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