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 BLOCK_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.
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 /* All timestamp below or equal to this define are invalid/unset
94 * XXX the numerical value is 0 because of historical reason and will change.*/
95 #define BLOCK_TS_INVALID (0)
97 typedef void (*block_free_t) (block_t *);
109 int i_samples; /* Used for audio */
115 /* Rudimentary support for overloading block (de)allocation. */
116 block_free_t pf_release;
119 /****************************************************************************
121 ****************************************************************************
122 * - block_Alloc : create a new block with the requested size ( >= 0 ), return
124 * - block_Release : release a block allocated with block_Alloc.
125 * - block_Realloc : realloc a block,
126 * i_pre: how many bytes to insert before body if > 0, else how many
127 * bytes of body to skip (the latter can be done without using
128 * block_Realloc i_buffer -= -i_pre, p_buffer += -i_pre as i_pre < 0)
129 * i_body (>= 0): the final size of the body (decreasing it can directly
130 * be done with i_buffer = i_body).
131 * with preheader and or body (increase
132 * and decrease are supported). Use it as it is optimised.
133 * - block_Duplicate : create a copy of a block.
134 ****************************************************************************/
135 VLC_EXPORT( void, block_Init, ( block_t *, void *, size_t ) );
136 VLC_EXPORT( block_t *, block_Alloc, ( size_t ) LIBVLC_USED );
137 VLC_EXPORT( block_t *, block_Realloc, ( block_t *, ssize_t i_pre, size_t i_body ) LIBVLC_USED );
139 #define block_New( dummy, size ) block_Alloc(size)
142 static inline block_t *block_Duplicate( block_t *p_block )
144 block_t *p_dup = block_Alloc( p_block->i_buffer );
148 p_dup->i_dts = p_block->i_dts;
149 p_dup->i_pts = p_block->i_pts;
150 p_dup->i_flags = p_block->i_flags;
151 p_dup->i_length = p_block->i_length;
152 p_dup->i_rate = p_block->i_rate;
153 p_dup->i_samples = p_block->i_samples;
154 memcpy( p_dup->p_buffer, p_block->p_buffer, p_block->i_buffer );
159 static inline void block_Release( block_t *p_block )
161 p_block->pf_release( p_block );
164 VLC_EXPORT( block_t *, block_mmap_Alloc, (void *addr, size_t length) LIBVLC_USED );
165 VLC_EXPORT( block_t *, block_File, (int fd) LIBVLC_USED );
167 static inline void block_Cleanup (void *block)
169 block_Release ((block_t *)block);
171 #define block_cleanup_push( block ) vlc_cleanup_push (block_Cleanup, block)
173 /****************************************************************************
174 * Chains of blocks functions helper
175 ****************************************************************************
176 * - block_ChainAppend : append a block to the last block of a chain. Try to
177 * avoid using with a lot of data as it's really slow, prefer
178 * block_ChainLastAppend
179 * - block_ChainLastAppend : use a pointer over a pointer to the next blocks,
181 * - block_ChainRelease : release a chain of block
182 * - block_ChainExtract : extract data from a chain, return real bytes counts
183 * - block_ChainGather : gather a chain, free it and return one block.
184 ****************************************************************************/
185 static inline void block_ChainAppend( block_t **pp_list, block_t *p_block )
187 if( *pp_list == NULL )
193 block_t *p = *pp_list;
195 while( p->p_next ) p = p->p_next;
200 static inline void block_ChainLastAppend( block_t ***ppp_last, block_t *p_block )
202 block_t *p_last = p_block;
204 **ppp_last = p_block;
206 while( p_last->p_next ) p_last = p_last->p_next;
207 *ppp_last = &p_last->p_next;
210 static inline void block_ChainRelease( block_t *p_block )
214 block_t *p_next = p_block->p_next;
215 block_Release( p_block );
220 static size_t block_ChainExtract( block_t *p_list, void *p_data, size_t i_max )
223 uint8_t *p = (uint8_t*)p_data;
225 while( p_list && i_max )
227 size_t i_copy = __MIN( i_max, p_list->i_buffer );
228 memcpy( p, p_list->p_buffer, i_copy );
233 p_list = p_list->p_next;
238 static inline void block_ChainProperties( block_t *p_list, int *pi_count, size_t *pi_size, mtime_t *pi_length )
241 mtime_t i_length = 0;
246 i_size += p_list->i_buffer;
247 i_length += p_list->i_length;
250 p_list = p_list->p_next;
256 *pi_length = i_length;
261 static inline block_t *block_ChainGather( block_t *p_list )
264 mtime_t i_length = 0;
267 if( p_list->p_next == NULL )
268 return p_list; /* Already gathered */
270 block_ChainProperties( p_list, NULL, &i_total, &i_length );
272 g = block_Alloc( i_total );
273 block_ChainExtract( p_list, g->p_buffer, g->i_buffer );
275 g->i_flags = p_list->i_flags;
276 g->i_pts = p_list->i_pts;
277 g->i_dts = p_list->i_dts;
278 g->i_length = i_length;
281 block_ChainRelease( p_list );
285 /****************************************************************************
287 ****************************************************************************
288 * - block_FifoNew : create and init a new fifo
289 * - block_FifoRelease : destroy a fifo and free all blocks in it.
290 * - block_FifoEmpty : free all blocks in a fifo
291 * - block_FifoPut : put a block
292 * - block_FifoGet : get a packet from the fifo (and wait if it is empty)
293 * - block_FifoShow : show the first packet of the fifo (and wait if
294 * needed), be carefull, you can use it ONLY if you are sure to be the
295 * only one getting data from the fifo.
296 * - block_FifoCount : how many packets are waiting in the fifo
297 * - block_FifoWake : wake ups a thread with block_FifoGet() = NULL
298 * (this is used to wakeup a thread when there is no data to queue)
300 * block_FifoGet and block_FifoShow are cancellation points.
301 ****************************************************************************/
303 VLC_EXPORT( block_fifo_t *, block_FifoNew, ( void ) LIBVLC_USED );
304 VLC_EXPORT( void, block_FifoRelease, ( block_fifo_t * ) );
305 /* TODO: do we need to export this? */
306 void block_FifoPace (block_fifo_t *fifo, size_t max_depth, size_t max_size);
307 VLC_EXPORT( void, block_FifoEmpty, ( block_fifo_t * ) );
308 VLC_EXPORT( size_t, block_FifoPut, ( block_fifo_t *, block_t * ) );
309 VLC_EXPORT( void, block_FifoWake, ( block_fifo_t * ) );
310 VLC_EXPORT( block_t *, block_FifoGet, ( block_fifo_t * ) LIBVLC_USED );
311 VLC_EXPORT( block_t *, block_FifoShow, ( block_fifo_t * ) );
312 size_t block_FifoSize( const block_fifo_t *p_fifo ) LIBVLC_USED;
313 VLC_EXPORT( size_t, block_FifoCount, ( const block_fifo_t *p_fifo ) LIBVLC_USED );
315 #endif /* VLC_BLOCK_H */