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Commit b1f8dfcb authored by Laurent Aimar's avatar Laurent Aimar
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Reworked mp3 demuxer to allow generic ES demuxer.

parent d3d941a6
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modules/demux/mpeg/mpga.c
View file @ b1f8dfcb
/*****************************************************************************
* mpga.c : MPEG-I/II Audio input module for vlc
* es.c : Generic audio ES input module for vlc
*****************************************************************************
* Copyright (C) 2001-2004 the VideoLAN team
* Copyright (C) 2001-2008 the VideoLAN team
* $Id$
*
* Authors: Laurent Aimar <fenrir@via.ecp.fr>
......@@ -36,8 +36,6 @@
#include <vlc_codec.h>
#include <vlc_input.h>
#define MPGA_PACKET_SIZE 1024
/*****************************************************************************
* Module descriptor
*****************************************************************************/
......@@ -50,8 +48,12 @@ vlc_module_begin();
set_description( N_("MPEG audio / MP3 demuxer" ) );
set_capability( "demux", 100 );
set_callbacks( Open, Close );
add_shortcut( "mpga" );
add_shortcut( "mp3" );
//add_shortcut( "ac3" );
//add_shortcut( "a52" );
vlc_module_end();
/*****************************************************************************
......@@ -69,48 +71,29 @@ struct demux_sys_t
mtime_t i_pts;
mtime_t i_time_offset;
int i_bitrate_avg; /* extracted from Xing header */
bool b_initial_sync_failed;
int i_xing_frames;
int i_xing_bytes;
int i_xing_bitrate_avg;
int i_xing_frame_samples;
};
int i_packet_size;
static int HeaderCheck( uint32_t h )
{
if( ((( h >> 21 )&0x07FF) != 0x07FF ) /* header sync */
|| (((h >> 17)&0x03) == 0 ) /* valid layer ?*/
|| (((h >> 12)&0x0F) == 0x0F )
|| (((h >> 12)&0x0F) == 0x00 ) /* valid bitrate ? */
|| (((h >> 10) & 0x03) == 0x03 ) /* valide sampling freq ? */
|| ((h & 0x03) == 0x02 )) /* valid emphasis ? */
int64_t i_stream_offset;
/* Mpga specific */
struct
{
return false;
}
return true;
}
int i_frames;
int i_bytes;
int i_bitrate_avg;
int i_frame_samples;
} xing;
};
#define MPGA_VERSION( h ) ( 1 - (((h)>>19)&0x01) )
#define MPGA_LAYER( h ) ( 3 - (((h)>>17)&0x03) )
#define MPGA_MODE(h) (((h)>> 6)&0x03)
#define FCC_MPGA VLC_FOURCC( 'm', 'p', 'g', 'a' )
static int mpga_frame_samples( uint32_t h )
{
switch( MPGA_LAYER(h) )
{
case 0:
return 384;
case 1:
return 1152;
case 2:
return MPGA_VERSION(h) ? 576 : 1152;
default:
return 0;
}
}
static int MpgaProbe( demux_t *p_demux, int64_t *pi_offset );
static int MpgaInit( demux_t *p_demux );
/*****************************************************************************
* Open: initializes demux structures
......@@ -119,116 +102,36 @@ static int Open( vlc_object_t * p_this )
{
demux_t *p_demux = (demux_t*)p_this;
demux_sys_t *p_sys;
bool b_forced = false;
uint32_t header;
const uint8_t *p_peek;
if( demux_IsPathExtension( p_demux, ".mp3" ) )
b_forced = true;
if( stream_Peek( p_demux->s, &p_peek, 4 ) < 4 ) return VLC_EGENERIC;
if( !HeaderCheck( header = GetDWBE( p_peek ) ) )
{
bool b_ok = false;
int i_peek;
if( !p_demux->b_force && !b_forced ) return VLC_EGENERIC;
int64_t i_offset;
i_peek = stream_Peek( p_demux->s, &p_peek, 8096 );
while( i_peek > 4 )
{
if( HeaderCheck( header = GetDWBE( p_peek ) ) )
{
b_ok = true;
break;
}
p_peek += 1;
i_peek -= 1;
}
if( !b_ok && !p_demux->b_force ) return VLC_EGENERIC;
}
if( MpgaProbe( p_demux, &i_offset ) )
return VLC_EGENERIC;
DEMUX_INIT_COMMON(); p_sys = p_demux->p_sys;
memset( p_sys, 0, sizeof( demux_sys_t ) );
p_sys->p_es = 0;
p_sys->p_es = NULL;
p_sys->b_start = true;
p_sys->i_stream_offset = i_offset;
p_sys->i_bitrate_avg = 0;
/* Load the mpeg audio packetizer */
INIT_APACKETIZER( p_sys->p_packetizer, 'm', 'p', 'g', 'a' );
es_format_Init( &p_sys->p_packetizer->fmt_out, UNKNOWN_ES, 0 );
LOAD_PACKETIZER_OR_FAIL( p_sys->p_packetizer, "mpga" );
/* Xing header */
if( HeaderCheck( header ) )
if( stream_Seek( p_demux->s, p_sys->i_stream_offset ) )
{
int i_xing, i_skip;
const uint8_t *p_xing;
if( ( i_xing = stream_Peek( p_demux->s, &p_xing, 1024 ) ) < 21 )
return VLC_SUCCESS; /* No header */
if( MPGA_VERSION( header ) == 0 )
{
i_skip = MPGA_MODE( header ) != 3 ? 36 : 21;
}
else
{
i_skip = MPGA_MODE( header ) != 3 ? 21 : 13;
}
if( i_skip + 8 < i_xing && !strncmp( (char *)&p_xing[i_skip], "Xing", 4 ) )
{
unsigned int i_flags = GetDWBE( &p_xing[i_skip+4] );
p_xing += i_skip + 8;
i_xing -= i_skip + 8;
i_skip = 0;
if( i_flags&0x01 && i_skip + 4 <= i_xing ) /* XING_FRAMES */
{
p_sys->i_xing_frames = GetDWBE( &p_xing[i_skip] );
i_skip += 4;
}
if( i_flags&0x02 && i_skip + 4 <= i_xing ) /* XING_BYTES */
{
p_sys->i_xing_bytes = GetDWBE( &p_xing[i_skip] );
i_skip += 4;
}
if( i_flags&0x04 ) /* XING_TOC */
{
i_skip += 100;
}
// FIXME: doesn't return the right bitrage average, at least
// with some MP3's
if( i_flags&0x08 && i_skip + 4 <= i_xing ) /* XING_VBR */
{
p_sys->i_xing_bitrate_avg = GetDWBE( &p_xing[i_skip] );
msg_Dbg( p_demux, "xing vbr value present (%d)",
p_sys->i_xing_bitrate_avg );
}
if( p_sys->i_xing_frames > 0 && p_sys->i_xing_bytes > 0 )
{
p_sys->i_xing_frame_samples = mpga_frame_samples( header );
msg_Dbg( p_demux, "xing frames&bytes value present "
"(%d bytes, %d frames, %d samples/frame)",
p_sys->i_xing_bytes, p_sys->i_xing_frames,
p_sys->i_xing_frame_samples );
}
}
free( p_sys );
return VLC_EGENERIC;
}
if( p_sys->i_xing_bytes && p_sys->i_xing_frames &&
p_sys->i_xing_frame_samples )
if( MpgaInit( p_demux ) )
{
p_sys->i_bitrate_avg = p_sys->i_xing_bytes * INT64_C(8) *
p_sys->p_packetizer->fmt_out.audio.i_rate /
p_sys->i_xing_frames / p_sys->i_xing_frame_samples;
free( p_sys );
return VLC_EGENERIC;
}
/* Load the mpeg audio packetizer */
INIT_APACKETIZER( p_sys->p_packetizer, 'm', 'p', 'g', 'a' );
es_format_Init( &p_sys->p_packetizer->fmt_out, UNKNOWN_ES, 0 );
LOAD_PACKETIZER_OR_FAIL( p_sys->p_packetizer, "mpga" );
return VLC_SUCCESS;
}
......@@ -242,10 +145,8 @@ static int Demux( demux_t *p_demux )
demux_sys_t *p_sys = p_demux->p_sys;
block_t *p_block_in, *p_block_out;
if( ( p_block_in = stream_Block( p_demux->s, MPGA_PACKET_SIZE ) ) == NULL )
{
if( ( p_block_in = stream_Block( p_demux->s, p_sys->i_packet_size ) ) == NULL )
return 0;
}
p_block_in->i_pts = p_block_in->i_dts = p_sys->b_start || p_sys->b_initial_sync_failed ? 1 : 0;
p_sys->b_initial_sync_failed = p_sys->b_start; /* Only try to resync once */
......@@ -263,6 +164,16 @@ static int Demux( demux_t *p_demux )
p_sys->p_es = es_out_Add( p_demux->out,
&p_sys->p_packetizer->fmt_out);
/* Try the xing header */
if( p_sys->xing.i_bytes && p_sys->xing.i_frames &&
p_sys->xing.i_frame_samples )
{
p_sys->i_bitrate_avg = p_sys->xing.i_bytes * INT64_C(8) *
p_sys->p_packetizer->fmt_out.audio.i_rate /
p_sys->xing.i_frames / p_sys->xing.i_frame_samples;
}
/* Use the bitrate */
if( p_sys->i_bitrate_avg <= 0 )
p_sys->i_bitrate_avg = p_sys->p_packetizer->fmt_out.i_bitrate;
}
......@@ -296,7 +207,6 @@ static void Close( vlc_object_t * p_this )
demux_sys_t *p_sys = p_demux->p_sys;
DESTROY_PACKETIZER( p_sys->p_packetizer );
free( p_sys );
}
......@@ -326,7 +236,7 @@ static int Control( demux_t *p_demux, int i_query, va_list args )
return VLC_SUCCESS;
case DEMUX_GET_LENGTH:
i_ret = demux_vaControlHelper( p_demux->s, 0, -1,
i_ret = demux_vaControlHelper( p_demux->s, p_sys->i_stream_offset, -1,
p_sys->i_bitrate_avg, 1, i_query,
args );
/* No bitrate, we can't have it precisely, but we can compute
......@@ -352,13 +262,13 @@ static int Control( demux_t *p_demux, int i_query, va_list args )
/* FIXME TODO: implement a high precision seek (with mp3 parsing)
* needed for multi-input */
default:
i_ret = demux_vaControlHelper( p_demux->s, 0, -1,
i_ret = demux_vaControlHelper( p_demux->s, p_sys->i_stream_offset, -1,
p_sys->i_bitrate_avg, 1, i_query,
args );
if( !i_ret && p_sys->i_bitrate_avg > 0 &&
(i_query == DEMUX_SET_POSITION || i_query == DEMUX_SET_TIME) )
{
int64_t i_time = INT64_C(8000000) * stream_Tell(p_demux->s) /
int64_t i_time = INT64_C(8000000) * ( stream_Tell(p_demux->s) - p_sys->i_stream_offset ) /
p_sys->i_bitrate_avg;
/* Fix time_offset */
......@@ -368,3 +278,168 @@ static int Control( demux_t *p_demux, int i_query, va_list args )
return i_ret;
}
}
/*****************************************************************************
* Mpeg I/II Audio
*****************************************************************************/
static int CheckSyncMpga( const uint8_t *p_peek )
{
uint32_t h = GetDWBE( p_peek );
if( ((( h >> 21 )&0x07FF) != 0x07FF ) /* header sync */
|| (((h >> 17)&0x03) == 0 ) /* valid layer ?*/
|| (((h >> 12)&0x0F) == 0x0F )
|| (((h >> 12)&0x0F) == 0x00 ) /* valid bitrate ? */
|| (((h >> 10) & 0x03) == 0x03 ) /* valide sampling freq ? */
|| ((h & 0x03) == 0x02 )) /* valid emphasis ? */
{
return false;
}
return true;
}
#define MPGA_VERSION( h ) ( 1 - (((h)>>19)&0x01) )
#define MPGA_MODE(h) (((h)>> 6)&0x03)
static int MpgaGetFrameSamples( uint32_t h )
{
const int i_layer = 3 - (((h)>>17)&0x03);
switch( i_layer )
{
case 0:
return 384;
case 1:
return 1152;
case 2:
return MPGA_VERSION(h) ? 576 : 1152;
default:
return 0;
}
}
static int MpgaProbe( demux_t *p_demux, int64_t *pi_offset )
{
bool b_forced;
bool b_forced_demux;
int64_t i_offset;
const uint8_t *p_peek;
b_forced = demux_IsPathExtension( p_demux, ".mp3" );
b_forced_demux = demux_IsForced( p_demux, "mp3" ) ||
demux_IsForced( p_demux, "mpga" );
i_offset = stream_Tell( p_demux->s );
if( stream_Peek( p_demux->s, &p_peek, 4 ) < 4 )
return VLC_EGENERIC;
if( !CheckSyncMpga( p_peek ) )
{
bool b_ok = false;
int i_peek;
if( !b_forced_demux && !b_forced )
return VLC_EGENERIC;
i_peek = stream_Peek( p_demux->s, &p_peek, 8096 );
while( i_peek > 4 )
{
if( CheckSyncMpga( p_peek ) )
{
b_ok = true;
break;
}
p_peek += 1;
i_peek -= 1;
i_offset++;
}
if( !b_ok && !b_forced_demux )
return VLC_EGENERIC;
}
*pi_offset = i_offset;
return VLC_SUCCESS;
}
static void MpgaXingSkip( const uint8_t **pp_xing, int *pi_xing, int i_count )
{
if(i_count > *pi_xing )
i_count = *pi_xing;
(*pp_xing) += i_count;
(*pi_xing) -= i_count;
}
static uint32_t MpgaXingGetDWBE( const uint8_t **pp_xing, int *pi_xing, uint32_t i_default )
{
if( *pi_xing < 4 )
return i_default;
uint32_t v = GetDWBE( *pp_xing );
MpgaXingSkip( pp_xing, pi_xing, 4 );
return v;
}
static int MpgaInit( demux_t *p_demux )
{
demux_sys_t *p_sys = p_demux->p_sys;
const uint8_t *p_peek;
int i_peek;
/* */
p_sys->i_packet_size = 1024;
/* Load a potential xing header */
i_peek = stream_Peek( p_demux->s, &p_peek, 4 + 1024 );
if( i_peek < 4 + 21 )
return VLC_SUCCESS;
const uint32_t header = GetDWBE( p_peek );
if( !CheckSyncMpga( p_peek ) )
return VLC_SUCCESS;
/* Xing header */
const uint8_t *p_xing = p_peek;
int i_xing = i_peek;
int i_skip;
if( MPGA_VERSION( header ) == 0 )
i_skip = MPGA_MODE( header ) != 3 ? 36 : 21;
else
i_skip = MPGA_MODE( header ) != 3 ? 21 : 13;
if( i_skip + 8 >= i_xing || memcmp( &p_xing[i_skip], "Xing", 4 ) )
return VLC_SUCCESS;
const uint32_t i_flags = GetDWBE( &p_xing[i_skip+4] );
MpgaXingSkip( &p_xing, &i_xing, i_skip + 8 );
if( i_flags&0x01 )
p_sys->xing.i_frames = MpgaXingGetDWBE( &p_xing, &i_xing, 0 );
if( i_flags&0x02 )
p_sys->xing.i_bytes = MpgaXingGetDWBE( &p_xing, &i_xing, 0 );
if( i_flags&0x04 ) /* TODO Support XING TOC to improve seeking accuracy */
MpgaXingSkip( &p_xing, &i_xing, 100 );
if( i_flags&0x08 )
{
/* FIXME: doesn't return the right bitrage average, at least
with some MP3's */
p_sys->xing.i_bitrate_avg = MpgaXingGetDWBE( &p_xing, &i_xing, 0 );
msg_Dbg( p_demux, "xing vbr value present (%d)",
p_sys->xing.i_bitrate_avg );
}
if( p_sys->xing.i_frames > 0 && p_sys->xing.i_bytes > 0 )
{
p_sys->xing.i_frame_samples = MpgaGetFrameSamples( header );
msg_Dbg( p_demux, "xing frames&bytes value present "
"(%d bytes, %d frames, %d samples/frame)",
p_sys->xing.i_bytes, p_sys->xing.i_frames,
p_sys->xing.i_frame_samples );
}
return VLC_SUCCESS;
}
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