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

   1 /*****************************************************************************
   2  * packetizer_helper.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 it
  10  * under the terms of the GNU Lesser General Public License as published by
  11  * the Free Software Foundation; either version 2.1 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 Lesser General Public License for more details.
  18  *
  19  * You should have received a copy of the GNU Lesser General Public License
  20  * along with this program; if not, write to the Free Software Foundation,
  21  * 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_SYNC,
  33     STATE_HEADER,
  34     STATE_NEXT_SYNC,
  35     STATE_GET_DATA,
  36     STATE_SEND_DATA
  37 };
  38
  39 typedef void (*packetizer_reset_t)( void *p_private, bool b_broken );
  40 typedef block_t *(*packetizer_parse_t)( void *p_private, bool *pb_ts_used, block_t * );
  41 typedef int (*packetizer_validate_t)( void *p_private, block_t * );
  42
  43 typedef struct
  44 {
  45     int i_state;
  46     block_bytestream_t bytestream;
  47     size_t i_offset;
  48     bool   b_flushing;
  49
  50     int i_startcode;
  51     const uint8_t *p_startcode;
  52
  53     int i_au_prepend;
  54     const uint8_t *p_au_prepend;
  55
  56     unsigned i_au_min_size;
  57
  58     void *p_private;
  59     packetizer_reset_t    pf_reset;
  60     packetizer_parse_t    pf_parse;
  61     packetizer_validate_t pf_validate;
  62
  63 } packetizer_t;
  64
  65 static inline void packetizer_Init( packetizer_t *p_pack,
  66                                     const uint8_t *p_startcode, int i_startcode,
  67                                     const uint8_t *p_au_prepend, int i_au_prepend,
  68                                     unsigned i_au_min_size,
  69                                     packetizer_reset_t pf_reset,
  70                                     packetizer_parse_t pf_parse,
  71                                     packetizer_validate_t pf_validate,
  72                                     void *p_private )
  73 {
  74     p_pack->i_state = STATE_NOSYNC;
  75     block_BytestreamInit( &p_pack->bytestream );
  76     p_pack->i_offset = 0;
  77     p_pack->b_flushing = false;
  78
  79     p_pack->i_au_prepend = i_au_prepend;
  80     p_pack->p_au_prepend = p_au_prepend;
  81     p_pack->i_au_min_size = i_au_min_size;
  82
  83     p_pack->i_startcode = i_startcode;
  84     p_pack->p_startcode = p_startcode;
  85     p_pack->pf_reset = pf_reset;
  86     p_pack->pf_parse = pf_parse;
  87     p_pack->pf_validate = pf_validate;
  88     p_pack->p_private = p_private;
  89 }
  90
  91 static inline void packetizer_Clean( packetizer_t *p_pack )
  92 {
  93     block_BytestreamRelease( &p_pack->bytestream );
  94 }
  95
  96 static inline block_t *packetizer_Packetize( packetizer_t *p_pack, block_t **pp_block )
  97 {
  98     if( !pp_block || !*pp_block )
  99         return NULL;
 100
 101     if( unlikely( (*pp_block)->i_flags&(BLOCK_FLAG_DISCONTINUITY|BLOCK_FLAG_CORRUPTED) ) )
 102     {
 103         const bool b_broken = ( (*pp_block)->i_flags&BLOCK_FLAG_CORRUPTED ) != 0;
 104         if( b_broken )
 105         {
 106             p_pack->i_state = STATE_NOSYNC;
 107             block_BytestreamEmpty( &p_pack->bytestream );
 108             p_pack->i_offset = 0;
 109         }
 110         p_pack->pf_reset( p_pack->p_private, b_broken );
 111
 112         block_Release( *pp_block );
 113         return NULL;
 114     }
 115
 116     block_BytestreamPush( &p_pack->bytestream, *pp_block );
 117
 118     for( ;; )
 119     {
 120         bool b_used_ts;
 121         block_t *p_pic;
 122
 123         switch( p_pack->i_state )
 124         {
 125         case STATE_NOSYNC:
 126             /* Find a startcode */
 127             if( !block_FindStartcodeFromOffset( &p_pack->bytestream, &p_pack->i_offset,
 128                                                 p_pack->p_startcode, p_pack->i_startcode ) )
 129                 p_pack->i_state = STATE_NEXT_SYNC;
 130
 131             if( p_pack->i_offset )
 132             {
 133                 block_SkipBytes( &p_pack->bytestream, p_pack->i_offset );
 134                 p_pack->i_offset = 0;
 135                 block_BytestreamFlush( &p_pack->bytestream );
 136             }
 137
 138             if( p_pack->i_state != STATE_NEXT_SYNC )
 139                 return NULL; /* Need more data */
 140
 141             p_pack->i_offset = 1; /* To find next startcode */
 142
 143         case STATE_NEXT_SYNC:
 144             /* Find the next startcode */
 145             if( block_FindStartcodeFromOffset( &p_pack->bytestream, &p_pack->i_offset,
 146                                                p_pack->p_startcode, p_pack->i_startcode ) )
 147             {
 148                 if( !p_pack->b_flushing || !p_pack->bytestream.p_chain )
 149                     return NULL; /* Need more data */
 150
 151                 /* When flusing and we don't find a startcode, suppose that
 152                  * the data extend up to the end */
 153                 block_ChainProperties( p_pack->bytestream.p_chain,
 154                                        NULL, &p_pack->i_offset, NULL );
 155                 p_pack->i_offset -= p_pack->bytestream .i_offset;
 156
 157                 if( p_pack->i_offset <= (size_t)p_pack->i_startcode )
 158                     return NULL;
 159             }
 160
 161             block_BytestreamFlush( &p_pack->bytestream );
 162
 163             /* Get the new fragment and set the pts/dts */
 164             block_t *p_block_bytestream = p_pack->bytestream.p_block;
 165
 166             p_pic = block_Alloc( p_pack->i_offset + p_pack->i_au_prepend );
 167             p_pic->i_pts = p_block_bytestream->i_pts;
 168             p_pic->i_dts = p_block_bytestream->i_dts;
 169
 170             block_GetBytes( &p_pack->bytestream, &p_pic->p_buffer[p_pack->i_au_prepend],
 171                             p_pic->i_buffer - p_pack->i_au_prepend );
 172             if( p_pack->i_au_prepend > 0 )
 173                 memcpy( p_pic->p_buffer, p_pack->p_au_prepend, p_pack->i_au_prepend );
 174
 175             p_pack->i_offset = 0;
 176
 177             /* Parse the NAL */
 178             if( p_pic->i_buffer < p_pack->i_au_min_size )
 179             {
 180                 block_Release( p_pic );
 181                 p_pic = NULL;
 182             }
 183             else
 184             {
 185                 p_pic = p_pack->pf_parse( p_pack->p_private, &b_used_ts, p_pic );
 186                 if( b_used_ts )
 187                 {
 188                     p_block_bytestream->i_dts = VLC_TS_INVALID;
 189                     p_block_bytestream->i_pts = VLC_TS_INVALID;
 190                 }
 191             }
 192
 193             if( !p_pic )
 194             {
 195                 p_pack->i_state = STATE_NOSYNC;
 196                 break;
 197             }
 198             if( p_pack->pf_validate( p_pack->p_private, p_pic ) )
 199             {
 200                 p_pack->i_state = STATE_NOSYNC;
 201                 block_Release( p_pic );
 202                 break;
 203             }
 204
 205             /* So p_block doesn't get re-added several times */
 206             *pp_block = block_BytestreamPop( &p_pack->bytestream );
 207
 208             p_pack->i_state = STATE_NOSYNC;
 209
 210             return p_pic;
 211         }
 212     }
 213 }
 214
 215 static inline void packetizer_Header( packetizer_t *p_pack,
 216                                       const uint8_t *p_header, int i_header )
 217 {
 218     block_t *p_init = block_Alloc( i_header );
 219     if( !p_init )
 220         return;
 221
 222     memcpy( p_init->p_buffer, p_header, i_header );
 223
 224     p_pack->b_flushing = true;
 225
 226     block_t *p_pic;
 227     while( ( p_pic = packetizer_Packetize( p_pack, &p_init ) ) )
 228         block_Release( p_pic ); /* Should not happen (only sequence header) */
 229
 230     p_pack->i_state = STATE_NOSYNC;
 231     block_BytestreamEmpty( &p_pack->bytestream );
 232     p_pack->i_offset = 0;
 233     p_pack->b_flushing = false;
 234 }
 235
 236 #endif
 237