/******************************************************************** * * * THIS FILE IS PART OF THE Ogg Reference Library 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 Ogg Reference Library SOURCE CODE IS (C) COPYRIGHT 1994-2004 * * by the Xiph.Org Foundation http://www.xiph.org/ * * * ******************************************************************** function: decode stream sync and memory management foundation code; takes in raw data, spits out 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 #include #include "ogginternal.h" /* proper way to suck in ogg/ogg.h from a libogg compile */ /* A complete description of Ogg framing exists in docs/framing.html */ int ogg2_page_version(ogg2_page *og){ ogg2byte_buffer ob; ogg2byte_init(&ob,og->header,0); return ogg2byte_read1(&ob,4); } int ogg2_page_continued(ogg2_page *og){ ogg2byte_buffer ob; ogg2byte_init(&ob,og->header,0); return ogg2byte_read1(&ob,5)&0x01; } int ogg2_page_bos(ogg2_page *og){ ogg2byte_buffer ob; ogg2byte_init(&ob,og->header,0); return ogg2byte_read1(&ob,5)&0x02; } int ogg2_page_eos(ogg2_page *og){ ogg2byte_buffer ob; ogg2byte_init(&ob,og->header,0); return ogg2byte_read1(&ob,5)&0x04; } ogg_int64_t ogg2_page_granulepos(ogg2_page *og){ ogg2byte_buffer ob; ogg2byte_init(&ob,og->header,0); return ogg2byte_read8(&ob,6); } ogg_uint32_t ogg2_page_serialno(ogg2_page *og){ ogg2byte_buffer ob; ogg2byte_init(&ob,og->header,0); return ogg2byte_read4(&ob,14); } ogg_uint32_t ogg2_page_pageno(ogg2_page *og){ ogg2byte_buffer ob; ogg2byte_init(&ob,og->header,0); return ogg2byte_read4(&ob,18); } /* 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: ogg2_page_packets(page) ==1, ogg2_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: ogg2_page_packets(page) ==0, ogg2_page_continued(page) !=0 */ int ogg2_page_packets(ogg2_page *og){ int i; int n; int count=0; ogg2byte_buffer ob; ogg2byte_init(&ob,og->header,0); n=ogg2byte_read1(&ob,26); for(i=0;iheader,0); b=ogg2byte_read1(&ob,5); if(value)ogg2byte_set1(&ob,b|0x01,5); else ogg2byte_set1(&ob,b&0xFE,5); ogg2_page_checksum_set(og); } void ogg2_page_set_bos(ogg2_page *og, int value){ int b; ogg2byte_buffer ob; ogg2byte_init(&ob,og->header,0); b=ogg2byte_read1(&ob,5); if(value)ogg2byte_set1(&ob,b|0x02,5); else ogg2byte_set1(&ob,b&0xFD,5); ogg2_page_checksum_set(og); } void ogg2_page_set_eos(ogg2_page *og, int value){ int b; ogg2byte_buffer ob; ogg2byte_init(&ob,og->header,0); b=ogg2byte_read1(&ob,5); if(value)ogg2byte_set1(&ob,b|0x04,5); else ogg2byte_set1(&ob,b&0xFB,5); ogg2_page_checksum_set(og); } void ogg2_page_set_granulepos(ogg2_page *og, ogg_int64_t value){ ogg2byte_buffer ob; ogg2byte_init(&ob,og->header,0); ogg2byte_set8(&ob,value,6); ogg2_page_checksum_set(og); } void ogg2_page_set_serialno(ogg2_page *og, ogg_uint32_t value){ ogg2byte_buffer ob; ogg2byte_init(&ob,og->header,0); ogg2byte_set4(&ob,value,14); ogg2_page_checksum_set(og); } void ogg2_page_set_pageno(ogg2_page *og, ogg_uint32_t value){ ogg2byte_buffer ob; ogg2byte_init(&ob,og->header,0); ogg2byte_set4(&ob,value,18); ogg2_page_checksum_set(og); } /* Static CRC calculation table. See older code in SVN for dead run-time initialization code. */ 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}; /* DECODING PRIMITIVES: raw stream and page layer *******************/ /* This has two layers (split page decode and packet decode) to place more of the multi-serialno and paging control in the hands of higher layers (eg, OggFile). First, we expose a data buffer using ogg2_sync_buffer(). The app either copies into the buffer, or passes it directly to read(), etc. We then call ogg2_sync_wrote() to tell how many bytes we just added. Efficiency note: request the same buffer size each time if at all possible. Pages are returned (pointers into the buffer in ogg2_sync_state) by ogg2_sync_pageout(). */ ogg2_sync_state *ogg2_sync_create(void){ ogg2_sync_state *oy=_ogg_calloc(1,sizeof(*oy)); memset(oy,0,sizeof(*oy)); oy->bufferpool=ogg2_buffer_create(); return oy; } int ogg2_sync_destroy(ogg2_sync_state *oy){ if(oy){ ogg2_sync_reset(oy); ogg2_buffer_destroy(oy->bufferpool); memset(oy,0,sizeof(*oy)); _ogg_free(oy); } return OGG2_SUCCESS; } unsigned char *ogg2_sync_bufferin(ogg2_sync_state *oy, long bytes){ /* [allocate and] expose a buffer for data submission. If there is no head fragment allocate one and expose it else if the current head fragment has sufficient unused space expose it else if the current head fragment is unused resize and expose it else allocate new fragment and expose it */ /* base case; fifo uninitialized */ if(!oy->fifo_head){ oy->fifo_head=oy->fifo_tail=ogg2_buffer_alloc(oy->bufferpool,bytes); return oy->fifo_head->buffer->data; } /* space left in current fragment case */ if(oy->fifo_head->buffer->size- oy->fifo_head->length- oy->fifo_head->begin >= bytes) return oy->fifo_head->buffer->data+ oy->fifo_head->length+oy->fifo_head->begin; /* current fragment is unused, but too small */ if(!oy->fifo_head->length){ ogg2_buffer_realloc(oy->fifo_head,bytes); return oy->fifo_head->buffer->data+oy->fifo_head->begin; } /* current fragment used/full; get new fragment */ { ogg2_reference *new=ogg2_buffer_alloc(oy->bufferpool,bytes); oy->fifo_head->next=new; oy->fifo_head=new; } return oy->fifo_head->buffer->data; } int ogg2_sync_wrote(ogg2_sync_state *oy, long bytes){ if(!oy->fifo_head)return OGG2_EINVAL; if(oy->fifo_head->buffer->size-oy->fifo_head->length-oy->fifo_head->begin < bytes)return OGG2_EINVAL; oy->fifo_head->length+=bytes; oy->fifo_fill+=bytes; return OGG2_SUCCESS; } static ogg_uint32_t _checksum(ogg2_reference *or, int bytes){ ogg_uint32_t crc_reg=0; int j,post; while(or){ unsigned char *data=or->buffer->data+or->begin; post=(byteslength?bytes:or->length); for(j=0;j> 24)&0xff)^data[j]]; bytes-=j; or=or->next; } return crc_reg; } /* 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 8*/ long ogg2_sync_pageseek(ogg2_sync_state *oy,ogg2_page *og){ ogg2byte_buffer page; long bytes,ret=0; /* don't leak a valid reference */ ogg2_page_release(og); bytes=oy->fifo_fill; ogg2byte_init(&page,oy->fifo_tail,0); if(oy->headerbytes==0){ if(bytes<27)goto sync_out; /* not enough for even a minimal header */ /* verify capture pattern */ if(ogg2byte_read1(&page,0)!=(int)'O' || ogg2byte_read1(&page,1)!=(int)'g' || ogg2byte_read1(&page,2)!=(int)'g' || ogg2byte_read1(&page,3)!=(int)'S' ) goto sync_fail; oy->headerbytes=ogg2byte_read1(&page,26)+27; } if(bytesheaderbytes)goto sync_out; /* not enough for header + seg table */ if(oy->bodybytes==0){ int i; /* count up body length in the segment table */ for(i=0;iheaderbytes-27;i++) oy->bodybytes+=ogg2byte_read1(&page,27+i); } if(oy->bodybytes+oy->headerbytes>bytes)goto sync_out; /* we have what appears to be a complete page; last test: verify checksum */ { ogg_uint32_t chksum=ogg2byte_read4(&page,22); ogg2byte_set4(&page,0,22); /* Compare checksums; memory continues to be common access */ if(chksum!=_checksum(oy->fifo_tail,oy->bodybytes+oy->headerbytes)){ /* D'oh. Mismatch! Corrupt page (or miscapture and not a page at all). replace the computed checksum with the one actually read in; remember all the memory is common access */ ogg2byte_set4(&page,chksum,22); goto sync_fail; } ogg2byte_set4(&page,chksum,22); } /* We have a page. Set up page return. */ if(og){ /* set up page output */ og->header=ogg2_buffer_split(&oy->fifo_tail,&oy->fifo_head,oy->headerbytes); og->header_len=oy->headerbytes; og->body=ogg2_buffer_split(&oy->fifo_tail,&oy->fifo_head,oy->bodybytes); og->body_len=oy->bodybytes; }else{ /* simply advance */ oy->fifo_tail= ogg2_buffer_pretruncate(oy->fifo_tail,oy->headerbytes+oy->bodybytes); if(!oy->fifo_tail)oy->fifo_head=0; } ret=oy->headerbytes+oy->bodybytes; oy->unsynced=0; oy->headerbytes=0; oy->bodybytes=0; oy->fifo_fill-=ret; return ret; sync_fail: oy->headerbytes=0; oy->bodybytes=0; oy->fifo_tail=ogg2_buffer_pretruncate(oy->fifo_tail,1); ret--; /* search forward through fragments for possible capture */ while(oy->fifo_tail){ /* invariant: fifo_cursor points to a position in fifo_tail */ unsigned char *now=oy->fifo_tail->buffer->data+oy->fifo_tail->begin; unsigned char *next=memchr(now, 'O', oy->fifo_tail->length); if(next){ /* possible capture in this segment */ long bytes=next-now; oy->fifo_tail=ogg2_buffer_pretruncate(oy->fifo_tail,bytes); ret-=bytes; break; }else{ /* no capture. advance to next segment */ long bytes=oy->fifo_tail->length; ret-=bytes; oy->fifo_tail=ogg2_buffer_pretruncate(oy->fifo_tail,bytes); } } if(!oy->fifo_tail)oy->fifo_head=0; oy->fifo_fill+=ret; sync_out: return ret; } /* sync the stream and get a page. Keep trying until we find a page. Supress 'sync errors' after reporting the first. return values: OGG2_HOLE) 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 ogg2_sync_pageout(ogg2_sync_state *oy, ogg2_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=ogg2_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 OGG2_HOLE; } /* loop. keep looking */ } } /* clear things to an initial state. Good to call, eg, before seeking */ int ogg2_sync_reset(ogg2_sync_state *oy){ ogg2_buffer_release(oy->fifo_tail); oy->fifo_tail=0; oy->fifo_head=0; oy->fifo_fill=0; oy->unsynced=0; oy->headerbytes=0; oy->bodybytes=0; return OGG2_SUCCESS; } /* checksum the page; direct table CRC */ int ogg2_page_checksum_set(ogg2_page *og){ if(og && og->header){ ogg2byte_buffer ob; ogg2_reference *or; ogg_uint32_t crc_reg=0; int j; /* safety; needed for API behavior, but not framing code */ ogg2byte_init(&ob,og->header,0); ogg2byte_set4(&ob,0,22); or=og->header; while(or){ unsigned char *data=or->buffer->data+or->begin; for(j=0;jlength;j++) crc_reg=(crc_reg<<8)^crc_lookup[((crc_reg >> 24)&0xff)^data[j]]; or=or->next; } or=og->body; while(or){ unsigned char *data=or->buffer->data+or->begin; for(j=0;jlength;j++) crc_reg=(crc_reg<<8)^crc_lookup[((crc_reg >> 24)&0xff)^data[j]]; or=or->next; } ogg2byte_set4(&ob,crc_reg,22); return OGG2_SUCCESS; } return OGG2_EINVAL; } /* ENCODING PRIMITIVES: raw stream and page layer *******************/ /* On encode side, the sync layer provides centralized memory management, buffering, and and abstraction to deal with fragmented linked buffers as an iteration over flat char buffers. ogg2_sync_encode and ogg2_sync_destroy are as in decode. */ int ogg2_sync_pagein(ogg2_sync_state *oy,ogg2_page *og){ /* buffer new */ if(oy->fifo_head) oy->fifo_head=ogg2_buffer_cat(oy->fifo_head,og->header); else oy->fifo_head=ogg2_buffer_walk(oy->fifo_tail=og->header); oy->fifo_head=ogg2_buffer_cat(oy->fifo_head,og->body); memset(og,0,sizeof(*og)); return OGG2_SUCCESS; } long ogg2_sync_bufferout(ogg2_sync_state *oy, unsigned char **buffer){ long ret=0; /* return next fragment */ while(!ret){ if(!oy->fifo_tail){ *buffer=0; return 0; } *buffer=oy->fifo_tail->buffer->data+oy->fifo_tail->begin; ret=oy->fifo_tail->length; } return ret; } int ogg2_sync_read(ogg2_sync_state *oy, long bytes){ if(!oy->fifo_tail)return OGG2_EINVAL; oy->fifo_tail=ogg2_buffer_pretruncate(oy->fifo_tail,bytes); if(!oy->fifo_tail)oy->fifo_head=0; return OGG2_SUCCESS; } void ogg2_page_dup(ogg2_page *dup,ogg2_page *orig){ dup->header_len=orig->header_len; dup->body_len=orig->body_len; dup->header=ogg2_buffer_dup(orig->header); dup->body=ogg2_buffer_dup(orig->body); } void ogg2_packet_dup(ogg2_packet *dup,ogg2_packet *orig){ dup->bytes=orig->bytes; dup->b_o_s=orig->b_o_s; dup->e_o_s=orig->e_o_s; dup->top_granule=orig->top_granule; dup->end_granule=orig->end_granule; dup->packetno=orig->packetno; dup->packet=ogg2_buffer_dup(orig->packet); }