Use channel mask instead of channel count for track creation

Record and playback objects (resp AudioRecord and AudioTrack)
are created using a channel mask, but this information is lost
in the mixer because only the channel count is known to
AudioFlinger. A channel count can always be derived from a
channel mask.

The change consists in:
- disambiguiting variable names for channel masks and counts
- passing the mask information from the client to AudioFlinger
 and the mixer.
- when using the DIRECT ouput, only verifying the format of
 the track is compatible with the output's for PCM.

Change-Id: I50d87bfb7d7afcabdf5f12d4ab75ef3a54132c0e

1 files changed, 15 insertions, 5 deletions

diff --git a/services/audioflinger/AudioMixer.cpp b/services/audioflinger/AudioMixer.cpp
index 50dcda7..6e9319d 100644
--- a/services/audioflinger/AudioMixer.cpp
+++ b/services/audioflinger/AudioMixer.cpp
@@ -26,6 +26,10 @@
 #include <utils/Errors.h>
 #include <utils/Log.h>
 
+#include <cutils/bitops.h>
+
+#include <system/audio.h>
+
 #include "AudioMixer.h"
 
 namespace android {
@@ -61,6 +65,7 @@ AudioMixer::AudioMixer(size_t frameCount, uint32_t sampleRate)
         t->channelCount = 2;
         t->enabled = 0;
         t->format = 16;
+        t->channelMask = AUDIO_CHANNEL_OUT_STEREO;
         t->buffer.raw = 0;
         t->bufferProvider = 0;
         t->hook = 0;
@@ -180,13 +185,18 @@ status_t AudioMixer::setParameter(int target, int name, void *value)
 
     switch (target) {
     case TRACK:
-        if (name == CHANNEL_COUNT) {
-            if ((uint32_t(valueInt) <= MAX_NUM_CHANNELS) && (valueInt)) {
-                if (mState.tracks[ mActiveTrack ].channelCount != valueInt) {
-                    mState.tracks[ mActiveTrack ].channelCount = valueInt;
-                    LOGV("setParameter(TRACK, CHANNEL_COUNT, %d)", valueInt);
+        if (name == CHANNEL_MASK) {
+            uint32_t mask = (uint32_t)value;
+            if (mState.tracks[ mActiveTrack ].channelMask != mask) {
+                uint8_t channelCount = popcount(mask);
+                if ((channelCount <= MAX_NUM_CHANNELS) && (channelCount)) {
+                    mState.tracks[ mActiveTrack ].channelMask = mask;
+                    mState.tracks[ mActiveTrack ].channelCount = channelCount;
+                    LOGV("setParameter(TRACK, CHANNEL_MASK, %x)", mask);
                     invalidateState(1<<mActiveTrack);
+                    return NO_ERROR;
                 }
+            } else {
                 return NO_ERROR;
             }
         }