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Xiph.Org
Ogg
Commits
bc82844d
Commit
bc82844d
authored
Apr 30, 2018
by
Robert Kausch
1
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Switch to slicing-by-8 CRC32 algorithm.
parent
c8391c2b
Changes
3
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3 changed files
with
323 additions
and
89 deletions
+323
-89
src/Makefile.am
src/Makefile.am
+2
-2
src/crctable.h
src/crctable.h
+278
-0
src/framing.c
src/framing.c
+43
-87
No files found.
src/Makefile.am
View file @
bc82844d
...
...
@@ -4,7 +4,7 @@ AM_CPPFLAGS = -I$(top_srcdir)/include -I$(top_builddir)/include
lib_LTLIBRARIES
=
libogg.la
libogg_la_SOURCES
=
framing.c bitwise.c
libogg_la_SOURCES
=
framing.c bitwise.c
crctable.h
libogg_la_LDFLAGS
=
-no-undefined
-version-info
@LIB_CURRENT@:@LIB_REVISION@:@LIB_AGE@
# build and run the self tests on 'make check'
...
...
@@ -14,7 +14,7 @@ noinst_PROGRAMS = test_bitwise test_framing
test_bitwise_SOURCES
=
bitwise.c
test_bitwise_CFLAGS
=
-D_V_SELFTEST
test_framing_SOURCES
=
framing.c
test_framing_SOURCES
=
framing.c
crctable.h
test_framing_CFLAGS
=
-D_V_SELFTEST
check
:
$(noinst_PROGRAMS)
...
...
src/crctable.h
0 → 100644
View file @
bc82844d
This diff is collapsed.
Click to expand it.
src/framing.c
View file @
bc82844d
...
...
@@ -5,7 +5,7 @@
* 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 1994-201
0
*
* THE OggVorbis SOURCE CODE IS (C) COPYRIGHT 1994-201
8
*
* by the Xiph.Org Foundation http://www.xiph.org/ *
* *
********************************************************************
...
...
@@ -102,90 +102,31 @@ int ogg_page_packets(const ogg_page *og){
#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);
use the static init in crctable.h) */
static void _ogg_crc_init(){
int i, j;
ogg_uint32_t polynomial, crc;
polynomial = 0x04c11db7; /* The same as the ethernet generator
polynomial, although we use an
unreflected alg and an init/final
of 0, not 0xffffffff */
for (i = 0; i <= 0xFF; i++){
crc = i << 24;
for (j = 0; j < 8; j++)
crc = (crc << 1) ^ (crc & (1 << 31) ? polynomial : 0);
crc_lookup[0][i] = crc;
}
for (i = 0; i <= 0xFF; i++)
for (j = 1; j < 8; j++)
crc_lookup[j][i] = crc_lookup[0][(crc_lookup[j - 1][i] >> 24) & 0xFF] ^ (crc_lookup[j - 1][i] << 8);
}
#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
};
#include "crctable.h"
/* init the encode/decode logical stream state */
...
...
@@ -293,10 +234,27 @@ static int _os_lacing_expand(ogg_stream_state *os,long needed){
/* Direct table CRC; note that this will be faster in the future if we
perform the checksum simultaneously with other copies */
static
ogg_uint32_t
_os_update_crc
(
ogg_uint32_t
crc
,
unsigned
char
*
buffer
,
int
size
){
while
(
size
>=
8
){
crc
^=
buffer
[
0
]
<<
24
|
buffer
[
1
]
<<
16
|
buffer
[
2
]
<<
8
|
buffer
[
3
];
crc
=
crc_lookup
[
7
][
crc
>>
24
]
^
crc_lookup
[
6
][(
crc
>>
16
)
&
0xFF
]
^
crc_lookup
[
5
][(
crc
>>
8
)
&
0xFF
]
^
crc_lookup
[
4
][
crc
&
0xFF
]
^
crc_lookup
[
3
][
buffer
[
4
]
]
^
crc_lookup
[
2
][
buffer
[
5
]
]
^
crc_lookup
[
1
][
buffer
[
6
]
]
^
crc_lookup
[
0
][
buffer
[
7
]
];
buffer
+=
8
;
size
-=
8
;
}
while
(
size
--
)
crc
=
(
crc
<<
8
)
^
crc_lookup
[
0
][((
crc
>>
24
)
&
0xff
)
^*
buffer
++
];
return
crc
;
}
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
;
...
...
@@ -304,10 +262,8 @@ void ogg_page_checksum_set(ogg_page *og){
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
]];
crc_reg
=
_os_update_crc
(
crc_reg
,
og
->
header
,
og
->
header_len
);
crc_reg
=
_os_update_crc
(
crc_reg
,
og
->
body
,
og
->
body_len
);
og
->
header
[
22
]
=
(
unsigned
char
)(
crc_reg
&
0xff
);
og
->
header
[
23
]
=
(
unsigned
char
)((
crc_reg
>>
8
)
&
0xff
);
...
...
Tristan Matthews
@tmatth
mentioned in issue
#2297 (closed)
·
Mar 01, 2019
mentioned in issue
#2297 (closed)
mentioned in issue #2297
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