I'm working on a native android project and trying to use OpenSL to play some audio effects. Working from the native audio sample project VisualGDB provides, I've written the code posted below.
Near the end, you can see I have commented a line that stores the contents of a variable called hello in the buffer to the destination. hello comes from the sample project, and contains about 700 lines of character bytes like this:
"\x02\x00\x01\x00\xff\xff\x09\x00\x0c\x00\x10\x00\x07\x00\x07\x00"
which make an audio file of someone saying "hello". When reading that byte data into the stream, my code works fine and I hear "hello" when I run the application. When I read from wav file to play the asset I want, however, I only hear static. The size of the data buffer is the same as the size of the file, so it appears it's being read in properly. The static plays for the duration of the wav file (or very close to it).
I really know nothing about data formats or audio programming. I've tried tweaking the format_pcm variables some with different enum values, but had no success. Using a tool called GSpot I found on The Internet, I know the following about the audio file I'm trying to play:
File Size: 557 KB (570,503 bytes) (this is the same size as the data buffer AAsset_read returns
Codec: PCM Audio
Sample rate: 48000Hz
Bit rate: 1152 kb/s
Channels: 1
Any help or direction would be greatly appreciated.
SLDataLocator_AndroidSimpleBufferQueue loc_bufq = { SL_DATALOCATOR_ANDROIDSIMPLEBUFFERQUEUE, 1 };
SLDataFormat_PCM format_pcm;
format_pcm.formatType = SL_DATAFORMAT_PCM;
format_pcm.numChannels = 1;
format_pcm.samplesPerSec = SL_SAMPLINGRATE_48;// SL_SAMPLINGRATE_8;
format_pcm.bitsPerSample = SL_PCMSAMPLEFORMAT_FIXED_8; // SL_PCMSAMPLEFORMAT_FIXED_16;
format_pcm.containerSize = 16;
format_pcm.channelMask = SL_SPEAKER_FRONT_CENTER;
format_pcm.endianness = SL_BYTEORDER_LITTLEENDIAN;
SLDataSource audioSrc = { &loc_bufq, &format_pcm };
// configure audio sink
SLDataLocator_OutputMix loc_outmix = { SL_DATALOCATOR_OUTPUTMIX, manager->GetOutputMixObject() };
SLDataSink audioSnk = { &loc_outmix, NULL };
//create audio player
const SLInterfaceID ids[3] = { SL_IID_BUFFERQUEUE, SL_IID_EFFECTSEND, SL_IID_VOLUME };
const SLboolean req[3] = { SL_BOOLEAN_TRUE, SL_BOOLEAN_TRUE, SL_BOOLEAN_TRUE };
SLEngineItf engineEngine = manager->GetEngine();
result = (*engineEngine)->CreateAudioPlayer(engineEngine, &bqPlayerObject, &audioSrc, &audioSnk,
3, ids, req);
// realize the player
result = (*bqPlayerObject)->Realize(bqPlayerObject, SL_BOOLEAN_FALSE);
// get the play interface
result = (*bqPlayerObject)->GetInterface(bqPlayerObject, SL_IID_PLAY, &bqPlayerPlay);
// get the buffer queue interface
result = (*bqPlayerObject)->GetInterface(bqPlayerObject, SL_IID_BUFFERQUEUE,
&bqPlayerBufferQueue);
// register callback on the buffer queue
result = (*bqPlayerBufferQueue)->RegisterCallback(bqPlayerBufferQueue, bqPlayerCallback, NULL);
// get the effect send interface
result = (*bqPlayerObject)->GetInterface(bqPlayerObject, SL_IID_EFFECTSEND,
&bqPlayerEffectSend);
// get the volume interface
result = (*bqPlayerObject)->GetInterface(bqPlayerObject, SL_IID_VOLUME, &bqPlayerVolume);
// set the player's state to playing
result = (*bqPlayerPlay)->SetPlayState(bqPlayerPlay, SL_PLAYSTATE_PLAYING);
uint8* pOutBytes = nullptr;
uint32 outSize = 0;
result = MyFileManager::GetInstance()->OpenFile(m_strAbsolutePath, (void**)&pOutBytes, &outSize, true);
const char* filename = m_strAbsolutePath->GetUTF8String();
result = (*bqPlayerBufferQueue)->Enqueue(bqPlayerBufferQueue, pOutBytes, outSize);
// result = (*bqPlayerBufferQueue)->Enqueue(bqPlayerBufferQueue, hello, sizeof(hello));
if (SL_RESULT_SUCCESS != result) {
return JNI_FALSE;
}
