1 /*****************************************************************************
2 * vlc_block_helper.h: Helper functions for data blocks management.
3 *****************************************************************************
4 * Copyright (C) 2003 the VideoLAN team
7 * Authors: Gildas Bazin <gbazin@netcourrier.com>
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 *****************************************************************************/
24 #ifndef VLC_BLOCK_HELPER_H
25 #define VLC_BLOCK_HELPER_H 1
27 #include <vlc_block.h>
29 typedef struct block_bytestream_t
37 /*****************************************************************************
38 * block_bytestream_t management
39 *****************************************************************************/
40 static inline block_bytestream_t
block_BytestreamInit( void )
42 block_bytestream_t bytestream
;
44 bytestream
.i_offset
= 0;
45 bytestream
.p_chain
= bytestream
.p_block
= NULL
;
50 static inline void block_BytestreamRelease( block_bytestream_t
*p_bytestream
)
52 while( p_bytestream
->p_chain
)
55 p_next
= p_bytestream
->p_chain
->p_next
;
56 p_bytestream
->p_chain
->pf_release( p_bytestream
->p_chain
);
57 p_bytestream
->p_chain
= p_next
;
59 p_bytestream
->i_offset
= 0;
60 p_bytestream
->p_chain
= p_bytestream
->p_block
= NULL
;
63 static inline void block_BytestreamFlush( block_bytestream_t
*p_bytestream
)
65 while( p_bytestream
->p_chain
!= p_bytestream
->p_block
)
68 p_next
= p_bytestream
->p_chain
->p_next
;
69 p_bytestream
->p_chain
->pf_release( p_bytestream
->p_chain
);
70 p_bytestream
->p_chain
= p_next
;
72 while( p_bytestream
->p_block
&&
73 (p_bytestream
->p_block
->i_buffer
- p_bytestream
->i_offset
) == 0 )
76 p_next
= p_bytestream
->p_chain
->p_next
;
77 p_bytestream
->p_chain
->pf_release( p_bytestream
->p_chain
);
78 p_bytestream
->p_chain
= p_bytestream
->p_block
= p_next
;
79 p_bytestream
->i_offset
= 0;
83 static inline void block_BytestreamPush( block_bytestream_t
*p_bytestream
,
86 block_ChainAppend( &p_bytestream
->p_chain
, p_block
);
87 if( !p_bytestream
->p_block
) p_bytestream
->p_block
= p_block
;
91 static inline block_t
*block_BytestreamPop( block_bytestream_t
*p_bytestream
)
95 block_BytestreamFlush( p_bytestream
);
97 p_block
= p_bytestream
->p_block
;
102 else if( !p_block
->p_next
)
104 p_block
->p_buffer
+= p_bytestream
->i_offset
;
105 p_block
->i_buffer
-= p_bytestream
->i_offset
;
106 p_bytestream
->i_offset
= 0;
107 p_bytestream
->p_chain
= p_bytestream
->p_block
= NULL
;
111 while( p_block
->p_next
&& p_block
->p_next
->p_next
)
112 p_block
= p_block
->p_next
;
115 block_t
*p_block_old
= p_block
;
116 p_block
= p_block
->p_next
;
117 p_block_old
->p_next
= NULL
;
123 static inline int block_SkipByte( block_bytestream_t
*p_bytestream
)
125 /* Most common case first */
126 if( p_bytestream
->p_block
->i_buffer
- p_bytestream
->i_offset
)
128 p_bytestream
->i_offset
++;
135 /* Less common case which is also slower */
136 for( p_block
= p_bytestream
->p_block
->p_next
;
137 p_block
!= NULL
; p_block
= p_block
->p_next
)
139 if( p_block
->i_buffer
)
141 p_bytestream
->i_offset
= 1;
142 p_bytestream
->p_block
= p_block
;
148 /* Not enough data, bail out */
152 static inline int block_PeekByte( block_bytestream_t
*p_bytestream
,
155 /* Most common case first */
156 if( p_bytestream
->p_block
->i_buffer
- p_bytestream
->i_offset
)
158 *p_data
= p_bytestream
->p_block
->p_buffer
[p_bytestream
->i_offset
];
165 /* Less common case which is also slower */
166 for( p_block
= p_bytestream
->p_block
->p_next
;
167 p_block
!= NULL
; p_block
= p_block
->p_next
)
169 if( p_block
->i_buffer
)
171 *p_data
= p_block
->p_buffer
[0];
177 /* Not enough data, bail out */
181 static inline int block_GetByte( block_bytestream_t
*p_bytestream
,
184 /* Most common case first */
185 if( p_bytestream
->p_block
->i_buffer
- p_bytestream
->i_offset
)
187 *p_data
= p_bytestream
->p_block
->p_buffer
[p_bytestream
->i_offset
];
188 p_bytestream
->i_offset
++;
195 /* Less common case which is also slower */
196 for( p_block
= p_bytestream
->p_block
->p_next
;
197 p_block
!= NULL
; p_block
= p_block
->p_next
)
199 if( p_block
->i_buffer
)
201 *p_data
= p_block
->p_buffer
[0];
202 p_bytestream
->i_offset
= 1;
203 p_bytestream
->p_block
= p_block
;
209 /* Not enough data, bail out */
213 static inline int block_WaitBytes( block_bytestream_t
*p_bytestream
,
217 size_t i_offset
, i_copy
, i_size
;
219 /* Check we have that much data */
220 i_offset
= p_bytestream
->i_offset
;
223 for( p_block
= p_bytestream
->p_block
;
224 p_block
!= NULL
; p_block
= p_block
->p_next
)
226 i_copy
= __MIN( i_size
, p_block
->i_buffer
- i_offset
);
235 /* Not enough data, bail out */
241 static inline int block_SkipBytes( block_bytestream_t
*p_bytestream
,
245 size_t i_offset
, i_copy
;
247 /* Check we have that much data */
248 i_offset
= p_bytestream
->i_offset
;
250 for( p_block
= p_bytestream
->p_block
;
251 p_block
!= NULL
; p_block
= p_block
->p_next
)
253 i_copy
= __MIN( i_data
, p_block
->i_buffer
- i_offset
);
263 /* Not enough data, bail out */
267 p_bytestream
->p_block
= p_block
;
268 p_bytestream
->i_offset
= i_offset
+ i_copy
;
272 static inline int block_PeekBytes( block_bytestream_t
*p_bytestream
,
273 uint8_t *p_data
, size_t i_data
)
276 size_t i_offset
, i_copy
, i_size
;
278 /* Check we have that much data */
279 i_offset
= p_bytestream
->i_offset
;
282 for( p_block
= p_bytestream
->p_block
;
283 p_block
!= NULL
; p_block
= p_block
->p_next
)
285 i_copy
= __MIN( i_size
, p_block
->i_buffer
- i_offset
);
294 /* Not enough data, bail out */
299 i_offset
= p_bytestream
->i_offset
;
302 for( p_block
= p_bytestream
->p_block
;
303 p_block
!= NULL
; p_block
= p_block
->p_next
)
305 i_copy
= __MIN( i_size
, p_block
->i_buffer
- i_offset
);
310 memcpy( p_data
, p_block
->p_buffer
+ i_offset
, i_copy
);
322 static inline int block_GetBytes( block_bytestream_t
*p_bytestream
,
323 uint8_t *p_data
, size_t i_data
)
326 size_t i_offset
, i_copy
, i_size
;
328 /* Check we have that much data */
329 i_offset
= p_bytestream
->i_offset
;
332 for( p_block
= p_bytestream
->p_block
;
333 p_block
!= NULL
; p_block
= p_block
->p_next
)
335 i_copy
= __MIN( i_size
, p_block
->i_buffer
- i_offset
);
344 /* Not enough data, bail out */
349 i_offset
= p_bytestream
->i_offset
;
352 for( p_block
= p_bytestream
->p_block
;
353 p_block
!= NULL
; p_block
= p_block
->p_next
)
355 i_copy
= __MIN( i_size
, p_block
->i_buffer
- i_offset
);
360 memcpy( p_data
, p_block
->p_buffer
+ i_offset
, i_copy
);
369 /* No buffer given, just skip the data */
370 p_bytestream
->p_block
= p_block
;
371 p_bytestream
->i_offset
= i_offset
+ i_copy
;
376 static inline int block_PeekOffsetBytes( block_bytestream_t
*p_bytestream
,
377 size_t i_peek_offset
, uint8_t *p_data
, size_t i_data
)
380 size_t i_offset
, i_copy
, i_size
;
382 /* Check we have that much data */
383 i_offset
= p_bytestream
->i_offset
;
384 i_size
= i_data
+ i_peek_offset
;
386 for( p_block
= p_bytestream
->p_block
;
387 p_block
!= NULL
; p_block
= p_block
->p_next
)
389 i_copy
= __MIN( i_size
, p_block
->i_buffer
- i_offset
);
398 /* Not enough data, bail out */
402 /* Find the right place */
403 i_offset
= p_bytestream
->i_offset
;
404 i_size
= i_peek_offset
;
406 for( p_block
= p_bytestream
->p_block
;
407 p_block
!= NULL
; p_block
= p_block
->p_next
)
409 i_copy
= __MIN( i_size
, p_block
->i_buffer
- i_offset
);
421 for( ; p_block
!= NULL
; p_block
= p_block
->p_next
)
423 i_copy
= __MIN( i_size
, p_block
->i_buffer
- i_offset
);
428 memcpy( p_data
, p_block
->p_buffer
+ i_offset
, i_copy
);
440 static inline int block_FindStartcodeFromOffset(
441 block_bytestream_t
*p_bytestream
, size_t *pi_offset
,
442 const uint8_t *p_startcode
, int i_startcode_length
)
444 block_t
*p_block
, *p_block_backup
= 0;
446 size_t i_offset
, i_offset_backup
= 0;
447 int i_caller_offset_backup
= 0, i_match
;
449 /* Find the right place */
450 i_size
= *pi_offset
+ p_bytestream
->i_offset
;
451 for( p_block
= p_bytestream
->p_block
;
452 p_block
!= NULL
; p_block
= p_block
->p_next
)
454 i_size
-= p_block
->i_buffer
;
455 if( i_size
< 0 ) break;
460 /* Not enough data, bail out */
465 * We first look for an occurrence of the 1st startcode byte and
466 * if found, we do a more thorough check. */
467 i_size
+= p_block
->i_buffer
;
468 *pi_offset
-= i_size
;
470 for( ; p_block
!= NULL
; p_block
= p_block
->p_next
)
472 for( i_offset
= i_size
; i_offset
< p_block
->i_buffer
; i_offset
++ )
474 if( p_block
->p_buffer
[i_offset
] == p_startcode
[i_match
] )
478 p_block_backup
= p_block
;
479 i_offset_backup
= i_offset
;
480 i_caller_offset_backup
= *pi_offset
;
483 if( i_match
+ 1 == i_startcode_length
)
486 *pi_offset
+= i_offset
- i_match
;
495 p_block
= p_block_backup
;
496 i_offset
= i_offset_backup
;
497 *pi_offset
= i_caller_offset_backup
;
503 *pi_offset
+= i_offset
;
506 *pi_offset
-= i_match
;
510 #endif /* VLC_BLOCK_HELPER_H */