ref: 53caf120ea045b1ede35d76d14fdb397da2d4b7a
dir: /examples/opusfile_example.c/
/*For fileno()*/
#if !defined(_POSIX_SOURCE)
# define _POSIX_SOURCE 1
#endif
#include <stdio.h>
#include <stdlib.h>
#include <errno.h>
#include <string.h>
#if defined(_WIN32)
/*We need the following two to set stdin/stdout to binary.*/
# include <io.h>
# include <fcntl.h>
#endif
#include <opus/opusfile.h>
/*Matrices for downmixing from the supported channel counts to stereo.*/
static const float DOWNMIX_MATRIX[8][8][2]={
/*mono*/
{
{1.F,1.F}
},
/*stereo*/
{
{1.F,0.F},{0.F,1.F}
},
/*3.0*/
{
{0.5858F,0.F},{0.4142F,0.4142F},{0,0.5858F}
},
/*quadrophonic*/
{
{0.4226F,0.F},{0,0.4226F},{0.366F,0.2114F},{0.2114F,0.336F}
},
/*5.0*/
{
{0.651F,0.F},{0.46F,0.46F},{0,0.651F},{0.5636F,0.3254F},{0.3254F,0.5636F}
},
/*5.1*/
{
{0.529F,0.F},{0.3741F,0.3741F},{0.F,0.529F},{0.4582F,0.2645F},
{0.2645F,0.4582F},{0.3741F,0.3741F}
},
/*6.1*/
{
{0.4553F,0.F},{0.322F,0.322F},{0.F,0.4553F},{0.3943F,0.2277F},
{0.2277F,0.3943F},{0.2788F,0.2788F},{0.322F,0.322F}
},
/*7.1*/
{
{0.3886F,0.F},{0.2748F,0.2748F},{0.F,0.3886F},{0.3366F,0.1943F},
{0.1943F,0.3366F},{0.3366F,0.1943F},{0.1943F,0.3366F},{0.2748F,0.2748F}
}
};
int main(int _argc,const char **_argv){
OggOpusFile *of;
ogg_int64_t pcm_offset;
ogg_int64_t nsamples;
int ret;
int prev_li;
#if defined(_WIN32)
# undef fileno
# define fileno _fileno
/*We need to set stdin/stdout to binary mode. Damn windows.*/
/*Beware the evil ifdef. We avoid these where we can, but this one we
cannot.
Don't add any more.
You'll probably go to hell if you do.*/
_setmode(fileno(stdin),_O_BINARY);
_setmode(fileno(stdout),_O_BINARY);
#endif
if(_argc!=2){
fprintf(stderr,"Usage: %s <file.opus>\n",_argv[0]);
return EXIT_FAILURE;
}
if(strcmp(_argv[1],"-")==0){
OpusFileCallbacks cb={NULL,NULL,NULL,NULL};
of=op_open_callbacks(op_fdopen(&cb,fileno(stdin),"rb"),&cb,NULL,0,NULL);
}
#if 0
/*For debugging: force a file to not be seekable.*/
else{
OpusFileCallbacks cb={NULL,NULL,NULL,NULL};
void *fp;
fp=op_fopen(&cb,_argv[1],"rb");
cb.seek=NULL;
cb.tell=NULL;
of=op_open_callbacks(fp,&cb,NULL,0,NULL);
}
#else
else of=op_open_file(_argv[1],NULL);
#endif
if(of==NULL){
fprintf(stderr,"Failed to open file '%s'.\n",_argv[1]);
return EXIT_FAILURE;
}
if(op_seekable(of)){
ogg_int64_t duration;
fprintf(stderr,"Total number of links: %i\n",op_link_count(of));
duration=op_pcm_total(of,-1);
fprintf(stderr,"Total duration: %f seconds (%li samples @ 48 kHz).\n",
duration/48000.0,(long)duration);
}
prev_li=-1;
nsamples=0;
pcm_offset=op_pcm_tell(of);
if(pcm_offset!=0){
fprintf(stderr,"Non-zero starting PCM offset: %li\n",(long)pcm_offset);
}
for(;;){
ogg_int64_t next_pcm_offset;
float pcm[120*48*8];
float stereo_pcm[120*48*2];
int nchannels;
int li;
int i;
ret=op_read_float(of,pcm,sizeof(pcm)/sizeof(*pcm),&li);
if(ret<0){
fprintf(stderr,"Error decoding '%s': %i\n",_argv[1],ret);
ret=EXIT_FAILURE;
break;
}
if(li!=prev_li){
const OpusHead *head;
const OpusTags *tags;
int ci;
/*We found a new link.
Print out some information.*/
fprintf(stderr,"Decoding link %i:\n",li);
head=op_head(of,li);
fprintf(stderr," Channels: %i\n",head->channel_count);
if(op_seekable(of)){
ogg_int64_t duration;
duration=op_pcm_total(of,li);
fprintf(stderr," Duration: %f seconds (%li samples @ 48 kHz).\n",
duration/48000.0,(long)duration);
}
if(head->input_sample_rate){
fprintf(stderr," Original sampling rate: %lu Hz\n",
(unsigned long)head->input_sample_rate);
}
tags=op_tags(of,li);
fprintf(stderr," Encoded by: %s\n",tags->vendor);
for(ci=0;ci<tags->comments;ci++){
fprintf(stderr," %s\n",tags->user_comments[ci]);
}
fprintf(stderr,"\n");
if(!op_seekable(of)){
pcm_offset=op_pcm_tell(of)-ret;
if(pcm_offset!=0){
fprintf(stderr,"Non-zero starting PCM offset in link %i: %li\n",
li,(long)pcm_offset);
}
}
}
next_pcm_offset=op_pcm_tell(of);
if(pcm_offset+ret!=next_pcm_offset){
fprintf(stderr,"PCM offset gap! %li+%i!=%li\n",
(long)pcm_offset,ret,(long)next_pcm_offset);
}
pcm_offset=next_pcm_offset;
if(ret<=0){
ret=EXIT_SUCCESS;
break;
}
/*Downmix to stereo so we can have a consistent output format.*/
nchannels=op_channel_count(of,li);
if(nchannels<0||nchannels>8){
fprintf(stderr,"Unsupported channel count: %i\n",nchannels);
ret=EXIT_FAILURE;
break;
}
for(i=0;i<ret;i++){
float l;
float r;
int ci;
l=r=0.F;
for(ci=0;ci<nchannels;ci++){
l+=DOWNMIX_MATRIX[nchannels-1][ci][0]*pcm[i*nchannels+ci];
r+=DOWNMIX_MATRIX[nchannels-1][ci][1]*pcm[i*nchannels+ci];
}
stereo_pcm[2*i+0]=l;
stereo_pcm[2*i+1]=r;
}
if(!fwrite(stereo_pcm,sizeof(*stereo_pcm)*2,ret,stdout)){
fprintf(stderr,"Error writing decoded audio data: %s\n",strerror(errno));
ret=EXIT_FAILURE;
break;
}
nsamples+=ret;
prev_li=li;
}
op_free(of);
if(ret==EXIT_SUCCESS){
fprintf(stderr,"Done (played %li samples).\n",(long)nsamples);
}
return ret;
}