/***************************************************************************** * mpga.c : MPEG-I/II Audio input module for vlc ***************************************************************************** * Copyright (C) 2001-2004 the VideoLAN team * $Id: mpga.c 17050 2006-10-13 00:07:54Z hartman $ * * Authors: Laurent Aimar <fenrir@via.ecp.fr> *          Gildas Bazin <gbazin@videolan.org> * * 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., 51 Franklin Street, Fifth Floor, Boston MA 02110-1301, USA. *****************************************************************************//***************************************************************************** * Preamble *****************************************************************************/#include <stdlib.h>                                      /* malloc(), free() */#include <vlc/vlc.h>#include <vlc/input.h>#include "vlc_codec.h"#include "vlc_meta.h"#define MPGA_PACKET_SIZE 1024/***************************************************************************** * Module descriptor *****************************************************************************/static int  Open ( vlc_object_t * );static void Close( vlc_object_t * );vlc_module_begin();    set_category( CAT_INPUT );    set_subcategory( SUBCAT_INPUT_DEMUX );    set_description( _("MPEG audio / MP3 demuxer" ) );    set_capability( "demux2", 100 );    set_callbacks( Open, Close );    add_shortcut( "mpga" );    add_shortcut( "mp3" );vlc_module_end();/***************************************************************************** * Local prototypes *****************************************************************************/static int Demux  ( demux_t * );static int Control( demux_t *, int, va_list );struct demux_sys_t{    es_out_id_t *p_es;    vlc_meta_t  *meta;    vlc_bool_t  b_start;    decoder_t   *p_packetizer;    mtime_t     i_pts;    mtime_t     i_time_offset;    int         i_bitrate_avg;  /* extracted from Xing header */    vlc_bool_t b_initial_sync_failed;    int i_xing_frames;    int i_xing_bytes;    int i_xing_bitrate_avg;    int i_xing_frame_samples;    block_t *p_block_in, *p_block_out;};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 ? */    {        return VLC_FALSE;    }    return VLC_TRUE;}#define MPGA_VERSION( h )   ( 1 - (((h)>>19)&0x01) )#define MPGA_LAYER( h )     ( 3 - (((h)>>17)&0x03) )#define MPGA_MODE(h)        (((h)>> 6)&0x03)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;    }}/***************************************************************************** * Open: initializes demux structures *****************************************************************************/static int Open( vlc_object_t * p_this ){    demux_t     *p_demux = (demux_t*)p_this;    demux_sys_t *p_sys;    vlc_bool_t   b_forced = VLC_FALSE;    uint32_t     header;    uint8_t     *p_peek;    module_t    *p_id3;    block_t     *p_block_in, *p_block_out;    if( p_demux->psz_path )    {        int  i_len = strlen( p_demux->psz_path );        if( i_len > 4 && !strcasecmp( &p_demux->psz_path[i_len - 4], ".mp3" ) )        {            b_forced = VLC_TRUE;        }    }    if( stream_Peek( p_demux->s, &p_peek, 4 ) < 4 ) return VLC_EGENERIC;    if( !HeaderCheck( header = GetDWBE( p_peek ) ) )    {        vlc_bool_t b_ok = VLC_FALSE;        int i_peek;        if( !p_demux->b_force && !b_forced ) return VLC_EGENERIC;        i_peek = stream_Peek( p_demux->s, &p_peek, 8096 );        while( i_peek > 4 )        {            if( HeaderCheck( header = GetDWBE( p_peek ) ) )            {                b_ok = VLC_TRUE;                break;            }            p_peek += 1;            i_peek -= 1;        }        if( !b_ok && !p_demux->b_force ) return VLC_EGENERIC;    }    p_demux->p_sys = p_sys = malloc( sizeof( demux_sys_t ) );    memset( p_sys, 0, sizeof( demux_sys_t ) );    p_sys->p_es = 0;    p_sys->p_packetizer = 0;    p_sys->b_start = VLC_TRUE;    p_sys->meta = 0;    p_demux->pf_demux   = Demux;    p_demux->pf_control = Control;    /*     * Load the mpeg audio packetizer     */    p_sys->p_packetizer = vlc_object_create( p_demux, VLC_OBJECT_PACKETIZER );    p_sys->p_packetizer->pf_decode_audio = NULL;    p_sys->p_packetizer->pf_decode_video = NULL;    p_sys->p_packetizer->pf_decode_sub = NULL;    p_sys->p_packetizer->pf_packetize = NULL;    es_format_Init( &p_sys->p_packetizer->fmt_in, AUDIO_ES,                    VLC_FOURCC( 'm', 'p', 'g', 'a' ) );    es_format_Init( &p_sys->p_packetizer->fmt_out, UNKNOWN_ES, 0 );    p_sys->p_packetizer->p_module =        module_Need( p_sys->p_packetizer, "packetizer", NULL, 0 );    if( p_sys->p_packetizer->p_module == NULL )    {        msg_Err( p_demux, "cannot find mpga packetizer" );        Close( VLC_OBJECT(p_demux ) );        return VLC_EGENERIC;    }    /* Xing header */    if( HeaderCheck( header ) )    {        int i_xing, i_skip;        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 );            }        }    }    if( ( p_block_in = stream_Block( p_demux->s, MPGA_PACKET_SIZE ) ) == NULL )    {        return VLC_EGENERIC;    }    p_block_in->i_pts = p_block_in->i_dts = 1;    p_block_out = p_sys->p_packetizer->pf_packetize(        p_sys->p_packetizer, &p_block_in );    if( p_block_out == NULL )    {        msg_Dbg( p_demux, "did not sync on first block" );        p_sys->b_initial_sync_failed = VLC_TRUE;    }    else        p_sys->b_initial_sync_failed = VLC_FALSE;    p_sys->p_packetizer->fmt_out.b_packetized = VLC_TRUE;    p_sys->p_es = es_out_Add( p_demux->out,                              &p_sys->p_packetizer->fmt_out);    p_sys->i_bitrate_avg = p_sys->p_packetizer->fmt_out.i_bitrate;    if( p_sys->i_xing_bytes && p_sys->i_xing_frames &&        p_sys->i_xing_frame_samples )    {        p_sys->i_bitrate_avg = p_sys->i_xing_bytes * I64C(8) *            p_sys->p_packetizer->fmt_out.audio.i_rate /            p_sys->i_xing_frames / p_sys->i_xing_frame_samples;    }    p_sys->p_block_in = p_block_in;    p_sys->p_block_out = p_block_out;    /* Parse possible id3 header */    if( ( p_id3 = module_Need( p_demux, "id3", NULL, 0 ) ) )    {        p_sys->meta = (vlc_meta_t *)p_demux->p_private;        p_demux->p_private = NULL;        module_Unneed( p_demux, p_id3 );    }    return VLC_SUCCESS;}/***************************************************************************** * Demux: reads and demuxes data packets ***************************************************************************** * Returns -1 in case of error, 0 in case of EOF, 1 otherwise *****************************************************************************/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_sys->b_start )    {        p_sys->b_start = VLC_FALSE;        p_block_in = p_sys->p_block_in;        p_sys->p_block_in = NULL;        p_block_out = p_sys->p_block_out;        p_sys->p_block_out = NULL;    }    else    {        if( ( p_block_in = stream_Block( p_demux->s, MPGA_PACKET_SIZE ) )            == NULL )        {            return 0;        }        if( p_demux->p_sys->b_initial_sync_failed == VLC_TRUE )        {            p_block_in->i_pts = p_block_in->i_dts = 1;            /* Only try to resync once */            p_demux->p_sys->b_initial_sync_failed = 0;        }        else            p_block_in->i_pts = p_block_in->i_dts = 0;        p_block_out = p_sys->p_packetizer->pf_packetize(            p_sys->p_packetizer, &p_block_in );    }    while( p_block_out )    {        while( p_block_out )        {            block_t *p_next = p_block_out->p_next;            es_out_Control( p_demux->out, ES_OUT_SET_PCR, p_block_out->i_dts );            p_block_out->p_next = NULL;            p_sys->i_pts = p_block_out->i_pts;            es_out_Send( p_demux->out, p_sys->p_es, p_block_out );            p_block_out = p_next;        }        p_block_out = p_sys->p_packetizer->pf_packetize(            p_sys->p_packetizer, &p_block_in );    }    return 1;}/***************************************************************************** * Close: frees unused data *****************************************************************************/static void Close( vlc_object_t * p_this ){    demux_t     *p_demux = (demux_t*)p_this;    demux_sys_t *p_sys = p_demux->p_sys;    if( p_sys->meta ) vlc_meta_Delete( p_sys->meta );    if( p_sys->p_block_out ) block_Release( p_sys->p_block_out );    if( p_sys->p_packetizer && p_sys->p_packetizer->p_module )        module_Unneed( p_sys->p_packetizer, p_sys->p_packetizer->p_module );    if( p_sys->p_packetizer )        vlc_object_destroy( p_sys->p_packetizer );    free( p_sys );}/***************************************************************************** * Control: *****************************************************************************/static int Control( demux_t *p_demux, int i_query, va_list args ){    demux_sys_t *p_sys  = p_demux->p_sys;    int64_t *pi64;    vlc_meta_t **pp_meta;    int i_ret;    switch( i_query )    {        case DEMUX_GET_META:            pp_meta = (vlc_meta_t **)va_arg( args, vlc_meta_t** );            if( p_sys->meta ) *pp_meta = vlc_meta_Duplicate( p_sys->meta );            else *pp_meta = NULL;            return VLC_SUCCESS;        case DEMUX_GET_TIME:            pi64 = (int64_t*)va_arg( args, int64_t * );            *pi64 = p_sys->i_pts + p_sys->i_time_offset;            return VLC_SUCCESS;        case DEMUX_SET_TIME:            /* FIXME TODO: implement a high precision seek (with mp3 parsing)             * needed for multi-input */        default:            i_ret = demux2_vaControlHelper( p_demux->s, 0, -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 = I64C(8000000) * stream_Tell(p_demux->s) /                    p_sys->i_bitrate_avg;                /* Fix time_offset */                if( i_time >= 0 ) p_sys->i_time_offset = i_time - p_sys->i_pts;            }            return i_ret;    }}