315 lines
12 KiB
C
315 lines
12 KiB
C
|
/********************************************************************
|
||
|
* *
|
||
|
* THIS FILE IS PART OF THE OggVorbis SOFTWARE CODEC SOURCE CODE. *
|
||
|
* USE, DISTRIBUTION AND REPRODUCTION OF THIS LIBRARY SOURCE IS *
|
||
|
* GOVERNED BY A BSD-STYLE SOURCE LICENSE INCLUDED WITH THIS SOURCE *
|
||
|
* IN 'COPYING'. PLEASE READ THESE TERMS BEFORE DISTRIBUTING. *
|
||
|
* *
|
||
|
* THE OggVorbis SOURCE CODE IS (C) COPYRIGHT 1994-2009 *
|
||
|
* by the Xiph.Org Foundation http://www.xiph.org/ *
|
||
|
* *
|
||
|
********************************************************************
|
||
|
|
||
|
function: simple example decoder
|
||
|
last mod: $Id: decoder_example.c 16243 2009-07-10 02:49:31Z xiphmont $
|
||
|
|
||
|
********************************************************************/
|
||
|
|
||
|
/* Takes a vorbis bitstream from stdin and writes raw stereo PCM to
|
||
|
stdout. Decodes simple and chained OggVorbis files from beginning
|
||
|
to end. Vorbisfile.a is somewhat more complex than the code below. */
|
||
|
|
||
|
/* Note that this is POSIX, not ANSI code */
|
||
|
|
||
|
#include <stdio.h>
|
||
|
#include <stdlib.h>
|
||
|
#include <math.h>
|
||
|
#include <vorbis/codec.h>
|
||
|
|
||
|
#ifdef _WIN32 /* We need the following two to set stdin/stdout to binary */
|
||
|
#include <io.h>
|
||
|
#include <fcntl.h>
|
||
|
#endif
|
||
|
|
||
|
#if defined(__MACOS__) && defined(__MWERKS__)
|
||
|
#include <console.h> /* CodeWarrior's Mac "command-line" support */
|
||
|
#endif
|
||
|
|
||
|
ogg_int16_t convbuffer[4096]; /* take 8k out of the data segment, not the stack */
|
||
|
int convsize=4096;
|
||
|
|
||
|
extern void _VDBG_dump(void);
|
||
|
|
||
|
int main(){
|
||
|
ogg_sync_state oy; /* sync and verify incoming physical bitstream */
|
||
|
ogg_stream_state os; /* take physical pages, weld into a logical
|
||
|
stream of packets */
|
||
|
ogg_page og; /* one Ogg bitstream page. Vorbis packets are inside */
|
||
|
ogg_packet op; /* one raw packet of data for decode */
|
||
|
|
||
|
vorbis_info vi; /* struct that stores all the static vorbis bitstream
|
||
|
settings */
|
||
|
vorbis_comment vc; /* struct that stores all the bitstream user comments */
|
||
|
vorbis_dsp_state vd; /* central working state for the packet->PCM decoder */
|
||
|
vorbis_block vb; /* local working space for packet->PCM decode */
|
||
|
|
||
|
char *buffer;
|
||
|
int bytes;
|
||
|
|
||
|
#ifdef _WIN32 /* 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 defined(macintosh) && defined(__MWERKS__)
|
||
|
{
|
||
|
int argc;
|
||
|
char **argv;
|
||
|
argc=ccommand(&argv); /* get a "command line" from the Mac user */
|
||
|
/* this also lets the user set stdin and stdout */
|
||
|
}
|
||
|
#endif
|
||
|
|
||
|
/********** Decode setup ************/
|
||
|
|
||
|
ogg_sync_init(&oy); /* Now we can read pages */
|
||
|
|
||
|
while(1){ /* we repeat if the bitstream is chained */
|
||
|
int eos=0;
|
||
|
int i;
|
||
|
|
||
|
/* grab some data at the head of the stream. We want the first page
|
||
|
(which is guaranteed to be small and only contain the Vorbis
|
||
|
stream initial header) We need the first page to get the stream
|
||
|
serialno. */
|
||
|
|
||
|
/* submit a 4k block to libvorbis' Ogg layer */
|
||
|
buffer=ogg_sync_buffer(&oy,4096);
|
||
|
bytes=fread(buffer,1,4096,stdin);
|
||
|
ogg_sync_wrote(&oy,bytes);
|
||
|
|
||
|
/* Get the first page. */
|
||
|
if(ogg_sync_pageout(&oy,&og)!=1){
|
||
|
/* have we simply run out of data? If so, we're done. */
|
||
|
if(bytes<4096)break;
|
||
|
|
||
|
/* error case. Must not be Vorbis data */
|
||
|
fprintf(stderr,"Input does not appear to be an Ogg bitstream.\n");
|
||
|
exit(1);
|
||
|
}
|
||
|
|
||
|
/* Get the serial number and set up the rest of decode. */
|
||
|
/* serialno first; use it to set up a logical stream */
|
||
|
ogg_stream_init(&os,ogg_page_serialno(&og));
|
||
|
|
||
|
/* extract the initial header from the first page and verify that the
|
||
|
Ogg bitstream is in fact Vorbis data */
|
||
|
|
||
|
/* I handle the initial header first instead of just having the code
|
||
|
read all three Vorbis headers at once because reading the initial
|
||
|
header is an easy way to identify a Vorbis bitstream and it's
|
||
|
useful to see that functionality seperated out. */
|
||
|
|
||
|
vorbis_info_init(&vi);
|
||
|
vorbis_comment_init(&vc);
|
||
|
if(ogg_stream_pagein(&os,&og)<0){
|
||
|
/* error; stream version mismatch perhaps */
|
||
|
fprintf(stderr,"Error reading first page of Ogg bitstream data.\n");
|
||
|
exit(1);
|
||
|
}
|
||
|
|
||
|
if(ogg_stream_packetout(&os,&op)!=1){
|
||
|
/* no page? must not be vorbis */
|
||
|
fprintf(stderr,"Error reading initial header packet.\n");
|
||
|
exit(1);
|
||
|
}
|
||
|
|
||
|
if(vorbis_synthesis_headerin(&vi,&vc,&op)<0){
|
||
|
/* error case; not a vorbis header */
|
||
|
fprintf(stderr,"This Ogg bitstream does not contain Vorbis "
|
||
|
"audio data.\n");
|
||
|
exit(1);
|
||
|
}
|
||
|
|
||
|
/* At this point, we're sure we're Vorbis. We've set up the logical
|
||
|
(Ogg) bitstream decoder. Get the comment and codebook headers and
|
||
|
set up the Vorbis decoder */
|
||
|
|
||
|
/* The next two packets in order are the comment and codebook headers.
|
||
|
They're likely large and may span multiple pages. Thus we read
|
||
|
and submit data until we get our two packets, watching that no
|
||
|
pages are missing. If a page is missing, error out; losing a
|
||
|
header page is the only place where missing data is fatal. */
|
||
|
|
||
|
i=0;
|
||
|
while(i<2){
|
||
|
while(i<2){
|
||
|
int result=ogg_sync_pageout(&oy,&og);
|
||
|
if(result==0)break; /* Need more data */
|
||
|
/* Don't complain about missing or corrupt data yet. We'll
|
||
|
catch it at the packet output phase */
|
||
|
if(result==1){
|
||
|
ogg_stream_pagein(&os,&og); /* we can ignore any errors here
|
||
|
as they'll also become apparent
|
||
|
at packetout */
|
||
|
while(i<2){
|
||
|
result=ogg_stream_packetout(&os,&op);
|
||
|
if(result==0)break;
|
||
|
if(result<0){
|
||
|
/* Uh oh; data at some point was corrupted or missing!
|
||
|
We can't tolerate that in a header. Die. */
|
||
|
fprintf(stderr,"Corrupt secondary header. Exiting.\n");
|
||
|
exit(1);
|
||
|
}
|
||
|
result=vorbis_synthesis_headerin(&vi,&vc,&op);
|
||
|
if(result<0){
|
||
|
fprintf(stderr,"Corrupt secondary header. Exiting.\n");
|
||
|
exit(1);
|
||
|
}
|
||
|
i++;
|
||
|
}
|
||
|
}
|
||
|
}
|
||
|
/* no harm in not checking before adding more */
|
||
|
buffer=ogg_sync_buffer(&oy,4096);
|
||
|
bytes=fread(buffer,1,4096,stdin);
|
||
|
if(bytes==0 && i<2){
|
||
|
fprintf(stderr,"End of file before finding all Vorbis headers!\n");
|
||
|
exit(1);
|
||
|
}
|
||
|
ogg_sync_wrote(&oy,bytes);
|
||
|
}
|
||
|
|
||
|
/* Throw the comments plus a few lines about the bitstream we're
|
||
|
decoding */
|
||
|
{
|
||
|
char **ptr=vc.user_comments;
|
||
|
while(*ptr){
|
||
|
fprintf(stderr,"%s\n",*ptr);
|
||
|
++ptr;
|
||
|
}
|
||
|
fprintf(stderr,"\nBitstream is %d channel, %ldHz\n",vi.channels,vi.rate);
|
||
|
fprintf(stderr,"Encoded by: %s\n\n",vc.vendor);
|
||
|
}
|
||
|
|
||
|
convsize=4096/vi.channels;
|
||
|
|
||
|
/* OK, got and parsed all three headers. Initialize the Vorbis
|
||
|
packet->PCM decoder. */
|
||
|
if(vorbis_synthesis_init(&vd,&vi)==0){ /* central decode state */
|
||
|
vorbis_block_init(&vd,&vb); /* local state for most of the decode
|
||
|
so multiple block decodes can
|
||
|
proceed in parallel. We could init
|
||
|
multiple vorbis_block structures
|
||
|
for vd here */
|
||
|
|
||
|
/* The rest is just a straight decode loop until end of stream */
|
||
|
while(!eos){
|
||
|
while(!eos){
|
||
|
int result=ogg_sync_pageout(&oy,&og);
|
||
|
if(result==0)break; /* need more data */
|
||
|
if(result<0){ /* missing or corrupt data at this page position */
|
||
|
fprintf(stderr,"Corrupt or missing data in bitstream; "
|
||
|
"continuing...\n");
|
||
|
}else{
|
||
|
ogg_stream_pagein(&os,&og); /* can safely ignore errors at
|
||
|
this point */
|
||
|
while(1){
|
||
|
result=ogg_stream_packetout(&os,&op);
|
||
|
|
||
|
if(result==0)break; /* need more data */
|
||
|
if(result<0){ /* missing or corrupt data at this page position */
|
||
|
/* no reason to complain; already complained above */
|
||
|
}else{
|
||
|
/* we have a packet. Decode it */
|
||
|
float **pcm;
|
||
|
int samples;
|
||
|
|
||
|
if(vorbis_synthesis(&vb,&op)==0) /* test for success! */
|
||
|
vorbis_synthesis_blockin(&vd,&vb);
|
||
|
/*
|
||
|
|
||
|
**pcm is a multichannel float vector. In stereo, for
|
||
|
example, pcm[0] is left, and pcm[1] is right. samples is
|
||
|
the size of each channel. Convert the float values
|
||
|
(-1.<=range<=1.) to whatever PCM format and write it out */
|
||
|
|
||
|
while((samples=vorbis_synthesis_pcmout(&vd,&pcm))>0){
|
||
|
int j;
|
||
|
int clipflag=0;
|
||
|
int bout=(samples<convsize?samples:convsize);
|
||
|
|
||
|
/* convert floats to 16 bit signed ints (host order) and
|
||
|
interleave */
|
||
|
for(i=0;i<vi.channels;i++){
|
||
|
ogg_int16_t *ptr=convbuffer+i;
|
||
|
float *mono=pcm[i];
|
||
|
for(j=0;j<bout;j++){
|
||
|
#if 1
|
||
|
int val=floor(mono[j]*32767.f+.5f);
|
||
|
#else /* optional dither */
|
||
|
int val=mono[j]*32767.f+drand48()-0.5f;
|
||
|
#endif
|
||
|
/* might as well guard against clipping */
|
||
|
if(val>32767){
|
||
|
val=32767;
|
||
|
clipflag=1;
|
||
|
}
|
||
|
if(val<-32768){
|
||
|
val=-32768;
|
||
|
clipflag=1;
|
||
|
}
|
||
|
*ptr=val;
|
||
|
ptr+=vi.channels;
|
||
|
}
|
||
|
}
|
||
|
|
||
|
if(clipflag)
|
||
|
fprintf(stderr,"Clipping in frame %ld\n",(long)(vd.sequence));
|
||
|
|
||
|
|
||
|
fwrite(convbuffer,2*vi.channels,bout,stdout);
|
||
|
|
||
|
vorbis_synthesis_read(&vd,bout); /* tell libvorbis how
|
||
|
many samples we
|
||
|
actually consumed */
|
||
|
}
|
||
|
}
|
||
|
}
|
||
|
if(ogg_page_eos(&og))eos=1;
|
||
|
}
|
||
|
}
|
||
|
if(!eos){
|
||
|
buffer=ogg_sync_buffer(&oy,4096);
|
||
|
bytes=fread(buffer,1,4096,stdin);
|
||
|
ogg_sync_wrote(&oy,bytes);
|
||
|
if(bytes==0)eos=1;
|
||
|
}
|
||
|
}
|
||
|
|
||
|
/* ogg_page and ogg_packet structs always point to storage in
|
||
|
libvorbis. They're never freed or manipulated directly */
|
||
|
|
||
|
vorbis_block_clear(&vb);
|
||
|
vorbis_dsp_clear(&vd);
|
||
|
}else{
|
||
|
fprintf(stderr,"Error: Corrupt header during playback initialization.\n");
|
||
|
}
|
||
|
|
||
|
/* clean up this logical bitstream; before exit we see if we're
|
||
|
followed by another [chained] */
|
||
|
|
||
|
ogg_stream_clear(&os);
|
||
|
vorbis_comment_clear(&vc);
|
||
|
vorbis_info_clear(&vi); /* must be called last */
|
||
|
}
|
||
|
|
||
|
/* OK, clean up the framer */
|
||
|
ogg_sync_clear(&oy);
|
||
|
|
||
|
fprintf(stderr,"Done.\n");
|
||
|
return(0);
|
||
|
}
|