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 #if !defined( __LIBVLC__ )
  25   #error You are not libvlc or one of its plugins. You cannot include this file
  26 #endif
  27
  28 #ifndef _VLC_BLOCK_H
  29 #define _VLC_BLOCK_H 1
  30
  31 /****************************************************************************
  32  * block:
  33  ****************************************************************************
  34  * - block_sys_t is opaque and thus block_t->p_sys is PRIVATE
  35  * - i_flags may not always be set (ie could be 0, even for a key frame
  36  *      it depends where you receive the buffer (before/after a packetizer
  37  *      and the demux/packetizer implementations.
  38  * - i_dts/i_pts could be 0, it means no pts
  39  * - i_length: length in microseond of the packet, can be null except in the
  40  *      sout where it is mandatory.
  41  * - i_rate 0 or a valid input rate, look at vlc_input.h
  42  *
  43  * - i_buffer number of valid data pointed by p_buffer
  44  *      you can freely decrease it but never increase it yourself
  45  *      (use block_Realloc)
  46  * - p_buffer: pointer over datas. You should never overwrite it, you can
  47  *   only incremment it to skip datas, in others cases use block_Realloc
  48  *   (don't duplicate yourself in a bigger buffer, block_Realloc is
  49  *   optimised for prehader/postdatas increase)
  50  ****************************************************************************/
  51 typedef struct block_sys_t block_sys_t;
  52
  53 /** The content doesn't follow the last block, or is probably broken */
  54 #define BLOCK_FLAG_DISCONTINUITY 0x0001
  55 /** Intra frame */
  56 #define BLOCK_FLAG_TYPE_I        0x0002
  57 /** Inter frame with backward reference only */
  58 #define BLOCK_FLAG_TYPE_P        0x0004
  59 /** Inter frame with backward and forward reference */
  60 #define BLOCK_FLAG_TYPE_B        0x0008
  61 /** For inter frame when you don't know the real type */
  62 #define BLOCK_FLAG_TYPE_PB       0x0010
  63 /** Warn that this block is a header one */
  64 #define BLOCK_FLAG_HEADER        0x0020
  65 /** This is the last block of the frame */
  66 #define BLOCK_FLAG_END_OF_FRAME  0x0040
  67 /** This is not a key frame for bitrate shaping */
  68 #define BLOCK_FLAG_NO_KEYFRAME   0x0080
  69 /** This block contains a clock reference */
  70 #define BLOCK_FLAG_CLOCK         0x0200
  71 /** This block is scrambled */
  72 #define BLOCK_FLAG_SCRAMBLED     0x0400
  73 /** This block has to be decoded but not be displayed */
  74 #define BLOCK_FLAG_PREROLL       0x0800
  75 /** This block is corrupted and/or there is data loss  */
  76 #define BLOCK_FLAG_CORRUPTED     0x1000
  77
  78 #define BLOCK_FLAG_PRIVATE_MASK  0xffff0000
  79 #define BLOCK_FLAG_PRIVATE_SHIFT 16
  80
  81 struct block_t
  82 {
  83     block_t     *p_next;
  84     block_t     *p_prev;
  85
  86     uint32_t    i_flags;
  87
  88     mtime_t     i_pts;
  89     mtime_t     i_dts;
  90     mtime_t     i_length;
  91
  92     int         i_samples; /* Used for audio */
  93     int         i_rate;
  94
  95     int         i_buffer;
  96     uint8_t     *p_buffer;
  97
  98     /* This way the block_Release can be overloaded
  99      * Don't mess with it now, if you need it the ask on ML
 100      */
 101     void        (*pf_release)   ( block_t * );
 102
 103     /* It's an object that should be valid as long as the block_t is valid */
 104     /* It should become a true block manager to reduce malloc/free */
 105     vlc_object_t    *p_manager;
 106
 107     /* Following fields are private, user should never touch it */
 108     /* XXX never touch that OK !!! the first that access that will
 109      * have Subversion account removed ;) XXX */
 110     block_sys_t *p_sys;
 111 };
 112
 113 /****************************************************************************
 114  * Blocks functions:
 115  ****************************************************************************
 116  * - block_New : create a new block with the requested size ( >= 0 ), return
 117  *      NULL for failure.
 118  * - block_Release : release a block allocated with block_New.
 119  * - block_Realloc : realloc a block,
 120  *      i_pre: how many bytes to insert before body if > 0, else how many
 121  *      bytes of body to skip (the latter can be done without using
 122  *      block_Realloc i_buffer -= -i_pre, p_buffer += -i_pre as i_pre < 0)
 123  *      i_body (>= 0): the final size of the body (decreasing it can directly
 124  *      be done with i_buffer = i_body).
 125  *      with preheader and or body (increase
 126  *      and decrease are supported). Use it as it is optimised.
 127  * - block_Duplicate : create a copy of a block.
 128  ****************************************************************************/
 129 #define block_New( a, b ) __block_New( VLC_OBJECT(a), b )
 130 VLC_EXPORT( block_t *,  __block_New,        ( vlc_object_t *, int ) );
 131 VLC_EXPORT( block_t *, block_Realloc,       ( block_t *, int i_pre, int i_body ) );
 132
 133 static inline block_t *block_Duplicate( block_t *p_block )
 134 {
 135     block_t *p_dup = block_New( p_block->p_manager, p_block->i_buffer );
 136     if( p_dup == NULL )
 137         return NULL;
 138
 139     p_dup->i_dts     = p_block->i_dts;
 140     p_dup->i_pts     = p_block->i_pts;
 141     p_dup->i_flags   = p_block->i_flags;
 142     p_dup->i_length  = p_block->i_length;
 143     p_dup->i_rate    = p_block->i_rate;
 144     p_dup->i_samples = p_block->i_samples;
 145     memcpy( p_dup->p_buffer, p_block->p_buffer, p_block->i_buffer );
 146
 147     return p_dup;
 148 }
 149 static inline void block_Release( block_t *p_block )
 150 {
 151     p_block->pf_release( p_block );
 152 }
 153
 154 /****************************************************************************
 155  * Chains of blocks functions helper
 156  ****************************************************************************
 157  * - block_ChainAppend : append a block the the last block of a chain. Try to
 158  *      avoid using with a lot of data as it's really slow, prefer
 159  *      block_ChainLastAppend
 160  * - block_ChainLastAppend : use a pointer over a pointer to the next blocks,
 161  *      and update it.
 162  * - block_ChainRelease : release a chain of block
 163  * - block_ChainExtract : extract data from a chain, return real bytes counts
 164  * - block_ChainGather : gather a chain, free it and return a block.
 165  ****************************************************************************/
 166 static inline void block_ChainAppend( block_t **pp_list, block_t *p_block )
 167 {
 168     if( *pp_list == NULL )
 169     {
 170         *pp_list = p_block;
 171     }
 172     else
 173     {
 174         block_t *p = *pp_list;
 175
 176         while( p->p_next ) p = p->p_next;
 177         p->p_next = p_block;
 178     }
 179 }
 180
 181 static inline void block_ChainLastAppend( block_t ***ppp_last, block_t *p_block  )
 182 {
 183     block_t *p_last = p_block;
 184
 185     **ppp_last = p_block;
 186
 187     while( p_last->p_next ) p_last = p_last->p_next;
 188     *ppp_last = &p_last->p_next;
 189 }
 190
 191 static inline void block_ChainRelease( block_t *p_block )
 192 {
 193     while( p_block )
 194     {
 195         block_t *p_next = p_block->p_next;
 196         block_Release( p_block );
 197         p_block = p_next;
 198     }
 199 }
 200 static int block_ChainExtract( block_t *p_list, void *p_data, int i_max )
 201 {
 202     block_t *b;
 203     int     i_total = 0;
 204     uint8_t *p = (uint8_t*)p_data;
 205
 206     for( b = p_list; b != NULL; b = b->p_next )
 207     {
 208         int i_copy = __MIN( i_max, b->i_buffer );
 209         if( i_copy > 0 )
 210         {
 211             memcpy( p, b->p_buffer, i_copy );
 212             i_max   -= i_copy;
 213             i_total += i_copy;
 214             p       += i_copy;
 215
 216             if( i_max == 0 )
 217                 return i_total;
 218         }
 219     }
 220     return i_total;
 221 }
 222
 223 static inline block_t *block_ChainGather( block_t *p_list )
 224 {
 225     int     i_total = 0;
 226     mtime_t i_length = 0;
 227     block_t *b, *g;
 228
 229     if( p_list->p_next == NULL )
 230         return p_list;  /* Already gathered */
 231
 232     for( b = p_list; b != NULL; b = b->p_next )
 233     {
 234         i_total += b->i_buffer;
 235         i_length += b->i_length;
 236     }
 237
 238     g = block_New( p_list->p_manager, i_total );
 239     block_ChainExtract( p_list, g->p_buffer, g->i_buffer );
 240
 241     g->i_flags = p_list->i_flags;
 242     g->i_pts   = p_list->i_pts;
 243     g->i_dts   = p_list->i_dts;
 244     g->i_length = i_length;
 245
 246     /* free p_list */
 247     block_ChainRelease( p_list );
 248     return g;
 249 }
 250
 251
 252 /****************************************************************************
 253  * Fifos of blocks.
 254  ****************************************************************************
 255  * - block_FifoNew : create and init a new fifo
 256  * - block_FifoRelease : destroy a fifo and free all blocks in it.
 257  * - block_FifoEmpty : free all blocks in a fifo
 258  * - block_FifoPut : put a block
 259  * - block_FifoGet : get a packet from the fifo (and wait if it is empty)
 260  * - block_FifoShow : show the first packet of the fifo (and wait if
 261  *      needed), be carefull, you can use it ONLY if you are sure to be the
 262  *      only one getting data from the fifo.
 263  * - block_FifoCount : how many packets are waiting in the fifo
 264  * - block_FifoSize : how many cumulated bytes are waiting in the fifo
 265  * - block_FifoWake : wake ups a thread with block_FifoGet() = NULL
 266  *   (this is used to wakeup a thread when there is no data to queue)
 267  ****************************************************************************/
 268
 269 #define block_FifoNew( a ) __block_FifoNew( VLC_OBJECT(a) )
 270 VLC_EXPORT( block_fifo_t *, __block_FifoNew,    ( vlc_object_t * ) );
 271 VLC_EXPORT( void,           block_FifoRelease,  ( block_fifo_t * ) );
 272 VLC_EXPORT( void,           block_FifoEmpty,    ( block_fifo_t * ) );
 273 VLC_EXPORT( int,            block_FifoPut,      ( block_fifo_t *, block_t * ) );
 274 VLC_EXPORT( void,           block_FifoWake,     ( block_fifo_t * ) );
 275 VLC_EXPORT( block_t *,      block_FifoGet,      ( block_fifo_t * ) );
 276 VLC_EXPORT( block_t *,      block_FifoShow,     ( block_fifo_t * ) );
 277 VLC_EXPORT( size_t,         block_FifoSize,     ( const block_fifo_t *p_fifo ) );
 278 VLC_EXPORT( size_t,         block_FifoCount,    ( const block_fifo_t *p_fifo ) );
 279
 280 #endif /* VLC_BLOCK_H */