_NONE;
 }
 
-ChannelLayout OpusChannelCountToChromeChannelLayout(int channels) {
+// Converts a channel count into a channel layout.  Layouts chosen based on the
+// Vorbis / Opus channel layout.
+static ChannelLayout GuessChannelLayout(int channels) {
   switch (channels) {
     case 1:
-      return ChannelLayoutToChromeChannelLayout(AV_CH_LAYOUT_MONO, channels);
+      return CHANNEL_LAYOUT_MONO;
     case 2:
-      return ChannelLayoutToChromeChannelLayout(AV_CH_LAYOUT_STEREO, channels);
+      return CHANNEL_LAYOUT_STEREO;
     case 3:
-      return ChannelLayoutToChromeChannelLayout(AV_CH_LAYOUT_SURROUND,
-                                                channels);
+      return CHANNEL_LAYOUT_SURROUND;
     case 4:
-      return ChannelLayoutToChromeChannelLayout(AV_CH_LAYOUT_QUAD, channels);
+      return CHANNEL_LAYOUT_QUAD;
     case 5:
-      return ChannelLayoutToChromeChannelLayout(AV_CH_LAYOUT_5POINT0, channels);
+      return CHANNEL_LAYOUT_5_0;
     case 6:
-      return ChannelLayoutToChromeChannelLayout(AV_CH_LAYOUT_5POINT1, channels);
+      return CHANNEL_LAYOUT_5_1;
     case 7:
-      return ChannelLayoutToChromeChannelLayout(AV_CH_LAYOUT_6POINT1, channels);
+      return CHANNEL_LAYOUT_6_1;
     case 8:
-      return ChannelLayoutToChromeChannelLayout(AV_CH_LAYOUT_7POINT1, channels);
+      return CHANNEL_LAYOUT_7_1;
     default:
-      LOG(ERROR) << "Unsupported Opus channel count: " << channels;
+      DVLOG(1) << "Unsupported channel count: " << channels;
   }
   return CHANNEL_LAYOUT_UNSUPPORTED;
 }
@@ -300,14 +301,9 @@ void AVCodecContextToAudioDecoderConfig(
       codec_context->channel_layout, codec_context->channels);
 
   if (codec == kCodecOpus) {
-    // |channel_layout| and |sample_fmt| in |codec_context| are not set by
-    // FFmpeg. This happens because Opus is not enabled in ffmpegsumo. This is
-    // not that big a deal, because:
-    // 1. OpusAudioDecoder always uses signed 16 bit samples, and...
-    // 2. OpusAudioDecoder outputs audio using the same channel order as FFmpeg.
+    // |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;
-    channel_layout =
-        OpusChannelCountToChromeChannelLayout(codec_context->channels);
   }
 
   config->Initialize(codec,
@@ -420,8 +416,7 @@ void VideoDecoderConfigToAVCodecContext(
   }
 }
 
-ChannelLayout ChannelLayoutToChromeChannelLayout(int64_t layout,
-                                                 int channels) {
+ChannelLayout ChannelLayoutToChromeChannelLayout(int64_t layout, int channels) {
   switch (layout) {
     case AV_CH_LAYOUT_MONO:
       return CHANNEL_LAYOUT_MONO;
@@ -478,15 +473,10 @@ ChannelLayout ChannelLayoutToChromeChannelLayout(int64_t layout,
     case AV_CH_LAYOUT_OCTAGONAL:
       return CHANNEL_LAYOUT_OCTAGONAL;
     default:
-      // FFmpeg channel_layout is 0 for .wav and .mp3.  We know mono and stereo
-      // from the number of channels, otherwise report errors.
-      if (channels == 1)
-        return CHANNEL_LAYOUT_MONO;
-      if (channels == 2)
-        return CHANNEL_LAYOUT_STEREO;
-      LOG(ERROR) << "Unsupported channel layout: " << layout;
+      // FFmpeg channel_layout is 0 for .wav and .mp3.  Attempt to guess layout
+      // based on the channel count.
+      return GuessChannelLayout(channels);
   }
-  return CHANNEL_LAYOUT_UNSUPPORTED;
 }
 
 VideoFrame::Format PixelFormatToVideoFormat(PixelFormat pixel_format) {
diff --git a/media/filters/audio_file_reader_unittest.cc b/media/filters/audio_file_reader_unittest.cc
index 9bceadc..72c2603 100644
--- a/media/filters/audio_file_reader_unittest.cc
+++ b/media/filters/audio_file_reader_unittest.cc
@@ -140,4 +140,9 @@ TEST_F(AudioFileReaderTest, VorbisInvalidChannelLayout) {
   RunFailingTest("9ch.ogg");
 }
 
+TEST_F(AudioFileReaderTest, WaveValidFourChannelLayout) {
+  RunTest("4ch.wav", "d40bb7dbe532b2f1cf2e3558e780caa2", 4, 44100,
+          base::TimeDelta::FromMicroseconds(100001), 4410, 4410);
+}
+
 }  // namespace media
-- 
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