diff options
| -rw-r--r-- | include/ogg/ogg.h | 4 | ||||
| -rw-r--r-- | src/framing.c | 38 |
2 files changed, 26 insertions, 16 deletions
diff --git a/include/ogg/ogg.h b/include/ogg/ogg.h index b42e4fc..db47592 100644 --- a/include/ogg/ogg.h +++ b/include/ogg/ogg.h @@ -11,7 +11,7 @@ ******************************************************************** function: toplevel libogg include - last mod: $Id: ogg.h,v 1.11 2001/05/24 01:04:36 xiphmont Exp $ + last mod: $Id: ogg.h,v 1.12 2001/11/24 07:49:31 xiphmont Exp $ ********************************************************************/ #ifndef _OGG_H @@ -155,6 +155,8 @@ extern int ogg_stream_reset(ogg_stream_state *os); extern int ogg_stream_destroy(ogg_stream_state *os); extern int ogg_stream_eos(ogg_stream_state *os); +extern void ogg_page_checksum_set(ogg_page *og); + extern int ogg_page_version(ogg_page *og); extern int ogg_page_continued(ogg_page *og); extern int ogg_page_bos(ogg_page *og); diff --git a/src/framing.c b/src/framing.c index bdb097f..041344a 100644 --- a/src/framing.c +++ b/src/framing.c @@ -12,7 +12,7 @@ function: code raw [Vorbis] packets into framed OggSquish stream and decode Ogg streams back into raw packets - last mod: $Id: framing.c,v 1.18 2001/11/24 06:19:46 xiphmont Exp $ + last mod: $Id: framing.c,v 1.19 2001/11/24 07:49:32 xiphmont Exp $ note: The CRC code is directly derived from public domain code by Ross Williams (ross@guest.adelaide.edu.au). See docs/framing.html @@ -244,19 +244,27 @@ static void _os_lacing_expand(ogg_stream_state *os,int needed){ /* Direct table CRC; note that this will be faster in the future if we perform the checksum silmultaneously with other copies */ -static void _os_checksum(ogg_page *og){ - ogg_uint32_t crc_reg=0; - int i; +void ogg_page_checksum_set(ogg_page *og){ + if(og){ + ogg_uint32_t crc_reg=0; + int i; - 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; + /* 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; + } } /* submit data to the internal buffer of the framing engine */ @@ -424,7 +432,7 @@ int ogg_stream_flush(ogg_stream_state *os,ogg_page *og){ /* calculate the checksum */ - _os_checksum(og); + ogg_page_checksum_set(og); /* done */ return(1); @@ -573,7 +581,7 @@ long ogg_sync_pageseek(ogg_sync_state *oy,ogg_page *og){ log.header_len=oy->headerbytes; log.body=page+oy->headerbytes; log.body_len=oy->bodybytes; - _os_checksum(&log); + ogg_page_checksum_set(&log); /* Compare */ if(memcmp(chksum,page+22,4)){ |