axmol/cocos/audio/android/AudioDecoder.h

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#pragma once

#include "audio/android/OpenSLHelper.h"
#include "audio/android/PcmData.h"

#include <mutex>
#include <condition_variable>

namespace cocos2d { namespace experimental {

class AudioDecoder
{
public:
    AudioDecoder(SLEngineItf engineItf, const std::string &url, int bufferSizeInFrames, int sampleRate);

    virtual ~AudioDecoder();

    bool start(const FdGetterCallback &fdGetterCallback);

    inline PcmData getResult()
    { return _result; };

private:
    void resample();

    void signalEos();

    void decodeToPcmCallback(SLAndroidSimpleBufferQueueItf queueItf);

    void prefetchCallback(SLPrefetchStatusItf caller, SLuint32 event);

    void decodeProgressCallback(SLPlayItf caller, SLuint32 event);

private:
    SLEngineItf _engineItf;
    std::string _url;
    PcmData _result;

    SLObjectItf _playObj;
    /* Local storage for decoded audio data */
    char* _pcmData;

    /* we only want to query / display the PCM format once */
    bool _formatQueried;
    /* Used to signal prefetching failures */
    bool _prefetchError;

    /* to display the number of decode iterations */
    int _counter;

    /* metadata key index for the PCM format information we want to retrieve */
    int _numChannelsKeyIndex;
    int _sampleRateKeyIndex;
    int _bitsPerSampleKeyIndex;
    int _containerSizeKeyIndex;
    int _channelMaskKeyIndex;
    int _endiannessKeyIndex;

    /* to signal to the test app the end of the stream to decode has been reached */
    bool _eos;
    std::mutex _eosLock;
    std::condition_variable _eosCondition;

    /* 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;

    CallbackCntxt _decContext;
    int _bufferSizeInFrames;
    int _sampleRate;
    int _assetFd;

    friend class SLAudioDecoderCallbackProxy;

    void interleave();
};

}} // namespace cocos2d { namespace experimental {