/***************************************************************************** * mpga.c : MPEG-I/II Audio input module for vlc ***************************************************************************** * Copyright (C) 2001-2004 VideoLAN * $Id: mpga.c,v 1.16 2004/01/25 20:05:28 hartman Exp $ * * Authors: Laurent Aimar <fenrir@via.ecp.fr> * * 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 <stdlib.h>                                      /* malloc(), free() */#include <vlc/vlc.h>#include <vlc/input.h>/***************************************************************************** * Module descriptor *****************************************************************************/static int  Open    ( vlc_object_t * );static void Close  ( vlc_object_t * );vlc_module_begin();    set_description( _("MPEG-I/II audio demuxer" ) );    set_capability( "demux", 100 );    set_callbacks( Open, Close );    add_shortcut( "mpga" );    add_shortcut( "mp3" );vlc_module_end();/* TODO: * - free bitrate *//***************************************************************************** * Local prototypes *****************************************************************************/static int  Demux       ( input_thread_t * );struct demux_sys_t{    mtime_t         i_time;    int             i_bitrate_avg;  /* extracted from Xing header */    es_out_id_t     *p_es;};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 );}static int mpga_sample_rate[2][4] ={    { 44100, 48000, 32000, 0 },    { 22050, 24000, 16000, 0 }};static int mpga_bitrate[2][3][16] ={  {    { 0, 32, 64, 96, 128, 160, 192, 224, 256, 288, 320, 352, 384, 416, 448, 0},    { 0, 32, 48, 56,  64,  80,  96, 112, 128, 160, 192, 224, 256, 320, 384, 0},    { 0, 32, 40, 48,  56,  64,  80,  96, 112, 128, 160, 192, 224, 256, 320, 0}  },  {    { 0, 32, 48, 56,  64,  80,  96, 112, 128, 144, 160, 176, 192, 224, 256, 0},    { 0,  8, 16, 24,  32,  40,  48,  56,  64,  80,  96, 112, 128, 144, 160, 0},    { 0,  8, 16, 24,  32,  40,  48,  56,  64,  80,  96, 112, 128, 144, 160, 0}  }};#define MPGA_VERSION( h )   ( 1 - (((h)>>19)&0x01) )#define MPGA_LAYER( h )     ( 3 - (((h)>>17)&0x03) )#define MPGA_SAMPLE_RATE(h) \    ( mpga_sample_rate[MPGA_VERSION(h)][((h)>>10)&0x03] / ( ((h>>20)&0x01) ? 1 : 2) )#define MPGA_CHANNELS(h)    ( (((h)>>6)&0x03) == 3 ? 1 : 2)#define MPGA_BITRATE(h)     mpga_bitrate[MPGA_VERSION(h)][MPGA_LAYER(h)][((h)>>12)&0x0f]#define MPGA_PADDING(h)     ( ((h)>>9)&0x01 )#define MPGA_MODE(h)        (((h)>> 6)&0x03)static int mpga_frame_size( uint32_t h ){    switch( MPGA_LAYER(h) )    {        case 0:            return ( ( 12000 * MPGA_BITRATE(h) ) / MPGA_SAMPLE_RATE(h) + MPGA_PADDING(h) ) * 4;        case 1:            return ( 144000 * MPGA_BITRATE(h) ) / MPGA_SAMPLE_RATE(h) + MPGA_PADDING(h);        case 2:            return ( ( MPGA_VERSION(h) ? 72000 : 144000 ) * MPGA_BITRATE(h) ) / MPGA_SAMPLE_RATE(h) + MPGA_PADDING(h);        default:            return 0;    }}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;    }}#if 0static int CheckPS( input_thread_t *p_input ){    uint8_t  *p_peek;    int i_startcode = 0;    int i_size = input_Peek( p_input, &p_peek, 8196 );    while( i_size > 4 )    {        if( ( p_peek[0] == 0 ) && ( p_peek[1] == 0 ) &&            ( p_peek[2] == 1 ) && ( p_peek[3] >= 0xb9 ) &&            ++i_startcode >= 3 )        {            return 1;        }        p_peek++;        i_size--;    }    return 0;}#endif/***************************************************************************** * Open: initializes demux structures *****************************************************************************/static int Open( vlc_object_t * p_this ){    input_thread_t *p_input = (input_thread_t *)p_this;    demux_sys_t    *p_sys;    vlc_bool_t     b_forced = VLC_FALSE;    vlc_bool_t     b_extention = VLC_FALSE;    uint32_t       header;    uint8_t        *p_peek;    module_t       *p_id3;    es_format_t    fmt;    if( p_input->psz_demux &&        ( !strncmp( p_input->psz_demux, "mpga", 4 ) ||          !strncmp( p_input->psz_demux, "mp3", 3 ) ) )    {        b_forced = VLC_TRUE;    }    if( p_input->psz_name )    {        int  i_len = strlen( p_input->psz_name );        if( i_len > 4 && !strcasecmp( &p_input->psz_name[i_len - 4], ".mp3" ) )        {            b_extention = VLC_TRUE;        }    }    /* skip possible id3 header */    p_id3 = module_Need( p_input, "id3", NULL );    if ( p_id3 )    {        module_Unneed( p_input, p_id3 );    }    if( input_Peek( p_input, &p_peek, 4 ) < 4 )    {        msg_Err( p_input, "cannot peek" );        return VLC_EGENERIC;    }    if( !HeaderCheck( header = GetDWBE( p_peek ) ) )    {        vlc_bool_t b_ok = VLC_FALSE;        int i_peek;        if( !b_forced && !b_extention )        {            msg_Warn( p_input, "mpga module discarded" );            return VLC_EGENERIC;        }        i_peek = input_Peek( p_input, &p_peek, 8096 );        while( i_peek > 4 )        {            if( HeaderCheck( header = GetDWBE( p_peek ) ) )            {                b_ok = VLC_TRUE;                break;            }            p_peek += 4;            i_peek -= 4;        }        if( !b_ok && !b_forced )        {            msg_Warn( p_input, "mpga module discarded" );            return VLC_EGENERIC;        }    }    p_input->pf_demux = Demux;    p_input->pf_demux_control = demux_vaControlDefault;    p_input->p_demux_data = p_sys = malloc( sizeof( demux_sys_t ) );    p_sys->i_time = 0;    p_sys->i_bitrate_avg = 0;    es_format_Init( &fmt, AUDIO_ES, VLC_FOURCC( 'm', 'p', 'g', 'a' ) );    if( HeaderCheck( header ) )    {        int     i_xing;        uint8_t *p_xing;        char psz_description[50];        p_sys->i_bitrate_avg = MPGA_BITRATE( header ) * 1000;        if( ( i_xing = stream_Peek( p_input->s, &p_xing, 1024 ) ) >= 21 )        {            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 &&                !strncmp( &p_xing[i_skip], "Xing", 4 ) )            {                unsigned int i_flags = GetDWBE( &p_xing[i_skip+4] );                unsigned int i_bytes = 0, i_frames = 0;                p_xing += i_skip + 8;                i_xing -= i_skip + 8;                i_skip = 0;                if( i_flags&0x01 && i_skip + 4 <= i_xing )   /* XING_FRAMES */                {                    i_frames = GetDWBE( &p_xing[i_skip] );                    i_skip += 4;                }                if( i_flags&0x02 && i_skip + 4 <= i_xing )   /* XING_BYTES */                {                    i_bytes = GetDWBE( &p_xing[i_skip] );                    i_skip += 4;                }                if( i_flags&0x04 )   /* XING_TOC */                {                    i_skip += 100;                }#if 0// 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_bitrate_avg = GetDWBE( &p_xing[i_skip] );    fprintf(stderr,"rate2 %d\n", p_sys->i_bitrate_avg);                    msg_Dbg( p_input, "xing vbr value present (%d)", p_sys->i_bitrate_avg );                }                else#endif                if( i_frames > 0 && i_bytes > 0 )                {                    p_sys->i_bitrate_avg = (int64_t)i_bytes *                                           (int64_t)8 *                                           (int64_t)MPGA_SAMPLE_RATE( header ) /                                           (int64_t)i_frames /                                           (int64_t)mpga_frame_samples( header );                    msg_Dbg( p_input, "xing frames&bytes value present (%db/s)", p_sys->i_bitrate_avg );                }            }        }        msg_Dbg( p_input, "version=%d layer=%d channels=%d samplerate=%d",                 MPGA_VERSION( header ) + 1,                 MPGA_LAYER( header ) + 1,                 MPGA_CHANNELS( header ),                 MPGA_SAMPLE_RATE( header ) );        fmt.audio.i_channels = MPGA_CHANNELS( header );        fmt.audio.i_rate = MPGA_SAMPLE_RATE( header );        fmt.i_bitrate = p_sys->i_bitrate_avg;        sprintf( psz_description, "MPEG Audio Layer %d, version %d",                 MPGA_LAYER ( header ) + 1, MPGA_VERSION ( header ) + 1 );        fmt.psz_description = strdup( psz_description );    }    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" );        if( fmt.psz_description ) free( fmt.psz_description );        goto error;    }    p_input->stream.i_mux_rate = p_sys->i_bitrate_avg / 8 / 50;    vlc_mutex_unlock( &p_input->stream.stream_lock );    p_sys->p_es = es_out_Add( p_input->p_es_out, &fmt );    if( fmt.psz_description ) free( fmt.psz_description );    return VLC_SUCCESS;error:    free( p_sys );    return VLC_EGENERIC;}/***************************************************************************** * 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_frame;    uint32_t     header;    uint8_t      *p_peek;    if( stream_Peek( p_input->s, &p_peek, 4 ) < 4 )    {        msg_Warn( p_input, "cannot peek" );        return 0;    }    if( !HeaderCheck( header = GetDWBE( p_peek ) ) )    {        /* we need to resynch */        vlc_bool_t  b_ok = VLC_FALSE;        int         i_skip = 0;        int         i_peek;        i_peek = stream_Peek( p_input->s, &p_peek, 8096 );        if( i_peek < 4 )        {            msg_Warn( p_input, "cannot peek" );            return 0;        }        while( i_peek >= 4 )        {            if( HeaderCheck( header = GetDWBE( p_peek ) ) )            {                b_ok = VLC_TRUE;                break;            }            p_peek++;            i_peek--;            i_skip++;        }        msg_Warn( p_input, "garbage=%d bytes", i_skip );        stream_Read( p_input->s, NULL, i_skip );        return 1;    }    input_ClockManageRef( p_input,                          p_input->stream.p_selected_program,                          p_sys->i_time * 9 / 100 );    if( ( p_frame = stream_Block( p_input->s, mpga_frame_size( header ) ) ) == NULL )    {        msg_Warn( p_input, "cannot read data" );        return 0;    }    p_frame->i_dts =    p_frame->i_pts =        input_ClockGetTS( p_input,                          p_input->stream.p_selected_program,                          p_sys->i_time * 9 / 100 );    es_out_Send( p_input->p_es_out, p_sys->p_es, p_frame );    p_sys->i_time += (mtime_t)1000000 *                     (mtime_t)mpga_frame_samples( header ) /                     (mtime_t)MPGA_SAMPLE_RATE( header );    return( 1 );}/***************************************************************************** * 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;    free( p_sys );}