1 /*****************************************************************************
2 * vlc_block.h: Data blocks management functions
3 *****************************************************************************
4 * Copyright (C) 2003 the VideoLAN team
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., 51 Franklin Street, Fifth Floor, Boston MA 02110-1301, USA.
22 *****************************************************************************/
29 * This file implements functions and structures to handle blocks of data in vlc
33 /****************************************************************************
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
45 * - i_buffer number of valid data pointed by p_buffer
46 * you can freely decrease it but never increase it yourself
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
;
55 /** The content doesn't follow the last block, or is probably broken */
56 #define BLOCK_FLAG_DISCONTINUITY 0x0001
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
82 #define BLOCK_FLAG_TYPE_MASK \
83 (BLOCK_FLAG_TYPE_I|BLOCK_FLAG_TYPE_P|BLOCK_FLAG_TYPE_B|BLOCK_FLAG_TYPE_PB)
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
89 /* These are for module private usage only */
90 #define BLOCK_FLAG_PRIVATE_MASK 0xff000000
91 #define BLOCK_FLAG_PRIVATE_SHIFT 24
93 typedef void (*block_free_t
) (block_t
*);
106 int i_samples
; /* Used for audio */
112 /* Rudimentary support for overloading block (de)allocation. */
113 block_free_t pf_release
;
116 /****************************************************************************
118 ****************************************************************************
119 * - block_Alloc : create a new block with the requested size ( >= 0 ), return
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
);
136 #define block_New( dummy, size ) block_Alloc(size)
139 static inline block_t
*block_Duplicate( block_t
*p_block
)
141 block_t
*p_dup
= block_Alloc( p_block
->i_buffer
);
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
);
156 static inline void block_Release( block_t
*p_block
)
158 p_block
->pf_release( p_block
);
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
);
164 static inline void block_Cleanup (void *block
)
166 block_Release ((block_t
*)block
);
168 #define block_cleanup_push( block ) vlc_cleanup_push (block_Cleanup, block)
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,
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
)
184 if( *pp_list
== NULL
)
190 block_t
*p
= *pp_list
;
192 while( p
->p_next
) p
= p
->p_next
;
197 static inline void block_ChainLastAppend( block_t
***ppp_last
, block_t
*p_block
)
199 block_t
*p_last
= p_block
;
201 **ppp_last
= p_block
;
203 while( p_last
->p_next
) p_last
= p_last
->p_next
;
204 *ppp_last
= &p_last
->p_next
;
207 static inline void block_ChainRelease( block_t
*p_block
)
211 block_t
*p_next
= p_block
->p_next
;
212 block_Release( p_block
);
217 static size_t block_ChainExtract( block_t
*p_list
, void *p_data
, size_t i_max
)
220 uint8_t *p
= (uint8_t*)p_data
;
222 while( p_list
&& i_max
)
224 size_t i_copy
= __MIN( i_max
, p_list
->i_buffer
);
225 memcpy( p
, p_list
->p_buffer
, i_copy
);
230 p_list
= p_list
->p_next
;
235 static inline void block_ChainProperties( block_t
*p_list
, int *pi_count
, size_t *pi_size
, mtime_t
*pi_length
)
238 mtime_t i_length
= 0;
243 i_size
+= p_list
->i_buffer
;
244 i_length
+= p_list
->i_length
;
247 p_list
= p_list
->p_next
;
253 *pi_length
= i_length
;
258 static inline block_t
*block_ChainGather( block_t
*p_list
)
261 mtime_t i_length
= 0;
264 if( p_list
->p_next
== NULL
)
265 return p_list
; /* Already gathered */
267 block_ChainProperties( p_list
, NULL
, &i_total
, &i_length
);
269 g
= block_Alloc( i_total
);
270 block_ChainExtract( p_list
, g
->p_buffer
, g
->i_buffer
);
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
;
278 block_ChainRelease( p_list
);
282 /****************************************************************************
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_FifoWake : wake ups a thread with block_FifoGet() = NULL
295 * (this is used to wakeup a thread when there is no data to queue)
297 * block_FifoGet and block_FifoShow are cancellation points.
298 ****************************************************************************/
300 VLC_EXPORT( block_fifo_t
*, block_FifoNew
, ( void ) LIBVLC_USED
);
301 VLC_EXPORT( void, block_FifoRelease
, ( block_fifo_t
* ) );
302 /* TODO: do we need to export this? */
303 void block_FifoPace (block_fifo_t
*fifo
, size_t max_depth
, size_t max_size
);
304 VLC_EXPORT( void, block_FifoEmpty
, ( block_fifo_t
* ) );
305 VLC_EXPORT( size_t, block_FifoPut
, ( block_fifo_t
*, block_t
* ) );
306 VLC_EXPORT( void, block_FifoWake
, ( block_fifo_t
* ) );
307 VLC_EXPORT( block_t
*, block_FifoGet
, ( block_fifo_t
* ) LIBVLC_USED
);
308 VLC_EXPORT( block_t
*, block_FifoShow
, ( block_fifo_t
* ) );
309 size_t block_FifoSize( const block_fifo_t
*p_fifo
) LIBVLC_USED
;
310 VLC_EXPORT( size_t, block_FifoCount
, ( const block_fifo_t
*p_fifo
) LIBVLC_USED
);
312 #endif /* VLC_BLOCK_H */