libmpg123: mpglib.c Source File

00001 /*
00002         mpglib: test program for libmpg123, in the style of the legacy mpglib test program
00003 
00004         copyright 2007 by the mpg123 project - free software under the terms of the LGPL 2.1
00005         see COPYING and AUTHORS files in distribution or http://mpg123.org
00006         initially written by Thomas Orgis
00007 */
00008 
00009 #include <mpg123.h>
00010 
00011 /* unistd.h is not available under MSVC, 
00012  io.h defines the read and write functions */
00013 #ifndef _MSC_VER
00014 #include <unistd.h>
00015 #else
00016 #include <io.h>
00017 #endif
00018 
00019 #include <stdio.h>
00020 
00021 #define INBUFF  16384
00022 #define OUTBUFF 32768 
00023 
00024 int main(int argc, char **argv)
00025 {
00026         size_t size;
00027         unsigned char buf[INBUFF];  /* input buffer  */
00028         unsigned char out[OUTBUFF]; /* output buffer */
00029         ssize_t len;
00030         int ret;
00031         size_t in = 0, outc = 0;
00032         mpg123_handle *m;
00033 
00034         mpg123_init();
00035         m = mpg123_new(argc > 1 ? argv[1] : NULL, &ret);
00036         if(m == NULL)
00037         {
00038                 fprintf(stderr,"Unable to create mpg123 handle: %s\n", mpg123_plain_strerror(ret));
00039                 return -1;
00040         }
00041         mpg123_param(m, MPG123_VERBOSE, 2, 0); /* Brabble a bit about the parsing/decoding. */
00042 
00043         /* Now mpg123 is being prepared for feeding. The main loop will read chunks from stdin and feed them to mpg123;
00044            then take decoded data as available to write to stdout. */
00045         mpg123_open_feed(m);
00046         if(m == NULL) return -1;
00047 
00048         fprintf(stderr, "Feed me some MPEG audio to stdin, I will decode to stdout.\n");
00049         while(1) /* Read and write until everything is through. */
00050         {
00051                 len = read(0,buf,INBUFF);
00052                 if(len <= 0)
00053                 {
00054                         fprintf(stderr, "input data end\n");
00055                         break;
00056                 }
00057                 in += len;
00058                 /* Feed input chunk and get first chunk of decoded audio. */
00059                 ret = mpg123_decode(m,buf,len,out,OUTBUFF,&size);
00060                 if(ret == MPG123_NEW_FORMAT)
00061                 {
00062                         long rate;
00063                         int channels, enc;
00064                         mpg123_getformat(m, &rate, &channels, &enc);
00065                         fprintf(stderr, "New format: %li Hz, %i channels, encoding value %i\n", rate, channels, enc);
00066                 }
00067                 write(1,out,size);
00068                 outc += size;
00069                 while(ret != MPG123_ERR && ret != MPG123_NEED_MORE)
00070                 { /* Get all decoded audio that is available now before feeding more input. */
00071                         ret = mpg123_decode(m,NULL,0,out,OUTBUFF,&size);
00072                         write(1,out,size);
00073                         outc += size;
00074                 }
00075                 if(ret == MPG123_ERR){ fprintf(stderr, "some error: %s", mpg123_strerror(m)); break; }
00076         }
00077         fprintf(stderr, "%lu bytes in, %lu bytes out\n", (unsigned long)in, (unsigned long)outc);
00078 
00079         /* Done decoding, now just clean up and leave. */
00080         mpg123_delete(m);
00081         mpg123_exit();
00082         return 0;
00083 }