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Diffstat (limited to 'tremor/framing.c')
| -rw-r--r-- | tremor/framing.c | 672 |
1 files changed, 672 insertions, 0 deletions
diff --git a/tremor/framing.c b/tremor/framing.c new file mode 100644 index 0000000000..6b9650138b --- /dev/null +++ b/tremor/framing.c @@ -0,0 +1,672 @@ +/******************************************************************** + * * + * THIS FILE IS PART OF THE OggVorbis 'TREMOR' CODEC SOURCE CODE. * + * * + * THE OggVorbis 'TREMOR' SOURCE CODE IS (C) COPYRIGHT 1994-2002 * + * BY THE Xiph.Org FOUNDATION http://www.xiph.org/ * + * ALL REDISTRIBUTION RIGHTS RESERVED. * + * * + ******************************************************************** + + function: code raw [Vorbis] packets into framed OggSquish stream and + decode Ogg streams back into raw packets + + 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); +} + +static 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=(unsigned char *)_ogg_malloc(os->body_storage*sizeof(*os->body_data)); + + os->lacing_storage=1024; + os->lacing_vals=(int *)_ogg_malloc(os->lacing_storage*sizeof(*os->lacing_vals)); + os->granule_vals=(ogg_int64_t *)_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=(unsigned char *)_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=(int *)_ogg_realloc(os->lacing_vals,os->lacing_storage*sizeof(*os->lacing_vals)); + os->granule_vals=(ogg_int64_t *)_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]=crc_reg&0xff; + og->header[23]=(crc_reg>>8)&0xff; + og->header[24]=(crc_reg>>16)&0xff; + og->header[25]=(crc_reg>>24)&0xff; + } +} + +/* 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>8192){ + 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=(unsigned char *)_ogg_realloc(oy->data,newsize); + else + oy->data=(unsigned char *)_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=(unsigned char *)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. + Supress '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 */ + + while(1){ + 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>8192){ + 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>8192){ + /* 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'll need to skip + some segments */ + if(continued){ + 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); +} + +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)); +} + |