www.pudn.com > wav_mp3_recorder.rar > wave.c

/* wave.c 
 * 
 * Data input functions. 
 */ 
 
#include "types.h" 
 
/* 
 * wave_close: 
 * ----------- 
 */ 
void wave_close(void) 
{ 
  fclose(config.wave.file); 
} 
 
/* 
 * wave_open: 
 * ---------- 
 * Opens and verifies the header of the Input Wave file. The file pointer is 
 * left pointing to the start of the samples. 
 */ 
void wave_open(int raw, int mono_from_stereo) 
{ 
 
  static char *channel_mappings[] = {NULL,"mono","stereo"}; 
  static char *file_type[] = {"RIFF-WAVE PCM","RAW DATA PCM"}; 
 
  /* Wave file headers can vary from this, but we're only intereseted in this format */ 
  struct wave_header 
  { 
    char riff[4];             /* "RIFF" */ 
    unsigned long size;       /* length of rest of file = size of rest of header(36) + data length */ 
    char wave[4];             /* "WAVE" */ 
    char fmt[4];              /* "fmt " */ 
    unsigned long fmt_len;    /* length of rest of fmt chunk = 16 */ 
    unsigned short tag;       /* MS PCM = 1 */ 
    unsigned short channels;  /* channels, mono = 1, stereo = 2 */ 
    unsigned long samp_rate;  /* samples per second = 44100 */ 
    unsigned long byte_rate;  /* bytes per second = samp_rate * byte_samp = 176400 */ 
    unsigned short byte_samp; /* block align (bytes per sample) = channels * bits_per_sample / 8 = 4 */ 
    unsigned short bit_samp;  /* bits per sample = 16 for MS PCM (format specific) */ 
    char data[4];             /* "data" */ 
    unsigned long length;     /* data length (bytes) */ 
  } header; 
 
  /* open input file */ 
  if((config.wave.file = fopen(config.infile,"rb")) == NULL) 
    error("Unable to open file"); 
 
  if(raw) 
  { 
      fseek(config.wave.file, 0, SEEK_END); /* find length of file */ 
      header.length = ftell(config.wave.file); 
      fseek(config.wave.file, 0, SEEK_SET); 
      header.channels = (mono_from_stereo) ? 1 : 2; 
      header.samp_rate = config.wave.samplerate; /* 44100 if not set by user */ 
      header.bit_samp = 16;     /* assumed */ 
      header.byte_samp = header.channels * header.bit_samp / 8; 
      header.byte_rate = header.samp_rate * header.byte_samp; 
  } 
  else /* wave */ 
  { 
      if (fread(&header, sizeof(header), 1, config.wave.file) != 1) 
        error("Invalid Header"); 
      if(strncmp(header.riff,"RIFF",4) != 0) error("Not a MS-RIFF file"); 
      if(strncmp(header.wave,"WAVE",4) != 0) error("Not a WAVE audio"); 
      if(strncmp(header.fmt, "fmt ",4) != 0) error("Can't find format chunk"); 
      if(header.tag != 1)                    error("Unknown WAVE format"); 
      if(header.channels > 2)                error("More than 2 channels"); 
      if(header.bit_samp != 16)              error("Not 16 bit"); 
      if(strncmp(header.data,"data",4) != 0) error("Can't find data chunk"); 
  } 
 
 // printf("byte_samp = %d\n", header.byte_samp); 
 // printf("length = %ld\n", header.length ); 
  config.wave.channels      = header.channels; 
 // printf("channels = %d\n", config.wave.channels); 
  config.wave.samplerate    = header.samp_rate; 
 // printf("samplerate = %ld\n", config.wave.samplerate); 
  config.wave.bits          = header.bit_samp; 
 // printf("bits = %d\n", config.wave.bits); 
  config.wave.total_samples = header.length / header.byte_samp; 
 // printf("total_samples = %ld\n", config.wave.total_samples); 
  config.wave.length        = header.length / header.byte_rate; 
  //printf("length = %ld\n", config.wave.length); 
   
  if((config.wave.channels == 1) || mono_from_stereo) 
  { 
    config.mpeg.channels = 1; 
    config.mpeg.mode = MODE_MONO; 
  } 
 
  printf("%s, %s %ldHz %dbit, Length: %2ld:%2ld:%2ld\n", 
          file_type[raw], 
          channel_mappings[config.wave.channels], 
          config.wave.samplerate, 
          config.wave.bits, 
          config.wave.length/3600,(config.wave.length/60)%60,config.wave.length%60); 
} 
 
/* 
 * wave_get: 
 * --------- 
 * Reads samples from the file in longs. A long can 
 * hold one stereo or two mono samples. 
 * Returns the address of the start of the next frame or NULL if there are no 
 * more. The last frame will be padded with zero's. 
 */ 
/*unsigned long int *wave_get(short* buffer) 
{ 
  int n; 
  static unsigned long buff[samp_per_frame2]; 
  n = samp_per_frame2; 
  if( memcpy(buff, buffer, sizeof(unsigned long)*(short)n) == NULL ) 
  { 
  	printf("memcpy fails\n"); 
  	exit(1); 
  } 
  return buff; 
}*/ 
unsigned long int *wave_get(short* buffer) 
{ 
  int n = 288; 
  static unsigned long buff[288]; 
  if( memcpy(buff, buffer, 1152) == NULL ) //sizeof(unsigned long)*(short)n 
  { 
  	printf("memcpy fails\n"); 
  	exit(1); 
  } 
  return buff; 
}