main.c

MP3编码的完整实现(源代码和使用例子都有)

#include <stdlib.h>


#include <string.h>
#include <stdio.h>
#include <fcntl.h>

#ifdef _WIN32
#include <io.h>
#endif
#include "lame.h"

#ifdef __riscos__
//#include "asmstuff.h"
#endif

/************************************************************************
*
* main
*
* PURPOSE:  MPEG-1,2 Layer III encoder with GPSYCHO
* psychoacoustic model.
*
************************************************************************/


int main(int argc, char **argv)
{

  char mp3buffer[LAME_MAXMP3BUFFER];
  short int Buffer[2][1152];
  int iread,imp3;
  lame_global_flags gf;
  FILE *outf;
#ifdef __riscos__
  int i;
#endif


  lame_init(&gf);                  /* initialize libmp3lame */
  if(argc==1) lame_usage(&gf,argv[0]);  /* no command-line args, print usage, exit  */

  /* parse the command line arguments, setting various flags in the
   * struct 'gf'.  If you want to parse your own arguments,
   * or call libmp3lame from a program which uses a GUI to set arguments,
   * skip this call and set the values of interest in the gf struct.
   * (see lame.h for documentation about these parameters)
   */
  //lame_parse_args(&gf,argc, argv);

  //设置编码器格式信息
  gf.allow_diff_short		= 0;
  gf.ATHonly			= 0;
  gf.noATH=0;
  gf.bWriteVbrTag		= 1;
  gf.cwlimit			= 0;
  gf.disable_reservoir	= 0;
  gf.experimentalX		= 0;
  gf.experimentalY		= 0;
  gf.experimentalZ		= 0;
  gf.frameNum			= 0;
  gf.quality			= 2;
  gf.input_format		= sf_wave;
  
  gf.filter_type		= 0;
  gf.lowpassfreq		= 0;
  gf.highpassfreq		= 0;
  gf.lowpasswidth		= -1;
  gf.highpasswidth		= -1;
  gf.lowpass1			= 0;
  gf.lowpass2			= 0;
  gf.highpass1		= 0;
  gf.highpass2		= 0;
  gf.lowpass_band		= 32;
  gf.highpass_band		= -1;
  
  gf.no_short_blocks		= 0;
  gf.resample_ratio		= 1;
  gf.padding_type		= 2;
  gf.padding			= 0;
  gf.swapbytes		= 0;
  gf.silent			= 0;
  gf.totalframes		= 0;
  gf.VBR			= 0;
  gf.VBR_q			= 4;
  gf.VBR_min_bitrate_kbps	= 0;
  gf.VBR_max_bitrate_kbps	= 0;
  gf.VBR_min_bitrate		= 1;
  gf.VBR_max_bitrate		= 13;
  
  //修改	
  gf.version			= 1;   /* =1   Default: MPEG-1 */
  gf.in_samplerate		= 44100;
  gf.out_samplerate		= 44100;
  gf.num_channels		= 2;
  
  gf.mode			= 1;
  gf.mode_fixed			= 0;
  gf.force_ms			= 0;
  gf.brate			= 0;
  gf.copyright			= 0;
  gf.original			= 1;
  gf.extension			= 0;
  gf.error_protection		= 0;
  gf.emphasis			= 0;
  gf.num_samples		= 0xFFFFFFFF;
  
  gf.inPath			= NULL;
  gf.outPath			= NULL;
//  id3tag.used			= 0;
  
  //以标准的mp3音频质量格式初始化
  gf.VBR_min_bitrate_kbps	= 32;	//最小位率
  gf.VBR_max_bitrate_kbps	= 256;	//最大位率
  
  gf.brate			= 256;	//正常位率
  gf.lowpassfreq		= -1;
  gf.highpassfreq		= -1;
  gf.VBR_q			=  0;
  gf.VBR_min_bitrate_kbps	= 112;
  gf.VBR_max_bitrate_kbps	= 320;
  gf.mode			= 0; 
  gf.mode_fixed			= 1; 
  gf.quality			= 2;	//质量等级

  gf.inPath="C:\\test\\test.wav";	
  gf.outPath="C:\\test\\test.wav.mp3";	


  if (!gf.gtkflag) {
    /* open the MP3 output file */
    if (!strcmp(gf.outPath, "-")) {
#ifdef __EMX__
      _fsetmode(stdout,"b");
#elif (defined  __BORLANDC__)
      setmode(_fileno(stdout), O_BINARY);
#elif (defined  __CYGWIN__)
      setmode(fileno(stdout), _O_BINARY);
#elif (defined _WIN32)
      _setmode(_fileno(stdout), _O_BINARY);
#endif
      outf = stdout;
    } else {
      if ((outf = fopen(gf.outPath, "wb")) == NULL) {
	fprintf(stderr,"Could not create \"%s\".\n", gf.outPath);
	exit(1);
      }
    }
#ifdef __riscos__
    /* Assign correct file type */
    for (i = 0; gf.outPath[i]; i++)
      if (gf.outPath[i] == '.') gf.outPath[i] = '/';
    SetFiletype(gf.outPath, 0x1ad);
#endif
  }


  /* open the wav/aiff/raw pcm or mp3 input file.  This call will
   * open the file with name gf.inFile, try to parse the headers and
   * set gf.samplerate, gf.num_channels, gf.num_samples.
   * if you want to do your own file input, skip this call and set
   * these values yourself.
   */
  lame_init_infile(&gf);

  /* Now that all the options are set, lame needs to analyze them and
   * set some more options
   */
  lame_init_params(&gf);
 // lame_print_config(&gf);   /* print usefull information about options being used */




#ifdef HAVEGTK
  if (gf.gtkflag) gtk_init (&argc, &argv);
  if (gf.gtkflag) gtkcontrol(&gf);
  else
#endif
    {

      /* encode until we hit eof */
      do {
	/* read in 'iread' samples */
	iread=lame_readframe(&gf,Buffer);


	/* encode */
	imp3=lame_encode_buffer(&gf,Buffer[0],Buffer[1],iread,
              mp3buffer,(int)sizeof(mp3buffer)); 

	/* was our output buffer big enough? */
	if (imp3==-1) {
	  fprintf(stderr,"mp3 buffer is not big enough... \n");
	  exit(1);
	}

	if (fwrite(mp3buffer,1,imp3,outf) != imp3) {
	  fprintf(stderr,"Error writing mp3 output");
	  exit(1);
	}
      } while (iread);
    }

  //imp3=lame_encode_finish(&gf,mp3buffer,(int)sizeof(mp3buffer));   /* may return one more mp3 frame */
  //fwrite(mp3buffer,1,imp3,outf);
  fclose(outf);
  //lame_close_infile(&gf);            /* close the input file */
  //lame_mp3_tags(&gf);                /* add id3 or VBR tags to mp3 file */
  return 0;
}