modules/demux/dirac.c

   1 /*****************************************************************************
   2  * dirac.c : Dirac Video demuxer
   3  *****************************************************************************
   4  * Copyright (C) 2002-2008 VLC authors and VideoLAN
   5  * $Id$
   6  *
   7  * Authors: David Flynn <davidf@rd.bbc.co.uk>
   8  * Based on vc1.c by: Laurent Aimar <fenrir@via.ecp.fr>
   9  *
  10  * This program is free software; you can redistribute it and/or modify it
  11  * under the terms of the GNU Lesser General Public License as published by
  12  * the Free Software Foundation; either version 2.1 of the License, or
  13  * (at your option) any later version.
  14  *
  15  * This program is distributed in the hope that it will be useful,
  16  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  17  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
  18  * GNU Lesser General Public License for more details.
  19  *
  20  * You should have received a copy of the GNU Lesser General Public License
  21  * along with this program; if not, write to the Free Software Foundation,
  22  * Inc., 51 Franklin Street, Fifth Floor, Boston MA 02110-1301, USA.
  23  *****************************************************************************/
  24
  25 /*****************************************************************************
  26  * Preamble
  27  *****************************************************************************/
  28
  29 #ifdef HAVE_CONFIG_H
  30 # include "config.h"
  31 #endif
  32
  33 #include <vlc_common.h>
  34 #include <vlc_plugin.h>
  35 #include <vlc_demux.h>
  36 #include <vlc_codec.h>
  37
  38 #define DEMUX_CFG_PREFIX "dirac-"
  39
  40 #define DEMUX_DTSOFFSET "dts-offset"
  41 #define DEMUX_DTSOFFSET_TEXT N_("Value to adjust dts by")
  42 #define DEMUX_DTSOFFSET_LONGTEXT DEMUX_DTSOFFSET_TEXT
  43
  44 /*****************************************************************************
  45  * Module descriptor
  46  *****************************************************************************/
  47 static int  Open ( vlc_object_t * );
  48 static void Close( vlc_object_t * );
  49
  50 vlc_module_begin();
  51     set_shortname( "Dirac");
  52     set_category( CAT_INPUT );
  53     set_subcategory( SUBCAT_INPUT_DEMUX );
  54     set_description( N_("Dirac video demuxer" ) );
  55     set_capability( "demux", 50 );
  56     add_integer( DEMUX_CFG_PREFIX DEMUX_DTSOFFSET, 0,
  57                  DEMUX_DTSOFFSET_TEXT, DEMUX_DTSOFFSET_LONGTEXT, false )
  58     set_callbacks( Open, Close );
  59     add_shortcut( "dirac" )
  60 vlc_module_end();
  61
  62 /*****************************************************************************
  63  * Local prototypes
  64  *****************************************************************************/
  65 struct demux_sys_t
  66 {
  67     mtime_t i_dts;
  68     mtime_t i_dtsoffset;
  69     mtime_t i_pts_offset_lowtide;
  70     es_out_id_t *p_es;
  71
  72     enum {
  73         /* demuxer states, do not reorder (++ is used) */
  74         DIRAC_DEMUX_DISCONT = 0, /* signal a discontinuity to packetizer */
  75         DIRAC_DEMUX_FIRST, /* provide an origin timestamp for the packetizer */
  76         DIRAC_DEMUX_STEADY, /* normal operation */
  77     } i_state;
  78
  79     decoder_t *p_packetizer;
  80 };
  81
  82 static int Demux( demux_t * );
  83 static int Control( demux_t *, int, va_list );
  84
  85 #define DIRAC_PACKET_SIZE 4096
  86
  87 /*****************************************************************************
  88  * Open: initializes demux structures
  89  *****************************************************************************/
  90 static int Open( vlc_object_t * p_this )
  91 {
  92     demux_t     *p_demux = (demux_t*)p_this;
  93     demux_sys_t *p_sys;
  94     const uint8_t *p_peek;
  95     es_format_t fmt;
  96
  97     if( vlc_stream_Peek( p_demux->s, &p_peek, 5 ) < 5 ) return VLC_EGENERIC;
  98
  99     if( p_peek[0] != 'B' || p_peek[1] != 'B' ||
 100         p_peek[2] != 'C' || p_peek[3] != 'D') /* start of ParseInfo */
 101     {
 102         if( !p_demux->obj.force ) return VLC_EGENERIC;
 103
 104         msg_Err( p_demux, "This doesn't look like a Dirac stream (incorrect parsecode)" );
 105         msg_Warn( p_demux, "continuing anyway" );
 106     }
 107
 108     p_demux->pf_demux = Demux;
 109     p_demux->pf_control = Control;
 110     p_demux->p_sys = p_sys = calloc( 1, sizeof( demux_sys_t ) );
 111     if( !p_sys ) return VLC_ENOMEM;
 112
 113     p_sys->i_pts_offset_lowtide = INT64_MAX;
 114     p_sys->i_state = DIRAC_DEMUX_FIRST;
 115
 116     p_sys->i_dtsoffset = var_CreateGetInteger( p_demux, DEMUX_CFG_PREFIX DEMUX_DTSOFFSET );
 117
 118     /* Load the packetizer */
 119     es_format_Init( &fmt, VIDEO_ES, VLC_CODEC_DIRAC );
 120     p_sys->p_packetizer = demux_PacketizerNew( p_demux, &fmt, "dirac" );
 121     if( !p_sys->p_packetizer )
 122     {
 123         free( p_sys );
 124         return VLC_EGENERIC;
 125     }
 126
 127     return VLC_SUCCESS;
 128 }
 129
 130 /*****************************************************************************
 131  * Close: frees unused data
 132  *****************************************************************************/
 133 static void Close( vlc_object_t * p_this )
 134 {
 135     demux_t     *p_demux = (demux_t*)p_this;
 136     demux_sys_t *p_sys = p_demux->p_sys;
 137
 138     demux_PacketizerDestroy( p_sys->p_packetizer );
 139
 140     if( p_sys->i_pts_offset_lowtide < INT64_MAX &&
 141         p_sys->i_pts_offset_lowtide > 0 )
 142     {
 143         msg_Warn( p_demux, "For all packets seen, pts-dts (%"PRId64") could be reduced to 0",
 144                   p_sys->i_pts_offset_lowtide );
 145     }
 146     free( p_sys );
 147 }
 148
 149 /*****************************************************************************
 150  * Demux: reads and demuxes data packets
 151  *****************************************************************************
 152  * Returns -1 in case of error, 0 in case of EOF, 1 otherwise
 153  *****************************************************************************/
 154 static int Demux( demux_t *p_demux)
 155 {
 156     demux_sys_t *p_sys = p_demux->p_sys;
 157     block_t *p_block_in, *p_block_out;
 158
 159     bool b_eof = false;
 160
 161     if( p_sys->i_state == DIRAC_DEMUX_DISCONT )
 162     {
 163         p_sys->i_state++;
 164         p_block_in = block_Alloc( 128 );
 165         if( p_block_in )
 166         {
 167             p_block_in->i_flags = BLOCK_FLAG_DISCONTINUITY | BLOCK_FLAG_CORRUPTED;
 168         }
 169     }
 170     else
 171     {
 172         p_block_in = vlc_stream_Block( p_demux->s, DIRAC_PACKET_SIZE );
 173         if( !p_block_in )
 174         {
 175             b_eof = true;
 176         }
 177         else if ( p_sys->i_state == DIRAC_DEMUX_FIRST)
 178         {
 179             p_sys->i_state++;
 180             /* by default, timestamps are invalid.
 181              * Except when we need an anchor point */
 182             p_block_in->i_dts = VLC_TS_0;
 183         }
 184     }
 185
 186     while( (p_block_out = p_sys->p_packetizer->pf_packetize( p_sys->p_packetizer,
 187                                                              (p_block_in) ? &p_block_in : NULL )) )
 188     {
 189         while( p_block_out )
 190         {
 191             block_t *p_next = p_block_out->p_next;
 192             p_block_out->p_next = NULL;
 193
 194             if( p_sys->p_es == NULL )
 195                 p_sys->p_es = es_out_Add( p_demux->out, &p_sys->p_packetizer->fmt_out);
 196
 197             p_block_out->i_dts += p_sys->i_dtsoffset;
 198             p_sys->i_dts = p_block_out->i_dts;
 199
 200             /* track low watermark for pts_offset -- can be used to show
 201              * when it is too large */
 202             mtime_t i_delay = p_block_out->i_pts - p_block_out->i_dts;
 203             if( p_sys->i_pts_offset_lowtide > i_delay )
 204             {
 205                 p_sys->i_pts_offset_lowtide = i_delay;
 206             }
 207
 208             es_out_SetPCR( p_demux->out, p_block_out->i_dts );
 209             es_out_Send( p_demux->out, p_sys->p_es, p_block_out );
 210
 211             p_block_out = p_next;
 212         }
 213     }
 214
 215     return b_eof ? VLC_DEMUXER_EOF : VLC_DEMUXER_SUCCESS;
 216 }
 217
 218 /*****************************************************************************
 219  * Control:
 220  *****************************************************************************/
 221 static int Control( demux_t *p_demux, int i_query, va_list args )
 222 {
 223     demux_sys_t *p_sys  = p_demux->p_sys;
 224     if( DEMUX_GET_TIME == i_query )
 225     {
 226         int64_t *pi64 = va_arg( args, int64_t * );
 227         *pi64 = p_sys->i_dts;
 228         return VLC_SUCCESS;
 229     }
 230     else if( DEMUX_GET_FPS == i_query )
 231     {
 232         if( !p_sys->p_packetizer->fmt_out.video.i_frame_rate )
 233         {
 234             return VLC_EGENERIC;
 235         }
 236         double *pd = va_arg( args, double * );
 237         *pd = (float) p_sys->p_packetizer->fmt_out.video.i_frame_rate
 238             / p_sys->p_packetizer->fmt_out.video.i_frame_rate_base;
 239         return VLC_SUCCESS;
 240     }
 241     else
 242     {
 243         if( DEMUX_SET_POSITION == i_query || DEMUX_SET_TIME == i_query )
 244         {
 245             p_sys->i_state = DIRAC_DEMUX_DISCONT;
 246         }
 247         return demux_vaControlHelper( p_demux->s, 0, -1, 0, 1, i_query, args );
 248     }
 249 }
 250