⭐ 欢迎来到虫虫下载站! | 📦 资源下载 📁 资源专辑 ℹ️ 关于我们
⭐ 虫虫下载站

📄 au.c

📁 video linux conference
💻 C
字号:
/***************************************************************************** * au.c : au file input module for vlc ***************************************************************************** * Copyright (C) 2001-2003 VideoLAN * $Id: au.c 10150 2005-03-05 17:54:19Z gbazin $ * * 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>/* TODO: *  - all adpcm things (I _NEED_ samples) *  - ... *//***************************************************************************** * 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( _("AU demuxer") );    set_capability( "demux2", 10 );    set_callbacks( Open, Close );    add_shortcut( "au" );vlc_module_end();/***************************************************************************** * Local prototypes *****************************************************************************/enum AuType_e{    AU_UNKNOWN      =  0,    AU_MULAW_8      =  1,  /* 8-bit ISDN u-law */    AU_LINEAR_8     =  2,  /* 8-bit linear PCM */    AU_LINEAR_16    =  3,  /* 16-bit linear PCM */    AU_LINEAR_24    =  4,  /* 24-bit linear PCM */    AU_LINEAR_32    =  5,  /* 32-bit linear PCM */    AU_FLOAT        =  6,  /* 32-bit IEEE floating point */    AU_DOUBLE       =  7,  /* 64-bit IEEE floating point */    AU_ADPCM_G721   =  23, /* 4-bit CCITT g.721 ADPCM */    AU_ADPCM_G722   =  24, /* CCITT g.722 ADPCM */    AU_ADPCM_G723_3 =  25, /* CCITT g.723 3-bit ADPCM */    AU_ADPCM_G723_5 =  26, /* CCITT g.723 5-bit ADPCM */    AU_ALAW_8       =  27  /* 8-bit ISDN A-law */};enum AuCat_e{    AU_CAT_UNKNOWN  = 0,    AU_CAT_PCM      = 1,    AU_CAT_ADPCM    = 2};struct demux_sys_t{    es_format_t     fmt;    es_out_id_t     *es;    mtime_t         i_time;    int             i_frame_size;    mtime_t         i_frame_length;    int             i_header_size;};static int DemuxPCM( demux_t * );static int Control ( demux_t *, int i_query, va_list args );/***************************************************************************** * Open: check file and initializes structures *****************************************************************************/static int Open( vlc_object_t *p_this ){    demux_t     *p_demux = (demux_t*)p_this;    demux_sys_t *p_sys;    uint8_t      hdr[20];    uint8_t     *p_peek;    int          i_cat;    int          i_samples, i_modulo;    if( stream_Peek( p_demux->s, &p_peek, 4 ) < 4 ) return VLC_EGENERIC;    if( strncmp( p_peek, ".snd", 4 ) )    {        return VLC_EGENERIC;    }    /* skip signature */    stream_Read( p_demux->s, NULL, 4 );   /* cannot fail */    /* read header */    if( stream_Read( p_demux->s, hdr, 20 ) < 20 )    {        msg_Err( p_demux, "cannot read" );        return VLC_EGENERIC;    }    if( GetDWBE( &hdr[0]  ) < 24 )    {        msg_Err( p_demux, "invalid file" );        return VLC_EGENERIC;    }    p_sys = p_demux->p_sys = malloc( sizeof( demux_sys_t ) );    p_sys->i_time = 1;    p_sys->i_header_size = GetDWBE( &hdr[0] );    /* skip extra header data */    if( p_sys->i_header_size > 24 )    {        stream_Read( p_demux->s, NULL, p_sys->i_header_size - 24 );    }    /* init fmt */    es_format_Init( &p_sys->fmt, AUDIO_ES, 0 );    p_sys->fmt.audio.i_rate     = GetDWBE( &hdr[12] );    p_sys->fmt.audio.i_channels = GetDWBE( &hdr[16] );#if 0    p_sys->au.i_header_size   = GetDWBE( &p_sys->au.i_header_size );    p_sys->au.i_data_size     = GetDWBE( &p_sys->au.i_data_size );    p_sys->au.i_encoding      = GetDWBE( &p_sys->au.i_encoding );    p_sys->au.i_sample_rate   = GetDWBE( &p_sys->au.i_sample_rate );    p_sys->au.i_channels      = GetDWBE( &p_sys->au.i_channels );#endif    switch( GetDWBE( &hdr[8] ) )    {        case AU_ALAW_8:        /* 8-bit ISDN A-law */            p_sys->fmt.i_codec               = VLC_FOURCC( 'a','l','a','w' );            p_sys->fmt.audio.i_bitspersample = 8;            p_sys->fmt.audio.i_blockalign    = 1 * p_sys->fmt.audio.i_channels;            i_cat                    = AU_CAT_PCM;            break;        case AU_MULAW_8:       /* 8-bit ISDN u-law */            p_sys->fmt.i_codec               = VLC_FOURCC( 'u','l','a','w' );            p_sys->fmt.audio.i_bitspersample = 8;            p_sys->fmt.audio.i_blockalign    = 1 * p_sys->fmt.audio.i_channels;            i_cat                    = AU_CAT_PCM;            break;        case AU_LINEAR_8:      /* 8-bit linear PCM */            p_sys->fmt.i_codec               = VLC_FOURCC( 't','w','o','s' );            p_sys->fmt.audio.i_bitspersample = 8;            p_sys->fmt.audio.i_blockalign    = 1 * p_sys->fmt.audio.i_channels;            i_cat                    = AU_CAT_PCM;            break;        case AU_LINEAR_16:     /* 16-bit linear PCM */            p_sys->fmt.i_codec               = VLC_FOURCC( 't','w','o','s' );            p_sys->fmt.audio.i_bitspersample = 16;            p_sys->fmt.audio.i_blockalign    = 2 * p_sys->fmt.audio.i_channels;            i_cat                    = AU_CAT_PCM;            break;        case AU_LINEAR_24:     /* 24-bit linear PCM */            p_sys->fmt.i_codec               = VLC_FOURCC( 't','w','o','s' );            p_sys->fmt.audio.i_bitspersample = 24;            p_sys->fmt.audio.i_blockalign    = 3 * p_sys->fmt.audio.i_channels;            i_cat                    = AU_CAT_PCM;            break;        case AU_LINEAR_32:     /* 32-bit linear PCM */            p_sys->fmt.i_codec               = VLC_FOURCC( 't','w','o','s' );            p_sys->fmt.audio.i_bitspersample = 32;            p_sys->fmt.audio.i_blockalign    = 4 * p_sys->fmt.audio.i_channels;            i_cat                    = AU_CAT_PCM;            break;        case AU_FLOAT:         /* 32-bit IEEE floating point */            p_sys->fmt.i_codec               = VLC_FOURCC( 'a', 'u', 0, AU_FLOAT );            p_sys->fmt.audio.i_bitspersample = 32;            p_sys->fmt.audio.i_blockalign    = 4 * p_sys->fmt.audio.i_channels;            i_cat                    = AU_CAT_PCM;            break;        case AU_DOUBLE:        /* 64-bit IEEE floating point */            p_sys->fmt.i_codec               = VLC_FOURCC( 'a', 'u', 0, AU_DOUBLE );            p_sys->fmt.audio.i_bitspersample = 64;            p_sys->fmt.audio.i_blockalign    = 8 * p_sys->fmt.audio.i_channels;            i_cat                    = AU_CAT_PCM;            break;        case AU_ADPCM_G721:    /* 4-bit CCITT g.721 ADPCM */            p_sys->fmt.i_codec               = VLC_FOURCC( 'a', 'u', 0, AU_ADPCM_G721 );            p_sys->fmt.audio.i_bitspersample = 0;            p_sys->fmt.audio.i_blockalign    = 0 * p_sys->fmt.audio.i_channels;            i_cat                    = AU_CAT_ADPCM;            break;        case AU_ADPCM_G722:    /* CCITT g.722 ADPCM */            p_sys->fmt.i_codec               = VLC_FOURCC( 'a', 'u', 0, AU_ADPCM_G722 );            p_sys->fmt.audio.i_bitspersample = 0;            p_sys->fmt.audio.i_blockalign    = 0 * p_sys->fmt.audio.i_channels;            i_cat                    = AU_CAT_ADPCM;            break;        case AU_ADPCM_G723_3:  /* CCITT g.723 3-bit ADPCM */            p_sys->fmt.i_codec               = VLC_FOURCC( 'a', 'u', 0, AU_ADPCM_G723_3 );            p_sys->fmt.audio.i_bitspersample = 0;            p_sys->fmt.audio.i_blockalign    = 0 * p_sys->fmt.audio.i_channels;            i_cat                    = AU_CAT_ADPCM;            break;        case AU_ADPCM_G723_5:  /* CCITT g.723 5-bit ADPCM */            p_sys->fmt.i_codec               = VLC_FOURCC( 'a', 'u', 0, AU_ADPCM_G723_5 );            p_sys->fmt.audio.i_bitspersample = 0;            p_sys->fmt.audio.i_blockalign    = 0 * p_sys->fmt.audio.i_channels;            i_cat                    = AU_CAT_ADPCM;            break;        default:            msg_Warn( p_demux, "unknow encoding=0x%x", GetDWBE( &hdr[8] ) );            p_sys->fmt.audio.i_bitspersample = 0;            p_sys->fmt.audio.i_blockalign    = 0;            i_cat                    = AU_CAT_UNKNOWN;            break;    }    p_sys->fmt.i_bitrate = p_sys->fmt.audio.i_rate *                           p_sys->fmt.audio.i_channels *                           p_sys->fmt.audio.i_bitspersample;    if( i_cat == AU_CAT_UNKNOWN || i_cat == AU_CAT_ADPCM )    {        p_sys->i_frame_size = 0;        p_sys->i_frame_length = 0;        msg_Err( p_demux, "unsupported codec/type (Please report it)" );        free( p_sys );        return VLC_EGENERIC;    }    /* add the es */    p_sys->es = es_out_Add( p_demux->out, &p_sys->fmt );    /* calculate 50ms frame size/time */    i_samples = __MAX( p_sys->fmt.audio.i_rate / 20, 1 );    p_sys->i_frame_size = i_samples * p_sys->fmt.audio.i_channels *                          ( (p_sys->fmt.audio.i_bitspersample + 7) / 8 );    if( p_sys->fmt.audio.i_blockalign > 0 )    {        if( ( i_modulo = p_sys->i_frame_size % p_sys->fmt.audio.i_blockalign ) != 0 )        {            p_sys->i_frame_size += p_sys->fmt.audio.i_blockalign - i_modulo;        }    }    p_sys->i_frame_length = (mtime_t)1000000 *                            (mtime_t)i_samples /                            (mtime_t)p_sys->fmt.audio.i_rate;    /* finish to set up p_demux */    p_demux->pf_demux   = DemuxPCM;    p_demux->pf_control = Control;    return VLC_SUCCESS;}/***************************************************************************** * DemuxPCM: read packet and send them to decoders ***************************************************************************** * Returns -1 in case of error, 0 in case of EOF, 1 otherwise *****************************************************************************/static int DemuxPCM( demux_t *p_demux ){    demux_sys_t *p_sys = p_demux->p_sys;    block_t     *p_block;    /* set PCR */    es_out_Control( p_demux->out, ES_OUT_SET_PCR, p_sys->i_time );    if( ( p_block = stream_Block( p_demux->s, p_sys->i_frame_size ) ) == NULL )    {        msg_Warn( p_demux, "cannot read data" );        return 0;    }    p_block->i_dts =    p_block->i_pts = p_sys->i_time;    es_out_Send( p_demux->out, p_sys->es, p_block );    p_sys->i_time += p_sys->i_frame_length;    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;    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;    return demux2_vaControlHelper( p_demux->s, p_sys->i_header_size, -1,                                   p_sys->fmt.i_bitrate, p_sys->fmt.audio.i_blockalign,                                   i_query, args );}

⌨️ 快捷键说明

复制代码 Ctrl + C
搜索代码 Ctrl + F
全屏模式 F11
切换主题 Ctrl + Shift + D
显示快捷键 ?
增大字号 Ctrl + =
减小字号 Ctrl + -