include/vlc_block.h

   1 /*****************************************************************************
   2  * vlc_block.h: Data blocks management functions
   3  *****************************************************************************
   4  * Copyright (C) 2003 the VideoLAN team
   5  * $Id$
   6  *
   7  * Authors: Laurent Aimar <fenrir@via.ecp.fr>
   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 _VLC_BLOCK_H
  25 #define _VLC_BLOCK_H 1
  26
  27 /****************************************************************************
  28  * block:
  29  ****************************************************************************
  30  * - block_sys_t is opaque and thus block_t->p_sys is PRIVATE
  31  * - i_flags may not always be set (ie could be 0, even for a key frame
  32  *      it depends where you receive the buffer (before/after a packetizer
  33  *      and the demux/packetizer implementations.
  34  * - i_dts/i_pts could be 0, it means no pts
  35  * - i_length: length in microseond of the packet, can be null except in the
  36  *      sout where it is mandatory.
  37  * - i_rate 0 or a valid input rate, look at vlc_input.h
  38  *
  39  * - i_buffer number of valid data pointed by p_buffer
  40  *      you can freely decrease it but never increase it yourself
  41  *      (use block_Realloc)
  42  * - p_buffer: pointer over datas. You should never overwrite it, you can
  43  *   only incremment it to skip datas, in others cases use block_Realloc
  44  *   (don't duplicate yourself in a bigger buffer, block_Realloc is
  45  *   optimised for prehader/postdatas increase)
  46  ****************************************************************************/
  47 typedef struct block_sys_t block_sys_t;
  48
  49 /** The content doesn't follow the last block, or is probably broken */
  50 #define BLOCK_FLAG_DISCONTINUITY 0x0001
  51 /** Intra frame */
  52 #define BLOCK_FLAG_TYPE_I        0x0002
  53 /** Inter frame with backward reference only */
  54 #define BLOCK_FLAG_TYPE_P        0x0004
  55 /** Inter frame with backward and forward reference */
  56 #define BLOCK_FLAG_TYPE_B        0x0008
  57 /** For inter frame when you don't know the real type */
  58 #define BLOCK_FLAG_TYPE_PB       0x0010
  59 /** Warn that this block is a header one */
  60 #define BLOCK_FLAG_HEADER        0x0020
  61 /** This is the last block of the frame */
  62 #define BLOCK_FLAG_END_OF_FRAME  0x0040
  63 /** This is not a key frame for bitrate shaping */
  64 #define BLOCK_FLAG_NO_KEYFRAME   0x0080
  65 /** This block contains a clock reference */
  66 #define BLOCK_FLAG_CLOCK         0x0200
  67 /** This block is scrambled */
  68 #define BLOCK_FLAG_SCRAMBLED     0x0400
  69 /** This block has to be decoded but not be displayed */
  70 #define BLOCK_FLAG_PREROLL       0x0800
  71 /** This block is corrupted and/or there is data loss  */
  72 #define BLOCK_FLAG_CORRUPTED     0x1000
  73
  74 #define BLOCK_FLAG_PRIVATE_MASK  0xffff0000
  75 #define BLOCK_FLAG_PRIVATE_SHIFT 16
  76
  77 typedef void (*block_free_t) (block_t *);
  78
  79 struct block_t
  80 {
  81     block_t     *p_next;
  82     block_t     *p_prev;
  83
  84     uint32_t    i_flags;
  85
  86     mtime_t     i_pts;
  87     mtime_t     i_dts;
  88     mtime_t     i_length;
  89
  90     int         i_samples; /* Used for audio */
  91     int         i_rate;
  92
  93     size_t      i_buffer;
  94     uint8_t     *p_buffer;
  95
  96     /* Rudimentary support for overloading block (de)allocation. */
  97     block_free_t pf_release;
  98 };
  99
 100 /****************************************************************************
 101  * Blocks functions:
 102  ****************************************************************************
 103  * - block_Alloc : create a new block with the requested size ( >= 0 ), return
 104  *      NULL for failure.
 105  * - block_Release : release a block allocated with block_Alloc.
 106  * - block_Realloc : realloc a block,
 107  *      i_pre: how many bytes to insert before body if > 0, else how many
 108  *      bytes of body to skip (the latter can be done without using
 109  *      block_Realloc i_buffer -= -i_pre, p_buffer += -i_pre as i_pre < 0)
 110  *      i_body (>= 0): the final size of the body (decreasing it can directly
 111  *      be done with i_buffer = i_body).
 112  *      with preheader and or body (increase
 113  *      and decrease are supported). Use it as it is optimised.
 114  * - block_Duplicate : create a copy of a block.
 115  ****************************************************************************/
 116 VLC_EXPORT( void,      block_Init,    ( block_t *, void *, size_t ) );
 117 VLC_EXPORT( block_t *, block_Alloc,   ( size_t ) );
 118 VLC_EXPORT( block_t *, block_Realloc, ( block_t *, ssize_t i_pre, size_t i_body ) );
 119
 120 #define block_New( dummy, size ) block_Alloc(size)
 121
 122 static inline block_t *block_Duplicate( block_t *p_block )
 123 {
 124     block_t *p_dup = block_Alloc( p_block->i_buffer );
 125     if( p_dup == NULL )
 126         return NULL;
 127
 128     p_dup->i_dts     = p_block->i_dts;
 129     p_dup->i_pts     = p_block->i_pts;
 130     p_dup->i_flags   = p_block->i_flags;
 131     p_dup->i_length  = p_block->i_length;
 132     p_dup->i_rate    = p_block->i_rate;
 133     p_dup->i_samples = p_block->i_samples;
 134     memcpy( p_dup->p_buffer, p_block->p_buffer, p_block->i_buffer );
 135
 136     return p_dup;
 137 }
 138 static inline void block_Release( block_t *p_block )
 139 {
 140     p_block->pf_release( p_block );
 141 }
 142
 143 VLC_EXPORT( block_t *, block_mmap_Alloc, (void *addr, size_t length) );
 144 VLC_EXPORT( block_t *, block_File, (int fd) );
 145
 146 /****************************************************************************
 147  * Chains of blocks functions helper
 148  ****************************************************************************
 149  * - block_ChainAppend : append a block the the last block of a chain. Try to
 150  *      avoid using with a lot of data as it's really slow, prefer
 151  *      block_ChainLastAppend
 152  * - block_ChainLastAppend : use a pointer over a pointer to the next blocks,
 153  *      and update it.
 154  * - block_ChainRelease : release a chain of block
 155  * - block_ChainExtract : extract data from a chain, return real bytes counts
 156  * - block_ChainGather : gather a chain, free it and return a block.
 157  ****************************************************************************/
 158 static inline void block_ChainAppend( block_t **pp_list, block_t *p_block )
 159 {
 160     if( *pp_list == NULL )
 161     {
 162         *pp_list = p_block;
 163     }
 164     else
 165     {
 166         block_t *p = *pp_list;
 167
 168         while( p->p_next ) p = p->p_next;
 169         p->p_next = p_block;
 170     }
 171 }
 172
 173 static inline void block_ChainLastAppend( block_t ***ppp_last, block_t *p_block  )
 174 {
 175     block_t *p_last = p_block;
 176
 177     **ppp_last = p_block;
 178
 179     while( p_last->p_next ) p_last = p_last->p_next;
 180     *ppp_last = &p_last->p_next;
 181 }
 182
 183 static inline void block_ChainRelease( block_t *p_block )
 184 {
 185     while( p_block )
 186     {
 187         block_t *p_next = p_block->p_next;
 188         block_Release( p_block );
 189         p_block = p_next;
 190     }
 191 }
 192
 193 static size_t block_ChainExtract( block_t *p_list, void *p_data, size_t i_max )
 194 {
 195     size_t  i_total = 0;
 196     uint8_t *p = (uint8_t*)p_data;
 197
 198     while( p_list && i_max )
 199     {
 200         size_t i_copy = __MIN( i_max, p_list->i_buffer );
 201         memcpy( p, p_list->p_buffer, i_copy );
 202         i_max   -= i_copy;
 203         i_total += i_copy;
 204         p       += i_copy;
 205
 206         p_list = p_list->p_next;
 207     }
 208     return i_total;
 209 }
 210
 211 static inline block_t *block_ChainGather( block_t *p_list )
 212 {
 213     size_t  i_total = 0;
 214     mtime_t i_length = 0;
 215     block_t *b, *g;
 216
 217     if( p_list->p_next == NULL )
 218         return p_list;  /* Already gathered */
 219
 220     for( b = p_list; b != NULL; b = b->p_next )
 221     {
 222         i_total += b->i_buffer;
 223         i_length += b->i_length;
 224     }
 225
 226     g = block_Alloc( i_total );
 227     block_ChainExtract( p_list, g->p_buffer, g->i_buffer );
 228
 229     g->i_flags = p_list->i_flags;
 230     g->i_pts   = p_list->i_pts;
 231     g->i_dts   = p_list->i_dts;
 232     g->i_length = i_length;
 233
 234     /* free p_list */
 235     block_ChainRelease( p_list );
 236     return g;
 237 }
 238
 239
 240 /****************************************************************************
 241  * Fifos of blocks.
 242  ****************************************************************************
 243  * - block_FifoNew : create and init a new fifo
 244  * - block_FifoRelease : destroy a fifo and free all blocks in it.
 245  * - block_FifoEmpty : free all blocks in a fifo
 246  * - block_FifoPut : put a block
 247  * - block_FifoGet : get a packet from the fifo (and wait if it is empty)
 248  * - block_FifoShow : show the first packet of the fifo (and wait if
 249  *      needed), be carefull, you can use it ONLY if you are sure to be the
 250  *      only one getting data from the fifo.
 251  * - block_FifoCount : how many packets are waiting in the fifo
 252  * - block_FifoSize : how many cumulated bytes are waiting in the fifo
 253  * - block_FifoWake : wake ups a thread with block_FifoGet() = NULL
 254  *   (this is used to wakeup a thread when there is no data to queue)
 255  ****************************************************************************/
 256
 257 VLC_EXPORT( block_fifo_t *, block_FifoNew,      ( void ) );
 258 VLC_EXPORT( void,           block_FifoRelease,  ( block_fifo_t * ) );
 259 VLC_EXPORT( void,           block_FifoEmpty,    ( block_fifo_t * ) );
 260 VLC_EXPORT( size_t,         block_FifoPut,      ( block_fifo_t *, block_t * ) );
 261 VLC_EXPORT( void,           block_FifoWake,     ( block_fifo_t * ) );
 262 VLC_EXPORT( block_t *,      block_FifoGet,      ( block_fifo_t * ) );
 263 VLC_EXPORT( block_t *,      block_FifoShow,     ( block_fifo_t * ) );
 264 VLC_EXPORT( size_t,         block_FifoSize,     ( const block_fifo_t *p_fifo ) );
 265 VLC_EXPORT( size_t,         block_FifoCount,    ( const block_fifo_t *p_fifo ) );
 266
 267 #endif /* VLC_BLOCK_H */