vbr-g726.c

G.726协议的C源码

*/
int main(argc, argv)
  int             argc;
  char           *argv[];
{
  G726_state      encoder_state, decoder_state;
  long            N = 16, N1 = 1, N2 = 0, cur_blk, smpno;
  short           *tmp_buf, *inp_buf, *out_buf, reset=1;
  short           inp_type, out_type, *rate=0;
  char            encode = 1, decode = 1, law[4] = "A", def_rate[]="32";
  int             rateno=1, rate_idx;

  /* General-purpose, progress indication */
  static char     quiet=0, funny[9] = "|/-\\|/-\\";

/* File variables */
  char            FileIn[80], FileOut[80];
  FILE           *Fi, *Fo;
  int             inp, out;
  long            start_byte;
#ifdef VMS
  char            mrs[15];
#endif

/*
 * ......... PARAMETERS FOR PROCESSING .........
 */

  /* GETTING OPTIONS */

  if (argc < 2)
    display_usage();
  else
  {
    while (argc > 1 && argv[1][0] == '-')
      if (strcmp(argv[1], "-noreset") == 0)
      {
	/* No reset */
	reset = 0;

	/* Update argc/argv to next valid option/argument */
	argv++;
	argc--;
      }
      else if (strcmp(argv[1], "-enc") == 0)
      {
	/* Encoder-only operation */
	encode = 1;
	decode = 0;

	/* Move argv over the option to the next argument */
	argv++;
	argc--;
      }
      else if (strcmp(argv[1], "-dec") == 0)
      {
	/*Decoder-only operation */
	encode = 0;
	decode = 1;

	/* Move argv over the option to the next argument */
	argv++;
	argc--;
      }
      else if (strcmp(argv[1], "-law") == 0)
      {
	/* Define law for operation: A, u, or linear */
	switch (toupper(argv[2][0]))
	{
	case 'A':
	  law[0] = '1';
	  break;
	case 'U':
	  law[0] = '0';
	  break;
	case 'L':
	  law[0] = '2';
	  break;
	default:
	  HARAKIRI(" Invalid law (A or u)! Aborted...\n", 7);
	}

	/* Move argv over the option to the next argument */
	argv+=2;
	argc-=2;
      }
      else if (strcmp(argv[1], "-frame") == 0)
      {
	/* Define Frame size for rate change during operation */
        N = atoi(argv[2]);

	/* Move argv over the option to the next argument */
	argv+=2;
	argc-=2;
      }
      else if (strcmp(argv[1], "-rate") == 0)
      {
	/*Define rate(s) for operation */
        rateno = parse_rate(argv[2], &rate);
	if (rateno==0)
	{
	  fprintf(stderr, "Invalid bitrate list: %s\n", argv[2]);
	  exit(9);
        }
	/* Move argv over the option to the next argument */
	argv+=2;
	argc-=2;
      }
      else if (strcmp(argv[1], "-q") == 0)
      {
	/* Don't print progress indicator */
	quiet = 1;

	/* Move argv over the option to the next argument */
	argv++;
	argc--;
      }
      else if (strcmp(argv[1], "-?") == 0 || strcmp(argv[1], "-help") == 0)
      {
	/* Print help */
	display_usage();
      }
      else
      {
	fprintf(stderr, "ERROR! Invalid option \"%s\" in command line\n\n",
		argv[1]);
	display_usage();
      }
  }

  /* Now get regular parameters */
  GET_PAR_S(1, "_Input File: .................. ", FileIn);
  GET_PAR_S(2, "_Output File: ................. ", FileOut);
  FIND_PAR_L(3, "_Block Size: .................. ", N, N);
  FIND_PAR_L(4, "_Starting Block: .............. ", N1, N1);
  FIND_PAR_L(5, "_No. of Blocks: ............... ", N2, N2);

  /* Uses default rate if none is given */
  if (rate == 0)
    rateno = parse_rate(def_rate, &rate);

  /* Inform user of the compading law used: 0->u, 1->A, 2->linear */
  fprintf(stderr, "Using %s\n",
	  law[0] == '1'? "A-law" : ( law[0] == '0' ? "u-law" : "linear PCM"));

  /* Find starting byte in file */
  start_byte = sizeof(short) * (long) (--N1) * (long) N;

  /* Check if is to process the whole file */
  if (N2 == 0)
  {
    struct stat     st;

    /* ... find the input file size ... */
    stat(FileIn, &st);
    N2 = ceil((st.st_size - start_byte) / (double)(N * sizeof(short)));
  }

  /* Define correct data I/O types */
  if (encode && decode) 
  {  
    inp_type = out_type = (law[0] == '2'? IS_LIN : IS_LOG);
  }
  else if (encode)     
  {
    inp_type = law[0] == '2'? IS_LIN : IS_LOG;
    out_type = IS_ADPCM;
  }
  else     
  {
    inp_type = IS_ADPCM;
    out_type = law[0] == '2'? IS_LIN : IS_LOG;
  }

  /* Force law to be used *by the ADPCM* to A-law, if input is linear */
  if (law[0]=='2')
    law[0]='1';

/*
 * ...... MEMORY ALLOCATION .........
 */

  if ((inp_buf = (short *) calloc(N, sizeof(short))) == NULL) 
     HARAKIRI("Error in memory allocation!\n",1);
  if ((out_buf = (short *) calloc(N, sizeof(short))) == NULL) 
     HARAKIRI("Error in memory allocation!\n",1);
  if ((tmp_buf = (short *) calloc(N, sizeof(short))) == NULL) 
     HARAKIRI("Error in memory allocation!\n",1);

/*
 * ......... FILE PREPARATION .........
 */

  /* Opening input file; abort if there's any problem */
  if ((Fi = fopen(FileIn, "rb")) == NULL)
    KILL(FileIn, 2);
  inp = fileno(Fi);

  /* Creates output file */
#ifdef VMS
  sprintf(mrs, "mrs=%d", 512);
#endif
  if ((Fo = fopen(FileOut, WB)) == NULL)
    KILL(FileOut, 3);
  out = fileno(Fo);

  /* Move pointer to 1st block of interest */
  if (fseek(Fi, start_byte, 0) < 0l)
    KILL(FileIn, 4);

/*
 * ......... PROCESSING ACCORDING TO ITU-T G.726 .........
 */
  /* Reset VBR counters */
  rate_idx = 0;

  for (cur_blk = 0; cur_blk < N2; cur_blk++)
  {
    /* Set the proper rate index */
    rate_idx = cur_blk % rateno;

    /* Print progress flag */
    if (!quiet)
#ifdef DISPLAY_CURRENT_RATE
      fprintf(stderr, "%d-", 8 * rate[rate_idx]);
#else
      fprintf(stderr, "%c\r", funny[cur_blk % 8]);
#endif

    /* Read a block of samples */
    if ((smpno = fread(inp_buf, sizeof(short), N, Fi)) < 0)
      KILL(FileIn, 5);

    /* Compress linear input samples */
    if (inp_type == IS_LIN)
    {
      /* Compress using A-law */
      alaw_compress(smpno, inp_buf, tmp_buf);

      /* copy temporary buffer over input buffer */
      memcpy(inp_buf, tmp_buf, sizeof(short) * smpno);
    }

    /* Check if reset is needed */
    reset = (reset == 1 && cur_blk == 0) ? 1 : 0;

    /* Carry out the desired operation */
    if (encode && ! decode)
      G726_encode(inp_buf, out_buf, smpno, law, 
		  rate[rate_idx], reset, &encoder_state);
    else if (decode && !encode)
      G726_decode(inp_buf, out_buf, smpno, law, 
		  rate[rate_idx], reset, &decoder_state);
    else if (encode && decode)
    {
      G726_encode(inp_buf, tmp_buf, smpno, law, 
		  rate[rate_idx], reset, &encoder_state);
      G726_decode(tmp_buf, out_buf, smpno, law, 
		  rate[rate_idx], reset, &decoder_state);
    }

    /* Expand linear input samples */
    if (out_type == IS_LIN)
    {
      /* Compress using A-law */
      alaw_expand(smpno, out_buf, tmp_buf);

      /* copy temporary buffer over input buffer */
      memcpy(out_buf, tmp_buf, sizeof(short) * smpno);
    }

    /* Write ADPCM output word */
    if ((smpno = fwrite(out_buf, sizeof(short), smpno, Fo)) < 0)
      KILL(FileOut, 6);
  }

/*
 * ......... FINALIZATIONS .........
 */

  /* Free allocated memory */
  free(tmp_buf);
  free(out_buf);
  free(inp_buf);
  free(rate);

  /* Close input and output files */
  fclose(Fi);
  fclose(Fo);

  /* Exit with success for non-vms systems */
#ifndef VMS
  return (0);
#endif
}
/* ............................. end of main() ............................. */