libcw/cwAudioDevice.h

96 lines
4.6 KiB
C++

#ifndef cwAudioDevice_H
#define cwAudioDevice_H
namespace cw
{
namespace audio
{
namespace device
{
typedef float sample_t;
// audioPacket_t flags
enum
{
kInterleavedApFl = 0x01, // The audio samples are interleaved.
kFloatApFl = 0x02 // The audio samples are single precision floating point values.
};
// Audio packet record used by the audioPacket_t callback.
// Audio ports send and receive audio using this data structure.
typedef struct
{
unsigned devIdx; // device associated with packet
unsigned begChIdx; // first device channel
unsigned chCnt; // count of channels
unsigned audioFramesCnt; // samples per channel (see note below)
unsigned bitsPerSample; // bits per sample word
unsigned flags; // kInterleavedApFl | kFloatApFl
void* audioBytesPtr; // pointer to sample data
void* cbArg; // user defined argument passed in via deviceSetup()
time::spec_t timeStamp; // Packet time stamp.
} audioPacket_t;
// Audio port callback signature.
// inPktArray[inPktCnt] are full packets of audio coming from the ADC to the application.
// outPktArray[outPktCnt] are empty packets of audio which will be filled by the application
// and then sent to the DAC.
//
// The value of audioFrameCnt gives the number of samples per channel which are available
// in the packet data buffer 'audioBytesPtr'. The callback function may decrease this number in
// output packets if the number of samples available is less than the size of the buffer.
// It is the responsibility of the calling audio port to notice this change and pass the new,
// decreased number of samples to the hardware.
//
// In general it should be assmed that this call is made from a system thread which is not
// the same as the application thread.
// The usual thread safety precautions should therefore be taken if this function implementation
// interacts with data structures also handled by the application. The audio buffer class (\see cmApBuf.h)
// is designed to provide a safe and efficient way to communicate between
// the audio thread and the application.
typedef void (*cbFunc_t)( audioPacket_t* inPktArray, unsigned inPktCnt, audioPacket_t* outPktArray, unsigned outPktCnt );
typedef struct driver_str
{
void* drvArg;
rc_t (*deviceCount)( struct driver_str* drvArg);
const char* (*deviceLabel)( struct driver_str* drvArg, unsigned devIdx );
unsigned (*deviceChannelCount)( struct driver_str* drvArg, unsigned devIdx, bool inputFl );
double (*deviceSampleRate)( struct driver_str* drvArg, unsigned devIdx );
unsigned (*deviceFramesPerCycle)( struct driver_str* drvArg, unsigned devIdx, bool inputFl );
rc_t (*deviceSetup)( struct driver_str* drvArg, unsigned devIdx, double sr, unsigned frmPerCycle, cbFunc_t cb, void* cbData );
rc_t (*deviceStart)( struct driver_str* drvArg, unsigned devIdx );
rc_t (*deviceStop)( struct driver_str* drvArg, unsigned devIdx );
bool (*deviceIsStarted)( struct driver_str* drvArg, unsigned devIdx );
void (*deviceRealTimeReport)( struct driver_str* drvArg, unsigned devIdx );
} driver_t;
typedef handle<struct device_str> handle_t;
rc_t create( handle_t& hRef );
rc_t destroy( handle_t& hRef );
rc_t registerDriver( handle_t h, driver_t* drv );
unsigned deviceCount( handle_t h );
unsigned deviceLabelToIndex( handle_t h, const char* label );
const char* deviceLabel( handle_t h, unsigned devIdx );
unsigned deviceChannelCount( handle_t h, unsigned devIdx, bool inputFl );
double deviceSampleRate( handle_t h, unsigned devIdx );
unsigned deviceFramesPerCycle( handle_t h, unsigned devIdx, bool inputFl );
rc_t deviceSetup( handle_t h, unsigned devIdx, double sr, unsigned frmPerCycle, cbFunc_t cb, void* cbData );
rc_t deviceStart( handle_t h, unsigned devIdx );
rc_t deviceStop( handle_t h, unsigned devIdx );
bool deviceIsStarted( handle_t h, unsigned devIdx );
void deviceRealTimeReport( handle_t h, unsigned devIdx );
void report( handle_t h );
}
}
}
#endif