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     bool   b_flushing;
  45
  46     int i_startcode;
  47     const uint8_t *p_startcode;
  48
  49     int i_au_prepend;
  50     const uint8_t *p_au_prepend;
  51
  52     unsigned i_au_min_size;
  53
  54     void *p_private;
  55     packetizer_reset_t    pf_reset;
  56     packetizer_parse_t    pf_parse;
  57     packetizer_validate_t pf_validate;
  58
  59 } packetizer_t;
  60
  61 static inline void packetizer_Init( packetizer_t *p_pack,
  62                                     const uint8_t *p_startcode, int i_startcode,
  63                                     const uint8_t *p_au_prepend, int i_au_prepend,
  64                                     unsigned i_au_min_size,
  65                                     packetizer_reset_t pf_reset,
  66                                     packetizer_parse_t pf_parse,
  67                                     packetizer_validate_t pf_validate,
  68                                     void *p_private )
  69 {
  70     p_pack->i_state = STATE_NOSYNC;
  71     p_pack->bytestream = block_BytestreamInit();
  72     p_pack->i_offset = 0;
  73     p_pack->b_flushing = false;
  74
  75     p_pack->i_au_prepend = i_au_prepend;
  76     p_pack->p_au_prepend = p_au_prepend;
  77     p_pack->i_au_min_size = i_au_min_size;
  78
  79     p_pack->i_startcode = i_startcode;
  80     p_pack->p_startcode = p_startcode;
  81     p_pack->pf_reset = pf_reset;
  82     p_pack->pf_parse = pf_parse;
  83     p_pack->pf_validate = pf_validate;
  84     p_pack->p_private = p_private;
  85 }
  86
  87 static inline void packetizer_Clean( packetizer_t *p_pack )
  88 {
  89     block_BytestreamRelease( &p_pack->bytestream );
  90 }
  91
  92 static inline block_t *packetizer_Packetize( packetizer_t *p_pack, block_t **pp_block )
  93 {
  94     if( !pp_block || !*pp_block )
  95         return NULL;
  96
  97     if( (*pp_block)->i_flags&(BLOCK_FLAG_DISCONTINUITY|BLOCK_FLAG_CORRUPTED) )
  98     {
  99         const bool b_broken = ( (*pp_block)->i_flags&BLOCK_FLAG_CORRUPTED ) != 0;
 100         if( b_broken )
 101         {
 102             p_pack->i_state = STATE_NOSYNC;
 103             block_BytestreamEmpty( &p_pack->bytestream );
 104             p_pack->i_offset = 0;
 105         }
 106         p_pack->pf_reset( p_pack->p_private, b_broken );
 107
 108         block_Release( *pp_block );
 109         return NULL;
 110     }
 111
 112     block_BytestreamPush( &p_pack->bytestream, *pp_block );
 113
 114     for( ;; )
 115     {
 116         bool b_used_ts;
 117         block_t *p_pic;
 118
 119         switch( p_pack->i_state )
 120         {
 121         case STATE_NOSYNC:
 122             /* Find a startcode */
 123             if( !block_FindStartcodeFromOffset( &p_pack->bytestream, &p_pack->i_offset,
 124                                                 p_pack->p_startcode, p_pack->i_startcode ) )
 125                 p_pack->i_state = STATE_NEXT_SYNC;
 126
 127             if( p_pack->i_offset )
 128             {
 129                 block_SkipBytes( &p_pack->bytestream, p_pack->i_offset );
 130                 p_pack->i_offset = 0;
 131                 block_BytestreamFlush( &p_pack->bytestream );
 132             }
 133
 134             if( p_pack->i_state != STATE_NEXT_SYNC )
 135                 return NULL; /* Need more data */
 136
 137             p_pack->i_offset = 1; /* To find next startcode */
 138
 139         case STATE_NEXT_SYNC:
 140             /* Find the next startcode */
 141             if( block_FindStartcodeFromOffset( &p_pack->bytestream, &p_pack->i_offset,
 142                                                p_pack->p_startcode, p_pack->i_startcode ) )
 143             {
 144                 if( !p_pack->b_flushing || !p_pack->bytestream.p_chain )
 145                     return NULL; /* Need more data */
 146
 147                 /* When flusing and we don't find a startcode, suppose that
 148                  * the data extend up to the end */
 149                 block_ChainProperties( p_pack->bytestream.p_chain,
 150                                        NULL, &p_pack->i_offset, NULL );
 151                 p_pack->i_offset -= p_pack->bytestream .i_offset;
 152
 153                 if( p_pack->i_offset <= (size_t)p_pack->i_startcode )
 154                     return NULL;
 155             }
 156
 157             block_BytestreamFlush( &p_pack->bytestream );
 158
 159             /* Get the new fragment and set the pts/dts */
 160             block_t *p_block_bytestream = p_pack->bytestream.p_block;
 161
 162             p_pic = block_New( p_dec, p_pack->i_offset + p_pack->i_au_prepend );
 163             p_pic->i_pts = p_block_bytestream->i_pts;
 164             p_pic->i_dts = p_block_bytestream->i_dts;
 165
 166             block_GetBytes( &p_pack->bytestream, &p_pic->p_buffer[p_pack->i_au_prepend],
 167                             p_pic->i_buffer - p_pack->i_au_prepend );
 168             if( p_pack->i_au_prepend > 0 )
 169                 memcpy( p_pic->p_buffer, p_pack->p_au_prepend, p_pack->i_au_prepend );
 170
 171             p_pack->i_offset = 0;
 172
 173             /* Parse the NAL */
 174             if( p_pic->i_buffer < p_pack->i_au_min_size )
 175             {
 176                 block_Release( p_pic );
 177                 p_pic = NULL;
 178             }
 179             else
 180             {
 181                 p_pic = p_pack->pf_parse( p_pack->p_private, &b_used_ts, p_pic );
 182                 if( b_used_ts )
 183                 {
 184                     p_block_bytestream->i_dts = VLC_TS_INVALID;
 185                     p_block_bytestream->i_pts = VLC_TS_INVALID;
 186                 }
 187             }
 188
 189             if( !p_pic )
 190             {
 191                 p_pack->i_state = STATE_NOSYNC;
 192                 break;
 193             }
 194             if( p_pack->pf_validate( p_pack->p_private, p_pic ) )
 195             {
 196                 p_pack->i_state = STATE_NOSYNC;
 197                 block_Release( p_pic );
 198                 break;
 199             }
 200
 201             /* So p_block doesn't get re-added several times */
 202             *pp_block = block_BytestreamPop( &p_pack->bytestream );
 203
 204             p_pack->i_state = STATE_NOSYNC;
 205
 206             return p_pic;
 207         }
 208     }
 209 }
 210
 211 static inline void packetizer_Header( packetizer_t *p_pack,
 212                                       const uint8_t *p_header, int i_header )
 213 {
 214     block_t *p_init = block_Alloc( i_header );
 215     if( !p_init )
 216         return;
 217
 218     memcpy( p_init->p_buffer, p_header, i_header );
 219
 220     p_pack->b_flushing = true;
 221
 222     block_t *p_pic;
 223     while( ( p_pic = packetizer_Packetize( p_pack, &p_init ) ) )
 224         block_Release( p_pic ); /* Should not happen (only sequence header) */
 225
 226     p_pack->i_state = STATE_NOSYNC;
 227     block_BytestreamEmpty( &p_pack->bytestream );
 228     p_pack->i_offset = 0;
 229     p_pack->b_flushing = false;
 230 }
 231
 232 #endif
 233