tests/native-media/jni/native-media-jni.c - platform/frameworks/wilhelm - Git at Google

 /*
  * Copyright (C) 2010 The Android Open Source Project
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
  * You may obtain a copy of the License at
  *
  *      http://www.apache.org/licenses/LICENSE-2.0
  *
  * Unless required by applicable law or agreed to in writing, software
  * distributed under the License is distributed on an "AS IS" BASIS,
  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  * See the License for the specific language governing permissions and
  * limitations under the License.
  */

 #include <assert.h>
 #include <jni.h>
 #include <pthread.h>
 #include <string.h>
 //#define LOG_NDEBUG 0
 #define LOG_TAG "NativeMedia"
 #include <utils/Log.h>

 #include <OMXAL/OpenMAXAL.h>
 #include <OMXAL/OpenMAXAL_Android.h>

 #include <android/native_window_jni.h>

 // engine interfaces
 static XAObjectItf engineObject = NULL;
 static XAEngineItf engineEngine = NULL;

 // output mix interfaces
 static XAObjectItf outputMixObject = NULL;

 // streaming media player interfaces
 static XAObjectItf             playerObj = NULL;
 static XAPlayItf               playerPlayItf = NULL;
 static XAAndroidBufferQueueItf playerBQItf = NULL;
 static XAStreamInformationItf  playerStreamInfoItf = NULL;
 static XAVolumeItf             playerVolItf = NULL;

 // number of required interfaces for the MediaPlayer creation
 #define NB_MAXAL_INTERFACES 3 // XAAndroidBufferQueueItf, XAStreamInformationItf and XAPlayItf

 // video sink for the player
 static ANativeWindow* theNativeWindow;

 // number of buffers in our buffer queue, an arbitrary number
 #define NB_BUFFERS 16

 // we're streaming MPEG-2 transport stream data, operate on transport stream block size
 #define MPEG2_TS_BLOCK_SIZE 188

 // number of MPEG-2 transport stream blocks per buffer, an arbitrary number
 #define BLOCKS_PER_BUFFER 20

 // determines how much memory we're dedicating to memory caching
 #define BUFFER_SIZE (BLOCKS_PER_BUFFER*MPEG2_TS_BLOCK_SIZE)

 // where we cache in memory the data to play
 // note this memory is re-used by the buffer queue callback
 char dataCache[BUFFER_SIZE * NB_BUFFERS];

 // handle of the file to play
 FILE *file;

 // has the app reached the end of the file
 jboolean reachedEof = JNI_FALSE;

 // constant to identify a buffer context which is the end of the stream to decode
 static const int kEosBufferCntxt = 1980; // a magic value we can compare against

 // for mutual exclusion between callback thread and application thread(s)
 pthread_mutex_t mutex = PTHREAD_MUTEX_INITIALIZER;
 pthread_cond_t cond = PTHREAD_COND_INITIALIZER;

 // whether a discontinuity is in progress
 jboolean discontinuity = JNI_FALSE;

 static jboolean enqueueInitialBuffers(jboolean discontinuity);

 // Callback for XAPlayItf through which we receive the XA_PLAYEVENT_HEADATEND event */
 void PlayCallback(XAPlayItf caller, void *pContext, XAuint32 event) {
     if (event & XA_PLAYEVENT_HEADATEND) {
         ALOGV("XA_PLAYEVENT_HEADATEND received, all MP2TS data has been decoded\n");
     }
 }

 // AndroidBufferQueueItf callback for an audio player
 XAresult AndroidBufferQueueCallback(
         XAAndroidBufferQueueItf caller,
         void *pCallbackContext,        /* input */
         void *pBufferContext,          /* input */
         void *pBufferData,             /* input */
         XAuint32 dataSize,             /* input */
         XAuint32 dataUsed,             /* input */
         const XAAndroidBufferItem *pItems,/* input */
         XAuint32 itemsLength           /* input */)
 {
     XAresult res;
     int ok;

     // pCallbackContext was specified as NULL at RegisterCallback and is unused here
     assert(NULL == pCallbackContext);

     // note there is never any contention on this mutex unless a discontinuity request is active
     ok = pthread_mutex_lock(&mutex);
     assert(0 == ok);

     // was a discontinuity requested?
     if (discontinuity) {
         // FIXME sorry, can't rewind after EOS
         if (!reachedEof) {
             // clear the buffer queue
             res = (*playerBQItf)->Clear(playerBQItf);
             assert(XA_RESULT_SUCCESS == res);
             // rewind the data source so we are guaranteed to be at an appropriate point
             rewind(file);
             // Enqueue the initial buffers, with a discontinuity indicator on first buffer
             (void) enqueueInitialBuffers(JNI_TRUE);
         }
         // acknowledge the discontinuity request
         discontinuity = JNI_FALSE;
         ok = pthread_cond_signal(&cond);
         assert(0 == ok);
         goto exit;
     }

     if ((pBufferData == NULL) && (pBufferContext != NULL)) {
         const int processedCommand = *(int *)pBufferContext;
         if (kEosBufferCntxt == processedCommand) {
             ALOGV("EOS was processed\n");
             // our buffer with the EOS message has been consumed
             assert(0 == dataSize);
             goto exit;
         }
     }

     // pBufferData is a pointer to a buffer that we previously Enqueued
     assert(BUFFER_SIZE == dataSize);
     assert(dataCache <= (char *) pBufferData && (char *) pBufferData <
             &dataCache[BUFFER_SIZE * NB_BUFFERS]);
     assert(0 == (((char *) pBufferData - dataCache) % BUFFER_SIZE));

 #if 0
     // sample code to use the XAVolumeItf
     XAAndroidBufferQueueState state;
     (*caller)->GetState(caller, &state);
     switch (state.index) {
     case 300:
         (*playerVolItf)->SetVolumeLevel(playerVolItf, -600); // -6dB
         ALOGV("setting volume to -6dB");
         break;
     case 400:
         (*playerVolItf)->SetVolumeLevel(playerVolItf, -1200); // -12dB
         ALOGV("setting volume to -12dB");
         break;
     case 500:
         (*playerVolItf)->SetVolumeLevel(playerVolItf, 0); // full volume
         ALOGV("setting volume to 0dB (full volume)");
         break;
     case 600:
         (*playerVolItf)->SetMute(playerVolItf, XA_BOOLEAN_TRUE); // mute
         ALOGV("muting player");
         break;
     case 700:
         (*playerVolItf)->SetMute(playerVolItf, XA_BOOLEAN_FALSE); // unmute
         ALOGV("unmuting player");
         break;
     case 800:
         (*playerVolItf)->SetStereoPosition(playerVolItf, -1000);
         (*playerVolItf)->EnableStereoPosition(playerVolItf, XA_BOOLEAN_TRUE);
         ALOGV("pan sound to the left (hard-left)");
         break;
     case 900:
         (*playerVolItf)->EnableStereoPosition(playerVolItf, XA_BOOLEAN_FALSE);
         ALOGV("disabling stereo position");
         break;
     default:
         break;
     }
 #endif

     // don't bother trying to read more data once we've hit EOF
     if (reachedEof) {
         goto exit;
     }

     size_t nbRead;
     // note we do call fread from multiple threads, but never concurrently
     nbRead = fread(pBufferData, BUFFER_SIZE, 1, file);
     if (nbRead > 0) {
         assert(1 == nbRead);
         res = (*caller)->Enqueue(caller, NULL /*pBufferContext*/,
                 pBufferData /*pData*/,
                 nbRead * BUFFER_SIZE /*dataLength*/,
                 NULL /*pMsg*/,
                 0 /*msgLength*/);
         assert(XA_RESULT_SUCCESS == res);
     } else {
         // signal EOS
         XAAndroidBufferItem msgEos[1];
         msgEos[0].itemKey = XA_ANDROID_ITEMKEY_EOS;
         msgEos[0].itemSize = 0;
         // EOS message has no parameters, so the total size of the message is the size of the key
         //   plus the size if itemSize, both XAuint32
         res = (*caller)->Enqueue(caller, (void *)&kEosBufferCntxt /*pBufferContext*/,
                 NULL /*pData*/, 0 /*dataLength*/,
                 msgEos /*pMsg*/,
                 // FIXME == sizeof(BufferItem)? */
                 sizeof(XAuint32)*2 /*msgLength*/);
         assert(XA_RESULT_SUCCESS == res);
         reachedEof = JNI_TRUE;
     }

 exit:
     ok = pthread_mutex_unlock(&mutex);
     assert(0 == ok);
     return XA_RESULT_SUCCESS;
 }


 void StreamChangeCallback (XAStreamInformationItf caller,
         XAuint32 eventId,
         XAuint32 streamIndex,
         void * pEventData,
         void * pContext )
 {
     ALOGV("StreamChangeCallback called for stream %u", streamIndex);
     // pContext was specified as NULL at RegisterStreamChangeCallback and is unused here
     assert(NULL == pContext);
     switch (eventId) {
     case XA_STREAMCBEVENT_PROPERTYCHANGE: {
         /** From spec 1.0.1:
             "This event indicates that stream property change has occurred.
             The streamIndex parameter identifies the stream with the property change.
             The pEventData parameter for this event is not used and shall be ignored."
          */

         XAresult res;
         XAuint32 domain;
         res = (*caller)->QueryStreamType(caller, streamIndex, &domain);
         assert(XA_RESULT_SUCCESS == res);
         switch (domain) {
         case XA_DOMAINTYPE_VIDEO: {
             XAVideoStreamInformation videoInfo;
             res = (*caller)->QueryStreamInformation(caller, streamIndex, &videoInfo);
             assert(XA_RESULT_SUCCESS == res);
             ALOGI("Found video size %u x %u, codec ID=%u, frameRate=%u, bitRate=%u, duration=%u ms",
                         videoInfo.width, videoInfo.height, videoInfo.codecId, videoInfo.frameRate,
                         videoInfo.bitRate, videoInfo.duration);
         } break;
         default:
             fprintf(stderr, "Unexpected domain %u\n", domain);
             break;
         }
         } break;
     default:
         fprintf(stderr, "Unexpected stream event ID %u\n", eventId);
         break;
     }
 }


 // create the engine and output mix objects
 void Java_com_example_nativemedia_NativeMedia_createEngine(JNIEnv* env, jclass clazz)
 {
     XAresult res;

     // create engine
     res = xaCreateEngine(&engineObject, 0, NULL, 0, NULL, NULL);
     assert(XA_RESULT_SUCCESS == res);

     // realize the engine
     res = (*engineObject)->Realize(engineObject, XA_BOOLEAN_FALSE);
     assert(XA_RESULT_SUCCESS == res);

     // get the engine interface, which is needed in order to create other objects
     res = (*engineObject)->GetInterface(engineObject, XA_IID_ENGINE, &engineEngine);
     assert(XA_RESULT_SUCCESS == res);

     // create output mix
     res = (*engineEngine)->CreateOutputMix(engineEngine, &outputMixObject, 0, NULL, NULL);
     assert(XA_RESULT_SUCCESS == res);

     // realize the output mix
     res = (*outputMixObject)->Realize(outputMixObject, XA_BOOLEAN_FALSE);
     assert(XA_RESULT_SUCCESS == res);

 }


 // Enqueue the initial buffers, and optionally signal a discontinuity in the first buffer
 static jboolean enqueueInitialBuffers(jboolean discontinuity)
 {

     /* Fill our cache */
     size_t nbRead;
     nbRead = fread(dataCache, BUFFER_SIZE, NB_BUFFERS, file);
     if (nbRead <= 0) {
         // could be premature EOF or I/O error
         ALOGE("Error filling cache, exiting\n");
         return JNI_FALSE;
     }
     assert(1 <= nbRead && nbRead <= NB_BUFFERS);
     ALOGV("Initially queueing %zu buffers of %u bytes each", nbRead, BUFFER_SIZE);

     /* Enqueue the content of our cache before starting to play,
        we don't want to starve the player */
     size_t i;
     for (i = 0; i < nbRead; i++) {
         XAresult res;
         if (discontinuity) {
             // signal discontinuity
             XAAndroidBufferItem items[1];
             items[0].itemKey = XA_ANDROID_ITEMKEY_DISCONTINUITY;
             items[0].itemSize = 0;
             // DISCONTINUITY message has no parameters,
             //   so the total size of the message is the size of the key
             //   plus the size if itemSize, both XAuint32
             res = (*playerBQItf)->Enqueue(playerBQItf, NULL /*pBufferContext*/,
                     dataCache + i*BUFFER_SIZE, BUFFER_SIZE, items /*pMsg*/,
                     // FIXME == sizeof(BufferItem)? */
                     sizeof(XAuint32)*2 /*msgLength*/);
             discontinuity = JNI_FALSE;
         } else {
             res = (*playerBQItf)->Enqueue(playerBQItf, NULL /*pBufferContext*/,
                     dataCache + i*BUFFER_SIZE, BUFFER_SIZE, NULL, 0);
         }
         assert(XA_RESULT_SUCCESS == res);
     }

     return JNI_TRUE;
 }


 // create streaming media player
 jboolean Java_com_example_nativemedia_NativeMedia_createStreamingMediaPlayer(JNIEnv* env,
         jclass clazz, jstring filename)
 {
     XAresult res;

     // convert Java string to UTF-8
     const char *utf8 = (*env)->GetStringUTFChars(env, filename, NULL);
     assert(NULL != utf8);

     // open the file to play
     file = fopen(utf8, "rb");
     if (file == NULL) {
         ALOGE("Failed to open %s", utf8);
         return JNI_FALSE;
     }

     // configure data source
     XADataLocator_AndroidBufferQueue loc_abq = { XA_DATALOCATOR_ANDROIDBUFFERQUEUE, NB_BUFFERS };
     XADataFormat_MIME format_mime = {
             XA_DATAFORMAT_MIME, XA_ANDROID_MIME_MP2TS, XA_CONTAINERTYPE_MPEG_TS };
     XADataSource dataSrc = {&loc_abq, &format_mime};

     // configure audio sink
     XADataLocator_OutputMix loc_outmix = { XA_DATALOCATOR_OUTPUTMIX, outputMixObject };
     XADataSink audioSnk = { &loc_outmix, NULL };

     // configure image video sink
     XADataLocator_NativeDisplay loc_nd = {
             XA_DATALOCATOR_NATIVEDISPLAY,        // locatorType
             // the video sink must be an ANativeWindow
             // created from a Surface or SurfaceTextureClient
             (void*)theNativeWindow,              // hWindow
             // must be NULL
             NULL                                 // hDisplay
     };
     XADataSink imageVideoSink = {&loc_nd, NULL};

     // declare interfaces to use
     XAboolean     required[NB_MAXAL_INTERFACES]
                            = {XA_BOOLEAN_TRUE, XA_BOOLEAN_TRUE,           XA_BOOLEAN_TRUE};
     XAInterfaceID iidArray[NB_MAXAL_INTERFACES]
                            = {XA_IID_PLAY,     XA_IID_ANDROIDBUFFERQUEUESOURCE,
                                                XA_IID_STREAMINFORMATION};


     // create media player
     res = (*engineEngine)->CreateMediaPlayer(engineEngine, &playerObj, &dataSrc,
             NULL, &audioSnk, &imageVideoSink, NULL, NULL,
             NB_MAXAL_INTERFACES /*XAuint32 numInterfaces*/,
             iidArray /*const XAInterfaceID *pInterfaceIds*/,
             required /*const XAboolean *pInterfaceRequired*/);
     assert(XA_RESULT_SUCCESS == res);

     // release the Java string and UTF-8
     (*env)->ReleaseStringUTFChars(env, filename, utf8);

     // realize the player
     res = (*playerObj)->Realize(playerObj, XA_BOOLEAN_FALSE);
     assert(XA_RESULT_SUCCESS == res);

     // get the play interface
     res = (*playerObj)->GetInterface(playerObj, XA_IID_PLAY, &playerPlayItf);
     assert(XA_RESULT_SUCCESS == res);

     // get the stream information interface (for video size)
     res = (*playerObj)->GetInterface(playerObj, XA_IID_STREAMINFORMATION, &playerStreamInfoItf);
     assert(XA_RESULT_SUCCESS == res);

     // get the volume interface
     res = (*playerObj)->GetInterface(playerObj, XA_IID_VOLUME, &playerVolItf);
     assert(XA_RESULT_SUCCESS == res);

     // get the Android buffer queue interface
     res = (*playerObj)->GetInterface(playerObj, XA_IID_ANDROIDBUFFERQUEUESOURCE, &playerBQItf);
     assert(XA_RESULT_SUCCESS == res);

     // specify which events we want to be notified of
     res = (*playerBQItf)->SetCallbackEventsMask(playerBQItf, XA_ANDROIDBUFFERQUEUEEVENT_PROCESSED);

     // use the play interface to set up a callback for the XA_PLAYEVENT_HEADATEND event */
     res = (*playerPlayItf)->SetCallbackEventsMask(playerPlayItf, XA_PLAYEVENT_HEADATEND);
     assert(XA_RESULT_SUCCESS == res);
     res = (*playerPlayItf)->RegisterCallback(playerPlayItf,
             PlayCallback /*callback*/, NULL /*pContext*/);
     assert(XA_RESULT_SUCCESS == res);

     // register the callback from which OpenMAX AL can retrieve the data to play
     res = (*playerBQItf)->RegisterCallback(playerBQItf, AndroidBufferQueueCallback, NULL);
     assert(XA_RESULT_SUCCESS == res);

     // we want to be notified of the video size once it's found, so we register a callback for that
     res = (*playerStreamInfoItf)->RegisterStreamChangeCallback(playerStreamInfoItf,
             StreamChangeCallback, NULL);

     // enqueue the initial buffers
     if (!enqueueInitialBuffers(JNI_FALSE)) {
         return JNI_FALSE;
     }

     // prepare the player
     res = (*playerPlayItf)->SetPlayState(playerPlayItf, XA_PLAYSTATE_PAUSED);
     assert(XA_RESULT_SUCCESS == res);

     // set the volume
     res = (*playerVolItf)->SetVolumeLevel(playerVolItf, 0);//-300);
     assert(XA_RESULT_SUCCESS == res);

     // start the playback
     res = (*playerPlayItf)->SetPlayState(playerPlayItf, XA_PLAYSTATE_PLAYING);
     assert(XA_RESULT_SUCCESS == res);

     return JNI_TRUE;
 }


 // set the playing state for the streaming media player
 void Java_com_example_nativemedia_NativeMedia_setPlayingStreamingMediaPlayer(JNIEnv* env,
         jclass clazz, jboolean isPlaying)
 {
     XAresult res;

     // make sure the streaming media player was created
     if (NULL != playerPlayItf) {

         // set the player's state
         res = (*playerPlayItf)->SetPlayState(playerPlayItf, isPlaying ?
             XA_PLAYSTATE_PLAYING : XA_PLAYSTATE_PAUSED);
         assert(XA_RESULT_SUCCESS == res);

     }

 }


 // shut down the native media system
 void Java_com_example_nativemedia_NativeMedia_shutdown(JNIEnv* env, jclass clazz)
 {
     // destroy streaming media player object, and invalidate all associated interfaces
     if (playerObj != NULL) {
         (*playerObj)->Destroy(playerObj);
         playerObj = NULL;
         playerPlayItf = NULL;
         playerBQItf = NULL;
         playerStreamInfoItf = NULL;
         playerVolItf = NULL;
     }

     // destroy output mix object, and invalidate all associated interfaces
     if (outputMixObject != NULL) {
         (*outputMixObject)->Destroy(outputMixObject);
         outputMixObject = NULL;
     }

     // destroy engine object, and invalidate all associated interfaces
     if (engineObject != NULL) {
         (*engineObject)->Destroy(engineObject);
         engineObject = NULL;
         engineEngine = NULL;
     }

     // close the file
     if (file != NULL) {
         fclose(file);
         file = NULL;
     }

     // make sure we don't leak native windows
     if (theNativeWindow != NULL) {
         ANativeWindow_release(theNativeWindow);
         theNativeWindow = NULL;
     }
 }


 // set the surface
 void Java_com_example_nativemedia_NativeMedia_setSurface(JNIEnv *env, jclass clazz, jobject surface)
 {
     // obtain a native window from a Java surface
     theNativeWindow = ANativeWindow_fromSurface(env, surface);
 }


 // rewind the streaming media player
 void Java_com_example_nativemedia_NativeMedia_rewindStreamingMediaPlayer(JNIEnv *env, jclass clazz)
 {
     // make sure the streaming media player was created
     if (NULL != playerBQItf && NULL != file) {
         // first wait for buffers currently in queue to be drained
         int ok;
         ok = pthread_mutex_lock(&mutex);
         assert(0 == ok);
         discontinuity = JNI_TRUE;
         // wait for discontinuity request to be observed by buffer queue callback
         // FIXME sorry, can't rewind after EOS
         while (discontinuity && !reachedEof) {
             ok = pthread_cond_wait(&cond, &mutex);
             assert(0 == ok);
         }
         ok = pthread_mutex_unlock(&mutex);
         assert(0 == ok);
     }

 }
	/*
	* Copyright (C) 2010 The Android Open Source Project
	*
	* Licensed under the Apache License, Version 2.0 (the "License");
	* you may not use this file except in compliance with the License.
	* You may obtain a copy of the License at
	*
	* http://www.apache.org/licenses/LICENSE-2.0
	*
	* Unless required by applicable law or agreed to in writing, software
	* distributed under the License is distributed on an "AS IS" BASIS,
	* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
	* See the License for the specific language governing permissions and
	* limitations under the License.
	*/

	#include <assert.h>
	#include <jni.h>
	#include <pthread.h>
	#include <string.h>
	//#define LOG_NDEBUG 0
	#define LOG_TAG "NativeMedia"
	#include <utils/Log.h>

	#include <OMXAL/OpenMAXAL.h>
	#include <OMXAL/OpenMAXAL_Android.h>

	#include <android/native_window_jni.h>

	// engine interfaces
	static XAObjectItf engineObject = NULL;
	static XAEngineItf engineEngine = NULL;

	// output mix interfaces
	static XAObjectItf outputMixObject = NULL;

	// streaming media player interfaces
	static XAObjectItf playerObj = NULL;
	static XAPlayItf playerPlayItf = NULL;
	static XAAndroidBufferQueueItf playerBQItf = NULL;
	static XAStreamInformationItf playerStreamInfoItf = NULL;
	static XAVolumeItf playerVolItf = NULL;

	// number of required interfaces for the MediaPlayer creation
	#define NB_MAXAL_INTERFACES 3 // XAAndroidBufferQueueItf, XAStreamInformationItf and XAPlayItf

	// video sink for the player
	static ANativeWindow* theNativeWindow;

	// number of buffers in our buffer queue, an arbitrary number
	#define NB_BUFFERS 16

	// we're streaming MPEG-2 transport stream data, operate on transport stream block size
	#define MPEG2_TS_BLOCK_SIZE 188

	// number of MPEG-2 transport stream blocks per buffer, an arbitrary number
	#define BLOCKS_PER_BUFFER 20

	// determines how much memory we're dedicating to memory caching
	#define BUFFER_SIZE (BLOCKS_PER_BUFFER*MPEG2_TS_BLOCK_SIZE)

	// where we cache in memory the data to play
	// note this memory is re-used by the buffer queue callback
	char dataCache[BUFFER_SIZE * NB_BUFFERS];

	// handle of the file to play
	FILE *file;

	// has the app reached the end of the file
	jboolean reachedEof = JNI_FALSE;

	// constant to identify a buffer context which is the end of the stream to decode
	static const int kEosBufferCntxt = 1980; // a magic value we can compare against

	// for mutual exclusion between callback thread and application thread(s)
	pthread_mutex_t mutex = PTHREAD_MUTEX_INITIALIZER;
	pthread_cond_t cond = PTHREAD_COND_INITIALIZER;

	// whether a discontinuity is in progress
	jboolean discontinuity = JNI_FALSE;

	static jboolean enqueueInitialBuffers(jboolean discontinuity);

	// Callback for XAPlayItf through which we receive the XA_PLAYEVENT_HEADATEND event */
	void PlayCallback(XAPlayItf caller, void *pContext, XAuint32 event) {
	if (event & XA_PLAYEVENT_HEADATEND) {
	ALOGV("XA_PLAYEVENT_HEADATEND received, all MP2TS data has been decoded\n");
	}
	}

	// AndroidBufferQueueItf callback for an audio player
	XAresult AndroidBufferQueueCallback(
	XAAndroidBufferQueueItf caller,
	void pCallbackContext, / input */
	void pBufferContext, / input */
	void pBufferData, / input */
	XAuint32 dataSize, /* input */
	XAuint32 dataUsed, /* input */
	const XAAndroidBufferItem pItems,/ input */
	XAuint32 itemsLength /* input */)
	{
	XAresult res;
	int ok;

	// pCallbackContext was specified as NULL at RegisterCallback and is unused here
	assert(NULL == pCallbackContext);

	// note there is never any contention on this mutex unless a discontinuity request is active
	ok = pthread_mutex_lock(&mutex);
	assert(0 == ok);

	// was a discontinuity requested?
	if (discontinuity) {
	// FIXME sorry, can't rewind after EOS
	if (!reachedEof) {
	// clear the buffer queue
	res = (*playerBQItf)->Clear(playerBQItf);
	assert(XA_RESULT_SUCCESS == res);
	// rewind the data source so we are guaranteed to be at an appropriate point
	rewind(file);
	// Enqueue the initial buffers, with a discontinuity indicator on first buffer
	(void) enqueueInitialBuffers(JNI_TRUE);
	}
	// acknowledge the discontinuity request
	discontinuity = JNI_FALSE;
	ok = pthread_cond_signal(&cond);
	assert(0 == ok);
	goto exit;
	}

	if ((pBufferData == NULL) && (pBufferContext != NULL)) {
	const int processedCommand = (int )pBufferContext;
	if (kEosBufferCntxt == processedCommand) {
	ALOGV("EOS was processed\n");
	// our buffer with the EOS message has been consumed
	assert(0 == dataSize);
	goto exit;
	}
	}

	// pBufferData is a pointer to a buffer that we previously Enqueued
	assert(BUFFER_SIZE == dataSize);
	assert(dataCache <= (char ) pBufferData && (char ) pBufferData <
	&dataCache[BUFFER_SIZE * NB_BUFFERS]);
	assert(0 == (((char *) pBufferData - dataCache) % BUFFER_SIZE));

	#if 0
	// sample code to use the XAVolumeItf
	XAAndroidBufferQueueState state;
	(*caller)->GetState(caller, &state);
	switch (state.index) {
	case 300:
	(*playerVolItf)->SetVolumeLevel(playerVolItf, -600); // -6dB
	ALOGV("setting volume to -6dB");
	break;
	case 400:
	(*playerVolItf)->SetVolumeLevel(playerVolItf, -1200); // -12dB
	ALOGV("setting volume to -12dB");
	break;
	case 500:
	(*playerVolItf)->SetVolumeLevel(playerVolItf, 0); // full volume
	ALOGV("setting volume to 0dB (full volume)");
	break;
	case 600:
	(*playerVolItf)->SetMute(playerVolItf, XA_BOOLEAN_TRUE); // mute
	ALOGV("muting player");
	break;
	case 700:
	(*playerVolItf)->SetMute(playerVolItf, XA_BOOLEAN_FALSE); // unmute
	ALOGV("unmuting player");
	break;
	case 800:
	(*playerVolItf)->SetStereoPosition(playerVolItf, -1000);
	(*playerVolItf)->EnableStereoPosition(playerVolItf, XA_BOOLEAN_TRUE);
	ALOGV("pan sound to the left (hard-left)");
	break;
	case 900:
	(*playerVolItf)->EnableStereoPosition(playerVolItf, XA_BOOLEAN_FALSE);
	ALOGV("disabling stereo position");
	break;
	default:
	break;
	}
	#endif

	// don't bother trying to read more data once we've hit EOF
	if (reachedEof) {
	goto exit;
	}

	size_t nbRead;
	// note we do call fread from multiple threads, but never concurrently
	nbRead = fread(pBufferData, BUFFER_SIZE, 1, file);
	if (nbRead > 0) {
	assert(1 == nbRead);
	res = (caller)->Enqueue(caller, NULL /pBufferContext*/,
	pBufferData /pData/,
	nbRead * BUFFER_SIZE /dataLength/,
	NULL /pMsg/,
	0 /msgLength/);
	assert(XA_RESULT_SUCCESS == res);
	} else {
	// signal EOS
	XAAndroidBufferItem msgEos[1];
	msgEos[0].itemKey = XA_ANDROID_ITEMKEY_EOS;
	msgEos[0].itemSize = 0;
	// EOS message has no parameters, so the total size of the message is the size of the key
	// plus the size if itemSize, both XAuint32
	res = (caller)->Enqueue(caller, (void )&kEosBufferCntxt /pBufferContext/,
	NULL /pData/, 0 /dataLength/,
	msgEos /pMsg/,
	// FIXME == sizeof(BufferItem)? */
	sizeof(XAuint32)2 /msgLength*/);
	assert(XA_RESULT_SUCCESS == res);
	reachedEof = JNI_TRUE;
	}

	exit:
	ok = pthread_mutex_unlock(&mutex);
	assert(0 == ok);
	return XA_RESULT_SUCCESS;
	}


	void StreamChangeCallback (XAStreamInformationItf caller,
	XAuint32 eventId,
	XAuint32 streamIndex,
	void * pEventData,
	void * pContext )
	{
	ALOGV("StreamChangeCallback called for stream %u", streamIndex);
	// pContext was specified as NULL at RegisterStreamChangeCallback and is unused here
	assert(NULL == pContext);
	switch (eventId) {
	case XA_STREAMCBEVENT_PROPERTYCHANGE: {
	/** From spec 1.0.1:
	"This event indicates that stream property change has occurred.
	The streamIndex parameter identifies the stream with the property change.
	The pEventData parameter for this event is not used and shall be ignored."
	*/

	XAresult res;
	XAuint32 domain;
	res = (*caller)->QueryStreamType(caller, streamIndex, &domain);
	assert(XA_RESULT_SUCCESS == res);
	switch (domain) {
	case XA_DOMAINTYPE_VIDEO: {
	XAVideoStreamInformation videoInfo;
	res = (*caller)->QueryStreamInformation(caller, streamIndex, &videoInfo);
	assert(XA_RESULT_SUCCESS == res);
	ALOGI("Found video size %u x %u, codec ID=%u, frameRate=%u, bitRate=%u, duration=%u ms",
	videoInfo.width, videoInfo.height, videoInfo.codecId, videoInfo.frameRate,
	videoInfo.bitRate, videoInfo.duration);
	} break;
	default:
	fprintf(stderr, "Unexpected domain %u\n", domain);
	break;
	}
	} break;
	default:
	fprintf(stderr, "Unexpected stream event ID %u\n", eventId);
	break;
	}
	}


	// create the engine and output mix objects
	void Java_com_example_nativemedia_NativeMedia_createEngine(JNIEnv* env, jclass clazz)
	{
	XAresult res;

	// create engine
	res = xaCreateEngine(&engineObject, 0, NULL, 0, NULL, NULL);
	assert(XA_RESULT_SUCCESS == res);

	// realize the engine
	res = (*engineObject)->Realize(engineObject, XA_BOOLEAN_FALSE);
	assert(XA_RESULT_SUCCESS == res);

	// get the engine interface, which is needed in order to create other objects
	res = (*engineObject)->GetInterface(engineObject, XA_IID_ENGINE, &engineEngine);
	assert(XA_RESULT_SUCCESS == res);

	// create output mix
	res = (*engineEngine)->CreateOutputMix(engineEngine, &outputMixObject, 0, NULL, NULL);
	assert(XA_RESULT_SUCCESS == res);

	// realize the output mix
	res = (*outputMixObject)->Realize(outputMixObject, XA_BOOLEAN_FALSE);
	assert(XA_RESULT_SUCCESS == res);

	}


	// Enqueue the initial buffers, and optionally signal a discontinuity in the first buffer
	static jboolean enqueueInitialBuffers(jboolean discontinuity)
	{

	/* Fill our cache */
	size_t nbRead;
	nbRead = fread(dataCache, BUFFER_SIZE, NB_BUFFERS, file);
	if (nbRead <= 0) {
	// could be premature EOF or I/O error
	ALOGE("Error filling cache, exiting\n");
	return JNI_FALSE;
	}
	assert(1 <= nbRead && nbRead <= NB_BUFFERS);
	ALOGV("Initially queueing %zu buffers of %u bytes each", nbRead, BUFFER_SIZE);

	/* Enqueue the content of our cache before starting to play,
	we don't want to starve the player */
	size_t i;
	for (i = 0; i < nbRead; i++) {
	XAresult res;
	if (discontinuity) {
	// signal discontinuity
	XAAndroidBufferItem items[1];
	items[0].itemKey = XA_ANDROID_ITEMKEY_DISCONTINUITY;
	items[0].itemSize = 0;
	// DISCONTINUITY message has no parameters,
	// so the total size of the message is the size of the key
	// plus the size if itemSize, both XAuint32
	res = (playerBQItf)->Enqueue(playerBQItf, NULL /pBufferContext*/,
	dataCache + iBUFFER_SIZE, BUFFER_SIZE, items /pMsg*/,
	// FIXME == sizeof(BufferItem)? */
	sizeof(XAuint32)2 /msgLength*/);
	discontinuity = JNI_FALSE;
	} else {
	res = (playerBQItf)->Enqueue(playerBQItf, NULL /pBufferContext*/,
	dataCache + i*BUFFER_SIZE, BUFFER_SIZE, NULL, 0);
	}
	assert(XA_RESULT_SUCCESS == res);
	}

	return JNI_TRUE;
	}


	// create streaming media player
	jboolean Java_com_example_nativemedia_NativeMedia_createStreamingMediaPlayer(JNIEnv* env,
	jclass clazz, jstring filename)
	{
	XAresult res;

	// convert Java string to UTF-8
	const char utf8 = (env)->GetStringUTFChars(env, filename, NULL);
	assert(NULL != utf8);

	// open the file to play
	file = fopen(utf8, "rb");
	if (file == NULL) {
	ALOGE("Failed to open %s", utf8);
	return JNI_FALSE;
	}

	// configure data source
	XADataLocator_AndroidBufferQueue loc_abq = { XA_DATALOCATOR_ANDROIDBUFFERQUEUE, NB_BUFFERS };
	XADataFormat_MIME format_mime = {
	XA_DATAFORMAT_MIME, XA_ANDROID_MIME_MP2TS, XA_CONTAINERTYPE_MPEG_TS };
	XADataSource dataSrc = {&loc_abq, &format_mime};

	// configure audio sink
	XADataLocator_OutputMix loc_outmix = { XA_DATALOCATOR_OUTPUTMIX, outputMixObject };
	XADataSink audioSnk = { &loc_outmix, NULL };

	// configure image video sink
	XADataLocator_NativeDisplay loc_nd = {
	XA_DATALOCATOR_NATIVEDISPLAY, // locatorType
	// the video sink must be an ANativeWindow
	// created from a Surface or SurfaceTextureClient
	(void*)theNativeWindow, // hWindow
	// must be NULL
	NULL // hDisplay
	};
	XADataSink imageVideoSink = {&loc_nd, NULL};

	// declare interfaces to use
	XAboolean required[NB_MAXAL_INTERFACES]
	= {XA_BOOLEAN_TRUE, XA_BOOLEAN_TRUE, XA_BOOLEAN_TRUE};
	XAInterfaceID iidArray[NB_MAXAL_INTERFACES]
	= {XA_IID_PLAY, XA_IID_ANDROIDBUFFERQUEUESOURCE,
	XA_IID_STREAMINFORMATION};


	// create media player
	res = (*engineEngine)->CreateMediaPlayer(engineEngine, &playerObj, &dataSrc,
	NULL, &audioSnk, &imageVideoSink, NULL, NULL,
	NB_MAXAL_INTERFACES /XAuint32 numInterfaces/,
	iidArray /const XAInterfaceID pInterfaceIds*/,
	required /const XAboolean pInterfaceRequired*/);
	assert(XA_RESULT_SUCCESS == res);

	// release the Java string and UTF-8
	(*env)->ReleaseStringUTFChars(env, filename, utf8);

	// realize the player
	res = (*playerObj)->Realize(playerObj, XA_BOOLEAN_FALSE);
	assert(XA_RESULT_SUCCESS == res);

	// get the play interface
	res = (*playerObj)->GetInterface(playerObj, XA_IID_PLAY, &playerPlayItf);
	assert(XA_RESULT_SUCCESS == res);

	// get the stream information interface (for video size)
	res = (*playerObj)->GetInterface(playerObj, XA_IID_STREAMINFORMATION, &playerStreamInfoItf);
	assert(XA_RESULT_SUCCESS == res);

	// get the volume interface
	res = (*playerObj)->GetInterface(playerObj, XA_IID_VOLUME, &playerVolItf);
	assert(XA_RESULT_SUCCESS == res);

	// get the Android buffer queue interface
	res = (*playerObj)->GetInterface(playerObj, XA_IID_ANDROIDBUFFERQUEUESOURCE, &playerBQItf);
	assert(XA_RESULT_SUCCESS == res);

	// specify which events we want to be notified of
	res = (*playerBQItf)->SetCallbackEventsMask(playerBQItf, XA_ANDROIDBUFFERQUEUEEVENT_PROCESSED);

	// use the play interface to set up a callback for the XA_PLAYEVENT_HEADATEND event */
	res = (*playerPlayItf)->SetCallbackEventsMask(playerPlayItf, XA_PLAYEVENT_HEADATEND);
	assert(XA_RESULT_SUCCESS == res);
	res = (*playerPlayItf)->RegisterCallback(playerPlayItf,
	PlayCallback /callback/, NULL /pContext/);
	assert(XA_RESULT_SUCCESS == res);

	// register the callback from which OpenMAX AL can retrieve the data to play
	res = (*playerBQItf)->RegisterCallback(playerBQItf, AndroidBufferQueueCallback, NULL);
	assert(XA_RESULT_SUCCESS == res);

	// we want to be notified of the video size once it's found, so we register a callback for that
	res = (*playerStreamInfoItf)->RegisterStreamChangeCallback(playerStreamInfoItf,
	StreamChangeCallback, NULL);

	// enqueue the initial buffers
	if (!enqueueInitialBuffers(JNI_FALSE)) {
	return JNI_FALSE;
	}

	// prepare the player
	res = (*playerPlayItf)->SetPlayState(playerPlayItf, XA_PLAYSTATE_PAUSED);
	assert(XA_RESULT_SUCCESS == res);

	// set the volume
	res = (*playerVolItf)->SetVolumeLevel(playerVolItf, 0);//-300);
	assert(XA_RESULT_SUCCESS == res);

	// start the playback
	res = (*playerPlayItf)->SetPlayState(playerPlayItf, XA_PLAYSTATE_PLAYING);
	assert(XA_RESULT_SUCCESS == res);

	return JNI_TRUE;
	}


	// set the playing state for the streaming media player
	void Java_com_example_nativemedia_NativeMedia_setPlayingStreamingMediaPlayer(JNIEnv* env,
	jclass clazz, jboolean isPlaying)
	{
	XAresult res;

	// make sure the streaming media player was created
	if (NULL != playerPlayItf) {

	// set the player's state
	res = (*playerPlayItf)->SetPlayState(playerPlayItf, isPlaying ?
	XA_PLAYSTATE_PLAYING : XA_PLAYSTATE_PAUSED);
	assert(XA_RESULT_SUCCESS == res);

	}

	}


	// shut down the native media system
	void Java_com_example_nativemedia_NativeMedia_shutdown(JNIEnv* env, jclass clazz)
	{
	// destroy streaming media player object, and invalidate all associated interfaces
	if (playerObj != NULL) {
	(*playerObj)->Destroy(playerObj);
	playerObj = NULL;
	playerPlayItf = NULL;
	playerBQItf = NULL;
	playerStreamInfoItf = NULL;
	playerVolItf = NULL;
	}

	// destroy output mix object, and invalidate all associated interfaces
	if (outputMixObject != NULL) {
	(*outputMixObject)->Destroy(outputMixObject);
	outputMixObject = NULL;
	}

	// destroy engine object, and invalidate all associated interfaces
	if (engineObject != NULL) {
	(*engineObject)->Destroy(engineObject);
	engineObject = NULL;
	engineEngine = NULL;
	}

	// close the file
	if (file != NULL) {
	fclose(file);
	file = NULL;
	}

	// make sure we don't leak native windows
	if (theNativeWindow != NULL) {
	ANativeWindow_release(theNativeWindow);
	theNativeWindow = NULL;
	}
	}


	// set the surface
	void Java_com_example_nativemedia_NativeMedia_setSurface(JNIEnv *env, jclass clazz, jobject surface)
	{
	// obtain a native window from a Java surface
	theNativeWindow = ANativeWindow_fromSurface(env, surface);
	}


	// rewind the streaming media player
	void Java_com_example_nativemedia_NativeMedia_rewindStreamingMediaPlayer(JNIEnv *env, jclass clazz)
	{
	// make sure the streaming media player was created
	if (NULL != playerBQItf && NULL != file) {
	// first wait for buffers currently in queue to be drained
	int ok;
	ok = pthread_mutex_lock(&mutex);
	assert(0 == ok);
	discontinuity = JNI_TRUE;
	// wait for discontinuity request to be observed by buffer queue callback
	// FIXME sorry, can't rewind after EOS
	while (discontinuity && !reachedEof) {
	ok = pthread_cond_wait(&cond, &mutex);
	assert(0 == ok);
	}
	ok = pthread_mutex_unlock(&mutex);
	assert(0 == ok);
	}

	}