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 VLC_TS_INVALID, it means no pts/dts
41 * - i_length: length in microseond of the packet, can be null except in the
42 * sout where it is mandatory.
44 * - i_buffer number of valid data pointed by p_buffer
45 * you can freely decrease it but never increase it yourself
47 * - p_buffer: pointer over datas. You should never overwrite it, you can
48 * only incremment it to skip datas, in others cases use block_Realloc
49 * (don't duplicate yourself in a bigger buffer, block_Realloc is
50 * optimised for preheader/postdatas increase)
51 ****************************************************************************/
52 typedef struct block_sys_t block_sys_t;
54 /** The content doesn't follow the last block, or is probably broken */
55 #define BLOCK_FLAG_DISCONTINUITY 0x0001
57 #define BLOCK_FLAG_TYPE_I 0x0002
58 /** Inter frame with backward reference only */
59 #define BLOCK_FLAG_TYPE_P 0x0004
60 /** Inter frame with backward and forward reference */
61 #define BLOCK_FLAG_TYPE_B 0x0008
62 /** For inter frame when you don't know the real type */
63 #define BLOCK_FLAG_TYPE_PB 0x0010
64 /** Warn that this block is a header one */
65 #define BLOCK_FLAG_HEADER 0x0020
66 /** This is the last block of the frame */
67 #define BLOCK_FLAG_END_OF_FRAME 0x0040
68 /** This is not a key frame for bitrate shaping */
69 #define BLOCK_FLAG_NO_KEYFRAME 0x0080
70 /** This block contains the last part of a sequence */
71 #define BLOCK_FLAG_END_OF_SEQUENCE 0x0100
72 /** This block contains a clock reference */
73 #define BLOCK_FLAG_CLOCK 0x0200
74 /** This block is scrambled */
75 #define BLOCK_FLAG_SCRAMBLED 0x0400
76 /** This block has to be decoded but not be displayed */
77 #define BLOCK_FLAG_PREROLL 0x0800
78 /** This block is corrupted and/or there is data loss */
79 #define BLOCK_FLAG_CORRUPTED 0x1000
80 /** This block contains an interlaced picture with top field first */
81 #define BLOCK_FLAG_TOP_FIELD_FIRST 0x2000
82 /** This block contains an interlaced picture with bottom field first */
83 #define BLOCK_FLAG_BOTTOM_FIELD_FIRST 0x4000
85 /** This block contains an interlaced picture */
86 #define BLOCK_FLAG_INTERLACED_MASK \
87 (BLOCK_FLAG_TOP_FIELD_FIRST|BLOCK_FLAG_BOTTOM_FIELD_FIRST)
89 #define BLOCK_FLAG_TYPE_MASK \
90 (BLOCK_FLAG_TYPE_I|BLOCK_FLAG_TYPE_P|BLOCK_FLAG_TYPE_B|BLOCK_FLAG_TYPE_PB)
92 /* These are for input core private usage only */
93 #define BLOCK_FLAG_CORE_PRIVATE_MASK 0x00ff0000
94 #define BLOCK_FLAG_CORE_PRIVATE_SHIFT 16
96 /* These are for module private usage only */
97 #define BLOCK_FLAG_PRIVATE_MASK 0xff000000
98 #define BLOCK_FLAG_PRIVATE_SHIFT 24
100 typedef void (*block_free_t) (block_t *);
112 unsigned i_nb_samples; /* Used for audio */
117 /* Rudimentary support for overloading block (de)allocation. */
118 block_free_t pf_release;
121 /****************************************************************************
123 ****************************************************************************
124 * - block_Alloc : create a new block with the requested size ( >= 0 ), return
126 * - block_Release : release a block allocated with block_Alloc.
127 * - block_Realloc : realloc a block,
128 * i_pre: how many bytes to insert before body if > 0, else how many
129 * bytes of body to skip (the latter can be done without using
130 * block_Realloc i_buffer -= -i_pre, p_buffer += -i_pre as i_pre < 0)
131 * i_body (>= 0): the final size of the body (decreasing it can directly
132 * be done with i_buffer = i_body).
133 * with preheader and or body (increase
134 * and decrease are supported). Use it as it is optimised.
135 * - block_Duplicate : create a copy of a block.
136 ****************************************************************************/
137 VLC_API void block_Init( block_t *, void *, size_t );
138 VLC_API block_t * block_Alloc( size_t ) VLC_USED;
139 VLC_API block_t * block_Realloc( block_t *, ssize_t i_pre, size_t i_body ) VLC_USED;
141 #define block_New( dummy, size ) block_Alloc(size)
144 static inline block_t *block_Duplicate( block_t *p_block )
146 block_t *p_dup = block_Alloc( p_block->i_buffer );
150 p_dup->i_dts = p_block->i_dts;
151 p_dup->i_pts = p_block->i_pts;
152 p_dup->i_flags = p_block->i_flags;
153 p_dup->i_length = p_block->i_length;
154 p_dup->i_nb_samples = p_block->i_nb_samples;
155 memcpy( p_dup->p_buffer, p_block->p_buffer, p_block->i_buffer );
160 static inline void block_Release( block_t *p_block )
162 p_block->pf_release( p_block );
165 VLC_API block_t * block_heap_Alloc(void *, void *, size_t) VLC_USED;
166 VLC_API block_t * block_mmap_Alloc(void *addr, size_t length) VLC_USED;
167 VLC_API block_t * block_File(int fd) VLC_USED;
169 static inline void block_Cleanup (void *block)
171 block_Release ((block_t *)block);
173 #define block_cleanup_push( block ) vlc_cleanup_push (block_Cleanup, block)
175 /****************************************************************************
176 * Chains of blocks functions helper
177 ****************************************************************************
178 * - block_ChainAppend : append a block to the last block of a chain. Try to
179 * avoid using with a lot of data as it's really slow, prefer
180 * block_ChainLastAppend, p_block can be NULL
181 * - block_ChainLastAppend : use a pointer over a pointer to the next blocks,
183 * - block_ChainRelease : release a chain of block
184 * - block_ChainExtract : extract data from a chain, return real bytes counts
185 * - block_ChainGather : gather a chain, free it and return one block.
186 ****************************************************************************/
187 static inline void block_ChainAppend( block_t **pp_list, block_t *p_block )
189 if( *pp_list == NULL )
195 block_t *p = *pp_list;
197 while( p->p_next ) p = p->p_next;
202 static inline void block_ChainLastAppend( block_t ***ppp_last, block_t *p_block )
204 block_t *p_last = p_block;
206 **ppp_last = p_block;
208 while( p_last->p_next ) p_last = p_last->p_next;
209 *ppp_last = &p_last->p_next;
212 static inline void block_ChainRelease( block_t *p_block )
216 block_t *p_next = p_block->p_next;
217 block_Release( p_block );
222 static size_t block_ChainExtract( block_t *p_list, void *p_data, size_t i_max )
225 uint8_t *p = (uint8_t*)p_data;
227 while( p_list && i_max )
229 size_t i_copy = __MIN( i_max, p_list->i_buffer );
230 memcpy( p, p_list->p_buffer, i_copy );
235 p_list = p_list->p_next;
240 static inline void block_ChainProperties( block_t *p_list, int *pi_count, size_t *pi_size, mtime_t *pi_length )
243 mtime_t i_length = 0;
248 i_size += p_list->i_buffer;
249 i_length += p_list->i_length;
252 p_list = p_list->p_next;
258 *pi_length = i_length;
263 static inline block_t *block_ChainGather( block_t *p_list )
266 mtime_t i_length = 0;
269 if( p_list->p_next == NULL )
270 return p_list; /* Already gathered */
272 block_ChainProperties( p_list, NULL, &i_total, &i_length );
274 g = block_Alloc( i_total );
275 block_ChainExtract( p_list, g->p_buffer, g->i_buffer );
277 g->i_flags = p_list->i_flags;
278 g->i_pts = p_list->i_pts;
279 g->i_dts = p_list->i_dts;
280 g->i_length = i_length;
283 block_ChainRelease( p_list );
287 /****************************************************************************
289 ****************************************************************************
290 * - block_FifoNew : create and init a new fifo
291 * - block_FifoRelease : destroy a fifo and free all blocks in it.
292 * - block_FifoPace : wait for a fifo to drain to a specified number of packets or total data size
293 * - block_FifoEmpty : free all blocks in a fifo
294 * - block_FifoPut : put a block
295 * - block_FifoGet : get a packet from the fifo (and wait if it is empty)
296 * - block_FifoShow : show the first packet of the fifo (and wait if
297 * needed), be carefull, you can use it ONLY if you are sure to be the
298 * only one getting data from the fifo.
299 * - block_FifoCount : how many packets are waiting in the fifo
300 * - block_FifoWake : wake ups a thread with block_FifoGet() = NULL
301 * (this is used to wakeup a thread when there is no data to queue)
303 * block_FifoGet and block_FifoShow are cancellation points.
304 ****************************************************************************/
306 VLC_API block_fifo_t * block_FifoNew( void ) VLC_USED;
307 VLC_API void block_FifoRelease( block_fifo_t * );
308 VLC_API void block_FifoPace( block_fifo_t *fifo, size_t max_depth, size_t max_size );
309 VLC_API void block_FifoEmpty( block_fifo_t * );
310 VLC_API size_t block_FifoPut( block_fifo_t *, block_t * );
311 VLC_API void block_FifoWake( block_fifo_t * );
312 VLC_API block_t * block_FifoGet( block_fifo_t * ) VLC_USED;
313 VLC_API block_t * block_FifoShow( block_fifo_t * );
314 size_t block_FifoSize( const block_fifo_t *p_fifo ) VLC_USED;
315 VLC_API size_t block_FifoCount( const block_fifo_t *p_fifo ) VLC_USED;
317 #endif /* VLC_BLOCK_H */