1 /*****************************************************************************
2 * vlc_block.h: Data blocks management functions
3 *****************************************************************************
4 * Copyright (C) 2003 VLC authors and VideoLAN
7 * Authors: Laurent Aimar <fenrir@via.ecp.fr>
9 * This program is free software; you can redistribute it and/or modify it
10 * under the terms of the GNU Lesser General Public License as published by
11 * the Free Software Foundation; either version 2.1 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 Lesser General Public License for more details.
19 * You should have received a copy of the GNU Lesser General Public License
20 * along with this program; if not, write to the Free Software Foundation,
21 * 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 #include <sys/types.h> /* for ssize_t */
35 /****************************************************************************
37 ****************************************************************************
38 * - block_sys_t is opaque and thus block_t->p_sys is PRIVATE
39 * - i_flags may not always be set (ie could be 0, even for a key frame
40 * it depends where you receive the buffer (before/after a packetizer
41 * and the demux/packetizer implementations.
42 * - i_dts/i_pts could be VLC_TS_INVALID, it means no pts/dts
43 * - i_length: length in microseond of the packet, can be null except in the
44 * sout where it is mandatory.
46 * - i_buffer number of valid data pointed by p_buffer
47 * you can freely decrease it but never increase it yourself
49 * - p_buffer: pointer over datas. You should never overwrite it, you can
50 * only incremment it to skip datas, in others cases use block_Realloc
51 * (don't duplicate yourself in a bigger buffer, block_Realloc is
52 * optimised for preheader/postdatas increase)
53 ****************************************************************************/
54 typedef struct block_sys_t block_sys_t;
56 /** The content doesn't follow the last block, or is probably broken */
57 #define BLOCK_FLAG_DISCONTINUITY 0x0001
59 #define BLOCK_FLAG_TYPE_I 0x0002
60 /** Inter frame with backward reference only */
61 #define BLOCK_FLAG_TYPE_P 0x0004
62 /** Inter frame with backward and forward reference */
63 #define BLOCK_FLAG_TYPE_B 0x0008
64 /** For inter frame when you don't know the real type */
65 #define BLOCK_FLAG_TYPE_PB 0x0010
66 /** Warn that this block is a header one */
67 #define BLOCK_FLAG_HEADER 0x0020
68 /** This is the last block of the frame */
69 #define BLOCK_FLAG_END_OF_FRAME 0x0040
70 /** This is not a key frame for bitrate shaping */
71 #define BLOCK_FLAG_NO_KEYFRAME 0x0080
72 /** This block contains the last part of a sequence */
73 #define BLOCK_FLAG_END_OF_SEQUENCE 0x0100
74 /** This block contains a clock reference */
75 #define BLOCK_FLAG_CLOCK 0x0200
76 /** This block is scrambled */
77 #define BLOCK_FLAG_SCRAMBLED 0x0400
78 /** This block has to be decoded but not be displayed */
79 #define BLOCK_FLAG_PREROLL 0x0800
80 /** This block is corrupted and/or there is data loss */
81 #define BLOCK_FLAG_CORRUPTED 0x1000
82 /** This block contains an interlaced picture with top field first */
83 #define BLOCK_FLAG_TOP_FIELD_FIRST 0x2000
84 /** This block contains an interlaced picture with bottom field first */
85 #define BLOCK_FLAG_BOTTOM_FIELD_FIRST 0x4000
87 /** This block contains an interlaced picture */
88 #define BLOCK_FLAG_INTERLACED_MASK \
89 (BLOCK_FLAG_TOP_FIELD_FIRST|BLOCK_FLAG_BOTTOM_FIELD_FIRST)
91 #define BLOCK_FLAG_TYPE_MASK \
92 (BLOCK_FLAG_TYPE_I|BLOCK_FLAG_TYPE_P|BLOCK_FLAG_TYPE_B|BLOCK_FLAG_TYPE_PB)
94 /* These are for input core private usage only */
95 #define BLOCK_FLAG_CORE_PRIVATE_MASK 0x00ff0000
96 #define BLOCK_FLAG_CORE_PRIVATE_SHIFT 16
98 /* These are for module private usage only */
99 #define BLOCK_FLAG_PRIVATE_MASK 0xff000000
100 #define BLOCK_FLAG_PRIVATE_SHIFT 24
102 typedef void (*block_free_t) (block_t *);
112 unsigned i_nb_samples; /* Used for audio */
118 /* Rudimentary support for overloading block (de)allocation. */
119 block_free_t pf_release;
122 /****************************************************************************
124 ****************************************************************************
125 * - block_Alloc : create a new block with the requested size ( >= 0 ), return
127 * - block_Release : release a block allocated with block_Alloc.
128 * - block_Realloc : realloc a block,
129 * i_pre: how many bytes to insert before body if > 0, else how many
130 * bytes of body to skip (the latter can be done without using
131 * block_Realloc i_buffer -= -i_pre, p_buffer += -i_pre as i_pre < 0)
132 * i_body (>= 0): the final size of the body (decreasing it can directly
133 * be done with i_buffer = i_body).
134 * with preheader and or body (increase
135 * and decrease are supported). Use it as it is optimised.
136 * - block_Duplicate : create a copy of a block.
137 ****************************************************************************/
138 VLC_API void block_Init( block_t *, void *, size_t );
139 VLC_API block_t * block_Alloc( size_t ) VLC_USED;
140 VLC_API block_t * block_Realloc( block_t *, ssize_t i_pre, size_t i_body ) VLC_USED;
142 #define block_New( dummy, size ) block_Alloc(size)
145 static inline block_t *block_Duplicate( block_t *p_block )
147 block_t *p_dup = block_Alloc( p_block->i_buffer );
151 p_dup->i_flags = p_block->i_flags;
152 p_dup->i_nb_samples = p_block->i_nb_samples;
153 p_dup->i_dts = p_block->i_dts;
154 p_dup->i_pts = p_block->i_pts;
155 p_dup->i_length = p_block->i_length;
156 memcpy( p_dup->p_buffer, p_block->p_buffer, p_block->i_buffer );
161 static inline void block_Release( block_t *p_block )
163 p_block->pf_release( p_block );
166 VLC_API block_t * block_heap_Alloc(void *, void *, size_t) VLC_USED;
167 VLC_API block_t * block_mmap_Alloc(void *addr, size_t length) VLC_USED;
168 VLC_API block_t * block_File(int fd) VLC_USED;
170 static inline void block_Cleanup (void *block)
172 block_Release ((block_t *)block);
174 #define block_cleanup_push( block ) vlc_cleanup_push (block_Cleanup, block)
176 /****************************************************************************
177 * Chains of blocks functions helper
178 ****************************************************************************
179 * - block_ChainAppend : append a block to the last block of a chain. Try to
180 * avoid using with a lot of data as it's really slow, prefer
181 * block_ChainLastAppend, p_block can be NULL
182 * - block_ChainLastAppend : use a pointer over a pointer to the next blocks,
184 * - block_ChainRelease : release a chain of block
185 * - block_ChainExtract : extract data from a chain, return real bytes counts
186 * - block_ChainGather : gather a chain, free it and return one block.
187 ****************************************************************************/
188 static inline void block_ChainAppend( block_t **pp_list, block_t *p_block )
190 if( *pp_list == NULL )
196 block_t *p = *pp_list;
198 while( p->p_next ) p = p->p_next;
203 static inline void block_ChainLastAppend( block_t ***ppp_last, block_t *p_block )
205 block_t *p_last = p_block;
207 **ppp_last = p_block;
209 while( p_last->p_next ) p_last = p_last->p_next;
210 *ppp_last = &p_last->p_next;
213 static inline void block_ChainRelease( block_t *p_block )
217 block_t *p_next = p_block->p_next;
218 block_Release( p_block );
223 static size_t block_ChainExtract( block_t *p_list, void *p_data, size_t i_max )
226 uint8_t *p = (uint8_t*)p_data;
228 while( p_list && i_max )
230 size_t i_copy = __MIN( i_max, p_list->i_buffer );
231 memcpy( p, p_list->p_buffer, i_copy );
236 p_list = p_list->p_next;
241 static inline void block_ChainProperties( block_t *p_list, int *pi_count, size_t *pi_size, mtime_t *pi_length )
244 mtime_t i_length = 0;
249 i_size += p_list->i_buffer;
250 i_length += p_list->i_length;
253 p_list = p_list->p_next;
259 *pi_length = i_length;
264 static inline block_t *block_ChainGather( block_t *p_list )
267 mtime_t i_length = 0;
270 if( p_list->p_next == NULL )
271 return p_list; /* Already gathered */
273 block_ChainProperties( p_list, NULL, &i_total, &i_length );
275 g = block_Alloc( i_total );
276 block_ChainExtract( p_list, g->p_buffer, g->i_buffer );
278 g->i_flags = p_list->i_flags;
279 g->i_pts = p_list->i_pts;
280 g->i_dts = p_list->i_dts;
281 g->i_length = i_length;
284 block_ChainRelease( p_list );
288 /****************************************************************************
290 ****************************************************************************
291 * - block_FifoNew : create and init a new fifo
292 * - block_FifoRelease : destroy a fifo and free all blocks in it.
293 * - block_FifoPace : wait for a fifo to drain to a specified number of packets or total data size
294 * - block_FifoEmpty : free all blocks in a fifo
295 * - block_FifoPut : put a block
296 * - block_FifoGet : get a packet from the fifo (and wait if it is empty)
297 * - block_FifoShow : show the first packet of the fifo (and wait if
298 * needed), be carefull, you can use it ONLY if you are sure to be the
299 * only one getting data from the fifo.
300 * - block_FifoCount : how many packets are waiting in the fifo
301 * - block_FifoWake : wake ups a thread with block_FifoGet() = NULL
302 * (this is used to wakeup a thread when there is no data to queue)
304 * block_FifoGet and block_FifoShow are cancellation points.
305 ****************************************************************************/
307 VLC_API block_fifo_t * block_FifoNew( void ) VLC_USED;
308 VLC_API void block_FifoRelease( block_fifo_t * );
309 VLC_API void block_FifoPace( block_fifo_t *fifo, size_t max_depth, size_t max_size );
310 VLC_API void block_FifoEmpty( block_fifo_t * );
311 VLC_API size_t block_FifoPut( block_fifo_t *, block_t * );
312 VLC_API void block_FifoWake( block_fifo_t * );
313 VLC_API block_t * block_FifoGet( block_fifo_t * ) VLC_USED;
314 VLC_API block_t * block_FifoShow( block_fifo_t * );
315 size_t block_FifoSize( const block_fifo_t *p_fifo ) VLC_USED;
316 VLC_API size_t block_FifoCount( const block_fifo_t *p_fifo ) VLC_USED;
318 #endif /* VLC_BLOCK_H */