AudioMixer uses downmix effect for multichannel content
In the AudioMixer structure associated with each track, add an object
that acts as the buffer provider when the track has more than two
channels of input in the mixer. This object, DownmixerBufferProvider,
gets audio from the actual buffer provider of the track, and applies
a downmix effect on it.
The downmix effect is created and configured when the track gets
created in AudioFlinger, which causes AudioMixer::getTrackName()
to be called with the new track's channel mask. It is released
when the track is disabled in the mixer.
Change-Id: I05281ed5f61bef663a8af7ca7d5ceac3517c82db
diff --git a/services/audioflinger/AudioFlinger.h b/services/audioflinger/AudioFlinger.h
index e493a9a..8a787e1 100644
--- a/services/audioflinger/AudioFlinger.h
+++ b/services/audioflinger/AudioFlinger.h
@@ -964,8 +964,9 @@
protected:
SortedVector< wp<Track> > mActiveTracks;
- // Allocate a track name. Returns name >= 0 if successful, -1 on failure.
- virtual int getTrackName_l() = 0;
+ // Allocate a track name for a given channel mask.
+ // Returns name >= 0 if successful, -1 on failure.
+ virtual int getTrackName_l(audio_channel_mask_t channelMask) = 0;
virtual void deleteTrackName_l(int name) = 0;
// Time to sleep between cycles when:
@@ -1057,7 +1058,7 @@
protected:
virtual mixer_state prepareTracks_l(Vector< sp<Track> > *tracksToRemove);
- virtual int getTrackName_l();
+ virtual int getTrackName_l(audio_channel_mask_t channelMask);
virtual void deleteTrackName_l(int name);
virtual uint32_t idleSleepTimeUs() const;
virtual uint32_t suspendSleepTimeUs() const;
@@ -1082,7 +1083,7 @@
virtual bool checkForNewParameters_l();
protected:
- virtual int getTrackName_l();
+ virtual int getTrackName_l(audio_channel_mask_t channelMask);
virtual void deleteTrackName_l(int name);
virtual uint32_t activeSleepTimeUs() const;
virtual uint32_t idleSleepTimeUs() const;