--- /dev/null Thu Jan 01 00:00:00 1970 +0000
+++ b/misc/libtremor/tremor/vorbisfile.c Sun Oct 09 20:41:17 2011 +0200
@@ -0,0 +1,1586 @@
+/********************************************************************
+ * *
+ * THIS FILE IS PART OF THE OggVorbis 'TREMOR' 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 'TREMOR' SOURCE CODE IS (C) COPYRIGHT 1994-2003 *
+ * BY THE Xiph.Org FOUNDATION http://www.xiph.org/ *
+ * *
+ ********************************************************************
+
+ function: stdio-based convenience library for opening/seeking/decoding
+ last mod: $Id: vorbisfile.c,v 1.6 2003/03/30 23:40:56 xiphmont Exp $
+
+ ********************************************************************/
+
+#include <stdlib.h>
+#include <stdio.h>
+#include <errno.h>
+#include <string.h>
+#include <math.h>
+
+#include "ivorbiscodec.h"
+#include "ivorbisfile.h"
+
+#include "misc.h"
+
+/* A 'chained bitstream' is a Vorbis bitstream that contains more than
+ one logical bitstream arranged end to end (the only form of Ogg
+ multiplexing allowed in a Vorbis bitstream; grouping [parallel
+ multiplexing] is not allowed in Vorbis) */
+
+/* A Vorbis file can be played beginning to end (streamed) without
+ worrying ahead of time about chaining (see decoder_example.c). If
+ we have the whole file, however, and want random access
+ (seeking/scrubbing) or desire to know the total length/time of a
+ file, we need to account for the possibility of chaining. */
+
+/* We can handle things a number of ways; we can determine the entire
+ bitstream structure right off the bat, or find pieces on demand.
+ This example determines and caches structure for the entire
+ bitstream, but builds a virtual decoder on the fly when moving
+ between links in the chain. */
+
+/* There are also different ways to implement seeking. Enough
+ information exists in an Ogg bitstream to seek to
+ sample-granularity positions in the output. Or, one can seek by
+ picking some portion of the stream roughly in the desired area if
+ we only want coarse navigation through the stream. */
+
+/*************************************************************************
+ * Many, many internal helpers. The intention is not to be confusing;
+ * rampant duplication and monolithic function implementation would be
+ * harder to understand anyway. The high level functions are last. Begin
+ * grokking near the end of the file */
+
+
+/* read a little more data from the file/pipe into the ogg_sync framer */
+static long _get_data(OggVorbis_File *vf){
+ errno=0;
+ if(vf->datasource){
+ unsigned char *buffer=ogg_sync_bufferin(vf->oy,CHUNKSIZE);
+ long bytes=(vf->callbacks.read_func)(buffer,1,CHUNKSIZE,vf->datasource);
+ if(bytes>0)ogg_sync_wrote(vf->oy,bytes);
+ if(bytes==0 && errno)return(-1);
+ return(bytes);
+ }else
+ return(0);
+}
+
+/* save a tiny smidge of verbosity to make the code more readable */
+static void _seek_helper(OggVorbis_File *vf,ogg_int64_t offset){
+ if(vf->datasource){
+ (vf->callbacks.seek_func)(vf->datasource, offset, SEEK_SET);
+ vf->offset=offset;
+ ogg_sync_reset(vf->oy);
+ }else{
+ /* shouldn't happen unless someone writes a broken callback */
+ return;
+ }
+}
+
+/* The read/seek functions track absolute position within the stream */
+
+/* from the head of the stream, get the next page. boundary specifies
+ if the function is allowed to fetch more data from the stream (and
+ how much) or only use internally buffered data.
+
+ boundary: -1) unbounded search
+ 0) read no additional data; use cached only
+ n) search for a new page beginning for n bytes
+
+ return: <0) did not find a page (OV_FALSE, OV_EOF, OV_EREAD)
+ n) found a page at absolute offset n
+
+ produces a refcounted page */
+
+static ogg_int64_t _get_next_page(OggVorbis_File *vf,ogg_page *og,
+ ogg_int64_t boundary){
+ if(boundary>0)boundary+=vf->offset;
+ while(1){
+ long more;
+
+ if(boundary>0 && vf->offset>=boundary)return(OV_FALSE);
+ more=ogg_sync_pageseek(vf->oy,og);
+
+ if(more<0){
+ /* skipped n bytes */
+ vf->offset-=more;
+ }else{
+ if(more==0){
+ /* send more paramedics */
+ if(!boundary)return(OV_FALSE);
+ {
+ long ret=_get_data(vf);
+ if(ret==0)return(OV_EOF);
+ if(ret<0)return(OV_EREAD);
+ }
+ }else{
+ /* got a page. Return the offset at the page beginning,
+ advance the internal offset past the page end */
+ ogg_int64_t ret=vf->offset;
+ vf->offset+=more;
+ return(ret);
+
+ }
+ }
+ }
+}
+
+/* find the latest page beginning before the current stream cursor
+ position. Much dirtier than the above as Ogg doesn't have any
+ backward search linkage. no 'readp' as it will certainly have to
+ read. */
+/* returns offset or OV_EREAD, OV_FAULT and produces a refcounted page */
+
+static ogg_int64_t _get_prev_page(OggVorbis_File *vf,ogg_page *og){
+ ogg_int64_t begin=vf->offset;
+ ogg_int64_t end=begin;
+ ogg_int64_t ret;
+ ogg_int64_t offset=-1;
+
+ while(offset==-1){
+ begin-=CHUNKSIZE;
+ if(begin<0)
+ begin=0;
+ _seek_helper(vf,begin);
+ while(vf->offset<end){
+ ret=_get_next_page(vf,og,end-vf->offset);
+ if(ret==OV_EREAD)return(OV_EREAD);
+ if(ret<0){
+ break;
+ }else{
+ offset=ret;
+ }
+ }
+ }
+
+ /* we have the offset. Actually snork and hold the page now */
+ _seek_helper(vf,offset);
+ ret=_get_next_page(vf,og,CHUNKSIZE);
+ if(ret<0)
+ /* this shouldn't be possible */
+ return(OV_EFAULT);
+
+ return(offset);
+}
+
+/* finds each bitstream link one at a time using a bisection search
+ (has to begin by knowing the offset of the lb's initial page).
+ Recurses for each link so it can alloc the link storage after
+ finding them all, then unroll and fill the cache at the same time */
+static int _bisect_forward_serialno(OggVorbis_File *vf,
+ ogg_int64_t begin,
+ ogg_int64_t searched,
+ ogg_int64_t end,
+ ogg_uint32_t currentno,
+ long m){
+ ogg_int64_t endsearched=end;
+ ogg_int64_t next=end;
+ ogg_page og={0,0,0,0};
+ ogg_int64_t ret;
+
+ /* the below guards against garbage seperating the last and
+ first pages of two links. */
+ while(searched<endsearched){
+ ogg_int64_t bisect;
+
+ if(endsearched-searched<CHUNKSIZE){
+ bisect=searched;
+ }else{
+ bisect=(searched+endsearched)/2;
+ }
+
+ _seek_helper(vf,bisect);
+ ret=_get_next_page(vf,&og,-1);
+ if(ret==OV_EREAD)return(OV_EREAD);
+ if(ret<0 || ogg_page_serialno(&og)!=currentno){
+ endsearched=bisect;
+ if(ret>=0)next=ret;
+ }else{
+ searched=ret+og.header_len+og.body_len;
+ }
+ ogg_page_release(&og);
+ }
+
+ _seek_helper(vf,next);
+ ret=_get_next_page(vf,&og,-1);
+ if(ret==OV_EREAD)return(OV_EREAD);
+
+ if(searched>=end || ret<0){
+ ogg_page_release(&og);
+ vf->links=m+1;
+ vf->offsets=_ogg_malloc((vf->links+1)*sizeof(*vf->offsets));
+ vf->serialnos=_ogg_malloc(vf->links*sizeof(*vf->serialnos));
+ vf->offsets[m+1]=searched;
+ }else{
+ ret=_bisect_forward_serialno(vf,next,vf->offset,
+ end,ogg_page_serialno(&og),m+1);
+ ogg_page_release(&og);
+ if(ret==OV_EREAD)return(OV_EREAD);
+ }
+
+ vf->offsets[m]=begin;
+ vf->serialnos[m]=currentno;
+ return(0);
+}
+
+/* uses the local ogg_stream storage in vf; this is important for
+ non-streaming input sources */
+/* consumes the page that's passed in (if any) */
+
+static int _fetch_headers(OggVorbis_File *vf,
+ vorbis_info *vi,
+ vorbis_comment *vc,
+ ogg_uint32_t *serialno,
+ ogg_page *og_ptr){
+ ogg_page og={0,0,0,0};
+ ogg_packet op={0,0,0,0,0,0};
+ int i,ret;
+
+ if(!og_ptr){
+ ogg_int64_t llret=_get_next_page(vf,&og,CHUNKSIZE);
+ if(llret==OV_EREAD)return(OV_EREAD);
+ if(llret<0)return OV_ENOTVORBIS;
+ og_ptr=&og;
+ }
+
+ ogg_stream_reset_serialno(vf->os,ogg_page_serialno(og_ptr));
+ if(serialno)*serialno=vf->os->serialno;
+ vf->ready_state=STREAMSET;
+
+ /* extract the initial header from the first page and verify that the
+ Ogg bitstream is in fact Vorbis data */
+
+ vorbis_info_init(vi);
+ vorbis_comment_init(vc);
+
+ i=0;
+ while(i<3){
+ ogg_stream_pagein(vf->os,og_ptr);
+ while(i<3){
+ int result=ogg_stream_packetout(vf->os,&op);
+ if(result==0)break;
+ if(result==-1){
+ ret=OV_EBADHEADER;
+ goto bail_header;
+ }
+ if((ret=vorbis_synthesis_headerin(vi,vc,&op))){
+ goto bail_header;
+ }
+ i++;
+ }
+ if(i<3)
+ if(_get_next_page(vf,og_ptr,CHUNKSIZE)<0){
+ ret=OV_EBADHEADER;
+ goto bail_header;
+ }
+ }
+
+ ogg_packet_release(&op);
+ ogg_page_release(&og);
+ return 0;
+
+ bail_header:
+ ogg_packet_release(&op);
+ ogg_page_release(&og);
+ vorbis_info_clear(vi);
+ vorbis_comment_clear(vc);
+ vf->ready_state=OPENED;
+
+ return ret;
+}
+
+/* last step of the OggVorbis_File initialization; get all the
+ vorbis_info structs and PCM positions. Only called by the seekable
+ initialization (local stream storage is hacked slightly; pay
+ attention to how that's done) */
+
+/* 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;
+ }
+
+ /* get the PCM length of this link. To do this,
+ get the last page of the stream */
+ {
+ ogg_int64_t 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->pcmlengths[i*2+1]=ogg_page_granulepos(&og)-vf->pcmlengths[i*2];
+ break;
+ }
+ vf->offset=ret;
+ }
+ }
+ }
+ ogg_page_release(&og);
+}
+
+static void _make_decode_ready(OggVorbis_File *vf){
+ if(vf->ready_state!=STREAMSET)return;
+ if(vf->seekable){
+ vorbis_synthesis_init(&vf->vd,vf->vi+vf->current_link);
+ }else{
+ vorbis_synthesis_init(&vf->vd,vf->vi);
+ }
+ vorbis_block_init(&vf->vd,&vf->vb);
+ vf->ready_state=INITSET;
+ vf->bittrack=0;
+ vf->samptrack=0;
+ return;
+}
+
+static int _open_seekable2(OggVorbis_File *vf){
+ ogg_uint32_t serialno=vf->current_serialno;
+ ogg_uint32_t tempserialno;
+ ogg_int64_t dataoffset=vf->offset, end;
+ ogg_page og={0,0,0,0};
+
+ /* we're partially open and have a first link header state in
+ storage in vf */
+ /* we can seek, so set out learning all about this file */
+ (vf->callbacks.seek_func)(vf->datasource,0,SEEK_END);
+ vf->offset=vf->end=(vf->callbacks.tell_func)(vf->datasource);
+
+ /* We get the offset for the last page of the physical bitstream.
+ Most OggVorbis files will contain a single logical bitstream */
+ end=_get_prev_page(vf,&og);
+ if(end<0)return(end);
+
+ /* more than one logical bitstream? */
+ tempserialno=ogg_page_serialno(&og);
+ ogg_page_release(&og);
+
+ if(tempserialno!=serialno){
+
+ /* Chained bitstream. Bisect-search each logical bitstream
+ section. Do so based on serial number only */
+ if(_bisect_forward_serialno(vf,0,0,end+1,serialno,0)<0)return(OV_EREAD);
+
+ }else{
+
+ /* Only one logical bitstream */
+ if(_bisect_forward_serialno(vf,0,end,end+1,serialno,0))return(OV_EREAD);
+
+ }
+
+ /* the initial header memory is referenced by vf after; don't free it */
+ _prefetch_all_headers(vf,dataoffset);
+ return(ov_raw_seek(vf,0));
+}
+
+/* clear out the current logical bitstream decoder */
+static void _decode_clear(OggVorbis_File *vf){
+ vorbis_dsp_clear(&vf->vd);
+ vorbis_block_clear(&vf->vb);
+ vf->ready_state=OPENED;
+}
+
+/* fetch and process a packet. Handles the case where we're at a
+ bitstream boundary and dumps the decoding machine. If the decoding
+ machine is unloaded, it loads it. It also keeps pcm_offset up to
+ date (seek and read both use this. seek uses a special hack with
+ readp).
+
+ return: <0) error, OV_HOLE (lost packet) or OV_EOF
+ 0) need more data (only if readp==0)
+ 1) got a packet
+*/
+
+static int _fetch_and_process_packet(OggVorbis_File *vf,
+ int readp,
+ int spanp){
+ ogg_page og={0,0,0,0};
+ ogg_packet op={0,0,0,0,0,0};
+ int ret=0;
+
+ /* 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) {
+ int result=ogg_stream_packetout(vf->os,&op);
+ ogg_int64_t granulepos;
+
+ if(result<0){
+ ret=OV_HOLE; /* hole in the data. */
+ goto cleanup;
+ }
+ if(result>0){
+ /* got a packet. process it */
+ granulepos=op.granulepos;
+ if(!vorbis_synthesis(&vf->vb,&op,1)){ /* 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);
+ /* for proper use of libvorbis within libvorbisfile,
+ oldsamples will always be zero. */
+ if(oldsamples){
+ ret=OV_EFAULT;
+ goto cleanup;
+ }
+
+ 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 */
+
+ if(vf->seekable && link>0)
+ granulepos-=vf->pcmlengths[link*2];
+ if(granulepos<0)granulepos=0; /* actually, this
+ shouldn't be possible
+ here unless the stream
+ is very broken */
+
+ samples=vorbis_synthesis_pcmout(&vf->vd,NULL);
+
+ granulepos-=samples;
+ for(i=0;i<link;i++)
+ granulepos+=vf->pcmlengths[i*2+1];
+ vf->pcm_offset=granulepos;
+ }
+ ret=1;
+ goto cleanup;
+ }
+ }
+ else
+ break;
+ }
+ }
+
+ if(vf->ready_state>=OPENED){
+ int ret;
+ if(!readp){
+ ret=0;
+ goto cleanup;
+ }
+ if((ret=_get_next_page(vf,&og,-1))<0){
+ ret=OV_EOF; /* eof. leave unitialized */
+ goto cleanup;
+ }
+
+ /* 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)){
+ if(!spanp){
+ ret=OV_EOF;
+ goto cleanup;
+ }
+
+ _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){
+ ret=OV_EBADLINK; /* sign of a bogus stream. error out,
+ leave machine uninitialized */
+ goto cleanup;
+ }
+
+ vf->current_link=link;
+
+ ogg_stream_reset_serialno(vf->os,vf->current_serialno);
+ 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) goto cleanup;
+ vf->current_link++;
+ link=0;
+ }
+ }
+
+ _make_decode_ready(vf);
+ }
+ ogg_stream_pagein(vf->os,&og);
+ }
+ cleanup:
+ ogg_packet_release(&op);
+ ogg_page_release(&og);
+ return ret;
+}
+
+/* if, eg, 64 bit stdio is configured by default, this will build with
+ fseek64 */
+static int _fseek64_wrap(FILE *f,ogg_int64_t off,int whence){
+ if(f==NULL)return(-1);
+ return fseek(f,off,whence);
+}
+
+static int _ov_open1(void *f,OggVorbis_File *vf,char *initial,
+ long ibytes, ov_callbacks callbacks){
+ int offsettest=(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 */
+ vf->oy=ogg_sync_create();
+
+ /* 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){
+ unsigned char *buffer=ogg_sync_bufferin(vf->oy,ibytes);
+ memcpy(buffer,initial,ibytes);
+ ogg_sync_wrote(vf->oy,ibytes);
+ }
+
+ /* can we seek? Stevens suggests the seek test was portable */
+ if(offsettest!=-1)vf->seekable=1;
+
+ /* No seeking yet; Set up a 'single' (current) logical bitstream
+ entry for partial open */
+ vf->links=1;
+ vf->vi=_ogg_calloc(vf->links,sizeof(*vf->vi));
+ vf->vc=_ogg_calloc(vf->links,sizeof(*vf->vc));
+ vf->os=ogg_stream_create(-1); /* fill in the serialno later */
+
+ /* 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);
+}
+
+static int _ov_open2(OggVorbis_File *vf){
+ if(vf->ready_state < OPENED)
+ vf->ready_state=OPENED;
+ if(vf->seekable){
+ int ret=_open_seekable2(vf);
+ if(ret){
+ vf->datasource=NULL;
+ ov_clear(vf);
+ }
+ return(ret);
+ }
+ return 0;
+}
+
+
+/* clear out the OggVorbis_File struct */
+int ov_clear(OggVorbis_File *vf){
+ if(vf){
+ vorbis_block_clear(&vf->vb);
+ vorbis_dsp_clear(&vf->vd);
+ ogg_stream_destroy(vf->os);
+
+ if(vf->vi && vf->links){
+ int i;
+ for(i=0;i<vf->links;i++){
+ vorbis_info_clear(vf->vi+i);
+ vorbis_comment_clear(vf->vc+i);
+ }
+ _ogg_free(vf->vi);
+ _ogg_free(vf->vc);
+ }
+ if(vf->dataoffsets)_ogg_free(vf->dataoffsets);
+ if(vf->pcmlengths)_ogg_free(vf->pcmlengths);
+ if(vf->serialnos)_ogg_free(vf->serialnos);
+ if(vf->offsets)_ogg_free(vf->offsets);
+ ogg_sync_destroy(vf->oy);
+
+ if(vf->datasource)(vf->callbacks.close_func)(vf->datasource);
+ memset(vf,0,sizeof(*vf));
+ }
+#ifdef DEBUG_LEAKS
+ _VDBG_dump();
+#endif
+ return(0);
+}
+
+/* inspects the OggVorbis file and finds/documents all the logical
+ bitstreams contained in it. Tries to be tolerant of logical
+ bitstream sections that are truncated/woogie.
+
+ return: -1) error
+ 0) OK
+*/
+
+int ov_open_callbacks(void *f,OggVorbis_File *vf,char *initial,long ibytes,
+ ov_callbacks callbacks){
+ int ret=_ov_open1(f,vf,initial,ibytes,callbacks);
+ if(ret)return ret;
+ return _ov_open2(vf);
+}
+
+int ov_open(FILE *f,OggVorbis_File *vf,char *initial,long ibytes){
+ ov_callbacks callbacks = {
+ (size_t (*)(void *, size_t, size_t, void *)) fread,
+ (int (*)(void *, ogg_int64_t, int)) _fseek64_wrap,
+ (int (*)(void *)) fclose,
+ (long (*)(void *)) ftell
+ };
+
+ return ov_open_callbacks((void *)f, vf, initial, ibytes, callbacks);
+}
+
+/* Only partially open the vorbis file; test for Vorbisness, and load
+ the headers for the first chain. Do not seek (although test for
+ seekability). Use ov_test_open to finish opening the file, else
+ ov_clear to close/free it. Same return codes as open. */
+
+int ov_test_callbacks(void *f,OggVorbis_File *vf,char *initial,long ibytes,
+ ov_callbacks callbacks)
+{
+ return _ov_open1(f,vf,initial,ibytes,callbacks);
+}
+
+int ov_test(FILE *f,OggVorbis_File *vf,char *initial,long ibytes){
+ ov_callbacks callbacks = {
+ (size_t (*)(void *, size_t, size_t, void *)) fread,
+ (int (*)(void *, ogg_int64_t, int)) _fseek64_wrap,
+ (int (*)(void *)) fclose,
+ (long (*)(void *)) ftell
+ };
+
+ return ov_test_callbacks((void *)f, vf, initial, ibytes, callbacks);
+}
+
+int ov_test_open(OggVorbis_File *vf){
+ if(vf->ready_state!=PARTOPEN)return(OV_EINVAL);
+ return _ov_open2(vf);
+}
+
+/* How many logical bitstreams in this physical bitstream? */
+long ov_streams(OggVorbis_File *vf){
+ return vf->links;
+}
+
+/* Is the FILE * associated with vf seekable? */
+long ov_seekable(OggVorbis_File *vf){
+ return vf->seekable;
+}
+
+/* returns the bitrate for a given logical bitstream or the entire
+ physical bitstream. If the file is open for random access, it will
+ find the *actual* average bitrate. If the file is streaming, it
+ returns the nominal bitrate (if set) else the average of the
+ upper/lower bounds (if set) else -1 (unset).
+
+ If you want the actual bitrate field settings, get them from the
+ vorbis_info structs */
+
+long ov_bitrate(OggVorbis_File *vf,int i){
+ if(vf->ready_state<OPENED)return(OV_EINVAL);
+ if(i>=vf->links)return(OV_EINVAL);
+ if(!vf->seekable && i!=0)return(ov_bitrate(vf,0));
+ if(i<0){
+ ogg_int64_t bits=0;
+ int i;
+ for(i=0;i<vf->links;i++)
+ bits+=(vf->offsets[i+1]-vf->dataoffsets[i])*8;
+ /* This once read: return(rint(bits/ov_time_total(vf,-1)));
+ * gcc 3.x on x86 miscompiled this at optimisation level 2 and above,
+ * so this is slightly transformed to make it work.
+ */
+ return(bits*1000/ov_time_total(vf,-1));
+ }else{
+ if(vf->seekable){
+ /* return the actual bitrate */
+ return((vf->offsets[i+1]-vf->dataoffsets[i])*8000/ov_time_total(vf,i));
+ }else{
+ /* return nominal if set */
+ if(vf->vi[i].bitrate_nominal>0){
+ return vf->vi[i].bitrate_nominal;
+ }else{
+ if(vf->vi[i].bitrate_upper>0){
+ if(vf->vi[i].bitrate_lower>0){
+ return (vf->vi[i].bitrate_upper+vf->vi[i].bitrate_lower)/2;
+ }else{
+ return vf->vi[i].bitrate_upper;
+ }
+ }
+ return(OV_FALSE);
+ }
+ }
+ }
+}
+
+/* returns the actual bitrate since last call. returns -1 if no
+ additional data to offer since last call (or at beginning of stream),
+ EINVAL if stream is only partially open
+*/
+long ov_bitrate_instant(OggVorbis_File *vf){
+ int link=(vf->seekable?vf->current_link:0);
+ long ret;
+ if(vf->ready_state<OPENED)return(OV_EINVAL);
+ if(vf->samptrack==0)return(OV_FALSE);
+ ret=vf->bittrack/vf->samptrack*vf->vi[link].rate;
+ vf->bittrack=0;
+ vf->samptrack=0;
+ return(ret);
+}
+
+/* Guess */
+long ov_serialnumber(OggVorbis_File *vf,int i){
+ if(i>=vf->links)return(ov_serialnumber(vf,vf->links-1));
+ if(!vf->seekable && i>=0)return(ov_serialnumber(vf,-1));
+ if(i<0){
+ return(vf->current_serialno);
+ }else{
+ return(vf->serialnos[i]);
+ }
+}
+
+/* returns: total raw (compressed) length of content if i==-1
+ raw (compressed) length of that logical bitstream for i==0 to n
+ OV_EINVAL if the stream is not seekable (we can't know the length)
+ or if stream is only partially open
+*/
+ogg_int64_t ov_raw_total(OggVorbis_File *vf,int i){
+ if(vf->ready_state<OPENED)return(OV_EINVAL);
+ if(!vf->seekable || i>=vf->links)return(OV_EINVAL);
+ if(i<0){
+ ogg_int64_t acc=0;
+ int i;
+ for(i=0;i<vf->links;i++)
+ acc+=ov_raw_total(vf,i);
+ return(acc);
+ }else{
+ return(vf->offsets[i+1]-vf->offsets[i]);
+ }
+}
+
+/* returns: total PCM length (samples) of content if i==-1 PCM length
+ (samples) of that logical bitstream for i==0 to n
+ OV_EINVAL if the stream is not seekable (we can't know the
+ length) or only partially open
+*/
+ogg_int64_t ov_pcm_total(OggVorbis_File *vf,int i){
+ if(vf->ready_state<OPENED)return(OV_EINVAL);
+ if(!vf->seekable || i>=vf->links)return(OV_EINVAL);
+ if(i<0){
+ ogg_int64_t acc=0;
+ int i;
+ for(i=0;i<vf->links;i++)
+ acc+=ov_pcm_total(vf,i);
+ return(acc);
+ }else{
+ return(vf->pcmlengths[i*2+1]);
+ }
+}
+
+/* returns: total milliseconds of content if i==-1
+ milliseconds in that logical bitstream for i==0 to n
+ OV_EINVAL if the stream is not seekable (we can't know the
+ length) or only partially open
+*/
+ogg_int64_t ov_time_total(OggVorbis_File *vf,int i){
+ if(vf->ready_state<OPENED)return(OV_EINVAL);
+ if(!vf->seekable || i>=vf->links)return(OV_EINVAL);
+ if(i<0){
+ ogg_int64_t acc=0;
+ int i;
+ for(i=0;i<vf->links;i++)
+ acc+=ov_time_total(vf,i);
+ return(acc);
+ }else{
+ return(((ogg_int64_t)vf->pcmlengths[i*2+1])*1000/vf->vi[i].rate);
+ }
+}
+
+/* seek to an offset relative to the *compressed* data. This also
+ scans packets to update the PCM cursor. It will cross a logical
+ bitstream boundary, but only if it can't get any packets out of the
+ tail of the bitstream we seek to (so no surprises).
+
+ returns zero on success, nonzero on failure */
+
+int ov_raw_seek(OggVorbis_File *vf,ogg_int64_t pos){
+ ogg_stream_state *work_os=NULL;
+ ogg_page og={0,0,0,0};
+ ogg_packet op={0,0,0,0,0,0};
+
+ if(vf->ready_state<OPENED)return(OV_EINVAL);
+ if(!vf->seekable)
+ return(OV_ENOSEEK); /* don't dump machine if we can't seek */
+
+ if(pos<0 || pos>vf->end)return(OV_EINVAL);
+
+ /* don't yet clear out decoding machine (if it's initialized), in
+ the case we're in the same link. Restart the decode lapping, and
+ let _fetch_and_process_packet deal with a potential bitstream
+ boundary */
+ vf->pcm_offset=-1;
+ ogg_stream_reset_serialno(vf->os,
+ vf->current_serialno); /* must set serialno */
+ vorbis_synthesis_restart(&vf->vd);
+
+ _seek_helper(vf,pos);
+
+ /* we need to make sure the pcm_offset is set, but we don't want to
+ advance the raw cursor past good packets just to get to the first
+ with a granulepos. That's not equivalent behavior to beginning
+ decoding as immediately after the seek position as possible.
+
+ So, a hack. We use two stream states; a local scratch state and
+ the shared vf->os stream state. We use the local state to
+ scan, and the shared state as a buffer for later decode.
+
+ Unfortuantely, on the last page we still advance to last packet
+ because the granulepos on the last page is not necessarily on a
+ packet boundary, and we need to make sure the granpos is
+ correct.
+ */
+
+ {
+ int lastblock=0;
+ int accblock=0;
+ int thisblock;
+ int eosflag=0;
+
+ work_os=ogg_stream_create(vf->current_serialno); /* get the memory ready */
+ while(1){
+ if(vf->ready_state>=STREAMSET){
+ /* snarf/scan a packet if we can */
+ int result=ogg_stream_packetout(work_os,&op);
+
+ if(result>0){
+
+ if(vf->vi[vf->current_link].codec_setup){
+ thisblock=vorbis_packet_blocksize(vf->vi+vf->current_link,&op);
+ if(thisblock<0){
+ ogg_stream_packetout(vf->os,NULL);
+ thisblock=0;
+ }else{
+
+ if(eosflag)
+ ogg_stream_packetout(vf->os,NULL);
+ else
+ if(lastblock)accblock+=(lastblock+thisblock)>>2;
+ }
+
+ if(op.granulepos!=-1){
+ int i,link=vf->current_link;
+ ogg_int64_t granulepos=op.granulepos-vf->pcmlengths[link*2];
+ if(granulepos<0)granulepos=0;
+
+ for(i=0;i<link;i++)
+ granulepos+=vf->pcmlengths[i*2+1];
+ vf->pcm_offset=granulepos-accblock;
+ break;
+ }
+ lastblock=thisblock;
+ continue;
+ }else
+ ogg_stream_packetout(vf->os,NULL);
+ }
+ }
+
+ if(!lastblock){
+ if(_get_next_page(vf,&og,-1)<0){
+ vf->pcm_offset=ov_pcm_total(vf,-1);
+ break;
+ }
+ }else{
+ /* huh? Bogus stream with packets but no granulepos */
+ vf->pcm_offset=-1;
+ break;
+ }
+
+ /* has our decoding just traversed a bitstream boundary? */
+ if(vf->ready_state>=STREAMSET)
+ if(vf->current_serialno!=ogg_page_serialno(&og)){
+ _decode_clear(vf); /* clear out stream state */
+ ogg_stream_destroy(work_os);
+ }
+
+ if(vf->ready_state<STREAMSET){
+ int link;
+
+ vf->current_serialno=ogg_page_serialno(&og);
+ for(link=0;link<vf->links;link++)
+ if(vf->serialnos[link]==vf->current_serialno)break;
+ if(link==vf->links)
+ goto seek_error; /* sign of a bogus stream. error out,
+ leave machine uninitialized */
+
+ vf->current_link=link;
+
+ ogg_stream_reset_serialno(vf->os,vf->current_serialno);
+ ogg_stream_reset_serialno(work_os,vf->current_serialno);
+ vf->ready_state=STREAMSET;
+
+ }
+
+ {
+ ogg_page dup;
+ ogg_page_dup(&dup,&og);
+ eosflag=ogg_page_eos(&og);
+ ogg_stream_pagein(vf->os,&og);
+ ogg_stream_pagein(work_os,&dup);
+ }
+ }
+ }
+
+ ogg_packet_release(&op);
+ ogg_page_release(&og);
+ ogg_stream_destroy(work_os);
+ vf->bittrack=0;
+ vf->samptrack=0;
+ return(0);
+
+ seek_error:
+ ogg_packet_release(&op);
+ ogg_page_release(&og);
+
+ /* dump the machine so we're in a known state */
+ vf->pcm_offset=-1;
+ ogg_stream_destroy(work_os);
+ _decode_clear(vf);
+ return OV_EBADLINK;
+}
+
+/* Page granularity seek (faster than sample granularity because we
+ don't do the last bit of decode to find a specific sample).
+
+ Seek to the last [granule marked] page preceeding the specified pos
+ location, such that decoding past the returned point will quickly
+ arrive at the requested position. */
+int ov_pcm_seek_page(OggVorbis_File *vf,ogg_int64_t pos){
+ int link=-1;
+ ogg_int64_t result=0;
+ ogg_int64_t total=ov_pcm_total(vf,-1);
+ ogg_page og={0,0,0,0};
+ ogg_packet op={0,0,0,0,0,0};
+
+ if(vf->ready_state<OPENED)return(OV_EINVAL);
+ if(!vf->seekable)return(OV_ENOSEEK);
+ if(pos<0 || pos>total)return(OV_EINVAL);
+
+ /* which bitstream section does this pcm offset occur in? */
+ for(link=vf->links-1;link>=0;link--){
+ total-=vf->pcmlengths[link*2+1];
+ if(pos>=total)break;
+ }
+
+ /* search within the logical bitstream for the page with the highest
+ pcm_pos preceeding (or equal to) pos. There is a danger here;
+ missing pages or incorrect frame number information in the
+ bitstream could make our task impossible. Account for that (it
+ would be an error condition) */
+
+ /* new search algorithm by HB (Nicholas Vinen) */
+ {
+ ogg_int64_t end=vf->offsets[link+1];
+ ogg_int64_t begin=vf->offsets[link];
+ ogg_int64_t begintime = vf->pcmlengths[link*2];
+ ogg_int64_t endtime = vf->pcmlengths[link*2+1]+begintime;
+ ogg_int64_t target=pos-total+begintime;
+ ogg_int64_t best=begin;
+
+ while(begin<end){
+ ogg_int64_t bisect;
+
+ if(end-begin<CHUNKSIZE){
+ bisect=begin;
+ }else{
+ /* take a (pretty decent) guess. */
+ bisect=begin +
+ (target-begintime)*(end-begin)/(endtime-begintime) - CHUNKSIZE;
+ if(bisect<=begin)
+ bisect=begin+1;
+ }
+
+ _seek_helper(vf,bisect);
+
+ while(begin<end){
+ result=_get_next_page(vf,&og,end-vf->offset);
+ if(result==OV_EREAD) goto seek_error;
+ if(result<0){
+ if(bisect<=begin+1)
+ end=begin; /* found it */
+ else{
+ if(bisect==0) goto seek_error;
+ bisect-=CHUNKSIZE;
+ if(bisect<=begin)bisect=begin+1;
+ _seek_helper(vf,bisect);
+ }
+ }else{
+ ogg_int64_t granulepos=ogg_page_granulepos(&og);
+ if(granulepos==-1)continue;
+ if(granulepos<target){
+ best=result; /* raw offset of packet with granulepos */
+ begin=vf->offset; /* raw offset of next page */
+ begintime=granulepos;
+
+ if(target-begintime>44100)break;
+ bisect=begin; /* *not* begin + 1 */
+ }else{
+ if(bisect<=begin+1)
+ end=begin; /* found it */
+ else{
+ if(end==vf->offset){ /* we're pretty close - we'd be stuck in */
+ end=result;
+ bisect-=CHUNKSIZE; /* an endless loop otherwise. */
+ if(bisect<=begin)bisect=begin+1;
+ _seek_helper(vf,bisect);
+ }else{
+ end=result;
+ endtime=granulepos;
+ break;
+ }
+ }
+ }
+ }
+ }
+ }
+
+ /* found our page. seek to it, update pcm offset. Easier case than
+ raw_seek, don't keep packets preceeding granulepos. */
+ {
+
+ /* seek */
+ _seek_helper(vf,best);
+ vf->pcm_offset=-1;
+
+ if(_get_next_page(vf,&og,-1)<0){
+ ogg_page_release(&og);
+ return(OV_EOF); /* shouldn't happen */
+ }
+
+ if(link!=vf->current_link){
+ /* Different link; dump entire decode machine */
+ _decode_clear(vf);
+
+ vf->current_link=link;
+ vf->current_serialno=ogg_page_serialno(&og);
+ vf->ready_state=STREAMSET;
+
+ }else{
+ vorbis_synthesis_restart(&vf->vd);
+ }
+
+ ogg_stream_reset_serialno(vf->os,vf->current_serialno);
+ ogg_stream_pagein(vf->os,&og);
+
+ /* pull out all but last packet; the one with granulepos */
+ while(1){
+ result=ogg_stream_packetpeek(vf->os,&op);
+ if(result==0){
+ /* !!! the packet finishing this page originated on a
+ preceeding page. Keep fetching previous pages until we
+ get one with a granulepos or without the 'continued' flag
+ set. Then just use raw_seek for simplicity. */
+
+ _seek_helper(vf,best);
+
+ while(1){
+ result=_get_prev_page(vf,&og);
+ if(result<0) goto seek_error;
+ if(ogg_page_granulepos(&og)>-1 ||
+ !ogg_page_continued(&og)){
+ return ov_raw_seek(vf,result);
+ }
+ vf->offset=result;
+ }
+ }
+ if(result<0){
+ result = OV_EBADPACKET;
+ goto seek_error;
+ }
+ if(op.granulepos!=-1){
+ vf->pcm_offset=op.granulepos-vf->pcmlengths[vf->current_link*2];
+ if(vf->pcm_offset<0)vf->pcm_offset=0;
+ vf->pcm_offset+=total;
+ break;
+ }else
+ result=ogg_stream_packetout(vf->os,NULL);
+ }
+ }
+ }
+
+ /* verify result */
+ if(vf->pcm_offset>pos || pos>ov_pcm_total(vf,-1)){
+ result=OV_EFAULT;
+ goto seek_error;
+ }
+ vf->bittrack=0;
+ vf->samptrack=0;
+
+ ogg_page_release(&og);
+ ogg_packet_release(&op);
+ return(0);
+
+ seek_error:
+
+ ogg_page_release(&og);
+ ogg_packet_release(&op);
+
+ /* dump machine so we're in a known state */
+ vf->pcm_offset=-1;
+ _decode_clear(vf);
+ return (int)result;
+}
+
+/* seek to a sample offset relative to the decompressed pcm stream
+ returns zero on success, nonzero on failure */
+
+int ov_pcm_seek(OggVorbis_File *vf,ogg_int64_t pos){
+ ogg_packet op={0,0,0,0,0,0};
+ ogg_page og={0,0,0,0};
+ int thisblock,lastblock=0;
+ int ret=ov_pcm_seek_page(vf,pos);
+ if(ret<0)return(ret);
+ _make_decode_ready(vf);
+
+ /* discard leading packets we don't need for the lapping of the
+ position we want; don't decode them */
+
+ while(1){
+
+ int ret=ogg_stream_packetpeek(vf->os,&op);
+ if(ret>0){
+ thisblock=vorbis_packet_blocksize(vf->vi+vf->current_link,&op);
+ if(thisblock<0){
+ ogg_stream_packetout(vf->os,NULL);
+ continue; /* non audio packet */
+ }
+ if(lastblock)vf->pcm_offset+=(lastblock+thisblock)>>2;
+
+ if(vf->pcm_offset+((thisblock+
+ vorbis_info_blocksize(vf->vi,1))>>2)>=pos)break;
+
+ /* remove the packet from packet queue and track its granulepos */
+ ogg_stream_packetout(vf->os,NULL);
+ vorbis_synthesis(&vf->vb,&op,0); /* set up a vb with
+ only tracking, no
+ pcm_decode */
+ vorbis_synthesis_blockin(&vf->vd,&vf->vb);
+
+ /* end of logical stream case is hard, especially with exact
+ length positioning. */
+
+ if(op.granulepos>-1){
+ int i;
+ /* always believe the stream markers */
+ vf->pcm_offset=op.granulepos-vf->pcmlengths[vf->current_link*2];
+ if(vf->pcm_offset<0)vf->pcm_offset=0;
+ for(i=0;i<vf->current_link;i++)
+ vf->pcm_offset+=vf->pcmlengths[i*2+1];
+ }
+
+ lastblock=thisblock;
+
+ }else{
+ if(ret<0 && ret!=OV_HOLE)break;
+
+ /* suck in a new page */
+ if(_get_next_page(vf,&og,-1)<0)break;
+ if(vf->current_serialno!=ogg_page_serialno(&og))_decode_clear(vf);
+
+ if(vf->ready_state<STREAMSET){
+ int link;
+
+ vf->current_serialno=ogg_page_serialno(&og);
+ for(link=0;link<vf->links;link++)
+ if(vf->serialnos[link]==vf->current_serialno)break;
+ if(link==vf->links){
+ ogg_page_release(&og);
+ ogg_packet_release(&op);
+ return(OV_EBADLINK);
+ }
+ vf->current_link=link;
+
+ ogg_stream_reset_serialno(vf->os,vf->current_serialno);
+ vf->ready_state=STREAMSET;
+ _make_decode_ready(vf);
+ lastblock=0;
+ }
+
+ ogg_stream_pagein(vf->os,&og);
+ }
+ }
+
+ vf->bittrack=0;
+ vf->samptrack=0;
+ /* discard samples until we reach the desired position. Crossing a
+ logical bitstream boundary with abandon is OK. */
+ while(vf->pcm_offset<pos){
+ ogg_int64_t target=pos-vf->pcm_offset;
+ long samples=vorbis_synthesis_pcmout(&vf->vd,NULL);
+
+ if(samples>target)samples=target;
+ vorbis_synthesis_read(&vf->vd,samples);
+ vf->pcm_offset+=samples;
+
+ if(samples<target)
+ if(_fetch_and_process_packet(vf,1,1)<=0)
+ vf->pcm_offset=ov_pcm_total(vf,-1); /* eof */
+ }
+
+ ogg_page_release(&og);
+ ogg_packet_release(&op);
+ return 0;
+}
+
+/* seek to a playback time relative to the decompressed pcm stream
+ returns zero on success, nonzero on failure */
+int ov_time_seek(OggVorbis_File *vf,ogg_int64_t milliseconds){
+ /* translate time to PCM position and call ov_pcm_seek */
+
+ int link=-1;
+ ogg_int64_t pcm_total=ov_pcm_total(vf,-1);
+ ogg_int64_t time_total=ov_time_total(vf,-1);
+
+ if(vf->ready_state<OPENED)return(OV_EINVAL);
+ if(!vf->seekable)return(OV_ENOSEEK);
+ if(milliseconds<0 || milliseconds>time_total)return(OV_EINVAL);
+
+ /* which bitstream section does this time offset occur in? */
+ for(link=vf->links-1;link>=0;link--){
+ pcm_total-=vf->pcmlengths[link*2+1];
+ time_total-=ov_time_total(vf,link);
+ if(milliseconds>=time_total)break;
+ }
+
+ /* enough information to convert time offset to pcm offset */
+ {
+ ogg_int64_t target=pcm_total+(milliseconds-time_total)*vf->vi[link].rate/1000;
+ return(ov_pcm_seek(vf,target));
+ }
+}
+
+/* page-granularity version of ov_time_seek
+ returns zero on success, nonzero on failure */
+int ov_time_seek_page(OggVorbis_File *vf,ogg_int64_t milliseconds){
+ /* translate time to PCM position and call ov_pcm_seek */
+
+ int link=-1;
+ ogg_int64_t pcm_total=ov_pcm_total(vf,-1);
+ ogg_int64_t time_total=ov_time_total(vf,-1);
+
+ if(vf->ready_state<OPENED)return(OV_EINVAL);
+ if(!vf->seekable)return(OV_ENOSEEK);
+ if(milliseconds<0 || milliseconds>time_total)return(OV_EINVAL);
+
+ /* which bitstream section does this time offset occur in? */
+ for(link=vf->links-1;link>=0;link--){
+ pcm_total-=vf->pcmlengths[link*2+1];
+ time_total-=ov_time_total(vf,link);
+ if(milliseconds>=time_total)break;
+ }
+
+ /* enough information to convert time offset to pcm offset */
+ {
+ ogg_int64_t target=pcm_total+(milliseconds-time_total)*vf->vi[link].rate/1000;
+ return(ov_pcm_seek_page(vf,target));
+ }
+}
+
+/* tell the current stream offset cursor. Note that seek followed by
+ tell will likely not give the set offset due to caching */
+ogg_int64_t ov_raw_tell(OggVorbis_File *vf){
+ if(vf->ready_state<OPENED)return(OV_EINVAL);
+ return(vf->offset);
+}
+
+/* return PCM offset (sample) of next PCM sample to be read */
+ogg_int64_t ov_pcm_tell(OggVorbis_File *vf){
+ if(vf->ready_state<OPENED)return(OV_EINVAL);
+ return(vf->pcm_offset);
+}
+
+/* return time offset (milliseconds) of next PCM sample to be read */
+ogg_int64_t ov_time_tell(OggVorbis_File *vf){
+ int link=0;
+ ogg_int64_t pcm_total=0;
+ ogg_int64_t time_total=0;
+
+ if(vf->ready_state<OPENED)return(OV_EINVAL);
+ if(vf->seekable){
+ pcm_total=ov_pcm_total(vf,-1);
+ time_total=ov_time_total(vf,-1);
+
+ /* which bitstream section does this time offset occur in? */
+ for(link=vf->links-1;link>=0;link--){
+ pcm_total-=vf->pcmlengths[link*2+1];
+ time_total-=ov_time_total(vf,link);
+ if(vf->pcm_offset>=pcm_total)break;
+ }
+ }
+
+ return(time_total+(1000*vf->pcm_offset-pcm_total)/vf->vi[link].rate);
+}
+
+/* link: -1) return the vorbis_info struct for the bitstream section
+ currently being decoded
+ 0-n) to request information for a specific bitstream section
+
+ In the case of a non-seekable bitstream, any call returns the
+ current bitstream. NULL in the case that the machine is not
+ initialized */
+
+vorbis_info *ov_info(OggVorbis_File *vf,int link){
+ if(vf->seekable){
+ if(link<0)
+ if(vf->ready_state>=STREAMSET)
+ return vf->vi+vf->current_link;
+ else
+ return vf->vi;
+ else
+ if(link>=vf->links)
+ return NULL;
+ else
+ return vf->vi+link;
+ }else{
+ return vf->vi;
+ }
+}
+
+/* grr, strong typing, grr, no templates/inheritence, grr */
+vorbis_comment *ov_comment(OggVorbis_File *vf,int link){
+ if(vf->seekable){
+ if(link<0)
+ if(vf->ready_state>=STREAMSET)
+ return vf->vc+vf->current_link;
+ else
+ return vf->vc;
+ else
+ if(link>=vf->links)
+ return NULL;
+ else
+ return vf->vc+link;
+ }else{
+ return vf->vc;
+ }
+}
+
+/* up to this point, everything could more or less hide the multiple
+ logical bitstream nature of chaining from the toplevel application
+ if the toplevel application didn't particularly care. However, at
+ the point that we actually read audio back, the multiple-section
+ nature must surface: Multiple bitstream sections do not necessarily
+ have to have the same number of channels or sampling rate.
+
+ ov_read returns the sequential logical bitstream number currently
+ being decoded along with the PCM data in order that the toplevel
+ application can take action on channel/sample rate changes. This
+ number will be incremented even for streamed (non-seekable) streams
+ (for seekable streams, it represents the actual logical bitstream
+ index within the physical bitstream. Note that the accessor
+ functions above are aware of this dichotomy).
+
+ input values: buffer) a buffer to hold packed PCM data for return
+ length) the byte length requested to be placed into buffer
+
+ return values: <0) error/hole in data (OV_HOLE), partial open (OV_EINVAL)
+ 0) EOF
+ n) number of bytes of PCM actually returned. The
+ below works on a packet-by-packet basis, so the
+ return length is not related to the 'length' passed
+ in, just guaranteed to fit.
+
+ *section) set to the logical bitstream number */
+
+long ov_read(OggVorbis_File *vf,char *buffer,int bytes_req,int *bitstream){
+ int i,j;
+
+ ogg_int32_t **pcm;
+ long samples;
+
+ if(vf->ready_state<OPENED)return(OV_EINVAL);
+
+ while(1){
+ if(vf->ready_state==INITSET){
+ samples=vorbis_synthesis_pcmout(&vf->vd,&pcm);
+ if(samples)break;
+ }
+
+ /* suck in another packet */
+ {
+ int ret=_fetch_and_process_packet(vf,1,1);
+ if(ret==OV_EOF)
+ return(0);
+ if(ret<=0)
+ return(ret);
+ }
+
+ }
+
+ if(samples>0){
+
+ /* yay! proceed to pack data into the byte buffer */
+
+ long channels=ov_info(vf,-1)->channels;
+
+ if(samples>(bytes_req/(2*channels)))
+ samples=bytes_req/(2*channels);
+
+ for(i=0;i<channels;i++) { /* It's faster in this order */
+ ogg_int32_t *src=pcm[i];
+ short *dest=((short *)buffer)+i;
+ for(j=0;j<samples;j++) {
+ *dest=CLIP_TO_15(src[j]>>9);
+ dest+=channels;
+ }
+ }
+
+ vorbis_synthesis_read(&vf->vd,samples);
+ vf->pcm_offset+=samples;
+ if(bitstream)*bitstream=vf->current_link;
+ return(samples*2*channels);
+ }else{
+ return(samples);
+ }
+}