/*****************************************************************************
- * 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>
#include <vlc_codec.h>
#include <vlc_input.h>
-#define MPGA_PACKET_SIZE 1024
-
/*****************************************************************************
* Module descriptor
*****************************************************************************/
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();
/*****************************************************************************
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
{
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;
}
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 */
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;
}
demux_sys_t *p_sys = p_demux->p_sys;
DESTROY_PACKETIZER( p_sys->p_packetizer );
-
free( p_sys );
}
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
/* 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 */
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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