Fix channel mask on tablets with 3.x versions of Android.

Get the android SDK version from JNI instead of guessing it from the symbols found in libmedia.so.

src/android/AudioTrack.cpp

@@ -38,18 +38,6 @@ namespace fake_android{
                                     int sessionId ){
 		mThis=new uint8_t[512];
 		mImpl=AudioTrackImpl::get();
-		
-		/* HACK for Froyo and Gingerbread */
-		/* This is needed because the enum values have changed between Gingerbread and ICS */
-		if (mImpl->mBeforeICS) {
-			ms_message("Android version older than ICS, apply audio channel hack for AudioTrack");
-			if ((channelMask & AUDIO_CHANNEL_OUT_MONO) == AUDIO_CHANNEL_OUT_MONO) {
-				channelMask = 0x4;
-			} else if ((channelMask & AUDIO_CHANNEL_OUT_STEREO) == AUDIO_CHANNEL_OUT_STEREO) {
-				channelMask = 0x4|0x8;
-			}
-		}
-		
 		mImpl->mCtor.invoke(mThis,streamType,sampleRate,format,channelMask,frameCount,flags,cbf,user,notificationFrames,sessionId);
 	}
 	
@@ -130,8 +118,7 @@ namespace fake_android{
 		mFlush(lib,"_ZN7android10AudioTrack5flushEv"),
 		mGetMinFrameCount(lib,"_ZN7android10AudioTrack16getMinFrameCountEPiij"),
 		mLatency(lib,"_ZNK7android10AudioTrack7latencyEv"),
-		mGetPosition(lib,"_ZN7android10AudioTrack11getPositionEPj"),
-		mBeforeICS(false)
+		mGetPosition(lib,"_ZN7android10AudioTrack11getPositionEPj")
 	{
 		// Try some Android 2.2 symbols if not found
 		if (!mCtor.isFound()) {
@@ -142,12 +129,6 @@ namespace fake_android{
 		if (!mGetMinFrameCount.isFound()) {
 			mGetMinFrameCount.load(lib,"_ZN7android10AudioTrack16getMinFrameCountEPi19audio_stream_type_tj");
 		}
-
-		// Dummy symbol loading to detect the Android version, this function did not exist before ICS,
-		Function0<uint32_t> getFrameRate(lib,"_ZN7android10AudioTrack9setLoop_lEjji");
-		if (!getFrameRate.isFound()) {
-			mBeforeICS = true;
-		}
 	}
 	
 	bool AudioTrackImpl::init(Library *lib){
@@ -171,4 +152,4 @@ namespace fake_android{
 	
 	
 	
-}//end of namespace
\ No newline at end of file
+}//end of namespace

src/android/AudioTrack.h

@@ -431,7 +431,6 @@ public:
 	Function3<status_t,int*,audio_stream_type_t,int> mGetMinFrameCount;
 	Function1<uint32_t,void*> mLatency;
 	Function2<status_t,void*,uint32_t*> mGetPosition;
-	bool mBeforeICS;
 private:
 	AudioTrackImpl(Library *lib);
 	static AudioTrackImpl *sImpl;

src/android/androidsound.cpp

@@ -219,6 +219,17 @@ static void android_snd_card_detect(MSSndCardManager *m){
 
 }
 
+static int sdk_version = 0;
+
+static void android_native_snd_card_init(MSSndCard *card) {
+	/* Get Android SDK version. */
+	JNIEnv *jni_env = ms_get_jni_env();
+	jclass version_class = jni_env->FindClass("android/os/Build$VERSION");
+	jfieldID fid = jni_env->GetStaticFieldID(version_class, "SDK_INT", "I");
+	sdk_version = jni_env->GetStaticIntField(version_class, fid);
+	ms_message("SDK version [%i] detected", sdk_version);
+}
+
 static void android_native_snd_card_uninit(MSSndCard *card){
 	
 	delete static_cast<AndroidNativeSndCardData*>(card->data);
@@ -227,7 +238,7 @@ static void android_native_snd_card_uninit(MSSndCard *card){
 MSSndCardDesc android_native_snd_card_desc={
 	"libmedia",
 	android_snd_card_detect,
-	NULL,
+	android_native_snd_card_init,
 	NULL,
 	NULL,
 	NULL,
@@ -552,6 +563,20 @@ static void android_snd_write_cb(int event, void *user, void * p_info){
 	}else ms_error("Untracked event %i",event);
 }
 
+static int channel_mask_for_audio_track(int nchannels) {
+	int channel_mask;
+	channel_mask = audio_channel_out_mask_from_count(nchannels);
+	if (sdk_version < 14) {
+		ms_message("Android version older than ICS, apply audio channel hack for AudioTrack");
+		if ((channel_mask & AUDIO_CHANNEL_OUT_MONO) == AUDIO_CHANNEL_OUT_MONO) {
+			channel_mask = 0x4;
+		} else if ((channel_mask & AUDIO_CHANNEL_OUT_STEREO) == AUDIO_CHANNEL_OUT_STEREO) {
+			channel_mask = 0x4|0x8;
+		}
+	}
+	return channel_mask;
+}
+
 static void android_snd_write_preprocess(MSFilter *obj){
 	AndroidSndWriteData *ad=(AndroidSndWriteData*)obj->data;
 	int play_buf_size;
@@ -571,7 +596,7 @@ static void android_snd_write_preprocess(MSFilter *obj){
 	ad->tr=new AudioTrack(ad->stype,
                      ad->rate,
                      AUDIO_FORMAT_PCM_16_BIT,
-                     audio_channel_out_mask_from_count(ad->nchannels),
+                     channel_mask_for_audio_track(ad->nchannels),
                      play_buf_size,
                      AUDIO_OUTPUT_FLAG_NONE, // AUDIO_OUTPUT_FLAG_NONE,
                      android_snd_write_cb, ad,notify_frames,0);