Requesting interface SL_IID_ANDROIDSIMPLEBUFFERQUEUE on OpenSL ES recorder object returns SL_RESULT_FEATURE_UNSUPPORTED

Question

I have written a basic recorder app using the Android NDK and OpenSL ES. It compiles and links fine, but when I try to run it on a Galaxy Nexus device I get the following error:

W/libOpenSLES(10708): Leaving Object::GetInterface (SL_RESULT_FEATURE_UNSUPPORTED)

This happens on the line:

res = (*recorderObj)->GetInterface(recorderObj, SL_IID_ANDROIDSIMPLEBUFFERQUEUE, &recorderBufferQueueItf);

Does this mean that recording using OpenSL ES on a Galaxy Nexus device isn't supported, or did I merely make a mistake? Below is the relevant code:

    static SLObjectItf recorderObj;
    static SLEngineItf EngineItf;
    static SLRecordItf recordItf;
    static SLAndroidSimpleBufferQueueItf recorderBufferQueueItf;
    static SLDataSink recDest;
    static SLDataLocator_AndroidSimpleBufferQueue recBuffQueue;
    static SLDataFormat_PCM pcm;

    /* Setup the data source structure */
    locator_mic.locatorType = SL_DATALOCATOR_IODEVICE;
    locator_mic.deviceType = SL_IODEVICE_AUDIOINPUT;
    locator_mic.deviceID   = SL_DEFAULTDEVICEID_AUDIOINPUT;
    locator_mic.device = NULL;
    audioSource.pLocator = (void *) &locator_mic;
    audioSource.pFormat = NULL;

    /* Setup the data sink structure */
    recBuffQueue.locatorType = SL_DATALOCATOR_ANDROIDSIMPLEBUFFERQUEUE;
    recBuffQueue.numBuffers = NB_BUFFERS_IN_QUEUE;

    /* set up the format of the data in the buffer queue */
    pcm.formatType = SL_DATAFORMAT_PCM;
    pcm.numChannels = 1;
    pcm.samplesPerSec = SL_SAMPLINGRATE_44_1;
    pcm.bitsPerSample = SL_PCMSAMPLEFORMAT_FIXED_16;
    pcm.containerSize = SL_PCMSAMPLEFORMAT_FIXED_16;
    pcm.channelMask = SL_SPEAKER_FRONT_CENTER;
    pcm.endianness = SL_BYTEORDER_LITTLEENDIAN;

    recDest.pLocator = (void *) &recBuffQueue;
    recDest.pFormat = (void * ) &pcm;

    /* Create audio recorder */
    res = (*EngineItf)->CreateAudioRecorder(EngineItf, &recorderObj, &audioSource, &recDest, 0, iidArray, required);
    CheckErr(res);

    /* Realizing the recorder in synchronous mode. */
    res = (*recorderObj)->Realize(recorderObj, SL_BOOLEAN_FALSE);
    CheckErr(res);

    /* Get the RECORD interface - it is an implicit interface */
    LOGI("GetInterface: Recorder");
    res = (*recorderObj)->GetInterface(recorderObj, SL_IID_RECORD, &recordItf);
    CheckErr(res);

    /* Get the buffer queue interface which was explicitly requested */
    LOGI("GetInterface: Buffer Queue");
    res = (*recorderObj)->GetInterface(recorderObj, SL_IID_ANDROIDSIMPLEBUFFERQUEUE, &recorderBufferQueueItf);
    CheckErr(res);

Any help with this issue would be most welcome :)

Answer 1

When you create the Audio Recorder, you specify "0" as the third-to-last argument, which is the number of non-implicit interfaces to be supported. The buffer queue is not an implicit interface for a recorder.

Try changing

res = (*EngineItf)->CreateAudioRecorder(EngineItf, &recorderObj, &audioSource, &recDest, 0, iidArray, required);

to

res = (*EngineItf)->CreateAudioRecorder(EngineItf, &recorderObj, &audioSource, &recDest, 1, iidArray, required);