* modules/demux/a52.c: rewritten from scratch to use the a52 packetizer and to handle a52 wav files and audio CD's.
* modules/codec/a52.c: a52 wav files and audio CD's use padding so don't always check for next sync code.

modules/codec/a52.c

@@ -2,7 +2,7 @@
  * a52.c: parse A/52 audio sync info and packetize the stream
  *****************************************************************************
  * Copyright (C) 2001-2002 VideoLAN
- * $Id: a52.c,v 1.32 2003/12/22 14:32:55 sam Exp $
+ * $Id: a52.c,v 1.33 2004/02/13 21:48:32 gbazin Exp $
  *
  * Authors: Stphane Borel <stef@via.ecp.fr>
  *          Christophe Massiot <massiot@via.ecp.fr>
@@ -248,6 +248,14 @@ static void *DecodeBlock( decoder_t *p_dec, block_t **pp_block )
                 return NULL;
             }
 
+            if( p_sys->b_packetizer &&
+                p_header[0] == 0 && p_header[1] == 0 )
+            {
+                /* A52 wav files and audio CD's use stuffing */
+                p_sys->i_state = STATE_GET_DATA;
+                break;
+            }
+
             if( p_header[0] != 0x0b || p_header[1] != 0x77 )
             {
                 msg_Dbg( p_dec, "emulated sync word "

modules/demux/Modules.am

-SOURCES_a52sys = a52sys.c
+SOURCES_a52sys = a52.c
 SOURCES_dtssys = dts.c
 SOURCES_flac = flac.c
 SOURCES_ogg = ogg.c

modules/demux/a52.c

+/*****************************************************************************
+ * a52.c : raw A/52 stream input module for vlc
+ *****************************************************************************
+ * Copyright (C) 2001 VideoLAN
+ * $Id: a52.c,v 1.1 2004/02/13 21:48:32 gbazin Exp $
+ *
+ * Authors: Gildas Bazin <gbazin@netcourrier.com>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA  02111, USA.
+ *****************************************************************************/
+
+/*****************************************************************************
+ * Preamble
+ *****************************************************************************/
+#include <vlc/vlc.h>
+#include <vlc/input.h>
+#include <vlc_codec.h>
+
+#define A52_PACKET_SIZE 16384
+#define A52_MAX_HEADER_SIZE 11
+
+/*****************************************************************************
+ * Local prototypes
+ *****************************************************************************/
+static int  Open  ( vlc_object_t * );
+static void Close ( vlc_object_t * );
+static int  Demux ( input_thread_t * );
+
+static int Control( input_thread_t *, int, va_list );
+
+struct demux_sys_t
+{
+    vlc_bool_t  b_start;
+    es_out_id_t *p_es;
+
+    /* Packetizer */
+    decoder_t *p_packetizer;
+
+    int i_mux_rate;
+    vlc_bool_t b_big_endian;
+};
+
+/*****************************************************************************
+ * Module descriptor
+ *****************************************************************************/
+vlc_module_begin();
+    set_description( _("Raw A/52 demuxer") );
+    set_capability( "demux", 155 );
+    set_callbacks( Open, Close );
+    add_shortcut( "a52" );
+vlc_module_end();
+
+/*****************************************************************************
+ * CheckSync: Check if buffer starts with an A52 sync code
+ *****************************************************************************/
+int CheckSync( uint8_t *p_peek, vlc_bool_t *p_big_endian )
+{
+    /* Little endian version of the bitstream */
+    if( p_peek[0] == 0x77 && p_peek[1] == 0x0b &&
+        p_peek[4] < 0x60 /* bsid < 12 */ )
+    {
+        return VLC_SUCCESS;
+    }
+    /* Big endian version of the bitstream */
+    else if( p_peek[0] == 0x0b && p_peek[1] == 0x77 &&
+             p_peek[5] < 0x60 /* bsid < 12 */ )
+    {
+        return VLC_SUCCESS;
+    }
+
+    return VLC_EGENERIC;
+}
+
+/*****************************************************************************
+ * Open: initializes ES structures
+ *****************************************************************************/
+static int Open( vlc_object_t * p_this )
+{
+    input_thread_t *p_input = (input_thread_t *)p_this;
+    demux_sys_t    *p_sys;
+    byte_t *       p_peek;
+    int            i_peek = 0;
+    vlc_bool_t     b_big_endian;
+
+    p_input->pf_demux = Demux;
+    p_input->pf_demux_control = Control;
+    p_input->pf_rewind = NULL;
+
+    /* Check if we are dealing with a WAV file */
+    if( input_Peek( p_input, &p_peek, 12 ) == 12 &&
+        !strncmp( p_peek, "RIFF", 4 ) && !strncmp( &p_peek[8], "WAVE", 4 ) )
+    {
+        int i_size;
+
+        /* Skip the wave header */
+        i_peek = 12 + 8;
+        while( input_Peek( p_input, &p_peek, i_peek ) == i_peek &&
+               strncmp( p_peek + i_peek - 8, "data", 4 ) )
+        {
+            i_peek += GetDWLE( p_peek + i_peek - 4 ) + 8;
+        }
+
+        /* TODO: should check wave format and sample_rate */
+
+        /* Some A52 wav files don't begin with a sync code so we do a more
+         * extensive search */
+        i_size = input_Peek( p_input, &p_peek, i_peek + A52_PACKET_SIZE * 2);
+        i_size -= A52_MAX_HEADER_SIZE;
+
+        while( i_peek < i_size )
+        {
+            if( CheckSync( p_peek + i_peek, &b_big_endian ) != VLC_SUCCESS )
+                /* The data is stored in 16 bits words */
+                i_peek += 2;
+            else
+                break;
+        }
+    }
+
+    /* Have a peep at the show. */
+    if( input_Peek( p_input, &p_peek, i_peek + A52_MAX_HEADER_SIZE * 2 ) <
+        i_peek + A52_MAX_HEADER_SIZE * 2 )
+    {
+        /* Stream too short */
+        msg_Warn( p_input, "cannot peek()" );
+        return VLC_EGENERIC;
+    }
+
+    if( CheckSync( p_peek + i_peek, &b_big_endian ) != VLC_SUCCESS )
+    {
+        if( p_input->psz_demux && !strncmp( p_input->psz_demux, "a52", 3 ) )
+        {
+            /* User forced */
+            msg_Err( p_input, "this doesn't look like a A52 audio stream, "
+                     "continuing anyway" );
+        }
+        else
+        {
+            return VLC_EGENERIC;
+        }
+    }
+
+    p_input->p_demux_data = p_sys = malloc( sizeof( demux_sys_t ) );
+    p_sys->b_start = VLC_TRUE;
+    p_sys->i_mux_rate = 0;
+    p_sys->b_big_endian = b_big_endian;
+
+    /*
+     * Load the A52 packetizer
+     */
+    p_sys->p_packetizer = vlc_object_create( p_input, VLC_OBJECT_DECODER );
+    p_sys->p_packetizer->pf_decode_audio = 0;
+    p_sys->p_packetizer->pf_decode_video = 0;
+    p_sys->p_packetizer->pf_decode_sub = 0;
+    p_sys->p_packetizer->pf_packetize = 0;
+
+    /* Initialization of decoder structure */
+    es_format_Init( &p_sys->p_packetizer->fmt_in, AUDIO_ES,
+                    VLC_FOURCC( 'a', '5', '2', ' ' ) );
+
+    p_sys->p_packetizer->p_module =
+        module_Need( p_sys->p_packetizer, "packetizer", NULL );
+    if( !p_sys->p_packetizer->p_module )
+    {
+        msg_Err( p_input, "cannot find A52 packetizer" );
+        return VLC_EGENERIC;
+    }
+
+    /* Create one program */
+    vlc_mutex_lock( &p_input->stream.stream_lock );
+    if( input_InitStream( p_input, 0 ) == -1 )
+    {
+        vlc_mutex_unlock( &p_input->stream.stream_lock );
+        msg_Err( p_input, "cannot init stream" );
+        return VLC_EGENERIC;
+    }
+    p_input->stream.i_mux_rate = 0;
+    vlc_mutex_unlock( &p_input->stream.stream_lock );
+
+    p_sys->p_es =
+        es_out_Add( p_input->p_es_out, &p_sys->p_packetizer->fmt_in );
+
+    return VLC_SUCCESS;
+}
+
+/*****************************************************************************
+ * Close: frees unused data
+ *****************************************************************************/
+static void Close( vlc_object_t * p_this )
+{
+    input_thread_t *p_input = (input_thread_t*)p_this;
+    demux_sys_t    *p_sys = p_input->p_demux_data;
+
+    /* Unneed module */
+    module_Unneed( p_sys->p_packetizer, p_sys->p_packetizer->p_module );
+
+    /* Delete the decoder */
+    vlc_object_destroy( p_sys->p_packetizer );
+
+    free( p_sys );
+}
+
+/*****************************************************************************
+ * Demux: reads and demuxes data packets
+ *****************************************************************************
+ * Returns -1 in case of error, 0 in case of EOF, 1 otherwise
+ *****************************************************************************/
+static int Demux( input_thread_t * p_input )
+{
+    demux_sys_t  *p_sys = p_input->p_demux_data;
+    block_t *p_block_in, *p_block_out;
+
+    if( !( p_block_in = stream_Block( p_input->s, A52_PACKET_SIZE ) ) )
+    {
+        return 0;
+    }
+
+    if( !p_sys->b_big_endian && p_block_in->i_buffer )
+    {
+        /* Convert to big endian */
+        int64_t i_pos = stream_Tell( p_input->s );
+        if( i_pos % 2 ) p_block_in->p_buffer++; /* Align stream */
+
+#ifdef HAVE_SWAB
+        swab(p_block_in->p_buffer, p_block_in->p_buffer, p_block_in->i_buffer);
+
+#else
+        int i;
+        byte_t *p_tmp, tmp;
+        p_tmp = p_block_in->p_buffer;
+        for( i = p_block_in->i_buffer / 2 ; i-- ; )
+        {
+            tmp = p_tmp[0];
+            p_tmp[0] = p_tmp[1];
+            p_tmp[1] = tmp;
+            p_tmp += 2;
+        }
+#endif
+    }
+
+    if( p_sys->b_start )
+        p_block_in->i_pts = p_block_in->i_dts = 1;
+    else
+        p_block_in->i_pts = p_block_in->i_dts = 0;
+
+    while( (p_block_out = p_sys->p_packetizer->pf_packetize(
+                p_sys->p_packetizer, &p_block_in )) )
+    {
+        p_sys->b_start = VLC_FALSE;
+
+        while( p_block_out )
+        {
+            block_t *p_next = p_block_out->p_next;
+
+            /* We assume a constant bitrate */
+            if( p_block_out->i_length )
+            p_sys->i_mux_rate =
+                p_block_out->i_buffer * I64C(1000000) / p_block_out->i_length;
+            p_input->stream.i_mux_rate = p_sys->i_mux_rate / 50;
+
+            input_ClockManageRef( p_input,
+                                  p_input->stream.p_selected_program,
+                                  p_block_out->i_pts * 9 / 100 );
+
+            p_block_in->b_discontinuity = 0;
+            p_block_out->i_dts = p_block_out->i_pts =
+                input_ClockGetTS( p_input, p_input->stream.p_selected_program,
+                                  p_block_out->i_pts * 9 / 100 );
+
+            es_out_Send( p_input->p_es_out, p_sys->p_es, p_block_out );
+
+            p_block_out = p_next;
+        }
+    }
+
+    return 1;
+}
+
+/*****************************************************************************
+ * Control:
+ *****************************************************************************/
+static int Control( input_thread_t *p_input, int i_query, va_list args )
+{
+    demux_sys_t *p_sys  = (demux_sys_t *)p_input->p_demux_data;
+    int64_t *pi64;
+
+    switch( i_query )
+    {
+        case DEMUX_GET_TIME:
+            pi64 = (int64_t*)va_arg( args, int64_t * );
+            if( p_sys->i_mux_rate > 0 )
+            {
+                *pi64 = I64C(1000000) * stream_Tell( p_input->s ) /
+                        p_sys->i_mux_rate;
+                return VLC_SUCCESS;
+            }
+            *pi64 = 0;
+            return VLC_EGENERIC;
+
+        case DEMUX_GET_LENGTH:
+            pi64 = (int64_t*)va_arg( args, int64_t * );
+            if( p_sys->i_mux_rate > 0 )
+            {
+                *pi64 = I64C(1000000) * stream_Size( p_input->s ) /
+                        p_sys->i_mux_rate;
+                return VLC_SUCCESS;
+            }
+            *pi64 = 0;
+            return VLC_EGENERIC;
+
+        default:
+            return demux_vaControlDefault( p_input, i_query, args );
+    }
+}