Merge "AudioTrack: add setBufferSizeInFrames()"
diff --git a/core/jni/android_media_AudioTrack.cpp b/core/jni/android_media_AudioTrack.cpp
index 42f3fb0..6ef97e6 100644
--- a/core/jni/android_media_AudioTrack.cpp
+++ b/core/jni/android_media_AudioTrack.cpp
@@ -656,18 +656,59 @@
 }
 
 // ----------------------------------------------------------------------------
-static jint android_media_AudioTrack_get_native_frame_count(JNIEnv *env,  jobject thiz) {
+static jint android_media_AudioTrack_get_buffer_size_frames(JNIEnv *env,  jobject thiz) {
     sp<AudioTrack> lpTrack = getAudioTrack(env, thiz);
     if (lpTrack == NULL) {
         jniThrowException(env, "java/lang/IllegalStateException",
-            "Unable to retrieve AudioTrack pointer for frameCount()");
+            "Unable to retrieve AudioTrack pointer for getBufferSizeInFrames()");
+        return (jint)AUDIO_JAVA_ERROR;
+    }
+
+    ssize_t result = lpTrack->getBufferSizeInFrames();
+    if (result < 0) {
+        jniThrowException(env, "java/lang/IllegalStateException",
+            "Internal error detected in getBufferSizeInFrames() = " + result);
+        return (jint)AUDIO_JAVA_ERROR;
+    }
+    return (jint)result;
+}
+
+// ----------------------------------------------------------------------------
+static jint android_media_AudioTrack_set_buffer_size_frames(JNIEnv *env,
+        jobject thiz, jint bufferSizeInFrames) {
+    sp<AudioTrack> lpTrack = getAudioTrack(env, thiz);
+    if (lpTrack == NULL) {
+        jniThrowException(env, "java/lang/IllegalStateException",
+            "Unable to retrieve AudioTrack pointer for setBufferSizeInFrames()");
+        return (jint)AUDIO_JAVA_ERROR;
+    }
+    // Value will be coerced into the valid range.
+    // But internal values are unsigned, size_t, so we need to clip
+    // against zero here where it is signed.
+    if (bufferSizeInFrames < 0) {
+        bufferSizeInFrames = 0;
+    }
+    ssize_t result = lpTrack->setBufferSizeInFrames(bufferSizeInFrames);
+    if (result < 0) {
+        jniThrowException(env, "java/lang/IllegalStateException",
+            "Internal error detected in setBufferSizeInFrames() = " + result);
+        return (jint)AUDIO_JAVA_ERROR;
+    }
+    return (jint)result;
+}
+
+// ----------------------------------------------------------------------------
+static jint android_media_AudioTrack_get_buffer_capacity_frames(JNIEnv *env,  jobject thiz) {
+    sp<AudioTrack> lpTrack = getAudioTrack(env, thiz);
+    if (lpTrack == NULL) {
+        jniThrowException(env, "java/lang/IllegalStateException",
+            "Unable to retrieve AudioTrack pointer for getBufferCapacityInFrames()");
         return (jint)AUDIO_JAVA_ERROR;
     }
 
     return lpTrack->frameCount();
 }
 
-
 // ----------------------------------------------------------------------------
 static jint android_media_AudioTrack_set_playback_rate(JNIEnv *env,  jobject thiz,
         jint sampleRateInHz) {
@@ -1073,8 +1114,12 @@
     {"native_write_short",   "([SIIIZ)I",(void *)android_media_AudioTrack_writeArray<jshortArray>},
     {"native_write_float",   "([FIIIZ)I",(void *)android_media_AudioTrack_writeArray<jfloatArray>},
     {"native_setVolume",     "(FF)V",    (void *)android_media_AudioTrack_set_volume},
-    {"native_get_native_frame_count",
-                             "()I",      (void *)android_media_AudioTrack_get_native_frame_count},
+    {"native_get_buffer_size_frames",
+                             "()I",      (void *)android_media_AudioTrack_get_buffer_size_frames},
+    {"native_set_buffer_size_frames",
+                             "(I)I",     (void *)android_media_AudioTrack_set_buffer_size_frames},
+    {"native_get_buffer_capacity_frames",
+                             "()I",      (void *)android_media_AudioTrack_get_buffer_capacity_frames},
     {"native_set_playback_rate",
                              "(I)I",     (void *)android_media_AudioTrack_set_playback_rate},
     {"native_get_playback_rate",
diff --git a/media/java/android/media/AudioTrack.java b/media/java/android/media/AudioTrack.java
index c110ce8..846922e 100644
--- a/media/java/android/media/AudioTrack.java
+++ b/media/java/android/media/AudioTrack.java
@@ -1053,8 +1053,68 @@
         }
     }
 
+// TODO Change getBufferCapacityInFrames() reference below to
+// {@link #getBufferCapacityInFrames()} after @hide is removed.
+// TODO Change setBufferSizeInFrames(int) reference below to
+// {@link #setBufferSizeInFrames(int)} after @hide is removed.
     /**
-     *  Returns the frame count of the native <code>AudioTrack</code> buffer.
+     *  Returns the effective size of the <code>AudioTrack</code> buffer
+     * that the application writes to.
+     *  <p> This will be less than or equal to the result of
+     * getBufferCapacityInFrames().
+     * It will be equal if setBufferSizeInFrames(int) has never been called.
+     *  <p> If the track is subsequently routed to a different output sink, the buffer
+     *  size and capacity may enlarge to accommodate.
+     *  <p> If the <code>AudioTrack</code> encoding indicates compressed data,
+     *  e.g. {@link AudioFormat#ENCODING_AC3}, then the frame count returned is
+     *  the size of the native <code>AudioTrack</code> buffer in bytes.
+     *  <p> See also {@link AudioManager#getProperty(String)} for key
+     *  {@link AudioManager#PROPERTY_OUTPUT_FRAMES_PER_BUFFER}.
+     *  @return current size in frames of the <code>AudioTrack</code> buffer.
+     *  @throws IllegalStateException
+     */
+    public int getBufferSizeInFrames() {
+        return native_get_buffer_size_frames();
+    }
+
+// TODO Change getBufferCapacityInFrames() reference below to
+// {@link #getBufferCapacityInFrames()} after @hide is removed.
+    /**
+     * Limits the effective size of the <code>AudioTrack</code> buffer
+     * that the application writes to.
+     * <p> A write to this AudioTrack will not fill the buffer beyond this limit.
+     * If a blocking write is used then the write will block until the the data
+     * can fit within this limit.
+     * <p>Changing this limit modifies the latency associated with
+     * the buffer for this track. A smaller size will give lower latency
+     * but there may be more glitches due to buffer underruns.
+     *  <p>The actual size used may not be equal to this requested size.
+     * It will be limited to a valid range with a maximum of
+     * getBufferCapacityInFrames().
+     * It may also be adjusted slightly for internal reasons.
+     * If bufferSizeInFrames is less than zero then {@link #ERROR_BAD_VALUE}
+     * will be returned.
+     * <p>This method is only supported for PCM audio.
+     * It is not supported for compressed audio tracks.
+     *
+     * @param bufferSizeInFrames requested buffer size
+     * @return error code or success, see {@link #SUCCESS}, {@link #ERROR_BAD_VALUE},
+     *    {@link #ERROR_INVALID_OPERATION}
+     *  @throws IllegalStateException
+     * @hide
+     */
+    public int setBufferSizeInFrames(int bufferSizeInFrames) {
+        if (mDataLoadMode == MODE_STATIC || mState == STATE_UNINITIALIZED) {
+            return ERROR_INVALID_OPERATION;
+        }
+        if (bufferSizeInFrames < 0) {
+            return ERROR_BAD_VALUE;
+        }
+        return native_set_buffer_size_frames(bufferSizeInFrames);
+    }
+
+    /**
+     *  Returns the maximum size of the native <code>AudioTrack</code> buffer.
      *  <p> If the track's creation mode is {@link #MODE_STATIC},
      *  it is equal to the specified bufferSizeInBytes on construction, converted to frame units.
      *  A static track's native frame count will not change.
@@ -1069,11 +1129,12 @@
      *  the size of the native <code>AudioTrack</code> buffer in bytes.
      *  <p> See also {@link AudioManager#getProperty(String)} for key
      *  {@link AudioManager#PROPERTY_OUTPUT_FRAMES_PER_BUFFER}.
-     *  @return current size in frames of the <code>AudioTrack</code> buffer.
+     *  @return maximum size in frames of the <code>AudioTrack</code> buffer.
      *  @throws IllegalStateException
+     * @hide
      */
-    public int getBufferSizeInFrames() {
-        return native_get_native_frame_count();
+    public int getBufferCapacityInFrames() {
+        return native_get_buffer_capacity_frames();
     }
 
     /**
@@ -1084,7 +1145,7 @@
      */
     @Deprecated
     protected int getNativeFrameCount() {
-        return native_get_native_frame_count();
+        return native_get_buffer_capacity_frames();
     }
 
     /**
@@ -2701,7 +2762,9 @@
 
     private native final int native_reload_static();
 
-    private native final int native_get_native_frame_count();
+    private native final int native_get_buffer_size_frames();
+    private native final int native_set_buffer_size_frames(int bufferSizeInFrames);
+    private native final int native_get_buffer_capacity_frames();
 
     private native final void native_setVolume(float leftVolume, float rightVolume);