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