include/vlc_demux.h

   1 /*****************************************************************************
   2  * vlc_demux.h: Demuxer descriptor, queries and methods
   3  *****************************************************************************
   4  * Copyright (C) 1999-2005 the VideoLAN team
   5  * $Id$
   6  *
   7  * Authors: Laurent Aimar <fenrir@via.ecp.fr>
   8  *
   9  * This program is free software; you can redistribute it and/or modify
  10  * it under the terms of the GNU General Public License as published by
  11  * the Free Software Foundation; either version 2 of the License, or
  12  * (at your option) any later version.
  13  *
  14  * This program is distributed in the hope that it will be useful,
  15  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  16  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  17  * GNU General Public License for more details.
  18  *
  19  * You should have received a copy of the GNU General Public License
  20  * along with this program; if not, write to the Free Software
  21  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston MA 02110-1301, USA.
  22  *****************************************************************************/
  23
  24 #ifndef VLC_DEMUX_H
  25 #define VLC_DEMUX_H 1
  26
  27 /**
  28  * \file
  29  * This files defines functions and structures used by demux objects in vlc
  30  */
  31
  32 #include <vlc_es.h>
  33 #include <vlc_stream.h>
  34 #include <vlc_es_out.h>
  35
  36 /**
  37  * \defgroup demux Demux
  38  * @{
  39  */
  40
  41 struct demux_t
  42 {
  43     VLC_COMMON_MEMBERS
  44
  45     /* Module properties */
  46     module_t    *p_module;
  47
  48     /* eg informative but needed (we can have access+demux) */
  49     char        *psz_access;
  50     char        *psz_demux;
  51     char        *psz_path;
  52
  53     /* input stream */
  54     stream_t    *s;     /* NULL in case of a access+demux in one */
  55
  56     /* es output */
  57     es_out_t    *out;   /* our p_es_out */
  58
  59     /* set by demuxer */
  60     int (*pf_demux)  ( demux_t * );   /* demux one frame only */
  61     int (*pf_control)( demux_t *, int i_query, va_list args);
  62
  63     /* Demux has to maintain them uptodate
  64      * when it is responsible of seekpoint/title */
  65     struct
  66     {
  67         unsigned int i_update;  /* Demux sets them on change,
  68                                    Input removes them once take into account*/
  69         /* Seekpoint/Title at demux level */
  70         int          i_title;       /* idem, start from 0 (could be menu) */
  71         int          i_seekpoint;   /* idem, start from 0 */
  72     } info;
  73     demux_sys_t *p_sys;
  74 };
  75
  76
  77 /* demux_meta_t is returned by "meta reader" module to the demuxer */
  78 struct demux_meta_t
  79 {
  80     vlc_meta_t *p_meta;                 /**< meta data */
  81
  82     int i_attachments;                  /**< number of attachments */
  83     input_attachment_t **attachments;    /**< array of attachments */
  84 };
  85
  86 enum demux_query_e
  87 {
  88     /* I. Common queries to access_demux and demux */
  89     /* POSITION double between 0.0 and 1.0 */
  90     DEMUX_GET_POSITION,         /* arg1= double *       res=    */
  91     DEMUX_SET_POSITION,         /* arg1= double         res=can fail    */
  92
  93     /* LENGTH/TIME in microsecond, 0 if unknown */
  94     DEMUX_GET_LENGTH,           /* arg1= int64_t *      res=    */
  95     DEMUX_GET_TIME,             /* arg1= int64_t *      res=    */
  96     DEMUX_SET_TIME,             /* arg1= int64_t        res=can fail    */
  97
  98     /* TITLE_INFO only if more than 1 title or 1 chapter */
  99     DEMUX_GET_TITLE_INFO,       /* arg1=input_title_t*** arg2=int*
 100                                    arg3=int*pi_title_offset(0), arg4=int*pi_seekpoint_offset(0) can fail */
 101     /* TITLE/SEEKPOINT, only when TITLE_INFO succeed */
 102     DEMUX_SET_TITLE,            /* arg1= int            can fail */
 103     DEMUX_SET_SEEKPOINT,        /* arg1= int            can fail */
 104
 105     /* DEMUX_SET_GROUP only a hit for demuxer (mainly DVB) to allow not
 106      * reading everything (you should not use this to call es_out_Control)
 107      * if you don't know what to do with it, just IGNORE it, it is safe(r)
 108      * -1 means all group, 0 default group (first es added) */
 109     DEMUX_SET_GROUP,            /* arg1= int            can fail */
 110
 111     /* Ask the demux to demux until the given date at the next pf_demux call
 112      * but not more (and not less, at the precision available of course).
 113      * XXX: not mandatory (except for subtitle demux) but I will help a lot
 114      * for multi-input
 115      */
 116     DEMUX_SET_NEXT_DEMUX_TIME,  /* arg1= int64_t *      can fail */
 117     /* FPS for correct subtitles handling */
 118     DEMUX_GET_FPS,              /* arg1= double *       res=can fail    */
 119
 120     /* Meta data */
 121     DEMUX_GET_META,             /* arg1= vlc_meta_t **  res=can fail    */
 122     DEMUX_HAS_UNSUPPORTED_META, /* arg1= bool *   res can fail    */
 123
 124     /* Attachments */
 125     DEMUX_GET_ATTACHMENTS,      /* arg1=input_attachment_t***, int* res=can fail */
 126
 127     /* II. Specific access_demux queries */
 128     DEMUX_CAN_PAUSE,            /* arg1= bool*    can fail (assume false)*/
 129     DEMUX_SET_PAUSE_STATE,      /* arg1= bool     can fail */
 130
 131     DEMUX_GET_PTS_DELAY,        /* arg1= int64_t*       cannot fail */
 132
 133     /* DEMUX_CAN_CONTROL_PACE returns true (*pb_pace) if we can read the
 134      * data at our pace */
 135     DEMUX_CAN_CONTROL_PACE,     /* arg1= bool*pb_pace    can fail (assume false) */
 136
 137     /* DEMUX_CAN_CONTROL_RATE is called only if DEMUX_CAN_CONTROL_PACE has returned false.
 138      * *pb_rate should be true when the rate can be changed (using DEMUX_SET_RATE)
 139      * *pb_ts_rescale should be true when the timestamps (pts/dts/pcr) have to be rescaled */
 140     DEMUX_CAN_CONTROL_RATE,     /* arg1= bool*pb_rate arg2= bool*pb_ts_rescale  can fail(assume false) */
 141     /* DEMUX_SET_RATE is called only if DEMUX_CAN_CONTROL_RATE has returned true.
 142      * It should return the value really used in *pi_rate */
 143     DEMUX_SET_RATE,             /* arg1= int*pi_rate                                        can fail */
 144
 145     DEMUX_CAN_SEEK,            /* arg1= bool*    can fail (assume false)*/
 146 };
 147
 148 VLC_EXPORT( int,       demux_vaControlHelper, ( stream_t *, int64_t i_start, int64_t i_end, int i_bitrate, int i_align, int i_query, va_list args ) );
 149
 150 /*************************************************************************
 151  * Miscellaneous helpers for demuxers
 152  *************************************************************************/
 153
 154 static inline bool demux_IsPathExtension( demux_t *p_demux, const char *psz_extension )
 155 {
 156     const char *psz_ext = strrchr ( p_demux->psz_path, '.' );
 157     if( !psz_ext || strcasecmp( psz_ext, psz_extension ) )
 158         return false;
 159     return true;
 160 }
 161
 162 static inline bool demux_IsForced( demux_t *p_demux, const char *psz_name )
 163 {
 164    if( !p_demux->psz_demux || strcmp( p_demux->psz_demux, psz_name ) )
 165         return false;
 166     return true;
 167 }
 168
 169 #define DEMUX_INIT_COMMON() do {            \
 170     p_demux->pf_control = Control;          \
 171     p_demux->pf_demux = Demux;              \
 172     MALLOC_ERR( p_demux->p_sys, demux_sys_t ); \
 173     memset( p_demux->p_sys, 0, sizeof( demux_sys_t ) ); } while(0)
 174
 175 #define STANDARD_DEMUX_INIT_MSG( msg ) do { \
 176     DEMUX_INIT_COMMON();                    \
 177     msg_Dbg( p_demux, "%s", msg ); } while(0)
 178
 179 #define DEMUX_BY_EXTENSION( ext ) \
 180     demux_t *p_demux = (demux_t *)p_this; \
 181     if( !demux_IsPathExtension( p_demux, ext ) ) \
 182         return VLC_EGENERIC; \
 183     DEMUX_INIT_COMMON();
 184
 185 #define DEMUX_BY_EXTENSION_MSG( ext, msg ) \
 186     demux_t *p_demux = (demux_t *)p_this; \
 187     if( !demux_IsPathExtension( p_demux, ext ) ) \
 188         return VLC_EGENERIC; \
 189     STANDARD_DEMUX_INIT_MSG( msg );
 190
 191 #define DEMUX_BY_EXTENSION_OR_FORCED( ext, module ) \
 192     demux_t *p_demux = (demux_t *)p_this; \
 193     if( !demux_IsPathExtension( p_demux, ext ) && !demux_IsForced( p_demux, module ) ) \
 194         return VLC_EGENERIC; \
 195     DEMUX_INIT_COMMON();
 196
 197 #define DEMUX_BY_EXTENSION_OR_FORCED_MSG( ext, module, msg ) \
 198     demux_t *p_demux = (demux_t *)p_this; \
 199     if( !demux_IsPathExtension( p_demux, ext ) && !demux_IsForced( p_demux, module ) ) \
 200         return VLC_EGENERIC; \
 201     STANDARD_DEMUX_INIT_MSG( msg );
 202
 203 #define CHECK_PEEK( zepeek, size ) \
 204     if( stream_Peek( p_demux->s , &zepeek, size ) < size ){ \
 205         msg_Dbg( p_demux, "not enough data" ); return VLC_EGENERIC; }
 206
 207 #define CHECK_PEEK_GOTO( zepeek, size ) \
 208     if( stream_Peek( p_demux->s , &zepeek, size ) < size ) { \
 209         msg_Dbg( p_demux, "not enough data" ); goto error; }
 210
 211 #define POKE( peek, stuff, size ) (strncasecmp( (const char *)peek, stuff, size )==0)
 212
 213 #define COMMON_INIT_PACKETIZER( location ) \
 214     location = vlc_object_create( p_demux, VLC_OBJECT_PACKETIZER ); \
 215     location->pf_decode_audio = 0; \
 216     location->pf_decode_video = 0; \
 217     location->pf_decode_sub = 0; \
 218     location->pf_packetize = 0; \
 219
 220 #define INIT_APACKETIZER( location, a,b,c,d ) \
 221     COMMON_INIT_PACKETIZER(location ); \
 222     es_format_Init( &location->fmt_in, AUDIO_ES, \
 223                     VLC_FOURCC( a, b, c, d ) );
 224
 225 #define INIT_VPACKETIZER( location, a,b,c,d ) \
 226     COMMON_INIT_PACKETIZER(location ); \
 227     es_format_Init( &location->fmt_in, VIDEO_ES, \
 228                     VLC_FOURCC( a, b, c, d ) );
 229
 230 /* BEWARE ! This can lead to memory leaks ! */
 231 #define LOAD_PACKETIZER_OR_FAIL( location, msg ) \
 232     location->p_module = \
 233         module_Need( location, "packetizer", NULL, 0 ); \
 234     if( location->p_module == NULL ) \
 235     { \
 236         vlc_object_release( location ); \
 237         msg_Err( p_demux, "cannot find packetizer for " # msg ); \
 238         free( p_sys ); \
 239         return VLC_EGENERIC; \
 240     }
 241
 242 #define DESTROY_PACKETIZER( location ) \
 243     if( location->p_module ) module_Unneed( location, location->p_module ); \
 244     vlc_object_release( location );
 245
 246 /**
 247  * @}
 248  */
 249
 250 #endif