modules/mux/mpeg/tsutil.c

   1 /*****************************************************************************
   2  * tsutil.c
   3  *****************************************************************************
   4  * Copyright (C) 2001-2005, 2015 VLC authors and VideoLAN
   5  *
   6  * This program is free software; you can redistribute it and/or modify it
   7  * under the terms of the GNU Lesser General Public License as published by
   8  * the Free Software Foundation; either version 2.1 of the License, or
   9  * (at your option) any later version.
  10  *
  11  * This program is distributed in the hope that it will be useful,
  12  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
  14  * GNU Lesser General Public License for more details.
  15  *
  16  * You should have received a copy of the GNU Lesser General Public License
  17  * along with this program; if not, write to the Free Software Foundation,
  18  * Inc., 51 Franklin Street, Fifth Floor, Boston MA 02110-1301, USA.
  19  *****************************************************************************/
  20 #ifdef HAVE_CONFIG_H
  21 # include "config.h"
  22 #endif
  23
  24 #include <vlc_common.h>
  25 #include <vlc_block.h>
  26
  27 #include "tsutil.h"
  28
  29 void PEStoTS( void *p_opaque, PEStoTSCallback pf_callback, block_t *p_pes,
  30               uint16_t i_pid, bool *pb_discontinuity, uint8_t *pi_continuity_counter )
  31 {
  32     /* get PES total size */
  33     uint8_t *p_data = p_pes->p_buffer;
  34     int      i_size = p_pes->i_buffer;
  35
  36     bool    b_new_pes = true;
  37
  38     for (;;)
  39     {
  40         /* write header
  41          * 8b   0x47    sync byte
  42          * 1b           transport_error_indicator
  43          * 1b           payload_unit_start
  44          * 1b           transport_priority
  45          * 13b          pid
  46          * 2b           transport_scrambling_control
  47          * 2b           if adaptation_field 0x03 else 0x01
  48          * 4b           continuity_counter
  49          */
  50
  51         int i_copy = __MIN( i_size, 184 );
  52         bool b_adaptation_field = i_size < 184;
  53         block_t *p_ts = block_Alloc( 188 );
  54
  55         p_ts->p_buffer[0] = 0x47;
  56         p_ts->p_buffer[1] = ( b_new_pes ? 0x40 : 0x00 )|
  57                             ( ( i_pid >> 8 )&0x1f );
  58         p_ts->p_buffer[2] = i_pid & 0xff;
  59         p_ts->p_buffer[3] = ( b_adaptation_field ? 0x30 : 0x10 )|
  60                             *pi_continuity_counter;
  61
  62         b_new_pes = false;
  63         *pi_continuity_counter = (*pi_continuity_counter+1)%16;
  64
  65         if( b_adaptation_field )
  66         {
  67             int i_stuffing = 184 - i_copy;
  68
  69             p_ts->p_buffer[4] = i_stuffing - 1;
  70             if( i_stuffing > 1 )
  71             {
  72                 p_ts->p_buffer[5] = 0x00;
  73                 if( *pb_discontinuity )
  74                 {
  75                     p_ts->p_buffer[5] |= 0x80;
  76                     *pb_discontinuity = false;
  77                 }
  78                 for (int i = 6; i < 6 + i_stuffing - 2; i++ )
  79                 {
  80                     p_ts->p_buffer[i] = 0xff;
  81                 }
  82             }
  83         }
  84         /* copy payload */
  85         memcpy( &p_ts->p_buffer[188 - i_copy], p_data, i_copy );
  86         p_data += i_copy;
  87         i_size -= i_copy;
  88
  89         pf_callback( p_opaque, p_ts );
  90
  91         if( i_size <= 0 )
  92         {
  93             block_t *p_next = p_pes->p_next;
  94
  95             p_pes->p_next = NULL;
  96             block_Release( p_pes );
  97             if( p_next == NULL )
  98                 return;
  99
 100             b_new_pes = true;
 101             p_pes = p_next;
 102             i_size = p_pes->i_buffer;
 103             p_data = p_pes->p_buffer;
 104         }
 105     }
 106 }