/*
* Copyright (C) 2011 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.
*/
/* Audio Decode Test
First run the program from shell:
# slesTest_decodeToBuffQueue /sdcard/myFile.mp3 4
These use adb on host to retrieve the decoded file:
% adb pull /sdcard/myFile.mp3.raw myFile.raw
How to examine the output with Audacity:
Project / Import raw data
Select myFile.raw file, then click Open button
Choose these options:
Signed 16-bit PCM
Little-endian
1 Channel (Mono) / 2 Channels (Stereo) based on the selected file
Sample rate same as the selected file
Click Import button
*/
#include <stdlib.h>
#include <stdio.h>
#include <string.h>
#include <unistd.h>
#include <sys/time.h>
#include <fcntl.h>
#include <utils/threads.h>
#include <SLES/OpenSLES.h>
#include <SLES/OpenSLES_Android.h>
/* Explicitly requesting SL_IID_ANDROIDSIMPLEBUFFERQUEUE and SL_IID_PREFETCHSTATUS
* on the AudioPlayer object for decoding, SL_IID_METADATAEXTRACTION for retrieving the
* format of the decoded audio */
#define NUM_EXPLICIT_INTERFACES_FOR_PLAYER 3
/* Size of the decode buffer queue */
#define NB_BUFFERS_IN_QUEUE 4
/* Size of each buffer in the queue */
#define BUFFER_SIZE_IN_SAMPLES 1152 // number of samples per MP3 frame
#define BUFFER_SIZE_IN_BYTES (2*BUFFER_SIZE_IN_SAMPLES)
/* Local storage for decoded audio data */
int8_t pcmData[NB_BUFFERS_IN_QUEUE * BUFFER_SIZE_IN_BYTES];
/* destination for decoded data */
static FILE* gFp;
/* to display the number of decode iterations */
static int counter=0;
/* metadata key index for the PCM format information we want to retrieve */
static int channelCountKeyIndex = -1;
static int sampleRateKeyIndex = -1;
/* size of the struct to retrieve the PCM format metadata values: the values we're interested in
* are SLuint32, but it is saved in the data field of a SLMetadataInfo, hence the larger size.
* Nate that this size is queried and displayed at l.452 for demonstration/test purposes.
* */
#define PCM_METADATA_VALUE_SIZE 32
/* used to query metadata values */
static SLMetadataInfo *pcmMetaData = NULL;
/* we only want to query / display the PCM format once */
static bool formatQueried = false;
/* to signal to the test app the end of the stream to decode has been reached */
bool eos = false;
android::Mutex eosLock;
android::Condition eosCondition;
/* used to detect errors likely to have occured when the OpenSL ES framework fails to open
* a resource, for instance because a file URI is invalid, or an HTTP server doesn't respond.
*/
#define PREFETCHEVENT_ERROR_CANDIDATE \
(SL_PREFETCHEVENT_STATUSCHANGE | SL_PREFETCHEVENT_FILLLEVELCHANGE)
//-----------------------------------------------------------------
/* Exits the application if an error is encountered */
#define ExitOnError(x) ExitOnErrorFunc(x,__LINE__)
void ExitOnErrorFunc( SLresult result , int line)
{
if (SL_RESULT_SUCCESS != result) {
fprintf(stderr, "Error code %u encountered at line %d, exiting\n", result, line);
exit(EXIT_FAILURE);
}
}
/* Used to signal prefetching failures */
bool prefetchError = false;
//-----------------------------------------------------------------
/* Structure for passing information to callback function */
typedef struct CallbackCntxt_ {
SLPlayItf playItf;
SLMetadataExtractionItf metaItf;
SLuint32 size;
SLint8* pDataBase; // Base address of local audio data storage
SLint8* pData; // Current address of local audio data storage
} CallbackCntxt;
//-----------------------------------------------------------------
void SignalEos() {
android::Mutex::Autolock autoLock(eosLock);
eos = true;
eosCondition.signal();
}
//-----------------------------------------------------------------
/* Callback for "prefetch" events, here used to detect audio resource opening errors */
void PrefetchEventCallback( SLPrefetchStatusItf caller, void *pContext, SLuint32 event)
{
SLpermille level = 0;
SLresult result;
result = (*caller)->GetFillLevel(caller, &level);
ExitOnError(result);
SLuint32 status;
//fprintf(stdout, "PrefetchEventCallback: received event %u\n", event);
result = (*caller)->GetPrefetchStatus(caller, &status);
ExitOnError(result);
if ((PREFETCHEVENT_ERROR_CANDIDATE == (event & PREFETCHEVENT_ERROR_CANDIDATE))
&& (level == 0) && (status == SL_PREFETCHSTATUS_UNDERFLOW)) {
fprintf(stdout, "PrefetchEventCallback: Error while prefetching data, exiting\n");
prefetchError = true;
SignalEos();
}
}
/* Callback for "playback" events, i.e. event happening during decoding */
void DecProgressCallback(
SLPlayItf caller,
void *pContext,
SLuint32 event)
{
SLresult result;
SLmillisecond msec;
result = (*caller)->GetPosition(caller, &msec);
ExitOnError(result);
if (SL_PLAYEVENT_HEADATEND & event) {
fprintf(stdout, "SL_PLAYEVENT_HEADATEND current position=%u ms\n", msec);
SignalEos();
}
if (SL_PLAYEVENT_HEADATNEWPOS & event) {
fprintf(stdout, "SL_PLAYEVENT_HEADATNEWPOS current position=%u ms\n", msec);
}
if (SL_PLAYEVENT_HEADATMARKER & event) {
fprintf(stdout, "SL_PLAYEVENT_HEADATMARKER current position=%u ms\n", msec);
}
}
//-----------------------------------------------------------------
/* Callback for decoding buffer queue events */
void DecPlayCallback(
SLAndroidSimpleBufferQueueItf queueItf,
void *pContext)
{
counter++;
CallbackCntxt *pCntxt = (CallbackCntxt*)pContext;
if (counter % 1000 == 0) {
SLmillisecond msec;
SLresult result = (*pCntxt->playItf)->GetPosition(pCntxt->playItf, &msec);
ExitOnError(result);
printf("DecPlayCallback called (iteration %d): current position=%u ms\n", counter, msec);
}
/* Save the decoded data */
if (fwrite(pCntxt->pDataBase, 1, BUFFER_SIZE_IN_BYTES, gFp) < BUFFER_SIZE_IN_BYTES) {
fprintf(stdout, "Error writing to output file, signaling EOS\n");
SignalEos();
return;
}
/* Increase data pointer by buffer size */
pCntxt->pData += BUFFER_SIZE_IN_BYTES;
if (pCntxt->pData >= pCntxt->pDataBase + (NB_BUFFERS_IN_QUEUE * BUFFER_SIZE_IN_BYTES)) {
pCntxt->pData = pCntxt->pDataBase;
}
ExitOnError( (*queueItf)->Enqueue(queueItf, pCntxt->pDataBase, BUFFER_SIZE_IN_BYTES) );
// Note: adding a sleep here or any sync point is a way to slow down the decoding, or
// synchronize it with some other event, as the OpenSL ES framework will block until the
// buffer queue callback return to proceed with the decoding.
#if 0
/* Example: buffer queue state display */
SLAndroidSimpleBufferQueueState decQueueState;
ExitOnError( (*queueItf)->GetState(queueItf, &decQueueState) );
fprintf(stderr, "\DecBufferQueueCallback now has pCntxt->pData=%p queue: "
"count=%u playIndex=%u\n",
pCntxt->pData, decQueueState.count, decQueueState.index);
#endif
#if 0
/* Example: display duration in callback where we use the callback context for the SLPlayItf*/
SLmillisecond durationInMsec = SL_TIME_UNKNOWN;
SLresult result = (*pCntxt->playItf)->GetDuration(pCntxt->playItf, &durationInMsec);
ExitOnError(result);
if (durationInMsec == SL_TIME_UNKNOWN) {
fprintf(stdout, "Content duration is unknown (in dec callback)\n");
} else {
fprintf(stdout, "Content duration is %ums (in dec callback)\n",
durationInMsec);
}
#endif
#if 0
/* Example: display position in callback where we use the callback context for the SLPlayItf*/
SLmillisecond posMsec = SL_TIME_UNKNOWN;
SLresult result = (*pCntxt->playItf)->GetPosition(pCntxt->playItf, &posMsec);
ExitOnError(result);
if (posMsec == SL_TIME_UNKNOWN) {
fprintf(stdout, "Content position is unknown (in dec callback)\n");
} else {
fprintf(stdout, "Content position is %ums (in dec callback)\n",
posMsec);
}
#endif
/* Example: query of the decoded PCM format */
if (formatQueried) {
return;
}
SLresult res = (*pCntxt->metaItf)->GetValue(pCntxt->metaItf, sampleRateKeyIndex,
PCM_METADATA_VALUE_SIZE, pcmMetaData); ExitOnError(res);
// Note: here we could verify the following:
// pcmMetaData->encoding == SL_CHARACTERENCODING_BINARY
// pcmMetaData->size == sizeof(SLuint32)
// but the call was successful for the PCM format keys, so those conditions are implied
fprintf(stdout, "sample rate = %dHz, ", *((SLuint32*)pcmMetaData->data));
res = (*pCntxt->metaItf)->GetValue(pCntxt->metaItf, channelCountKeyIndex,
PCM_METADATA_VALUE_SIZE, pcmMetaData); ExitOnError(res);
fprintf(stdout, " channel count = %d\n", *((SLuint32*)pcmMetaData->data));
formatQueried = true;
}
//-----------------------------------------------------------------
/* Decode an audio path by opening a file descriptor on that path */
void TestDecToBuffQueue( SLObjectItf sl, const char* path)
{
size_t len = strlen((const char *) path);
char* outputPath = (char*) malloc(len + 4 + 1); // save room to concatenate ".raw"
if (NULL == outputPath) {
ExitOnError(SL_RESULT_RESOURCE_ERROR);
}
memcpy(outputPath, path, len + 1);
strcat(outputPath, ".raw");
gFp = fopen(outputPath, "w");
if (NULL == gFp) {
ExitOnError(SL_RESULT_RESOURCE_ERROR);
}
SLresult result;
SLEngineItf EngineItf;
/* Objects this application uses: one audio player */
SLObjectItf player;
/* Interfaces for the audio player */
SLAndroidSimpleBufferQueueItf decBuffQueueItf;
SLPrefetchStatusItf prefetchItf;
SLPlayItf playItf;
SLMetadataExtractionItf mdExtrItf;
/* Source of audio data for the decoding */
SLDataSource decSource;
SLDataLocator_URI decUri;
SLDataFormat_MIME decMime;
/* Data sink for decoded audio */
SLDataSink decDest;
SLDataLocator_AndroidSimpleBufferQueue decBuffQueue;
SLDataFormat_PCM pcm;
SLboolean required[NUM_EXPLICIT_INTERFACES_FOR_PLAYER];
SLInterfaceID iidArray[NUM_EXPLICIT_INTERFACES_FOR_PLAYER];
/* Get the SL Engine Interface which is implicit */
result = (*sl)->GetInterface(sl, SL_IID_ENGINE, (void*)&EngineItf);
ExitOnError(result);
/* Initialize arrays required[] and iidArray[] */
for (int i=0 ; i < NUM_EXPLICIT_INTERFACES_FOR_PLAYER ; i++) {
required[i] = SL_BOOLEAN_FALSE;
iidArray[i] = SL_IID_NULL;
}
/* allocate memory to receive the PCM format metadata */
if (!pcmMetaData) {
pcmMetaData = (SLMetadataInfo*) malloc(PCM_METADATA_VALUE_SIZE);
}
formatQueried = false;
/* ------------------------------------------------------ */
/* Configuration of the player */
/* Request the AndroidSimpleBufferQueue interface */
required[0] = SL_BOOLEAN_TRUE;
iidArray[0] = SL_IID_ANDROIDSIMPLEBUFFERQUEUE;
/* Request the PrefetchStatus interface */
required[1] = SL_BOOLEAN_TRUE;
iidArray[1] = SL_IID_PREFETCHSTATUS;
/* Request the PrefetchStatus interface */
required[2] = SL_BOOLEAN_TRUE;
iidArray[2] = SL_IID_METADATAEXTRACTION;
/* Setup the data source */
decUri.locatorType = SL_DATALOCATOR_URI;
decUri.URI = (SLchar*)path;
decMime.formatType = SL_DATAFORMAT_MIME;
/* this is how ignored mime information is specified, according to OpenSL ES spec
* in 9.1.6 SLDataFormat_MIME and 8.23 SLMetadataTraversalItf GetChildInfo */
decMime.mimeType = (SLchar*)NULL;
decMime.containerType = SL_CONTAINERTYPE_UNSPECIFIED;
decSource.pLocator = (void *) &decUri;
decSource.pFormat = (void *) &decMime;
/* Setup the data sink */
decBuffQueue.locatorType = SL_DATALOCATOR_ANDROIDSIMPLEBUFFERQUEUE;
decBuffQueue.numBuffers = NB_BUFFERS_IN_QUEUE;
/* set up the format of the data in the buffer queue */
pcm.formatType = SL_DATAFORMAT_PCM;
// FIXME valid value required but currently ignored
pcm.numChannels = 1;
pcm.samplesPerSec = SL_SAMPLINGRATE_8;
pcm.bitsPerSample = SL_PCMSAMPLEFORMAT_FIXED_16;
pcm.containerSize = 16;
pcm.channelMask = SL_SPEAKER_FRONT_LEFT;
pcm.endianness = SL_BYTEORDER_LITTLEENDIAN;
decDest.pLocator = (void *) &decBuffQueue;
decDest.pFormat = (void * ) &pcm;
/* Create the audio player */
result = (*EngineItf)->CreateAudioPlayer(EngineItf, &player, &decSource, &decDest,
NUM_EXPLICIT_INTERFACES_FOR_PLAYER, iidArray, required);
ExitOnError(result);
fprintf(stdout, "Player created\n");
/* Realize the player in synchronous mode. */
result = (*player)->Realize(player, SL_BOOLEAN_FALSE);
ExitOnError(result);
fprintf(stdout, "Player realized\n");
/* Get the play interface which is implicit */
result = (*player)->GetInterface(player, SL_IID_PLAY, (void*)&playItf);
ExitOnError(result);
/* Set up the player callback to get events during the decoding */
// FIXME currently ignored
result = (*playItf)->SetMarkerPosition(playItf, 2000);
ExitOnError(result);
result = (*playItf)->SetPositionUpdatePeriod(playItf, 500);
ExitOnError(result);
result = (*playItf)->SetCallbackEventsMask(playItf,
SL_PLAYEVENT_HEADATMARKER | SL_PLAYEVENT_HEADATNEWPOS | SL_PLAYEVENT_HEADATEND);
ExitOnError(result);
result = (*playItf)->RegisterCallback(playItf, DecProgressCallback, NULL);
ExitOnError(result);
fprintf(stdout, "Play callback registered\n");
/* Get the buffer queue interface which was explicitly requested */
result = (*player)->GetInterface(player, SL_IID_ANDROIDSIMPLEBUFFERQUEUE,
(void*)&decBuffQueueItf);
ExitOnError(result);
/* Get the prefetch status interface which was explicitly requested */
result = (*player)->GetInterface(player, SL_IID_PREFETCHSTATUS, (void*)&prefetchItf);
ExitOnError(result);
/* Get the metadata extraction interface which was explicitly requested */
result = (*player)->GetInterface(player, SL_IID_METADATAEXTRACTION, (void*)&mdExtrItf);
ExitOnError(result);
/* ------------------------------------------------------ */
/* Initialize the callback and its context for the decoding buffer queue */
CallbackCntxt cntxt;
cntxt.playItf = playItf;
cntxt.metaItf = mdExtrItf;
cntxt.pDataBase = (int8_t*)&pcmData;
cntxt.pData = cntxt.pDataBase;
cntxt.size = sizeof(pcmData);
result = (*decBuffQueueItf)->RegisterCallback(decBuffQueueItf, DecPlayCallback, &cntxt);
ExitOnError(result);
/* Enqueue buffers to map the region of memory allocated to store the decoded data */
fprintf(stdout,"Enqueueing buffer ");
for(int i = 0 ; i < NB_BUFFERS_IN_QUEUE ; i++) {
fprintf(stdout,"%d ", i);
result = (*decBuffQueueItf)->Enqueue(decBuffQueueItf, cntxt.pData, BUFFER_SIZE_IN_BYTES);
ExitOnError(result);
cntxt.pData += BUFFER_SIZE_IN_BYTES;
}
fprintf(stdout,"\n");
cntxt.pData = cntxt.pDataBase;
/* ------------------------------------------------------ */
/* Initialize the callback for prefetch errors, if we can't open the resource to decode */
result = (*prefetchItf)->RegisterCallback(prefetchItf, PrefetchEventCallback, &prefetchItf);
ExitOnError(result);
result = (*prefetchItf)->SetCallbackEventsMask(prefetchItf, PREFETCHEVENT_ERROR_CANDIDATE);
ExitOnError(result);
/* ------------------------------------------------------ */
/* Prefetch the data so we can get information about the format before starting to decode */
/* 1/ cause the player to prefetch the data */
result = (*playItf)->SetPlayState( playItf, SL_PLAYSTATE_PAUSED );
ExitOnError(result);
/* 2/ block until data has been prefetched */
SLuint32 prefetchStatus = SL_PREFETCHSTATUS_UNDERFLOW;
SLuint32 timeOutIndex = 50; // time out prefetching after 5s
while ((prefetchStatus != SL_PREFETCHSTATUS_SUFFICIENTDATA) && (timeOutIndex > 0) &&
!prefetchError) {
usleep(10 * 1000);
(*prefetchItf)->GetPrefetchStatus(prefetchItf, &prefetchStatus);
timeOutIndex--;
}
if (timeOutIndex == 0 || prefetchError) {
fprintf(stderr, "Failure to prefetch data in time, exiting\n");
ExitOnError(SL_RESULT_CONTENT_NOT_FOUND);
}
/* ------------------------------------------------------ */
/* Display duration */
SLmillisecond durationInMsec = SL_TIME_UNKNOWN;
result = (*playItf)->GetDuration(playItf, &durationInMsec);
ExitOnError(result);
if (durationInMsec == SL_TIME_UNKNOWN) {
fprintf(stdout, "Content duration is unknown\n");
} else {
fprintf(stdout, "Content duration is %ums\n", durationInMsec);
}
/* ------------------------------------------------------ */
/* Display the metadata obtained from the decoder */
// This is for test / demonstration purposes only where we discover the key and value sizes
// of a PCM decoder. An application that would want to directly get access to those values
// can make assumptions about the size of the keys and their matching values (all SLuint32)
SLuint32 itemCount;
result = (*mdExtrItf)->GetItemCount(mdExtrItf, &itemCount);
SLuint32 i, keySize, valueSize;
SLMetadataInfo *keyInfo, *value;
for(i=0 ; i<itemCount ; i++) {
keyInfo = NULL; keySize = 0;
value = NULL; valueSize = 0;
result = (*mdExtrItf)->GetKeySize(mdExtrItf, i, &keySize);
ExitOnError(result);
result = (*mdExtrItf)->GetValueSize(mdExtrItf, i, &valueSize);
ExitOnError(result);
keyInfo = (SLMetadataInfo*) malloc(keySize);
if (NULL != keyInfo) {
result = (*mdExtrItf)->GetKey(mdExtrItf, i, keySize, keyInfo);
ExitOnError(result);
fprintf(stdout, "key[%d] size=%d, name=%s \tvalue size=%d \n",
i, keyInfo->size, keyInfo->data, valueSize);
/* find out the key index of the metadata we're interested in */
if (!strcmp((char*)keyInfo->data, ANDROID_KEY_PCMFORMAT_NUMCHANNELS)) {
channelCountKeyIndex = i;
} else if (!strcmp((char*)keyInfo->data, ANDROID_KEY_PCMFORMAT_SAMPLERATE)) {
sampleRateKeyIndex = i;
}
free(keyInfo);
}
}
if (channelCountKeyIndex != -1) {
fprintf(stdout, "Key %s is at index %d\n",
ANDROID_KEY_PCMFORMAT_NUMCHANNELS, channelCountKeyIndex);
} else {
fprintf(stderr, "Unable to find key %s\n", ANDROID_KEY_PCMFORMAT_NUMCHANNELS);
}
if (sampleRateKeyIndex != -1) {
fprintf(stdout, "Key %s is at index %d\n",
ANDROID_KEY_PCMFORMAT_SAMPLERATE, sampleRateKeyIndex);
} else {
fprintf(stderr, "Unable to find key %s\n", ANDROID_KEY_PCMFORMAT_SAMPLERATE);
}
/* ------------------------------------------------------ */
/* Start decoding */
result = (*playItf)->SetPlayState(playItf, SL_PLAYSTATE_PLAYING);
ExitOnError(result);
fprintf(stdout, "Starting to decode\n");
/* Decode until the end of the stream is reached */
{
android::Mutex::Autolock autoLock(eosLock);
while (!eos) {
eosCondition.wait(eosLock);
}
}
fprintf(stdout, "EOS signaled\n");
/* ------------------------------------------------------ */
/* End of decoding */
/* Stop decoding */
result = (*playItf)->SetPlayState(playItf, SL_PLAYSTATE_STOPPED);
ExitOnError(result);
fprintf(stdout, "Stopped decoding\n");
/* Destroy the AudioPlayer object */
(*player)->Destroy(player);
fclose(gFp);
free(pcmMetaData);
pcmMetaData = NULL;
}
//-----------------------------------------------------------------
int main(int argc, char* const argv[])
{
SLresult result;
SLObjectItf sl;
fprintf(stdout, "OpenSL ES test %s: exercises SLPlayItf and SLAndroidSimpleBufferQueueItf ",
argv[0]);
fprintf(stdout, "on an AudioPlayer object to decode a URI to PCM\n");
if (argc != 2) {
fprintf(stdout, "Usage: \t%s source_file\n", argv[0]);
fprintf(stdout, "Example: \"%s /sdcard/myFile.mp3\n", argv[0]);
exit(EXIT_FAILURE);
}
SLEngineOption EngineOption[] = {
{(SLuint32) SL_ENGINEOPTION_THREADSAFE, (SLuint32) SL_BOOLEAN_TRUE}
};
result = slCreateEngine( &sl, 1, EngineOption, 0, NULL, NULL);
ExitOnError(result);
/* Realizing the SL Engine in synchronous mode. */
result = (*sl)->Realize(sl, SL_BOOLEAN_FALSE);
ExitOnError(result);
TestDecToBuffQueue(sl, argv[1]);
/* Shutdown OpenSL ES */
(*sl)->Destroy(sl);
return EXIT_SUCCESS;
}