[vlc-devel] commit: Improved a52 in wav detection robustness. (Laurent Aimar )
git version control
git at videolan.org
Mon Apr 13 22:44:06 CEST 2009
vlc | branch: master | Laurent Aimar <fenrir at videolan.org> | Mon Apr 13 22:37:56 2009 +0200| [f509c1c4a3b6c308804579000e438229a28b1a3d] | committer: Laurent Aimar
Improved a52 in wav detection robustness.
It fixes #2648.
> http://git.videolan.org/gitweb.cgi/vlc.git/?a=commit;h=f509c1c4a3b6c308804579000e438229a28b1a3d
---
modules/demux/mpeg/es.c | 85 +++++++++++++++++++++++++++--------------------
1 files changed, 49 insertions(+), 36 deletions(-)
diff --git a/modules/demux/mpeg/es.c b/modules/demux/mpeg/es.c
index 862f102..abe04dc 100644
--- a/modules/demux/mpeg/es.c
+++ b/modules/demux/mpeg/es.c
@@ -36,6 +36,8 @@
#include <vlc_codec.h>
#include <vlc_input.h>
+#include "../../codec/a52.h"
+
/*****************************************************************************
* Module descriptor
*****************************************************************************/
@@ -639,7 +641,7 @@ static int WavSkipHeader( demux_t *p_demux, int *pi_skip )
static int GenericProbe( demux_t *p_demux, int64_t *pi_offset,
const char * ppsz_name[],
- bool (*pf_check)( const uint8_t * ), int i_check_size )
+ int (*pf_check)( const uint8_t * ), int i_check_size )
{
bool b_forced_demux;
@@ -679,8 +681,20 @@ static int GenericProbe( demux_t *p_demux, int64_t *pi_offset,
return VLC_EGENERIC;
break;
}
- if( pf_check( &p_peek[i_skip] ) )
- break;
+ const int i_size = pf_check( &p_peek[i_skip] );
+ if( i_size >= 0 )
+ {
+ if( i_size == 0 || 1)
+ break;
+
+ /* If we have the frame size, check the next frame for
+ * extra robustness */
+ if( i_skip + i_check_size + i_size <= i_peek )
+ {
+ if( pf_check( &p_peek[i_skip+i_size] ) >= 0 )
+ break;
+ }
+ }
i_skip++;
}
@@ -691,28 +705,26 @@ static int GenericProbe( demux_t *p_demux, int64_t *pi_offset,
/*****************************************************************************
* A52
*****************************************************************************/
-static bool A52CheckSync( const uint8_t *p_peek, bool *p_big_endian, bool b_eac3 )
+static int A52CheckSync( const uint8_t *p_peek, bool *p_big_endian, bool b_eac3 )
{
- /* bsid: 0-8 11-16 */
+ vlc_a52_header_t header;
+ uint8_t p_tmp[VLC_A52_HEADER_SIZE];
- /* Little endian version of the bitstream */
- if( p_peek[0] == 0x77 && p_peek[1] == 0x0b &&
- ( p_peek[4] >> 3 ) <= ( b_eac3 ? 16 : 10 ) /* bsid */ )
+ *p_big_endian = p_peek[0] == 0x0b && p_peek[1] == 0x77;
+ if( !*p_big_endian )
{
- *p_big_endian = false;
- return true;
- }
- /* Big endian version of the bitstream */
- else if( p_peek[0] == 0x0b && p_peek[1] == 0x77 &&
- ( p_peek[5] >> 3 ) <= ( b_eac3 ? 16 : 10 ) /* bsid */ )
- {
- *p_big_endian = true;
- return true;
+ swab( p_peek, p_tmp, VLC_A52_HEADER_SIZE );
+ p_peek = p_tmp;
}
- return false;
+ if( vlc_a52_header_Parse( &header, p_peek, VLC_A52_HEADER_SIZE ) )
+ return VLC_EGENERIC;
+
+ if( !header.b_eac3 != !b_eac3 )
+ return VLC_EGENERIC;
+ return header.i_size;
}
-static bool EA52CheckSyncProbe( const uint8_t *p_peek )
+static int EA52CheckSyncProbe( const uint8_t *p_peek )
{
bool b_dummy;
return A52CheckSync( p_peek, &b_dummy, true );
@@ -722,10 +734,10 @@ static int EA52Probe( demux_t *p_demux, int64_t *pi_offset )
{
const char *ppsz_name[] = { "eac3", NULL };
- return GenericProbe( p_demux, pi_offset, ppsz_name, EA52CheckSyncProbe, 10 );
+ return GenericProbe( p_demux, pi_offset, ppsz_name, EA52CheckSyncProbe, VLC_A52_HEADER_SIZE );
}
-static bool A52CheckSyncProbe( const uint8_t *p_peek )
+static int A52CheckSyncProbe( const uint8_t *p_peek )
{
bool b_dummy;
return A52CheckSync( p_peek, &b_dummy, false );
@@ -735,7 +747,7 @@ static int A52Probe( demux_t *p_demux, int64_t *pi_offset )
{
const char *ppsz_name[] = { "a52", "ac3", NULL };
- return GenericProbe( p_demux, pi_offset, ppsz_name, A52CheckSyncProbe, 10 );
+ return GenericProbe( p_demux, pi_offset, ppsz_name, A52CheckSyncProbe, VLC_A52_HEADER_SIZE );
}
static int A52Init( demux_t *p_demux )
@@ -747,8 +759,8 @@ static int A52Init( demux_t *p_demux )
const uint8_t *p_peek;
- /* peek the begining (10 is for a52 header) */
- if( stream_Peek( p_demux->s, &p_peek, 10 ) >= 10 )
+ /* peek the begining */
+ if( stream_Peek( p_demux->s, &p_peek, VLC_A52_HEADER_SIZE ) >= VLC_A52_HEADER_SIZE )
{
A52CheckSync( p_peek, &p_sys->b_big_endian, true );
}
@@ -758,36 +770,38 @@ static int A52Init( demux_t *p_demux )
/*****************************************************************************
* DTS
*****************************************************************************/
-static bool DtsCheckSync( const uint8_t *p_peek )
+static int DtsCheckSync( const uint8_t *p_peek )
{
+ /* TODO return frame size for robustness */
+
/* 14 bits, little endian version of the bitstream */
if( p_peek[0] == 0xff && p_peek[1] == 0x1f &&
p_peek[2] == 0x00 && p_peek[3] == 0xe8 &&
(p_peek[4] & 0xf0) == 0xf0 && p_peek[5] == 0x07 )
{
- return true;
+ return 0;
}
/* 14 bits, big endian version of the bitstream */
else if( p_peek[0] == 0x1f && p_peek[1] == 0xff &&
p_peek[2] == 0xe8 && p_peek[3] == 0x00 &&
p_peek[4] == 0x07 && (p_peek[5] & 0xf0) == 0xf0)
{
- return true;
+ return 0;
}
/* 16 bits, big endian version of the bitstream */
else if( p_peek[0] == 0x7f && p_peek[1] == 0xfe &&
p_peek[2] == 0x80 && p_peek[3] == 0x01 )
{
- return true;
+ return 0;
}
/* 16 bits, little endian version of the bitstream */
else if( p_peek[0] == 0xfe && p_peek[1] == 0x7f &&
p_peek[2] == 0x01 && p_peek[3] == 0x80 )
{
- return true;
+ return 0;
}
- return false;
+ return VLC_EGENERIC;
}
static int DtsProbe( demux_t *p_demux, int64_t *pi_offset )
@@ -808,17 +822,16 @@ static int DtsInit( demux_t *p_demux )
/*****************************************************************************
* MLP
*****************************************************************************/
-static bool MlpCheckSync( const uint8_t *p_peek )
+static int MlpCheckSync( const uint8_t *p_peek )
{
if( p_peek[4+0] != 0xf8 || p_peek[4+1] != 0x72 || p_peek[4+2] != 0x6f )
- return false;
+ return -1;
if( p_peek[4+3] != 0xba && p_peek[4+3] != 0xbb )
- return false;
+ return -1;
- /* TODO checksum */
-
- return true;
+ /* TODO checksum and real size for robustness */
+ return 0;
}
static int MlpProbe( demux_t *p_demux, int64_t *pi_offset )
{
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