5 files changed, 52 insertions, 0 deletions
diff --git a/core/jni/android_media_AudioSystem.cpp b/core/jni/android_media_AudioSystem.cpp
index 0827f7ca40c7..67c2cfdc9bb3 100644
--- a/core/jni/android_media_AudioSystem.cpp
+++ b/core/jni/android_media_AudioSystem.cpp
@@ -271,6 +271,17 @@ android_media_AudioSystem_getPrimaryOutputFrameCount(JNIEnv *env, jobject clazz)
     return (jint) AudioSystem::getPrimaryOutputFrameCount();
 }
 
+static jint
+android_media_AudioSystem_getOutputLatency(JNIEnv *env, jobject clazz, jint stream)
+{
+    uint32_t afLatency;
+    if (AudioSystem::getOutputLatency(&afLatency, static_cast <audio_stream_type_t>(stream))
+            != NO_ERROR) {
+        afLatency = -1;
+    }
+    return (jint) afLatency;
+}
+
 // ----------------------------------------------------------------------------
 
 static JNINativeMethod gMethods[] = {
@@ -296,6 +307,7 @@ static JNINativeMethod gMethods[] = {
     {"getDevicesForStream", "(I)I",     (void *)android_media_AudioSystem_getDevicesForStream},
     {"getPrimaryOutputSamplingRate", "()I", (void *)android_media_AudioSystem_getPrimaryOutputSamplingRate},
     {"getPrimaryOutputFrameCount",   "()I", (void *)android_media_AudioSystem_getPrimaryOutputFrameCount},
+    {"getOutputLatency",    "(I)I",     (void *)android_media_AudioSystem_getOutputLatency},
 };
 
 int register_android_media_AudioSystem(JNIEnv *env)
diff --git a/core/jni/android_media_AudioTrack.cpp b/core/jni/android_media_AudioTrack.cpp
index e2d34c9054a0..3ff9dda1de7b 100644
--- a/core/jni/android_media_AudioTrack.cpp
+++ b/core/jni/android_media_AudioTrack.cpp
@@ -728,6 +728,19 @@ static jint android_media_AudioTrack_get_position(JNIEnv *env,  jobject thiz) {
 
 
 // ----------------------------------------------------------------------------
+static jint android_media_AudioTrack_get_latency(JNIEnv *env,  jobject thiz) {
+    sp<AudioTrack> lpTrack = getAudioTrack(env, thiz);
+
+    if (lpTrack == NULL) {
+        jniThrowException(env, "java/lang/IllegalStateException",
+            "Unable to retrieve AudioTrack pointer for latency()");
+        return AUDIOTRACK_ERROR;
+    }
+    return (jint)lpTrack->latency();
+}
+
+
+// ----------------------------------------------------------------------------
 static jint android_media_AudioTrack_set_loop(JNIEnv *env,  jobject thiz,
         jint loopStart, jint loopEnd, jint loopCount) {
     sp<AudioTrack> lpTrack = getAudioTrack(env, thiz);
@@ -854,6 +867,7 @@ static JNINativeMethod gMethods[] = {
                              "()I",      (void *)android_media_AudioTrack_get_pos_update_period},
     {"native_set_position",  "(I)I",     (void *)android_media_AudioTrack_set_position},
     {"native_get_position",  "()I",      (void *)android_media_AudioTrack_get_position},
+    {"native_get_latency",   "()I",      (void *)android_media_AudioTrack_get_latency},
     {"native_set_loop",      "(III)I",   (void *)android_media_AudioTrack_set_loop},
     {"native_reload_static", "()I",      (void *)android_media_AudioTrack_reload},
     {"native_get_output_sample_rate",
diff --git a/media/java/android/media/AudioManager.java b/media/java/android/media/AudioManager.java
index 32e54460ebde..3144e8a7428e 100644
--- a/media/java/android/media/AudioManager.java
+++ b/media/java/android/media/AudioManager.java
@@ -2556,4 +2556,15 @@ public class AudioManager {
         }
     }
 
+    /**
+     * Returns the estimated latency for the given stream type in milliseconds.
+     *
+     * DO NOT UNHIDE. The existing approach for doing A/V sync has too many problems. We need
+     * a better solution.
+     * @hide
+     */
+    public int getOutputLatency(int streamType) {
+        return AudioSystem.getOutputLatency(streamType);
+    }
+
 }
diff --git a/media/java/android/media/AudioSystem.java b/media/java/android/media/AudioSystem.java
index 4a33743ae0dd..d42bfd4442eb 100644
--- a/media/java/android/media/AudioSystem.java
+++ b/media/java/android/media/AudioSystem.java
@@ -401,5 +401,6 @@ public class AudioSystem
     // helpers for android.media.AudioManager.getProperty(), see description there for meaning
     public static native int getPrimaryOutputSamplingRate();
     public static native int getPrimaryOutputFrameCount();
+    public static native int getOutputLatency(int stream);
 
 }
diff --git a/media/java/android/media/AudioTrack.java b/media/java/android/media/AudioTrack.java
index 60eaa92ae069..73227161f3cb 100644
--- a/media/java/android/media/AudioTrack.java
+++ b/media/java/android/media/AudioTrack.java
@@ -651,6 +651,18 @@ public class AudioTrack
     }
 
     /**
+     * Returns this track's estimated latency in milliseconds. This includes the latency due
+     * to AudioTrack buffer size, AudioMixer (if any) and audio hardware driver.
+     *
+     * DO NOT UNHIDE. The existing approach for doing A/V sync has too many problems. We need
+     * a better solution.
+     * @hide
+     */
+    public int getLatency() {
+        return native_get_latency();
+    }
+
+    /**
      *  Returns the output sample rate in Hz for the specified stream type.
      */
     static public int getNativeOutputSampleRate(int streamType) {
@@ -1315,6 +1327,8 @@ public class AudioTrack
     private native final int native_set_position(int position);
     private native final int native_get_position();
 
+    private native final int native_get_latency();
+
     private native final int native_set_loop(int start, int end, int loopCount);
 
     static private native final int native_get_output_sample_rate(int streamType);