Implement android.media.AudioManager.getProperty()

Bug: 6635041
Change-Id: I0e7d53b99559cdc89f2f107f23048e4b1a8dd383

Author: gkasten

core/jni/android_media_AudioSystem.cpp

@@ -242,6 +242,18 @@ android_media_AudioSystem_getDevicesForStream(JNIEnv *env, jobject thiz, jint st
     return (jint) AudioSystem::getDevicesForStream(static_cast <audio_stream_type_t>(stream));
 }
 
+static jint
+android_media_AudioSystem_getPrimaryOutputSamplingRate(JNIEnv *env, jobject clazz)
+{
+    return (jint) AudioSystem::getPrimaryOutputSamplingRate();
+}
+
+static jint
+android_media_AudioSystem_getPrimaryOutputFrameCount(JNIEnv *env, jobject clazz)
+{
+    return (jint) AudioSystem::getPrimaryOutputFrameCount();
+}
+
 // ----------------------------------------------------------------------------
 
 static JNINativeMethod gMethods[] = {
@@ -263,6 +275,8 @@ static JNINativeMethod gMethods[] = {
     {"setMasterMute",       "(Z)I",     (void *)android_media_AudioSystem_setMasterMute},
     {"getMasterMute",       "()Z",      (void *)android_media_AudioSystem_getMasterMute},
     {"getDevicesForStream", "(I)I",     (void *)android_media_AudioSystem_getDevicesForStream},
+    {"getPrimaryOutputSamplingRate", "()I", (void *)android_media_AudioSystem_getPrimaryOutputSamplingRate},
+    {"getPrimaryOutputFrameCount",   "()I", (void *)android_media_AudioSystem_getPrimaryOutputFrameCount},
 };
 
 int register_android_media_AudioSystem(JNIEnv *env)

media/java/android/media/AudioManager.java

@@ -2474,8 +2474,16 @@ public IRingtonePlayer getRingtonePlayer() {
      *         or null if there is no value for that key.
      */
     public String getProperty(String key) {
-        // implementation to be written
-        return null;
+        if (PROPERTY_OUTPUT_SAMPLE_RATE.equals(key)) {
+            int outputSampleRate = AudioSystem.getPrimaryOutputSamplingRate();
+            return outputSampleRate > 0 ? Integer.toString(outputSampleRate) : null;
+        } else if (PROPERTY_OUTPUT_FRAMES_PER_BUFFER.equals(key)) {
+            int outputFramesPerBuffer = AudioSystem.getPrimaryOutputFrameCount();
+            return outputFramesPerBuffer > 0 ? Integer.toString(outputFramesPerBuffer) : null;
+        } else {
+            // null or unknown key
+            return null;
+        }
     }
 
 }

media/java/android/media/AudioSystem.java

@@ -381,4 +381,9 @@ public static String getDeviceName(int device)
     public static native int setMasterMute(boolean mute);
     public static native boolean getMasterMute();
     public static native int getDevicesForStream(int stream);
+
+    // helpers for android.media.AudioManager.getProperty(), see description there for meaning
+    public static native int getPrimaryOutputSamplingRate();
+    public static native int getPrimaryOutputFrameCount();
+
 }