am 09ff9125: Merge "Convert record channel mask for dynamic mix" into lmp-mr1-dev

* commit '09ff91255e945f2588c377614bf7b7c0d512118e':
  Convert record channel mask for dynamic mix

media/java/android/media/AudioFormat.java

@@ -126,6 +126,29 @@ public class AudioFormat {
             CHANNEL_OUT_LOW_FREQUENCY);
     // CHANNEL_OUT_ALL is not yet defined; if added then it should match AUDIO_CHANNEL_OUT_ALL
 
+    /**
+     * @hide
+     * Return the input channel mask corresponding to an output channel mask.
+     * This can be used for submix rerouting for the mask of the recorder to map to that of the mix.
+     * @param outMask a combination of the CHANNEL_OUT_* definitions, but not CHANNEL_OUT_DEFAULT
+     * @return a combination of CHANNEL_IN_* definitions matching an output channel mask
+     * @throws IllegalArgumentException
+     */
+    public static int inChannelMaskFromOutChannelMask(int outMask) throws IllegalArgumentException {
+        if (outMask == CHANNEL_OUT_DEFAULT) {
+            throw new IllegalArgumentException(
+                    "Illegal CHANNEL_OUT_DEFAULT channel mask for input.");
+        }
+        switch (channelCountFromOutChannelMask(outMask)) {
+            case 1:
+                return CHANNEL_IN_MONO;
+            case 2:
+                return CHANNEL_IN_STEREO;
+            default:
+                throw new IllegalArgumentException("Unsupported channel configuration for input.");
+        }
+    }
+
     /**
      * @hide
      * Return the number of channels from an input channel mask

media/java/android/media/audiopolicy/AudioPolicy.java

@@ -155,6 +155,7 @@ public class AudioPolicy {
         {
             throw new IllegalArgumentException("Invalid AudioMix: not defined for loop back");
         }
+        // TODO also check mix is defined for playback or recording, and matches forTrack argument
     }
 
     /**
@@ -175,13 +176,19 @@ public class AudioPolicy {
             return null;
         }
         checkMixReadyToUse(mix, false/*not for an AudioTrack*/);
+        // create an AudioFormat from the mix format compatible with recording, as the mix
+        // was defined for playback
+        AudioFormat mixFormat = new AudioFormat.Builder(mix.getFormat())
+                .setChannelMask(AudioFormat.inChannelMaskFromOutChannelMask(
+                        mix.getFormat().getChannelMask()))
+                .build();
         // create the AudioRecord, configured for loop back, using the same format as the mix
         AudioRecord ar = new AudioRecord(
                 new AudioAttributes.Builder()
                         .setInternalCapturePreset(MediaRecorder.AudioSource.REMOTE_SUBMIX)
                         .addTag(mix.getRegistration())
                         .build(),
-                mix.getFormat(),
+                mixFormat,
                 AudioRecord.getMinBufferSize(mix.getFormat().getSampleRate(),
                         // using stereo for buffer size to avoid the current poor support for masks
                         AudioFormat.CHANNEL_IN_STEREO, mix.getFormat().getEncoding()),