git.sesse.net Git - vlc/blob - modules/packetizer/packetizer_helper.h

   1 /*****************************************************************************
   2  * packetizer.h: Packetizer helpers
   3  *****************************************************************************
   4  * Copyright (C) 2009 Laurent Aimar
   5  * $Id$
   6  *
   7  * Authors: Laurent Aimar <fenrir _AT_ videolan _DOT_ org>
   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 _PACKETIZER_H
  25 #define _PACKETIZER_H 1
  26
  27 #include <vlc_block.h>
  28
  29 enum
  30 {
  31     STATE_NOSYNC,
  32     STATE_NEXT_SYNC
  33 };
  34
  35 typedef void (*packetizer_reset_t)( void *p_private, bool b_broken );
  36 typedef block_t *(*packetizer_parse_t)( void *p_private, bool *pb_ts_used, block_t * );
  37 typedef int (*packetizer_validate_t)( void *p_private, block_t * );
  38
  39 typedef struct
  40 {
  41     int i_state;
  42     block_bytestream_t bytestream;
  43     size_t i_offset;
  44
  45     int i_startcode;
  46     const uint8_t *p_startcode;
  47
  48     int i_au_prepend;
  49     const uint8_t *p_au_prepend;
  50
  51     void *p_private;
  52     packetizer_reset_t    pf_reset;
  53     packetizer_parse_t    pf_parse;
  54     packetizer_validate_t pf_validate;
  55
  56 } packetizer_t;
  57
  58 static inline void packetizer_Init( packetizer_t *p_pack,
  59                                     const uint8_t *p_startcode, int i_startcode,
  60                                     const uint8_t *p_au_prepend, int i_au_prepend,
  61                                     packetizer_reset_t pf_reset,
  62                                     packetizer_parse_t pf_parse,
  63                                     packetizer_validate_t pf_validate,
  64                                     void *p_private )
  65 {
  66     p_pack->i_state = STATE_NOSYNC;
  67     p_pack->bytestream = block_BytestreamInit();
  68     p_pack->i_offset = 0;
  69
  70     p_pack->i_au_prepend = i_au_prepend;
  71     p_pack->p_au_prepend = p_au_prepend;
  72
  73     p_pack->i_startcode = i_startcode;
  74     p_pack->p_startcode = p_startcode;
  75     p_pack->pf_reset = pf_reset;
  76     p_pack->pf_parse = pf_parse;
  77     p_pack->pf_validate = pf_validate;
  78     p_pack->p_private = p_private;
  79 }
  80
  81 static inline void packetizer_Clean( packetizer_t *p_pack )
  82 {
  83     block_BytestreamRelease( &p_pack->bytestream );
  84 }
  85
  86 static inline block_t *packetizer_Packetize( packetizer_t *p_pack, block_t **pp_block )
  87 {
  88     if( !pp_block || !*pp_block )
  89         return NULL;
  90
  91     if( (*pp_block)->i_flags&(BLOCK_FLAG_DISCONTINUITY|BLOCK_FLAG_CORRUPTED) )
  92     {
  93         const bool b_broken = ( (*pp_block)->i_flags&BLOCK_FLAG_CORRUPTED ) != 0;
  94         if( b_broken )
  95         {
  96             p_pack->i_state = STATE_NOSYNC;
  97             block_BytestreamEmpty( &p_pack->bytestream );
  98             p_pack->i_offset = 0;
  99         }
 100         p_pack->pf_reset( p_pack->p_private, b_broken );
 101
 102         block_Release( *pp_block );
 103         return NULL;
 104     }
 105
 106     block_BytestreamPush( &p_pack->bytestream, *pp_block );
 107
 108     for( ;; )
 109     {
 110         bool b_used_ts;
 111         block_t *p_pic;
 112
 113         switch( p_pack->i_state )
 114         {
 115         case STATE_NOSYNC:
 116             /* Find a startcode */
 117             if( !block_FindStartcodeFromOffset( &p_pack->bytestream, &p_pack->i_offset,
 118                                                 p_pack->p_startcode, p_pack->i_startcode ) )
 119                 p_pack->i_state = STATE_NEXT_SYNC;
 120
 121             if( p_pack->i_offset )
 122             {
 123                 block_SkipBytes( &p_pack->bytestream, p_pack->i_offset );
 124                 p_pack->i_offset = 0;
 125                 block_BytestreamFlush( &p_pack->bytestream );
 126             }
 127
 128             if( p_pack->i_state != STATE_NEXT_SYNC )
 129                 return NULL; /* Need more data */
 130
 131             p_pack->i_offset = 1; /* To find next startcode */
 132
 133         case STATE_NEXT_SYNC:
 134             /* Find the next startcode */
 135             if( block_FindStartcodeFromOffset( &p_pack->bytestream, &p_pack->i_offset,
 136                                                p_pack->p_startcode, p_pack->i_startcode ) )
 137                 return NULL; /* Need more data */
 138
 139             block_BytestreamFlush( &p_pack->bytestream );
 140
 141             /* Get the new fragment and set the pts/dts */
 142             block_t *p_block_bytestream = p_pack->bytestream.p_block;
 143
 144             p_pic = block_New( p_dec, p_pack->i_offset + p_pack->i_au_prepend );
 145             p_pic->i_pts = p_block_bytestream->i_pts;
 146             p_pic->i_dts = p_block_bytestream->i_dts;
 147
 148             block_GetBytes( &p_pack->bytestream, &p_pic->p_buffer[p_pack->i_au_prepend],
 149                             p_pic->i_buffer - p_pack->i_au_prepend );
 150             if( p_pack->i_au_prepend > 0 )
 151                 memcpy( p_pic->p_buffer, p_pack->p_au_prepend, p_pack->i_au_prepend );
 152
 153             p_pack->i_offset = 0;
 154
 155             /* Parse the NAL */
 156             p_pic = p_pack->pf_parse( p_pack->p_private, &b_used_ts, p_pic );
 157             if( b_used_ts )
 158             {
 159                 p_block_bytestream->i_dts = -1;
 160                 p_block_bytestream->i_pts = -1;
 161             }
 162
 163             if( !p_pic )
 164             {
 165                 p_pack->i_state = STATE_NOSYNC;
 166                 break;
 167             }
 168             if( p_pack->pf_validate( p_pack->p_private, p_pic ) )
 169             {
 170                 p_pack->i_state = STATE_NOSYNC;
 171                 block_Release( p_pic );
 172                 break;
 173             }
 174
 175             /* So p_block doesn't get re-added several times */
 176             *pp_block = block_BytestreamPop( &p_pack->bytestream );
 177
 178             p_pack->i_state = STATE_NOSYNC;
 179
 180             return p_pic;
 181         }
 182     }
 183 }
 184
 185 #endif
 186