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  * \file
  29  * This file implements functions and structures to handle blocks of data in vlc
  30  *
  31  */
  32
  33 /****************************************************************************
  34  * block:
  35  ****************************************************************************
  36  * - block_sys_t is opaque and thus block_t->p_sys is PRIVATE
  37  * - i_flags may not always be set (ie could be 0, even for a key frame
  38  *      it depends where you receive the buffer (before/after a packetizer
  39  *      and the demux/packetizer implementations.
  40  * - i_dts/i_pts could be VLC_TS_INVALID, it means no pts/dts
  41  * - i_length: length in microseond of the packet, can be null except in the
  42  *      sout where it is mandatory.
  43  *
  44  * - i_buffer number of valid data pointed by p_buffer
  45  *      you can freely decrease it but never increase it yourself
  46  *      (use block_Realloc)
  47  * - p_buffer: pointer over datas. You should never overwrite it, you can
  48  *   only incremment it to skip datas, in others cases use block_Realloc
  49  *   (don't duplicate yourself in a bigger buffer, block_Realloc is
  50  *   optimised for preheader/postdatas increase)
  51  ****************************************************************************/
  52 typedef struct block_sys_t block_sys_t;
  53
  54 /** The content doesn't follow the last block, or is probably broken */
  55 #define BLOCK_FLAG_DISCONTINUITY 0x0001
  56 /** Intra frame */
  57 #define BLOCK_FLAG_TYPE_I        0x0002
  58 /** Inter frame with backward reference only */
  59 #define BLOCK_FLAG_TYPE_P        0x0004
  60 /** Inter frame with backward and forward reference */
  61 #define BLOCK_FLAG_TYPE_B        0x0008
  62 /** For inter frame when you don't know the real type */
  63 #define BLOCK_FLAG_TYPE_PB       0x0010
  64 /** Warn that this block is a header one */
  65 #define BLOCK_FLAG_HEADER        0x0020
  66 /** This is the last block of the frame */
  67 #define BLOCK_FLAG_END_OF_FRAME  0x0040
  68 /** This is not a key frame for bitrate shaping */
  69 #define BLOCK_FLAG_NO_KEYFRAME   0x0080
  70 /** This block contains the last part of a sequence  */
  71 #define BLOCK_FLAG_END_OF_SEQUENCE 0x0100
  72 /** This block contains a clock reference */
  73 #define BLOCK_FLAG_CLOCK         0x0200
  74 /** This block is scrambled */
  75 #define BLOCK_FLAG_SCRAMBLED     0x0400
  76 /** This block has to be decoded but not be displayed */
  77 #define BLOCK_FLAG_PREROLL       0x0800
  78 /** This block is corrupted and/or there is data loss  */
  79 #define BLOCK_FLAG_CORRUPTED     0x1000
  80 /** This block contains an interlaced picture with top field first */
  81 #define BLOCK_FLAG_TOP_FIELD_FIRST 0x2000
  82 /** This block contains an interlaced picture with bottom field first */
  83 #define BLOCK_FLAG_BOTTOM_FIELD_FIRST 0x4000
  84
  85 /** This block contains an interlaced picture */
  86 #define BLOCK_FLAG_INTERLACED_MASK \
  87     (BLOCK_FLAG_TOP_FIELD_FIRST|BLOCK_FLAG_BOTTOM_FIELD_FIRST)
  88
  89 #define BLOCK_FLAG_TYPE_MASK \
  90     (BLOCK_FLAG_TYPE_I|BLOCK_FLAG_TYPE_P|BLOCK_FLAG_TYPE_B|BLOCK_FLAG_TYPE_PB)
  91
  92 /* These are for input core private usage only */
  93 #define BLOCK_FLAG_CORE_PRIVATE_MASK  0x00ff0000
  94 #define BLOCK_FLAG_CORE_PRIVATE_SHIFT 16
  95
  96 /* These are for module private usage only */
  97 #define BLOCK_FLAG_PRIVATE_MASK  0xff000000
  98 #define BLOCK_FLAG_PRIVATE_SHIFT 24
  99
 100 typedef void (*block_free_t) (block_t *);
 101
 102 struct block_t
 103 {
 104     block_t     *p_next;
 105
 106     uint8_t     *p_buffer;
 107     size_t      i_buffer;
 108
 109     uint32_t    i_flags;
 110     unsigned    i_nb_samples; /* Used for audio */
 111
 112     mtime_t     i_pts;
 113     mtime_t     i_dts;
 114     mtime_t     i_length;
 115
 116     /* Rudimentary support for overloading block (de)allocation. */
 117     block_free_t pf_release;
 118 };
 119
 120 /****************************************************************************
 121  * Blocks functions:
 122  ****************************************************************************
 123  * - block_Alloc : create a new block with the requested size ( >= 0 ), return
 124  *      NULL for failure.
 125  * - block_Release : release a block allocated with block_Alloc.
 126  * - block_Realloc : realloc a block,
 127  *      i_pre: how many bytes to insert before body if > 0, else how many
 128  *      bytes of body to skip (the latter can be done without using
 129  *      block_Realloc i_buffer -= -i_pre, p_buffer += -i_pre as i_pre < 0)
 130  *      i_body (>= 0): the final size of the body (decreasing it can directly
 131  *      be done with i_buffer = i_body).
 132  *      with preheader and or body (increase
 133  *      and decrease are supported). Use it as it is optimised.
 134  * - block_Duplicate : create a copy of a block.
 135  ****************************************************************************/
 136 VLC_API void block_Init( block_t *, void *, size_t );
 137 VLC_API block_t * block_Alloc( size_t ) VLC_USED;
 138 VLC_API block_t * block_Realloc( block_t *, ssize_t i_pre, size_t i_body ) VLC_USED;
 139
 140 #define block_New( dummy, size ) block_Alloc(size)
 141
 142 VLC_USED
 143 static inline block_t *block_Duplicate( block_t *p_block )
 144 {
 145     block_t *p_dup = block_Alloc( p_block->i_buffer );
 146     if( p_dup == NULL )
 147         return NULL;
 148
 149     p_dup->i_flags   = p_block->i_flags;
 150     p_dup->i_nb_samples = p_block->i_nb_samples;
 151     p_dup->i_dts     = p_block->i_dts;
 152     p_dup->i_pts     = p_block->i_pts;
 153     p_dup->i_length  = p_block->i_length;
 154     memcpy( p_dup->p_buffer, p_block->p_buffer, p_block->i_buffer );
 155
 156     return p_dup;
 157 }
 158
 159 static inline void block_Release( block_t *p_block )
 160 {
 161     p_block->pf_release( p_block );
 162 }
 163
 164 VLC_API block_t * block_heap_Alloc(void *, void *, size_t) VLC_USED;
 165 VLC_API block_t * block_mmap_Alloc(void *addr, size_t length) VLC_USED;
 166 VLC_API block_t * block_File(int fd) VLC_USED;
 167
 168 static inline void block_Cleanup (void *block)
 169 {
 170     block_Release ((block_t *)block);
 171 }
 172 #define block_cleanup_push( block ) vlc_cleanup_push (block_Cleanup, block)
 173
 174 /****************************************************************************
 175  * Chains of blocks functions helper
 176  ****************************************************************************
 177  * - block_ChainAppend : append a block to the last block of a chain. Try to
 178  *      avoid using with a lot of data as it's really slow, prefer
 179  *      block_ChainLastAppend, p_block can be NULL
 180  * - block_ChainLastAppend : use a pointer over a pointer to the next blocks,
 181  *      and update it.
 182  * - block_ChainRelease : release a chain of block
 183  * - block_ChainExtract : extract data from a chain, return real bytes counts
 184  * - block_ChainGather : gather a chain, free it and return one block.
 185  ****************************************************************************/
 186 static inline void block_ChainAppend( block_t **pp_list, block_t *p_block )
 187 {
 188     if( *pp_list == NULL )
 189     {
 190         *pp_list = p_block;
 191     }
 192     else
 193     {
 194         block_t *p = *pp_list;
 195
 196         while( p->p_next ) p = p->p_next;
 197         p->p_next = p_block;
 198     }
 199 }
 200
 201 static inline void block_ChainLastAppend( block_t ***ppp_last, block_t *p_block )
 202 {
 203     block_t *p_last = p_block;
 204
 205     **ppp_last = p_block;
 206
 207     while( p_last->p_next ) p_last = p_last->p_next;
 208     *ppp_last = &p_last->p_next;
 209 }
 210
 211 static inline void block_ChainRelease( block_t *p_block )
 212 {
 213     while( p_block )
 214     {
 215         block_t *p_next = p_block->p_next;
 216         block_Release( p_block );
 217         p_block = p_next;
 218     }
 219 }
 220
 221 static size_t block_ChainExtract( block_t *p_list, void *p_data, size_t i_max )
 222 {
 223     size_t  i_total = 0;
 224     uint8_t *p = (uint8_t*)p_data;
 225
 226     while( p_list && i_max )
 227     {
 228         size_t i_copy = __MIN( i_max, p_list->i_buffer );
 229         memcpy( p, p_list->p_buffer, i_copy );
 230         i_max   -= i_copy;
 231         i_total += i_copy;
 232         p       += i_copy;
 233
 234         p_list = p_list->p_next;
 235     }
 236     return i_total;
 237 }
 238
 239 static inline void block_ChainProperties( block_t *p_list, int *pi_count, size_t *pi_size, mtime_t *pi_length )
 240 {
 241     size_t i_size = 0;
 242     mtime_t i_length = 0;
 243     int i_count = 0;
 244
 245     while( p_list )
 246     {
 247         i_size += p_list->i_buffer;
 248         i_length += p_list->i_length;
 249         i_count++;
 250
 251         p_list = p_list->p_next;
 252     }
 253
 254     if( pi_size )
 255         *pi_size = i_size;
 256     if( pi_length )
 257         *pi_length = i_length;
 258     if( pi_count )
 259         *pi_count = i_count;
 260 }
 261
 262 static inline block_t *block_ChainGather( block_t *p_list )
 263 {
 264     size_t  i_total = 0;
 265     mtime_t i_length = 0;
 266     block_t *g;
 267
 268     if( p_list->p_next == NULL )
 269         return p_list;  /* Already gathered */
 270
 271     block_ChainProperties( p_list, NULL, &i_total, &i_length );
 272
 273     g = block_Alloc( i_total );
 274     block_ChainExtract( p_list, g->p_buffer, g->i_buffer );
 275
 276     g->i_flags = p_list->i_flags;
 277     g->i_pts   = p_list->i_pts;
 278     g->i_dts   = p_list->i_dts;
 279     g->i_length = i_length;
 280
 281     /* free p_list */
 282     block_ChainRelease( p_list );
 283     return g;
 284 }
 285
 286 /****************************************************************************
 287  * Fifos of blocks.
 288  ****************************************************************************
 289  * - block_FifoNew : create and init a new fifo
 290  * - block_FifoRelease : destroy a fifo and free all blocks in it.
 291  * - block_FifoPace : wait for a fifo to drain to a specified number of packets or total data size
 292  * - block_FifoEmpty : free all blocks in a fifo
 293  * - block_FifoPut : put a block
 294  * - block_FifoGet : get a packet from the fifo (and wait if it is empty)
 295  * - block_FifoShow : show the first packet of the fifo (and wait if
 296  *      needed), be carefull, you can use it ONLY if you are sure to be the
 297  *      only one getting data from the fifo.
 298  * - block_FifoCount : how many packets are waiting in the fifo
 299  * - block_FifoWake : wake ups a thread with block_FifoGet() = NULL
 300  *   (this is used to wakeup a thread when there is no data to queue)
 301  *
 302  * block_FifoGet and block_FifoShow are cancellation points.
 303  ****************************************************************************/
 304
 305 VLC_API block_fifo_t * block_FifoNew( void ) VLC_USED;
 306 VLC_API void block_FifoRelease( block_fifo_t * );
 307 VLC_API void block_FifoPace( block_fifo_t *fifo, size_t max_depth, size_t max_size );
 308 VLC_API void block_FifoEmpty( block_fifo_t * );
 309 VLC_API size_t block_FifoPut( block_fifo_t *, block_t * );
 310 VLC_API void block_FifoWake( block_fifo_t * );
 311 VLC_API block_t * block_FifoGet( block_fifo_t * ) VLC_USED;
 312 VLC_API block_t * block_FifoShow( block_fifo_t * );
 313 size_t block_FifoSize( const block_fifo_t *p_fifo ) VLC_USED;
 314 VLC_API size_t block_FifoCount( const block_fifo_t *p_fifo ) VLC_USED;
 315
 316 #endif /* VLC_BLOCK_H */