Support Opus Ambisonics playback

media/renderers/audio_renderer_impl_unittest.cc

Index: media/renderers/audio_renderer_impl_unittest.cc
diff --git a/media/renderers/audio_renderer_impl_unittest.cc b/media/renderers/audio_renderer_impl_unittest.cc
index b67788937980f81c26a5bbb9f2069170838140ae..db67faf974193df20523e6ea0533e3e5b586e067 100644
--- a/media/renderers/audio_renderer_impl_unittest.cc
+++ b/media/renderers/audio_renderer_impl_unittest.cc
@@ -153,6 +153,13 @@ class AudioRendererImplTest : public ::testing::Test, public RendererClient {
     ConfigureDemuxerStream(true);
   }
 
+  // Reconfigures a demuxer stream using a given config.
+  void ConfigureChangeDemuxerStream(const AudioDecoderConfig& audio_config) {
+    demuxer_stream_.set_audio_decoder_config(audio_config);
+    ConfigureDecoder();
+    ConfigureDemuxerStream(true);
+  }
+
   void ExpectUnsupportedAudioDecoder() {
     EXPECT_CALL(*decoder_, Initialize(_, _, _, _))
         .WillOnce(DoAll(SaveArg<3>(&output_cb_), RunCallback<2>(false)));
@@ -648,6 +655,60 @@ TEST_F(AudioRendererImplTest, ChannelMask) {
     ASSERT_TRUE(mask[ch]);
 }
 
+// Verify that the proper reduced search space is configured for playback rate
+// changes when downmixing is applied to the input with discrete layout.
+// The default hardware layout is stereo.
+TEST_F(AudioRendererImplTest, ChannelMask_DownmixDiscreteLayout) {
+  int audio_channels = 6;

[DaleCurtis, 2017/03/31 19:06:53]

Should be impossible to get discrete + 6 channels per the ffmpeg_common code?

[flim-chromium, 2017/04/05 18:19:34]

Thanks for spotting this. It looks like UpmixDiscreteLayout below is also no
longer needed; I've removed it. 

+  AudioDecoderConfig audio_config(
+      kCodecOpus, kSampleFormat, CHANNEL_LAYOUT_DISCRETE,
+      kInputSamplesPerSecond, EmptyExtraData(), Unencrypted());
+  audio_config.SetChannelsForDiscrete(audio_channels);
+  ConfigureChangeDemuxerStream(audio_config);
+
+  Initialize();
+  std::vector<bool> mask = channel_mask();
+  EXPECT_FALSE(mask.empty());
+  ASSERT_EQ(mask.size(), static_cast<size_t>(audio_channels));
+  for (int ch = 0; ch < audio_channels; ++ch)
+    ASSERT_TRUE(mask[ch]);
+
+  // TODO (flim): channel configuration change?
+}
+
+// Verify that the proper reduced search space is configured for playback rate
+// changes when upmixing is applied to the input with discrete layout.
+TEST_F(AudioRendererImplTest, ChannelMask_UpmixDiscreteLayout) {
+  AudioParameters hw_params(AudioParameters::AUDIO_PCM_LOW_LATENCY,
+                            CHANNEL_LAYOUT_7_1, kOutputSamplesPerSecond,
+                            SampleFormatToBytesPerChannel(kSampleFormat) * 8,
+                            1024);
+  ConfigureConfigChangeRenderer(
+      AudioParameters(AudioParameters::AUDIO_PCM_LOW_LATENCY,
+                      CHANNEL_LAYOUT_DISCRETE, kOutputSamplesPerSecond,
+                      SampleFormatToBytesPerChannel(kSampleFormat) * 8, 1024),
+      hw_params);
+
+  AudioDecoderConfig audio_config(
+      kCodecOpus, kSampleFormat, CHANNEL_LAYOUT_DISCRETE,
+      kInputSamplesPerSecond, EmptyExtraData(), Unencrypted());
+  audio_config.SetChannelsForDiscrete(4);
+  ConfigureChangeDemuxerStream(audio_config);
+
+  Initialize();
+  std::vector<bool> mask = channel_mask();
+  EXPECT_FALSE(mask.empty());
+  ASSERT_EQ(mask.size(), static_cast<size_t>(hw_params.channels()));
+  for (int ch = 0; ch < hw_params.channels(); ++ch) {
+    if (ch > 3)
+      ASSERT_FALSE(mask[ch]);
+    else
+      ASSERT_TRUE(mask[ch]);
+  }
+
+  // TODO (flim): channel configuration change?
+}
+
 TEST_F(AudioRendererImplTest, Underflow_Flush) {
   Initialize();
   Preroll();