1 /*****************************************************************************
2 * vlc_block.h: Data blocks management functions
3 *****************************************************************************
4 * Copyright (C) 2003 VideoLAN
7 * Authors: Laurent Aimar <fenrir@via.ecp.fr>
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.
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.
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., 59 Temple Place - Suite 330, Boston, MA 02111, USA.
22 *****************************************************************************/
25 #define _VLC_BLOCK_H 1
27 /****************************************************************************
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
39 * - i_buffer number of valid data pointed by p_buffer
40 * you can freely decrease it but never increase it yourself
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;
49 /** The content doesn't follow the last block, or is probably broken */
50 #define BLOCK_FLAG_DISCONTINUITY 0x0001
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 /** Warm 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
64 #define BLOCK_FLAG_PRIVATE_MASK 0xffff0000
65 #define BLOCK_FLAG_PRIVATE_SHIFT 16
77 int i_samples; /* Used for audio */
83 /* This way the block_Release can be overloaded
84 * Don't mess with it now, if you need it the ask on ML
86 void (*pf_release) ( block_t * );
88 /* It's an object that should be valid as long as the block_t is valid */
89 /* It should become a true block manager to reduce malloc/free */
90 vlc_object_t *p_manager;
92 /* Following fields are private, user should never touch it */
93 /* XXX never touch that OK !!! the first that access that will
94 * have cvs account removed ;) XXX */
98 /****************************************************************************
100 ****************************************************************************
101 * - block_New : create a new block with the requested size ( >= 0 ), return
103 * - block_Release : release a block allocated with block_New.
104 * - block_Realloc : realloc a block,
105 * i_pre: how many bytes to insert before body if > 0, else how many
106 * bytes of body to skip (the latter can be done without using
107 * block_Realloc i_buffer -= -i_pre, p_buffer += -i_pre as i_pre < 0)
108 * i_body (>= 0): the final size of the body (decreasing it can directly
109 * be done with i_buffer = i_body).
110 * with preheader and or body (increase
111 * and decrease are supported). Use it as it is optimised.
112 * - block_Duplicate : create a copy of a block.
113 ****************************************************************************/
114 #define block_New( a, b ) __block_New( VLC_OBJECT(a), b )
115 VLC_EXPORT( block_t *, __block_New, ( vlc_object_t *, int ) );
116 VLC_EXPORT( block_t *, block_Realloc, ( block_t *, int i_pre, int i_body ) );
118 static inline block_t *block_Duplicate( block_t *p_block )
120 block_t *p_dup = block_New( p_block->p_manager, p_block->i_buffer );
122 if( p_dup && p_block->i_buffer > 0 )
123 memcpy( p_dup->p_buffer, p_block->p_buffer, p_block->i_buffer );
127 static inline void block_Release( block_t *p_block )
129 p_block->pf_release( p_block );
132 /****************************************************************************
133 * Chains of blocks functions helper
134 ****************************************************************************
135 * - block_ChainAppend : append a block the the last block of a chain. Try to
136 * avoid using with a lot of data as it's really slow, prefer
137 * block_ChainLastAppend
138 * - block_ChainLastAppend : use a pointer over a pointer to the next blocks,
140 * - block_ChainRelease : release a chain of block
141 * - block_ChainExtract : extract data from a chain, return real bytes counts
142 * - block_ChainGather : gather a chain, free it and return a block.
143 ****************************************************************************/
144 static inline void block_ChainAppend( block_t **pp_list, block_t *p_block )
146 if( *pp_list == NULL )
152 block_t *p = *pp_list;
154 while( p->p_next ) p = p->p_next;
159 static inline void block_ChainLastAppend( block_t ***ppp_last, block_t *p_block )
161 block_t *p_last = p_block;
163 **ppp_last = p_block;
165 while( p_last->p_next ) p_last = p_last->p_next;
166 *ppp_last = &p_last->p_next;
169 static inline void block_ChainRelease( block_t *p_block )
173 block_t *p_next = p_block->p_next;
174 block_Release( p_block );
178 static int block_ChainExtract( block_t *p_list, void *p_data, int i_max )
182 uint8_t *p = (uint8_t*)p_data;
184 for( b = p_list; b != NULL; b = b->p_next )
186 int i_copy = __MIN( i_max, b->i_buffer );
189 memcpy( p, b->p_buffer, i_copy );
201 static inline block_t *block_ChainGather( block_t *p_list )
206 if( p_list->p_next == NULL )
207 return p_list; /* Already gathered */
209 for( b = p_list; b != NULL; b = b->p_next )
210 i_total += b->i_buffer;
212 g = block_New( p_list->p_manager, i_total );
213 block_ChainExtract( p_list, g->p_buffer, g->i_buffer );
215 g->i_flags = p_list->i_flags;
216 g->i_pts = p_list->i_pts;
217 g->i_dts = p_list->i_dts;
220 block_ChainRelease( p_list );
225 /****************************************************************************
227 ****************************************************************************
228 * Avoid touching block_fifo_t unless you really know what you are doing.
229 * ( Some race conditions has to be correctly handled, like in win32 ;)
230 * - block_FifoNew : create and init a new fifo
231 * - block_FifoRelease : destroy a fifo and free all blocks in it.
232 * - block_FifoEmpty : free all blocks in a fifo
233 * - block_FifoPut : put a block
234 * - block_FifoGet : get a packet from the fifo (and wait if it is empty)
235 * - block_FifoShow : show the first packet of the fifo (and wait if
236 * needed), becarefull, you can use it ONLY if you are sure to be the
237 * only one getting data from the fifo.
238 ****************************************************************************/
241 vlc_mutex_t lock; /* fifo data lock */
242 vlc_cond_t wait; /* fifo data conditional variable */
251 #define block_FifoNew( a ) __block_FifoNew( VLC_OBJECT(a) )
252 VLC_EXPORT( block_fifo_t *, __block_FifoNew, ( vlc_object_t * ) );
253 VLC_EXPORT( void, block_FifoRelease, ( block_fifo_t * ) );
254 VLC_EXPORT( void, block_FifoEmpty, ( block_fifo_t * ) );
255 VLC_EXPORT( int, block_FifoPut, ( block_fifo_t *, block_t * ) );
256 VLC_EXPORT( block_t *, block_FifoGet, ( block_fifo_t * ) );
257 VLC_EXPORT( block_t *, block_FifoShow, ( block_fifo_t * ) );
259 #endif /* VLC_BLOCK_H */