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
63 /** This is not a key frame for bitrate shaping */
64 #define BLOCK_FLAG_NO_KEYFRAME 0x0080
65 /** This is the last block of the GOP */
66 #define BLOCK_FLAG_END_OF_GOP 0x0100
67 /** This block contains a clock reference */
68 #define BLOCK_FLAG_CLOCK 0x0200
69 /** This block is scrambled */
70 #define BLOCK_FLAG_SCRAMBLED 0x0400
72 #define BLOCK_FLAG_PRIVATE_MASK 0xffff0000
73 #define BLOCK_FLAG_PRIVATE_SHIFT 16
85 int i_samples; /* Used for audio */
91 /* This way the block_Release can be overloaded
92 * Don't mess with it now, if you need it the ask on ML
94 void (*pf_release) ( block_t * );
96 /* It's an object that should be valid as long as the block_t is valid */
97 /* It should become a true block manager to reduce malloc/free */
98 vlc_object_t *p_manager;
100 /* Following fields are private, user should never touch it */
101 /* XXX never touch that OK !!! the first that access that will
102 * have cvs account removed ;) XXX */
106 /****************************************************************************
108 ****************************************************************************
109 * - block_New : create a new block with the requested size ( >= 0 ), return
111 * - block_Release : release a block allocated with block_New.
112 * - block_Realloc : realloc a block,
113 * i_pre: how many bytes to insert before body if > 0, else how many
114 * bytes of body to skip (the latter can be done without using
115 * block_Realloc i_buffer -= -i_pre, p_buffer += -i_pre as i_pre < 0)
116 * i_body (>= 0): the final size of the body (decreasing it can directly
117 * be done with i_buffer = i_body).
118 * with preheader and or body (increase
119 * and decrease are supported). Use it as it is optimised.
120 * - block_Duplicate : create a copy of a block.
121 ****************************************************************************/
122 #define block_New( a, b ) __block_New( VLC_OBJECT(a), b )
123 VLC_EXPORT( block_t *, __block_New, ( vlc_object_t *, int ) );
124 VLC_EXPORT( block_t *, block_Realloc, ( block_t *, int i_pre, int i_body ) );
126 static inline block_t *block_Duplicate( block_t *p_block )
128 block_t *p_dup = block_New( p_block->p_manager, p_block->i_buffer );
130 p_dup->i_dts = p_block->i_dts;
131 p_dup->i_pts = p_block->i_pts;
132 p_dup->i_flags = p_block->i_flags;
133 p_dup->i_length = p_block->i_length;
134 p_dup->i_rate = p_block->i_rate;
135 p_dup->i_samples = p_block->i_samples;
137 if( p_dup && p_block->i_buffer > 0 )
138 memcpy( p_dup->p_buffer, p_block->p_buffer, p_block->i_buffer );
142 static inline void block_Release( block_t *p_block )
144 p_block->pf_release( p_block );
147 /****************************************************************************
148 * Chains of blocks functions helper
149 ****************************************************************************
150 * - block_ChainAppend : append a block the the last block of a chain. Try to
151 * avoid using with a lot of data as it's really slow, prefer
152 * block_ChainLastAppend
153 * - block_ChainLastAppend : use a pointer over a pointer to the next blocks,
155 * - block_ChainRelease : release a chain of block
156 * - block_ChainExtract : extract data from a chain, return real bytes counts
157 * - block_ChainGather : gather a chain, free it and return a block.
158 ****************************************************************************/
159 static inline void block_ChainAppend( block_t **pp_list, block_t *p_block )
161 if( *pp_list == NULL )
167 block_t *p = *pp_list;
169 while( p->p_next ) p = p->p_next;
174 static inline void block_ChainLastAppend( block_t ***ppp_last, block_t *p_block )
176 block_t *p_last = p_block;
178 **ppp_last = p_block;
180 while( p_last->p_next ) p_last = p_last->p_next;
181 *ppp_last = &p_last->p_next;
184 static inline void block_ChainRelease( block_t *p_block )
188 block_t *p_next = p_block->p_next;
189 block_Release( p_block );
193 static int block_ChainExtract( block_t *p_list, void *p_data, int i_max )
197 uint8_t *p = (uint8_t*)p_data;
199 for( b = p_list; b != NULL; b = b->p_next )
201 int i_copy = __MIN( i_max, b->i_buffer );
204 memcpy( p, b->p_buffer, i_copy );
216 static inline block_t *block_ChainGather( block_t *p_list )
221 if( p_list->p_next == NULL )
222 return p_list; /* Already gathered */
224 for( b = p_list; b != NULL; b = b->p_next )
225 i_total += b->i_buffer;
227 g = block_New( p_list->p_manager, i_total );
228 block_ChainExtract( p_list, g->p_buffer, g->i_buffer );
230 g->i_flags = p_list->i_flags;
231 g->i_pts = p_list->i_pts;
232 g->i_dts = p_list->i_dts;
235 block_ChainRelease( p_list );
240 /****************************************************************************
242 ****************************************************************************
243 * Avoid touching block_fifo_t unless you really know what you are doing.
244 * ( Some race conditions has to be correctly handled, like in win32 ;)
245 * - block_FifoNew : create and init a new fifo
246 * - block_FifoRelease : destroy a fifo and free all blocks in it.
247 * - block_FifoEmpty : free all blocks in a fifo
248 * - block_FifoPut : put a block
249 * - block_FifoGet : get a packet from the fifo (and wait if it is empty)
250 * - block_FifoShow : show the first packet of the fifo (and wait if
251 * needed), becarefull, you can use it ONLY if you are sure to be the
252 * only one getting data from the fifo.
253 ****************************************************************************/
256 vlc_mutex_t lock; /* fifo data lock */
257 vlc_cond_t wait; /* fifo data conditional variable */
266 #define block_FifoNew( a ) __block_FifoNew( VLC_OBJECT(a) )
267 VLC_EXPORT( block_fifo_t *, __block_FifoNew, ( vlc_object_t * ) );
268 VLC_EXPORT( void, block_FifoRelease, ( block_fifo_t * ) );
269 VLC_EXPORT( void, block_FifoEmpty, ( block_fifo_t * ) );
270 VLC_EXPORT( int, block_FifoPut, ( block_fifo_t *, block_t * ) );
271 VLC_EXPORT( block_t *, block_FifoGet, ( block_fifo_t * ) );
272 VLC_EXPORT( block_t *, block_FifoShow, ( block_fifo_t * ) );
274 #endif /* VLC_BLOCK_H */