audiooutputopensles.h

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#ifndef AUDIOOUTPUTOPENSLES
#define AUDIOOUTPUTOPENSLES
 
#include <QMutex>
// For native audio
#include <SLES/OpenSLES.h>
#include <SLES/OpenSLES_Android.h>
#include <jni.h>
 
// MythTV headers
#include "audiooutputbase.h"
 
using slCreateEngine_t = SLresult (*)(
        SLObjectItf*, SLuint32, const SLEngineOption*, SLuint32,
        const SLInterfaceID*, const SLboolean*);
 
class AudioOutputOpenSLES : public AudioOutputBase
{
  friend class AudioOutputOpenSLESPrivate;
  public:
    explicit AudioOutputOpenSLES(const AudioSettings &settings);
    ~AudioOutputOpenSLES() override;
 
  protected:
    bool OpenDevice(void) override; // AudioOutputBase
    void CloseDevice(void) override; // AudioOutputBase
    void WriteAudio(unsigned char *aubuf, int size) override; // AudioOutputBase
    int  GetBufferedOnSoundcard(void) const override; // AudioOutputBase
    AudioOutputSettings* GetOutputSettings(bool digital) override; // AudioOutputBase
 
    // Volume control
    int  GetVolumeChannel(int channel) const override; // VolumeBase
    void SetVolumeChannel(int channel, int volume) override; // VolumeBase
 
  private:
    int GetNumberOfBuffersQueued() const;
 
    //static const uint      kPacketCnt;
 
    bool CreateEngine();
    static void SPlayedCallback(SLAndroidSimpleBufferQueueItf caller, void *pContext);
    void PlayedCallback(SLAndroidSimpleBufferQueueItf caller);
    bool StartPlayer();
    bool Stop();
    bool Open();
    void Close();
 
  private:
    /* OpenSL objects */
    SLObjectItf                     m_engineObject      {nullptr};
    SLObjectItf                     m_outputMixObject   {nullptr};
    SLAndroidSimpleBufferQueueItf   m_playerBufferQueue {nullptr};
    SLObjectItf                     m_playerObject      {nullptr};
    SLVolumeItf                     m_volumeItf         {nullptr};
    SLEngineItf                     m_engineEngine      {nullptr};
    SLPlayItf                       m_playerPlay        {nullptr};
 
    /* OpenSL symbols */
    void                           *m_soHandle          {nullptr};
 
    slCreateEngine_t                m_slCreateEnginePtr {nullptr};
    SLInterfaceID                   m_slIidEngine       {nullptr};
    SLInterfaceID                   m_slIidAndroidSimpleBufferQueue {nullptr};
    SLInterfaceID                   m_slIidVolume       {nullptr};
    SLInterfaceID                   m_slIidPlay         {nullptr};
 
    /* audio buffered through opensles */
    std::vector<uint8_t>            m_buf;
    int                             m_bufWriteBase     {0}; // always fragment aligned
    int                             m_bufWriteIndex    {0}; // offset from base
 
    /* if we can measure latency already */
    bool                            m_started          {false};
    int                             m_nativeOutputSampleRate;
 
    QMutex                          m_lock;
 
};
 
#endif // AUDIOOUTPUTOPENSLES