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mpv/tremor/framing.c

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/********************************************************************
* *
* 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 1994-2002 *
* by the Xiph.Org Foundation http://www.xiph.org/ *
* *
********************************************************************
function: code raw [Vorbis] packets into framed OggSquish stream and
decode Ogg streams back into raw packets
last mod: $Id$
note: The CRC code is directly derived from public domain code by
Ross Williams (ross@guest.adelaide.edu.au). See docs/framing.html
for details.
********************************************************************/
#include <stdlib.h>
#include <string.h>
#include "ogg.h"
/* A complete description of Ogg framing exists in docs/framing.html */
int ogg_page_version(ogg_page *og){
return((int)(og->header[4]));
}
int ogg_page_continued(ogg_page *og){
return((int)(og->header[5]&0x01));
}
int ogg_page_bos(ogg_page *og){
return((int)(og->header[5]&0x02));
}
int ogg_page_eos(ogg_page *og){
return((int)(og->header[5]&0x04));
}
ogg_int64_t ogg_page_granulepos(ogg_page *og){
unsigned char *page=og->header;
ogg_int64_t granulepos=page[13]&(0xff);
granulepos= (granulepos<<8)|(page[12]&0xff);
granulepos= (granulepos<<8)|(page[11]&0xff);
granulepos= (granulepos<<8)|(page[10]&0xff);
granulepos= (granulepos<<8)|(page[9]&0xff);
granulepos= (granulepos<<8)|(page[8]&0xff);
granulepos= (granulepos<<8)|(page[7]&0xff);
granulepos= (granulepos<<8)|(page[6]&0xff);
return(granulepos);
}
int ogg_page_serialno(ogg_page *og){
return(og->header[14] |
(og->header[15]<<8) |
(og->header[16]<<16) |
(og->header[17]<<24));
}
long ogg_page_pageno(ogg_page *og){
return(og->header[18] |
(og->header[19]<<8) |
(og->header[20]<<16) |
(og->header[21]<<24));
}
/* returns the number of packets that are completed on this page (if
the leading packet is begun on a previous page, but ends on this
page, it's counted */
/* NOTE:
If a page consists of a packet begun on a previous page, and a new
packet begun (but not completed) on this page, the return will be:
ogg_page_packets(page) ==1,
ogg_page_continued(page) !=0
If a page happens to be a single packet that was begun on a
previous page, and spans to the next page (in the case of a three or
more page packet), the return will be:
ogg_page_packets(page) ==0,
ogg_page_continued(page) !=0
*/
int ogg_page_packets(ogg_page *og){
int i,n=og->header[26],count=0;
for(i=0;i<n;i++)
if(og->header[27+i]<255)count++;
return(count);
}
#if 0
/* helper to initialize lookup for direct-table CRC (illustrative; we
use the static init below) */
static ogg_uint32_t _ogg_crc_entry(unsigned long index){
int i;
unsigned long r;
r = index << 24;
for (i=0; i<8; i++)
if (r & 0x80000000UL)
r = (r << 1) ^ 0x04c11db7; /* The same as the ethernet generator
polynomial, although we use an
unreflected alg and an init/final
of 0, not 0xffffffff */
else
r<<=1;
return (r & 0xffffffffUL);
}
#endif
static const ogg_uint32_t crc_lookup[256]={
0x00000000,0x04c11db7,0x09823b6e,0x0d4326d9,
0x130476dc,0x17c56b6b,0x1a864db2,0x1e475005,
0x2608edb8,0x22c9f00f,0x2f8ad6d6,0x2b4bcb61,
0x350c9b64,0x31cd86d3,0x3c8ea00a,0x384fbdbd,
0x4c11db70,0x48d0c6c7,0x4593e01e,0x4152fda9,
0x5f15adac,0x5bd4b01b,0x569796c2,0x52568b75,
0x6a1936c8,0x6ed82b7f,0x639b0da6,0x675a1011,
0x791d4014,0x7ddc5da3,0x709f7b7a,0x745e66cd,
0x9823b6e0,0x9ce2ab57,0x91a18d8e,0x95609039,
0x8b27c03c,0x8fe6dd8b,0x82a5fb52,0x8664e6e5,
0xbe2b5b58,0xbaea46ef,0xb7a96036,0xb3687d81,
0xad2f2d84,0xa9ee3033,0xa4ad16ea,0xa06c0b5d,
0xd4326d90,0xd0f37027,0xddb056fe,0xd9714b49,
0xc7361b4c,0xc3f706fb,0xceb42022,0xca753d95,
0xf23a8028,0xf6fb9d9f,0xfbb8bb46,0xff79a6f1,
0xe13ef6f4,0xe5ffeb43,0xe8bccd9a,0xec7dd02d,
0x34867077,0x30476dc0,0x3d044b19,0x39c556ae,
0x278206ab,0x23431b1c,0x2e003dc5,0x2ac12072,
0x128e9dcf,0x164f8078,0x1b0ca6a1,0x1fcdbb16,
0x018aeb13,0x054bf6a4,0x0808d07d,0x0cc9cdca,
0x7897ab07,0x7c56b6b0,0x71159069,0x75d48dde,
0x6b93dddb,0x6f52c06c,0x6211e6b5,0x66d0fb02,
0x5e9f46bf,0x5a5e5b08,0x571d7dd1,0x53dc6066,
0x4d9b3063,0x495a2dd4,0x44190b0d,0x40d816ba,
0xaca5c697,0xa864db20,0xa527fdf9,0xa1e6e04e,
0xbfa1b04b,0xbb60adfc,0xb6238b25,0xb2e29692,
0x8aad2b2f,0x8e6c3698,0x832f1041,0x87ee0df6,
0x99a95df3,0x9d684044,0x902b669d,0x94ea7b2a,
0xe0b41de7,0xe4750050,0xe9362689,0xedf73b3e,
0xf3b06b3b,0xf771768c,0xfa325055,0xfef34de2,
0xc6bcf05f,0xc27dede8,0xcf3ecb31,0xcbffd686,
0xd5b88683,0xd1799b34,0xdc3abded,0xd8fba05a,
0x690ce0ee,0x6dcdfd59,0x608edb80,0x644fc637,
0x7a089632,0x7ec98b85,0x738aad5c,0x774bb0eb,
0x4f040d56,0x4bc510e1,0x46863638,0x42472b8f,
0x5c007b8a,0x58c1663d,0x558240e4,0x51435d53,
0x251d3b9e,0x21dc2629,0x2c9f00f0,0x285e1d47,
0x36194d42,0x32d850f5,0x3f9b762c,0x3b5a6b9b,
0x0315d626,0x07d4cb91,0x0a97ed48,0x0e56f0ff,
0x1011a0fa,0x14d0bd4d,0x19939b94,0x1d528623,
0xf12f560e,0xf5ee4bb9,0xf8ad6d60,0xfc6c70d7,
0xe22b20d2,0xe6ea3d65,0xeba91bbc,0xef68060b,
0xd727bbb6,0xd3e6a601,0xdea580d8,0xda649d6f,
0xc423cd6a,0xc0e2d0dd,0xcda1f604,0xc960ebb3,
0xbd3e8d7e,0xb9ff90c9,0xb4bcb610,0xb07daba7,
0xae3afba2,0xaafbe615,0xa7b8c0cc,0xa379dd7b,
0x9b3660c6,0x9ff77d71,0x92b45ba8,0x9675461f,
0x8832161a,0x8cf30bad,0x81b02d74,0x857130c3,
0x5d8a9099,0x594b8d2e,0x5408abf7,0x50c9b640,
0x4e8ee645,0x4a4ffbf2,0x470cdd2b,0x43cdc09c,
0x7b827d21,0x7f436096,0x7200464f,0x76c15bf8,
0x68860bfd,0x6c47164a,0x61043093,0x65c52d24,
0x119b4be9,0x155a565e,0x18197087,0x1cd86d30,
0x029f3d35,0x065e2082,0x0b1d065b,0x0fdc1bec,
0x3793a651,0x3352bbe6,0x3e119d3f,0x3ad08088,
0x2497d08d,0x2056cd3a,0x2d15ebe3,0x29d4f654,
0xc5a92679,0xc1683bce,0xcc2b1d17,0xc8ea00a0,
0xd6ad50a5,0xd26c4d12,0xdf2f6bcb,0xdbee767c,
0xe3a1cbc1,0xe760d676,0xea23f0af,0xeee2ed18,
0xf0a5bd1d,0xf464a0aa,0xf9278673,0xfde69bc4,
0x89b8fd09,0x8d79e0be,0x803ac667,0x84fbdbd0,
0x9abc8bd5,0x9e7d9662,0x933eb0bb,0x97ffad0c,
0xafb010b1,0xab710d06,0xa6322bdf,0xa2f33668,
0xbcb4666d,0xb8757bda,0xb5365d03,0xb1f740b4};
/* init the encode/decode logical stream state */
int ogg_stream_init(ogg_stream_state *os,int serialno){
if(os){
memset(os,0,sizeof(*os));
os->body_storage=16*1024;
os->body_data=_ogg_malloc(os->body_storage*sizeof(*os->body_data));
os->lacing_storage=1024;
os->lacing_vals=_ogg_malloc(os->lacing_storage*sizeof(*os->lacing_vals));
os->granule_vals=_ogg_malloc(os->lacing_storage*sizeof(*os->granule_vals));
os->serialno=serialno;
return(0);
}
return(-1);
}
/* _clear does not free os, only the non-flat storage within */
int ogg_stream_clear(ogg_stream_state *os){
if(os){
if(os->body_data)_ogg_free(os->body_data);
if(os->lacing_vals)_ogg_free(os->lacing_vals);
if(os->granule_vals)_ogg_free(os->granule_vals);
memset(os,0,sizeof(*os));
}
return(0);
}
int ogg_stream_destroy(ogg_stream_state *os){
if(os){
ogg_stream_clear(os);
_ogg_free(os);
}
return(0);
}
/* Helpers for ogg_stream_encode; this keeps the structure and
what's happening fairly clear */
static void _os_body_expand(ogg_stream_state *os,int needed){
if(os->body_storage<=os->body_fill+needed){
os->body_storage+=(needed+1024);
os->body_data=_ogg_realloc(os->body_data,os->body_storage*sizeof(*os->body_data));
}
}
static void _os_lacing_expand(ogg_stream_state *os,int needed){
if(os->lacing_storage<=os->lacing_fill+needed){
os->lacing_storage+=(needed+32);
os->lacing_vals=_ogg_realloc(os->lacing_vals,os->lacing_storage*sizeof(*os->lacing_vals));
os->granule_vals=_ogg_realloc(os->granule_vals,os->lacing_storage*sizeof(*os->granule_vals));
}
}
/* checksum the page */
/* Direct table CRC; note that this will be faster in the future if we
perform the checksum silmultaneously with other copies */
void ogg_page_checksum_set(ogg_page *og){
if(og){
ogg_uint32_t crc_reg=0;
int i;
/* safety; needed for API behavior, but not framing code */
og->header[22]=0;
og->header[23]=0;
og->header[24]=0;
og->header[25]=0;
for(i=0;i<og->header_len;i++)
crc_reg=(crc_reg<<8)^crc_lookup[((crc_reg >> 24)&0xff)^og->header[i]];
for(i=0;i<og->body_len;i++)
crc_reg=(crc_reg<<8)^crc_lookup[((crc_reg >> 24)&0xff)^og->body[i]];
og->header[22]=(unsigned char)(crc_reg&0xff);
og->header[23]=(unsigned char)((crc_reg>>8)&0xff);
og->header[24]=(unsigned char)((crc_reg>>16)&0xff);
og->header[25]=(unsigned char)((crc_reg>>24)&0xff);
}
}
/* submit data to the internal buffer of the framing engine */
int ogg_stream_packetin(ogg_stream_state *os,ogg_packet *op){
int lacing_vals=op->bytes/255+1,i;
if(os->body_returned){
/* advance packet data according to the body_returned pointer. We
had to keep it around to return a pointer into the buffer last
call */
os->body_fill-=os->body_returned;
if(os->body_fill)
memmove(os->body_data,os->body_data+os->body_returned,
os->body_fill);
os->body_returned=0;
}
/* make sure we have the buffer storage */
_os_body_expand(os,op->bytes);
_os_lacing_expand(os,lacing_vals);
/* Copy in the submitted packet. Yes, the copy is a waste; this is
the liability of overly clean abstraction for the time being. It
will actually be fairly easy to eliminate the extra copy in the
future */
memcpy(os->body_data+os->body_fill,op->packet,op->bytes);
os->body_fill+=op->bytes;
/* Store lacing vals for this packet */
for(i=0;i<lacing_vals-1;i++){
os->lacing_vals[os->lacing_fill+i]=255;
os->granule_vals[os->lacing_fill+i]=os->granulepos;
}
os->lacing_vals[os->lacing_fill+i]=(op->bytes)%255;
os->granulepos=os->granule_vals[os->lacing_fill+i]=op->granulepos;
/* flag the first segment as the beginning of the packet */
os->lacing_vals[os->lacing_fill]|= 0x100;
os->lacing_fill+=lacing_vals;
/* for the sake of completeness */
os->packetno++;
if(op->e_o_s)os->e_o_s=1;
return(0);
}
/* This will flush remaining packets into a page (returning nonzero),
even if there is not enough data to trigger a flush normally
(undersized page). If there are no packets or partial packets to
flush, ogg_stream_flush returns 0. Note that ogg_stream_flush will
try to flush a normal sized page like ogg_stream_pageout; a call to
ogg_stream_flush does not guarantee that all packets have flushed.
Only a return value of 0 from ogg_stream_flush indicates all packet
data is flushed into pages.
since ogg_stream_flush will flush the last page in a stream even if
it's undersized, you almost certainly want to use ogg_stream_pageout
(and *not* ogg_stream_flush) unless you specifically need to flush
an page regardless of size in the middle of a stream. */
int ogg_stream_flush(ogg_stream_state *os,ogg_page *og){
int i;
int vals=0;
int maxvals=(os->lacing_fill>255?255:os->lacing_fill);
int bytes=0;
long acc=0;
ogg_int64_t granule_pos=os->granule_vals[0];
if(maxvals==0)return(0);
/* construct a page */
/* decide how many segments to include */
/* If this is the initial header case, the first page must only include
the initial header packet */
if(os->b_o_s==0){ /* 'initial header page' case */
granule_pos=0;
for(vals=0;vals<maxvals;vals++){
if((os->lacing_vals[vals]&0x0ff)<255){
vals++;
break;
}
}
}else{
for(vals=0;vals<maxvals;vals++){
if(acc>4096)break;
acc+=os->lacing_vals[vals]&0x0ff;
granule_pos=os->granule_vals[vals];
}
}
/* construct the header in temp storage */
memcpy(os->header,"OggS",4);
/* stream structure version */
os->header[4]=0x00;
/* continued packet flag? */
os->header[5]=0x00;
if((os->lacing_vals[0]&0x100)==0)os->header[5]|=0x01;
/* first page flag? */
if(os->b_o_s==0)os->header[5]|=0x02;
/* last page flag? */
if(os->e_o_s && os->lacing_fill==vals)os->header[5]|=0x04;
os->b_o_s=1;
/* 64 bits of PCM position */
for(i=6;i<14;i++){
os->header[i]=(unsigned char)(granule_pos&0xff);
granule_pos>>=8;
}
/* 32 bits of stream serial number */
{
long serialno=os->serialno;
for(i=14;i<18;i++){
os->header[i]=(unsigned char)(serialno&0xff);
serialno>>=8;
}
}
/* 32 bits of page counter (we have both counter and page header
because this val can roll over) */
if(os->pageno==-1)os->pageno=0; /* because someone called
stream_reset; this would be a
strange thing to do in an
encode stream, but it has
plausible uses */
{
long pageno=os->pageno++;
for(i=18;i<22;i++){
os->header[i]=(unsigned char)(pageno&0xff);
pageno>>=8;
}
}
/* zero for computation; filled in later */
os->header[22]=0;
os->header[23]=0;
os->header[24]=0;
os->header[25]=0;
/* segment table */
os->header[26]=(unsigned char)(vals&0xff);
for(i=0;i<vals;i++)
bytes+=os->header[i+27]=(unsigned char)(os->lacing_vals[i]&0xff);
/* set pointers in the ogg_page struct */
og->header=os->header;
og->header_len=os->header_fill=vals+27;
og->body=os->body_data+os->body_returned;
og->body_len=bytes;
/* advance the lacing data and set the body_returned pointer */
os->lacing_fill-=vals;
memmove(os->lacing_vals,os->lacing_vals+vals,os->lacing_fill*sizeof(*os->lacing_vals));
memmove(os->granule_vals,os->granule_vals+vals,os->lacing_fill*sizeof(*os->granule_vals));
os->body_returned+=bytes;
/* calculate the checksum */
ogg_page_checksum_set(og);
/* done */
return(1);
}
/* This constructs pages from buffered packet segments. The pointers
returned are to static buffers; do not free. The returned buffers are
good only until the next call (using the same ogg_stream_state) */
int ogg_stream_pageout(ogg_stream_state *os, ogg_page *og){
if((os->e_o_s&&os->lacing_fill) || /* 'were done, now flush' case */
os->body_fill-os->body_returned > 4096 ||/* 'page nominal size' case */
os->lacing_fill>=255 || /* 'segment table full' case */
(os->lacing_fill&&!os->b_o_s)){ /* 'initial header page' case */
return(ogg_stream_flush(os,og));
}
/* not enough data to construct a page and not end of stream */
return(0);
}
int ogg_stream_eos(ogg_stream_state *os){
return os->e_o_s;
}
/* DECODING PRIMITIVES: packet streaming layer **********************/
/* This has two layers to place more of the multi-serialno and paging
control in the application's hands. First, we expose a data buffer
using ogg_sync_buffer(). The app either copies into the
buffer, or passes it directly to read(), etc. We then call
ogg_sync_wrote() to tell how many bytes we just added.
Pages are returned (pointers into the buffer in ogg_sync_state)
by ogg_sync_pageout(). The page is then submitted to
ogg_stream_pagein() along with the appropriate
ogg_stream_state* (ie, matching serialno). We then get raw
packets out calling ogg_stream_packetout() with a
ogg_stream_state. See the 'frame-prog.txt' docs for details and
example code. */
/* initialize the struct to a known state */
int ogg_sync_init(ogg_sync_state *oy){
if(oy){
memset(oy,0,sizeof(*oy));
}
return(0);
}
/* clear non-flat storage within */
int ogg_sync_clear(ogg_sync_state *oy){
if(oy){
if(oy->data)_ogg_free(oy->data);
ogg_sync_init(oy);
}
return(0);
}
int ogg_sync_destroy(ogg_sync_state *oy){
if(oy){
ogg_sync_clear(oy);
_ogg_free(oy);
}
return(0);
}
char *ogg_sync_buffer(ogg_sync_state *oy, long size){
/* first, clear out any space that has been previously returned */
if(oy->returned){
oy->fill-=oy->returned;
if(oy->fill>0)
memmove(oy->data,oy->data+oy->returned,oy->fill);
oy->returned=0;
}
if(size>oy->storage-oy->fill){
/* We need to extend the internal buffer */
long newsize=size+oy->fill+4096; /* an extra page to be nice */
if(oy->data)
oy->data=_ogg_realloc(oy->data,newsize);
else
oy->data=_ogg_malloc(newsize);
oy->storage=newsize;
}
/* expose a segment at least as large as requested at the fill mark */
return((char *)oy->data+oy->fill);
}
int ogg_sync_wrote(ogg_sync_state *oy, long bytes){
if(oy->fill+bytes>oy->storage)return(-1);
oy->fill+=bytes;
return(0);
}
/* sync the stream. This is meant to be useful for finding page
boundaries.
return values for this:
-n) skipped n bytes
0) page not ready; more data (no bytes skipped)
n) page synced at current location; page length n bytes
*/
long ogg_sync_pageseek(ogg_sync_state *oy,ogg_page *og){
unsigned char *page=oy->data+oy->returned;
unsigned char *next;
long bytes=oy->fill-oy->returned;
if(oy->headerbytes==0){
int headerbytes,i;
if(bytes<27)return(0); /* not enough for a header */
/* verify capture pattern */
if(memcmp(page,"OggS",4))goto sync_fail;
headerbytes=page[26]+27;
if(bytes<headerbytes)return(0); /* not enough for header + seg table */
/* count up body length in the segment table */
for(i=0;i<page[26];i++)
oy->bodybytes+=page[27+i];
oy->headerbytes=headerbytes;
}
if(oy->bodybytes+oy->headerbytes>bytes)return(0);
/* The whole test page is buffered. Verify the checksum */
{
/* Grab the checksum bytes, set the header field to zero */
char chksum[4];
ogg_page log;
memcpy(chksum,page+22,4);
memset(page+22,0,4);
/* set up a temp page struct and recompute the checksum */
log.header=page;
log.header_len=oy->headerbytes;
log.body=page+oy->headerbytes;
log.body_len=oy->bodybytes;
ogg_page_checksum_set(&log);
/* Compare */
if(memcmp(chksum,page+22,4)){
/* D'oh. Mismatch! Corrupt page (or miscapture and not a page
at all) */
/* replace the computed checksum with the one actually read in */
memcpy(page+22,chksum,4);
/* Bad checksum. Lose sync */
goto sync_fail;
}
}
/* yes, have a whole page all ready to go */
{
unsigned char *page=oy->data+oy->returned;
long bytes;
if(og){
og->header=page;
og->header_len=oy->headerbytes;
og->body=page+oy->headerbytes;
og->body_len=oy->bodybytes;
}
oy->unsynced=0;
oy->returned+=(bytes=oy->headerbytes+oy->bodybytes);
oy->headerbytes=0;
oy->bodybytes=0;
return(bytes);
}
sync_fail:
oy->headerbytes=0;
oy->bodybytes=0;
/* search for possible capture */
next=memchr(page+1,'O',bytes-1);
if(!next)
next=oy->data+oy->fill;
oy->returned=next-oy->data;
return(-(next-page));
}
/* sync the stream and get a page. Keep trying until we find a page.
Suppress 'sync errors' after reporting the first.
return values:
-1) recapture (hole in data)
0) need more data
1) page returned
Returns pointers into buffered data; invalidated by next call to
_stream, _clear, _init, or _buffer */
int ogg_sync_pageout(ogg_sync_state *oy, ogg_page *og){
/* all we need to do is verify a page at the head of the stream
buffer. If it doesn't verify, we look for the next potential
frame */
for(;;){
long ret=ogg_sync_pageseek(oy,og);
if(ret>0){
/* have a page */
return(1);
}
if(ret==0){
/* need more data */
return(0);
}
/* head did not start a synced page... skipped some bytes */
if(!oy->unsynced){
oy->unsynced=1;
return(-1);
}
/* loop. keep looking */
}
}
/* add the incoming page to the stream state; we decompose the page
into packet segments here as well. */
int ogg_stream_pagein(ogg_stream_state *os, ogg_page *og){
unsigned char *header=og->header;
unsigned char *body=og->body;
long bodysize=og->body_len;
int segptr=0;
int version=ogg_page_version(og);
int continued=ogg_page_continued(og);
int bos=ogg_page_bos(og);
int eos=ogg_page_eos(og);
ogg_int64_t granulepos=ogg_page_granulepos(og);
int serialno=ogg_page_serialno(og);
long pageno=ogg_page_pageno(og);
int segments=header[26];
/* clean up 'returned data' */
{
long lr=os->lacing_returned;
long br=os->body_returned;
/* body data */
if(br){
os->body_fill-=br;
if(os->body_fill)
memmove(os->body_data,os->body_data+br,os->body_fill);
os->body_returned=0;
}
if(lr){
/* segment table */
if(os->lacing_fill-lr){
memmove(os->lacing_vals,os->lacing_vals+lr,
(os->lacing_fill-lr)*sizeof(*os->lacing_vals));
memmove(os->granule_vals,os->granule_vals+lr,
(os->lacing_fill-lr)*sizeof(*os->granule_vals));
}
os->lacing_fill-=lr;
os->lacing_packet-=lr;
os->lacing_returned=0;
}
}
/* check the serial number */
if(serialno!=os->serialno)return(-1);
if(version>0)return(-1);
_os_lacing_expand(os,segments+1);
/* are we in sequence? */
if(pageno!=os->pageno){
int i;
/* unroll previous partial packet (if any) */
for(i=os->lacing_packet;i<os->lacing_fill;i++)
os->body_fill-=os->lacing_vals[i]&0xff;
os->lacing_fill=os->lacing_packet;
/* make a note of dropped data in segment table */
if(os->pageno!=-1){
os->lacing_vals[os->lacing_fill++]=0x400;
os->lacing_packet++;
}
}
/* are we a 'continued packet' page? If so, we may need to skip
some segments */
if(continued){
if(os->lacing_fill<1 ||
os->lacing_vals[os->lacing_fill-1]==0x400){
bos=0;
for(;segptr<segments;segptr++){
int val=header[27+segptr];
body+=val;
bodysize-=val;
if(val<255){
segptr++;
break;
}
}
}
}
if(bodysize){
_os_body_expand(os,bodysize);
memcpy(os->body_data+os->body_fill,body,bodysize);
os->body_fill+=bodysize;
}
{
int saved=-1;
while(segptr<segments){
int val=header[27+segptr];
os->lacing_vals[os->lacing_fill]=val;
os->granule_vals[os->lacing_fill]=-1;
if(bos){
os->lacing_vals[os->lacing_fill]|=0x100;
bos=0;
}
if(val<255)saved=os->lacing_fill;
os->lacing_fill++;
segptr++;
if(val<255)os->lacing_packet=os->lacing_fill;
}
/* set the granulepos on the last granuleval of the last full packet */
if(saved!=-1){
os->granule_vals[saved]=granulepos;
}
}
if(eos){
os->e_o_s=1;
if(os->lacing_fill>0)
os->lacing_vals[os->lacing_fill-1]|=0x200;
}
os->pageno=pageno+1;
return(0);
}
/* clear things to an initial state. Good to call, eg, before seeking */
int ogg_sync_reset(ogg_sync_state *oy){
oy->fill=0;
oy->returned=0;
oy->unsynced=0;
oy->headerbytes=0;
oy->bodybytes=0;
return(0);
}
int ogg_stream_reset(ogg_stream_state *os){
os->body_fill=0;
os->body_returned=0;
os->lacing_fill=0;
os->lacing_packet=0;
os->lacing_returned=0;
os->header_fill=0;
os->e_o_s=0;
os->b_o_s=0;
os->pageno=-1;
os->packetno=0;
os->granulepos=0;
return(0);
}
int ogg_stream_reset_serialno(ogg_stream_state *os,int serialno){
ogg_stream_reset(os);
os->serialno=serialno;
return(0);
}
static int _packetout(ogg_stream_state *os,ogg_packet *op,int adv){
/* The last part of decode. We have the stream broken into packet
segments. Now we need to group them into packets (or return the
out of sync markers) */
int ptr=os->lacing_returned;
if(os->lacing_packet<=ptr)return(0);
if(os->lacing_vals[ptr]&0x400){
/* we need to tell the codec there's a gap; it might need to
handle previous packet dependencies. */
os->lacing_returned++;
os->packetno++;
return(-1);
}
if(!op && !adv)return(1); /* just using peek as an inexpensive way
to ask if there's a whole packet
waiting */
/* Gather the whole packet. We'll have no holes or a partial packet */
{
int size=os->lacing_vals[ptr]&0xff;
int bytes=size;
int eos=os->lacing_vals[ptr]&0x200; /* last packet of the stream? */
int bos=os->lacing_vals[ptr]&0x100; /* first packet of the stream? */
while(size==255){
int val=os->lacing_vals[++ptr];
size=val&0xff;
if(val&0x200)eos=0x200;
bytes+=size;
}
if(op){
op->e_o_s=eos;
op->b_o_s=bos;
op->packet=os->body_data+os->body_returned;
op->packetno=os->packetno;
op->granulepos=os->granule_vals[ptr];
op->bytes=bytes;
}
if(adv){
os->body_returned+=bytes;
os->lacing_returned=ptr+1;
os->packetno++;
}
}
return(1);
}
int ogg_stream_packetout(ogg_stream_state *os,ogg_packet *op){
return _packetout(os,op,1);
}
int ogg_stream_packetpeek(ogg_stream_state *os,ogg_packet *op){
return _packetout(os,op,0);
}
void ogg_packet_clear(ogg_packet *op) {
_ogg_free(op->packet);
memset(op, 0, sizeof(*op));
}
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