mp3rtp.c

MPEG-4编解码的实现(包括MPEG4视音频编解码)

#include <stdlib.h>
#include <string.h>
#include <time.h>
#include <unistd.h>
#include "lame.h"
#include "rtp.h"


/*

encode (via LAME) to mp3 with RTP streaming of the output.

Author:  Felix von Leitner <[e-mail]>

mp3rtp  ip:port:ttl  [lame encoding options]  infile outfile

example:

arecord -b 16 -s 22050 -w | ./mp3rtp 224.17.23.42:5004:2 -b 56 - /dev/null



*/


struct rtpheader RTPheader;
struct sockaddr_in rtpsi;
int rtpsocket;

void rtp_output(char *mp3buffer,int mp3size)
{
  sendrtp(rtpsocket,&rtpsi,&RTPheader,mp3buffer,mp3size);
  RTPheader.timestamp+=5;
  RTPheader.b.sequence++;
}

void rtp_usage(void) {
    fprintf(stderr,"usage: mp3rtp ip:port:ttl  [encoder options] <infile> <outfile>\n");
    exit(1);
}



char mp3buffer[LAME_MAXMP3BUFFER];


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


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

  int i,port,ttl;
  char *tmp,*Arg;
  lame_global_flags gf;
  int iread,imp3;
  FILE *outf;
  short int Buffer[2][1152];

  if(argc<=2) {
    rtp_usage();
    exit(1);
  }

  /* process args */
  Arg = argv[1];
  tmp=strchr(Arg,':');

  if (!tmp) {
    rtp_usage();
    exit(1);
  }
  *tmp++=0;
  port=atoi(tmp);
  if (port<=0) {
    rtp_usage();
    exit(1);
  }
  tmp=strchr(tmp,':');
  if (!tmp) {
    rtp_usage();
    exit(1);
  }
  *tmp++=0;
  ttl=atoi(tmp);
  if (tmp<=0) {
    rtp_usage();
    exit(1);
  }
  rtpsocket=makesocket(Arg,port,ttl,&rtpsi);
  srand(getpid() ^ time(0));
  initrtp(&RTPheader);


  /* initialize encoder */
  lame_init(&gf);

  /* Remove the argumets that are rtp related, and then 
   * parse the command line arguments, setting various flags in the
   * struct pointed to by '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)
   */
  for (i=1; i<argc-1; i++)  /* remove first argument, it was for rtp */
    argv[i]=argv[i+1];
  lame_parse_args(&gf,argc-1, argv); 

  /* open the output file.  Filename parsed into gf.inPath */
  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);
    }
  }


  /* 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 */

  /* encode until we hit eof */
  do {
    /* read in 'iread' samples */
    iread=lame_readframe(&gf,Buffer);
    /* encode the frame */
    imp3=lame_encode_buffer(&gf,Buffer[0],Buffer[1],iread,
			    mp3buffer,sizeof(mp3buffer));
    fwrite(mp3buffer,1,imp3,outf);       /* write the MP3 output to file  */
    rtp_output(mp3buffer,imp3);          /* write MP3 output to RTP port */    
  } while (iread);
  

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