Added suggested public API exposure for regenerating checksum.
svn path=/trunk/ogg/; revision=2405
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_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 @@
/* 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 @@
/* calculate the checksum */
- _os_checksum(og);
+ ogg_page_checksum_set(og);
/* done */
return(1);
@@ -573,7 +581,7 @@
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)){
