src/alsa_pcm.h


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#ifndef ALSA_PCM__H
#define ALSA_PCM__H

#include <string>
#include <alsa/asoundlib.h>

const int FPP(1024);            // frames per period

class alsa_pcm{
public:
  snd_pcm_t* phndl;             // pcm handle
#if 0
  DO NOT save a pointer to any snd_pcm_hw_params_t object;
  alsa allocates space _on the stack_ and it goes out of
  scope quickly.
  snd_pcm_hw_params_t *hwparams;
#endif
  snd_output_t* errlog;
  unsigned int nchan;           // samples per frame; 2 ==> stereo
  unsigned int max_rate;
  unsigned int rate;            // frames per second
  int sbits;                    // significant bits
  snd_pcm_stream_t direction;
//  int sizeofsamp;             // bytes per sample
  snd_pcm_format_t format;
  const char* moniker;
  snd_htimestamp_t ss_time();   // start or stop time (usually start time)
  snd_htimestamp_t now();       // current time
  void error(const char*, const int, snd_pcm_hw_params_t*);
  int getrate(const std::string carddevice,
        snd_pcm_stream_t stream_dir,
        const int dumpflag);
  int setup(const int rate);
// Constructor doesn't do much,
// so it is cheap to allocate one that you're not
// necessarily going to use:
  inline alsa_pcm(const char* mm)
           : phndl(0), errlog(0), moniker(mm)
  {}
  int try_formats(snd_pcm_hw_params_t*);
  std::string alsa_state_name();
};

void device_list(const snd_pcm_stream_t direction);

#endif /* ALSA_PCM__H */