sound_sun.cc

ears-0.32, linux下有用的语音信号处理工具包

#pragma implementation
#ifdef SUN

// if supported use AUDIO_ENCODING_LINEAR, else AUDIO_ENCODING_ULAW
// if uncertain, try linear first and see if you get an error message
//#define AUDIO_ENCODING AUDIO_ENCODING_LINEAR
#define AUDIO_ENCODING AUDIO_ENCODING_ULAW
#define AUDIO_DEV     "/dev/audio"   
#define AUDIOCTL_DEV  "/dev/audioctl"
extern "C" {
#include <multimedia/libaudio.h>
#include <multimedia/audio_device.h>
#include <multimedia/audio_encode.h>   
}
#include <stdio.h>
#include <fcntl.h> 
#include <unistd.h> 
#include <stropts.h>
#include <errno.h>
#include <fcntl.h>
#include <string.h>
#include <fstream.h>
#include "sound_sun.h"
#include "others/sndblock.h"
#include "sample.h"       

SunSound::SunSound (int sample_rate, int b) : 
  name_("SunSound"), error_(false), bits(b)
{
  audio_fd = open(AUDIO_DEV, O_RDONLY);
  audio_pause_record(audio_fd);     
  if (audio_fd < 0) {
    errmsg_ = "Could not open " AUDIO_DEV;
    error_ = true;
    return; 
  }
#if AUDIO_ENCODING == AUDIO_ENCODING_LINEAR
    bytes_per_unit = bits/8;
#elif AUDIO_ENCODING == AUDIO_ENCODING_ULAW
    bytes_per_unit = 1;
    if (bits == 8) {
      errmsg_ = "Set SOUND_BITS 16 in .earsrc for ulaw encoding.\n";
      error_  = true;
      return;
    }
#endif
  int audioctl_fd = open(AUDIOCTL_DEV, O_RDWR);
  Audio_hdr config;
  config.sample_rate      = sample_rate;
  config.bytes_per_unit   = bytes_per_unit;
  config.encoding         = AUDIO_ENCODING;
  config.data_size        = AUDIO_UNKNOWN_SIZE;
  int error = audio_set_record_config(audioctl_fd, &config);
  audio_get_record_config(audioctl_fd, &config);
  if (AUDIO_ENCODING != config.encoding) {
    errmsg_ = 
      "Linear format not supported, change encoding to AUDIO_ENCODING_ULAW\n"
      "in modules/sound_sun.cc. See Readme.sun for details.\n";
    error_  = true;
    return;
  } else if (config.sample_rate != sample_rate || 
	     config.bytes_per_unit != bytes_per_unit) {
#if AUDIO_ENCODING == AUDIO_ENCODING_LINEAR
    errmsg_ = 
      "Could not set audio device to requested settings.\n" 
      "Try SOUND_BITS 8;  SOUND_SPEED 8000 in .earsrc.\n";
#elif AUDIO_ENCODING == AUDIO_ENCODING_ULAW
    errmsg_ = 
      "Could not set audio device to requested settings.\n" 
      "Try SOUND_BITS 16; SOUND_SPEED 8000 in .earsrc.\n";
#endif      
    error_  = true;
    return;
  }
}


SunSound::~SunSound()
{
  audio_flush_record(audio_fd);
  close(audio_fd);
}  

void SunSound::deaf_mic()
{
  audio_pause_record(audio_fd);     
}      

void SunSound::full_mic()
{
  audio_resume_record(audio_fd);
}
  
void SunSound::empty_buffer() const
{
  audio_flush_record(audio_fd);     
}    

void SunSound::save_sample (const class sample& s, const string& f) const
{
  // not implemented
}                    


static unsigned char buffer[400];  // should be big enough

void SunSound::fill_block (sndblock& s) const
{
  int size = s.size_;
  switch (bytes_per_unit) {
  case 1:
    for (int k = 0; k < size;) {
      k += read(audio_fd, (void *) (buffer + k), (size - k));
    }
    for (int k = size; k--;) {
#if AUDIO_ENCODING == AUDIO_ENCODING_LINEAR
      s.buf_[k] = buffer[k]; 
#elif AUDIO_ENCODING == AUDIO_ENCODING_ULAW
    /* convert ulaw to linear using freely redistributable code --
    ** per the copyright notice by Sun Microsystems in Readme.sun
    */
#define SIGN_BIT        (0x80)          /* Sign bit for a A-law byte. */
#define QUANT_MASK      (0xf)           /* Quantization field mask. */
#define SEG_SHIFT       (4)             /* Left shift for segment number. */
#define SEG_MASK        (0x70)          /* Segment field mask. */
#define BIAS            (0x84)          /* Bias for linear code. */   
      unsigned char u_val = ~buffer[k];
      int t = ((u_val & QUANT_MASK) << 3) + BIAS;
      t <<= ((unsigned)u_val & SEG_MASK) >> SEG_SHIFT;
      s.buf_[k] = ((u_val & SIGN_BIT) ? (BIAS - t) : (t - BIAS)); 
#endif
    }
    break;
  case 2:
    for (int k = 0; k < size;) {
      k += read(audio_fd, (void *) (s.buf_ + k), 2*(size - k))/2;
    }
  }
  long sum = 0;
  short last = s.buf_[size-1];
  int diff;
  for (int k = size; k--;) {
    diff = s.buf_[k]  - last;
    diff = (diff > 0) ? diff : -diff;
    sum += diff;
    last = s.buf_[k];
  }
  s.energy_ = sum / size;
}
#endif