/* we no longer preload all vorbis_info (and the associated
codec_setup) structs. Call this to seek and fetch the info from
the bitstream, if needed */
static int _set_link_number(OggVorbis_File *vf,int link){
if(link != vf->current_link) _decode_clear(vf);
if(vf->ready_state<STREAMSET){
_seek_helper(vf,vf->offsets[link]);
ogg_stream_reset_serialno(vf->os,vf->serialnos[link]);
vf->current_serialno=vf->serialnos[link];
vf->current_link=link;
return _fetch_headers(vf,&vf->vi,&vf->vc,&vf->current_serialno,NULL);
}
return 0;
}
/* this is void and does not propogate errors up because we want to be
able to open and use damaged bitstreams as well as we can. Just
watch out for missing information for links in the OggVorbis_File
struct */
static void _prefetch_all_headers(OggVorbis_File *vf, long dataoffset){
ogg_page og;
int i,ret;
vf->vi=(vorbis_info *)_ogg_realloc(vf->vi,vf->links*sizeof(*vf->vi));
vf->vc=(vorbis_comment *)_ogg_realloc(vf->vc,vf->links*sizeof(*vf->vc));
vf->dataoffsets=(ogg_int64_t *)_ogg_malloc(vf->links*sizeof(*vf->dataoffsets));
vf->pcmlengths=(ogg_int64_t *)_ogg_malloc(vf->links*sizeof(*vf->pcmlengths));
vf->serialnos=(long *)_ogg_malloc(vf->links*sizeof(*vf->serialnos));
for(i=0;i<vf->links;i++){
if(i==0){
/* we already grabbed the initial header earlier. Just set the offset */
vf->dataoffsets[i]=dataoffset;
}else{
/* seek to the location of the initial header */
_seek_helper(vf,vf->offsets[i]);
if(_fetch_headers(vf,vf->vi+i,vf->vc+i,NULL,NULL)<0){
vf->dataoffsets[i]=-1;
}else{
vf->dataoffsets[i]=vf->offset;
ogg_stream_clear(&vf->os);
}
}
/* get the serial number and PCM length of this link. To do this,
get the last page of the stream */
{
long end=vf->offsets[i+1];
_seek_helper(vf,end);
while(1){
ret=_get_prev_page(vf,&og);
if(ret<0){
/* this should not be possible */
vorbis_info_clear(vf->vi+i);
vorbis_comment_clear(vf->vc+i);
break;
}
if(ogg_page_granulepos(&og)!=-1){
vf->serialnos[i]=ogg_page_serialno(&og);
vf->pcmlengths[i]=ogg_page_granulepos(&og);
break;
}
vf->offset=ret;
}
}
}
}
static int _ov_open1(void *f,OggVorbis_File *vf,char *initial,
long ibytes, ov_callbacks callbacks){
long offset=(f?callbacks.seek_func(f,0,SEEK_CUR):-1);
int ret;
memset(vf,0,sizeof(*vf));
vf->datasource=f;
vf->callbacks = callbacks;
/* init the framing state */
ogg_sync_init(&vf->oy);
/* perhaps some data was previously read into a buffer for testing
against other stream types. Allow initialization from this
previously read data (as we may be reading from a non-seekable
stream) */
if(initial){
char *buffer=ogg_sync_buffer(&vf->oy,ibytes);
memcpy(buffer,initial,ibytes);
ogg_sync_wrote(&vf->oy,ibytes);
}
/* can we seek? Stevens suggests the seek test was portable */
if(offset!=-1)vf->seekable=1;
/* No seeking yet; Set up a 'single' (current) logical bitstream
entry for partial open */
vf->links=1;
vf->vi=(vorbis_info *)_ogg_calloc(vf->links,sizeof(*vf->vi));
vf->vc=(vorbis_comment *)_ogg_calloc(vf->links,sizeof(*vf->vc));
/* Try to fetch the headers, maintaining all the storage */
if((ret=_fetch_headers(vf,vf->vi,vf->vc,&vf->current_serialno,NULL))<0){
vf->datasource=NULL;
ov_clear(vf);
}else if(vf->ready_state < PARTOPEN)
vf->ready_state=PARTOPEN;
return(ret);
}
/* this is void and does not propogate errors up because we want to be
able to open and use damaged bitstreams as well as we can. Just
watch out for missing information for links in the OggVorbis_File
struct */
static void _prefetch_all_headers(OggVorbis_File *vf, ogg_int64_t dataoffset){
ogg_page og={0,0,0,0};
int i;
ogg_int64_t ret;
vf->vi=_ogg_realloc(vf->vi,vf->links*sizeof(*vf->vi));
vf->vc=_ogg_realloc(vf->vc,vf->links*sizeof(*vf->vc));
vf->dataoffsets=_ogg_malloc(vf->links*sizeof(*vf->dataoffsets));
vf->pcmlengths=_ogg_malloc(vf->links*2*sizeof(*vf->pcmlengths));
for(i=0;i<vf->links;i++){
if(i==0){
/* we already grabbed the initial header earlier. Just set the offset */
vf->dataoffsets[i]=dataoffset;
_seek_helper(vf,dataoffset);
}else{
/* seek to the location of the initial header */
_seek_helper(vf,vf->offsets[i]);
if(_fetch_headers(vf,vf->vi+i,vf->vc+i,NULL,NULL)<0){
vf->dataoffsets[i]=-1;
}else{
vf->dataoffsets[i]=vf->offset;
}
}
/* fetch beginning PCM offset */
if(vf->dataoffsets[i]!=-1){
ogg_int64_t accumulated=0,pos;
long lastblock=-1;
int result;
ogg_stream_reset_serialno(vf->os,vf->serialnos[i]);
while(1){
ogg_packet op={0,0,0,0,0,0};
ret=_get_next_page(vf,&og,-1);
if(ret<0)
/* this should not be possible unless the file is
truncated/mangled */
break;
if(ogg_page_serialno(&og)!=vf->serialnos[i])
break;
pos=ogg_page_granulepos(&og);
/* count blocksizes of all frames in the page */
ogg_stream_pagein(vf->os,&og);
while((result=ogg_stream_packetout(vf->os,&op))){
if(result>0){ /* ignore holes */
long thisblock=vorbis_packet_blocksize(vf->vi+i,&op);
if(lastblock!=-1)
accumulated+=(lastblock+thisblock)>>2;
lastblock=thisblock;
}
}
ogg_packet_release(&op);
if(pos!=-1){
/* pcm offset of last packet on the first audio page */
accumulated= pos-accumulated;
break;
}
}
/* less than zero? This is a stream with samples trimmed off
the beginning, a normal occurrence; set the offset to zero */
if(accumulated<0)accumulated=0;
vf->pcmlengths[i*2]=accumulated;
}
static int _process_packet(OggVorbis_File *vf,int readp){
ogg_page og;
/* handle one packet. Try to fetch it from current stream state */
/* extract packets from page */
while(1){
/* process a packet if we can. If the machine isn't loaded,
neither is a page */
if(vf->ready_state==INITSET){
while(1) {
ogg_packet op;
int result=ogg_stream_packetout(&vf->os,&op);
ogg_int64_t granulepos;
if(result==-1)return(OV_HOLE); /* hole in the data. */
if(result>0){
/* got a packet. process it */
granulepos=op.granulepos;
if(!vorbis_synthesis(&vf->vb,&op)){ /* lazy check for lazy
header handling. The
header packets aren't
audio, so if/when we
submit them,
vorbis_synthesis will
reject them */
/* suck in the synthesis data and track bitrate */
{
int oldsamples=vorbis_synthesis_pcmout(&vf->vd,NULL);
vorbis_synthesis_blockin(&vf->vd,&vf->vb);
vf->samptrack+=vorbis_synthesis_pcmout(&vf->vd,NULL)-oldsamples;
vf->bittrack+=op.bytes*8;
}
/* update the pcm offset. */
if(granulepos!=-1 && !op.e_o_s){
int link=(vf->seekable?vf->current_link:0);
int i,samples;
/* this packet has a pcm_offset on it (the last packet
completed on a page carries the offset) After processing
(above), we know the pcm position of the *last* sample
ready to be returned. Find the offset of the *first*
As an aside, this trick is inaccurate if we begin
reading anew right at the last page; the end-of-stream
granulepos declares the last frame in the stream, and the
last packet of the last page may be a partial frame.
So, we need a previous granulepos from an in-sequence page
to have a reference point. Thus the !op.e_o_s clause
above */
samples=vorbis_synthesis_pcmout(&vf->vd,NULL);
granulepos-=samples;
for(i=0;i<link;i++)
granulepos+=vf->pcmlengths[i];
vf->pcm_offset=granulepos;
}
return(1);
}
}
else
break;
}
}
if(vf->ready_state>=OPENED){
if(!readp)return(0);
if(_get_next_page(vf,&og,-1)<0)return(OV_EOF); /* eof.
leave unitialized */
/* bitrate tracking; add the header's bytes here, the body bytes
are done by packet above */
vf->bittrack+=og.header_len*8;
/* has our decoding just traversed a bitstream boundary? */
if(vf->ready_state==INITSET){
if(vf->current_serialno!=ogg_page_serialno(&og)){
_decode_clear(vf);
if(!vf->seekable){
vorbis_info_clear(vf->vi);
vorbis_comment_clear(vf->vc);
}
}
}
}
/* Do we need to load a new machine before submitting the page? */
/* This is different in the seekable and non-seekable cases.
In the seekable case, we already have all the header
information loaded and cached; we just initialize the machine
with it and continue on our merry way.
In the non-seekable (streaming) case, we'll only be at a
boundary if we just left the previous logical bitstream and
we're now nominally at the header of the next bitstream
*/
if(vf->ready_state!=INITSET){
int link;
if(vf->ready_state<STREAMSET){
if(vf->seekable){
vf->current_serialno=ogg_page_serialno(&og);
/* match the serialno to bitstream section. We use this rather than
offset positions to avoid problems near logical bitstream
boundaries */
for(link=0;link<vf->links;link++)
if(vf->serialnos[link]==vf->current_serialno)break;
if(link==vf->links)return(OV_EBADLINK); /* sign of a bogus
stream. error out,
leave machine
uninitialized */
vf->current_link=link;
ogg_stream_init(&vf->os,vf->current_serialno);
ogg_stream_reset(&vf->os);
vf->ready_state=STREAMSET;
}else{
/* we're streaming */
/* fetch the three header packets, build the info struct */
int ret=_fetch_headers(vf,vf->vi,vf->vc,&vf->current_serialno,&og);
if(ret)return(ret);
vf->current_link++;
link=0;
}
}
_make_decode_ready(vf);
}
ogg_stream_pagein(&vf->os,&og);
}
}
