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 #if !defined( __LIBVLC__ )
25 #error You are not libvlc or one of its plugins. You cannot include this file
28 #ifndef _VLC_BLOCK_HELPER_H
29 #define _VLC_BLOCK_HELPER_H 1
31 #include <vlc_block.h>
33 typedef struct block_bytestream_t
41 #define block_BytestreamInit( a ) __block_BytestreamInit( VLC_OBJECT(a) )
43 /*****************************************************************************
44 * block_bytestream_t management
45 *****************************************************************************/
46 static inline block_bytestream_t __block_BytestreamInit( vlc_object_t *p_obj )
48 block_bytestream_t bytestream;
50 bytestream.i_offset = 0;
51 bytestream.p_chain = bytestream.p_block = NULL;
56 static inline void block_BytestreamRelease( block_bytestream_t *p_bytestream )
58 while( p_bytestream->p_chain )
61 p_next = p_bytestream->p_chain->p_next;
62 p_bytestream->p_chain->pf_release( p_bytestream->p_chain );
63 p_bytestream->p_chain = p_next;
65 p_bytestream->i_offset = 0;
66 p_bytestream->p_chain = p_bytestream->p_block = NULL;
69 static inline void block_BytestreamFlush( block_bytestream_t *p_bytestream )
71 while( p_bytestream->p_chain != p_bytestream->p_block )
74 p_next = p_bytestream->p_chain->p_next;
75 p_bytestream->p_chain->pf_release( p_bytestream->p_chain );
76 p_bytestream->p_chain = p_next;
78 while( p_bytestream->p_block &&
79 (p_bytestream->p_block->i_buffer - p_bytestream->i_offset) == 0 )
82 p_next = p_bytestream->p_chain->p_next;
83 p_bytestream->p_chain->pf_release( p_bytestream->p_chain );
84 p_bytestream->p_chain = p_bytestream->p_block = p_next;
85 p_bytestream->i_offset = 0;
89 static inline void block_BytestreamPush( block_bytestream_t *p_bytestream,
92 block_ChainAppend( &p_bytestream->p_chain, p_block );
93 if( !p_bytestream->p_block ) p_bytestream->p_block = p_block;
96 static inline block_t *block_BytestreamPop( block_bytestream_t *p_bytestream )
100 block_BytestreamFlush( p_bytestream );
102 p_block = p_bytestream->p_block;
103 if( p_block == NULL )
107 else if( !p_block->p_next )
109 p_block->p_buffer += p_bytestream->i_offset;
110 p_block->i_buffer -= p_bytestream->i_offset;
111 p_bytestream->i_offset = 0;
112 p_bytestream->p_chain = p_bytestream->p_block = NULL;
116 while( p_block->p_next && p_block->p_next->p_next )
117 p_block = p_block->p_next;
120 block_t *p_block_old = p_block;
121 p_block = p_block->p_next;
122 p_block_old->p_next = NULL;
128 static inline int block_SkipByte( block_bytestream_t *p_bytestream )
130 /* Most common case first */
131 if( p_bytestream->p_block->i_buffer - p_bytestream->i_offset )
133 p_bytestream->i_offset++;
140 /* Less common case which is also slower */
141 for( p_block = p_bytestream->p_block->p_next;
142 p_block != NULL; p_block = p_block->p_next )
144 if( p_block->i_buffer )
146 p_bytestream->i_offset = 1;
147 p_bytestream->p_block = p_block;
153 /* Not enough data, bail out */
157 static inline int block_PeekByte( block_bytestream_t *p_bytestream,
160 /* Most common case first */
161 if( p_bytestream->p_block->i_buffer - p_bytestream->i_offset )
163 *p_data = p_bytestream->p_block->p_buffer[p_bytestream->i_offset];
170 /* Less common case which is also slower */
171 for( p_block = p_bytestream->p_block->p_next;
172 p_block != NULL; p_block = p_block->p_next )
174 if( p_block->i_buffer )
176 *p_data = p_block->p_buffer[0];
182 /* Not enough data, bail out */
186 static inline int block_GetByte( block_bytestream_t *p_bytestream,
189 /* Most common case first */
190 if( p_bytestream->p_block->i_buffer - p_bytestream->i_offset )
192 *p_data = p_bytestream->p_block->p_buffer[p_bytestream->i_offset];
193 p_bytestream->i_offset++;
200 /* Less common case which is also slower */
201 for( p_block = p_bytestream->p_block->p_next;
202 p_block != NULL; p_block = p_block->p_next )
204 if( p_block->i_buffer )
206 *p_data = p_block->p_buffer[0];
207 p_bytestream->i_offset = 1;
208 p_bytestream->p_block = p_block;
214 /* Not enough data, bail out */
218 static inline int block_WaitBytes( block_bytestream_t *p_bytestream,
222 int i_offset, i_copy, i_size;
224 /* Check we have that much data */
225 i_offset = p_bytestream->i_offset;
228 for( p_block = p_bytestream->p_block;
229 p_block != NULL; p_block = p_block->p_next )
231 i_copy = __MIN( i_size, p_block->i_buffer - i_offset );
240 /* Not enough data, bail out */
246 static inline int block_SkipBytes( block_bytestream_t *p_bytestream,
250 int i_offset, i_copy;
252 /* Check we have that much data */
253 i_offset = p_bytestream->i_offset;
255 for( p_block = p_bytestream->p_block;
256 p_block != NULL; p_block = p_block->p_next )
258 i_copy = __MIN( i_data, p_block->i_buffer - i_offset );
268 /* Not enough data, bail out */
272 p_bytestream->p_block = p_block;
273 p_bytestream->i_offset = i_offset + i_copy;
277 static inline int block_PeekBytes( block_bytestream_t *p_bytestream,
278 uint8_t *p_data, int i_data )
281 int i_offset, i_copy, i_size;
283 /* Check we have that much data */
284 i_offset = p_bytestream->i_offset;
287 for( p_block = p_bytestream->p_block;
288 p_block != NULL; p_block = p_block->p_next )
290 i_copy = __MIN( i_size, p_block->i_buffer - i_offset );
299 /* Not enough data, bail out */
304 i_offset = p_bytestream->i_offset;
307 for( p_block = p_bytestream->p_block;
308 p_block != NULL; p_block = p_block->p_next )
310 i_copy = __MIN( i_size, p_block->i_buffer - i_offset );
315 memcpy( p_data, p_block->p_buffer + i_offset, i_copy );
327 static inline int block_GetBytes( block_bytestream_t *p_bytestream,
328 uint8_t *p_data, int i_data )
331 int i_offset, i_copy, i_size;
333 /* Check we have that much data */
334 i_offset = p_bytestream->i_offset;
337 for( p_block = p_bytestream->p_block;
338 p_block != NULL; p_block = p_block->p_next )
340 i_copy = __MIN( i_size, p_block->i_buffer - i_offset );
349 /* Not enough data, bail out */
354 i_offset = p_bytestream->i_offset;
357 for( p_block = p_bytestream->p_block;
358 p_block != NULL; p_block = p_block->p_next )
360 i_copy = __MIN( i_size, p_block->i_buffer - i_offset );
365 memcpy( p_data, p_block->p_buffer + i_offset, i_copy );
374 /* No buffer given, just skip the data */
375 p_bytestream->p_block = p_block;
376 p_bytestream->i_offset = i_offset + i_copy;
381 static inline int block_PeekOffsetBytes( block_bytestream_t *p_bytestream,
382 int i_peek_offset, uint8_t *p_data, int i_data )
385 int i_offset, i_copy, i_size;
387 /* Check we have that much data */
388 i_offset = p_bytestream->i_offset;
389 i_size = i_data + i_peek_offset;
391 for( p_block = p_bytestream->p_block;
392 p_block != NULL; p_block = p_block->p_next )
394 i_copy = __MIN( i_size, p_block->i_buffer - i_offset );
403 /* Not enough data, bail out */
407 /* Find the right place */
408 i_offset = p_bytestream->i_offset;
409 i_size = i_peek_offset;
411 for( p_block = p_bytestream->p_block;
412 p_block != NULL; p_block = p_block->p_next )
414 i_copy = __MIN( i_size, p_block->i_buffer - i_offset );
426 for( ; p_block != NULL; p_block = p_block->p_next )
428 i_copy = __MIN( i_size, p_block->i_buffer - i_offset );
433 memcpy( p_data, p_block->p_buffer + i_offset, i_copy );
445 static inline int block_FindStartcodeFromOffset(
446 block_bytestream_t *p_bytestream, int *pi_offset,
447 uint8_t *p_startcode, int i_startcode_length )
449 block_t *p_block, *p_block_backup = 0;
450 int i_size, i_offset, i_offset_backup = 0;
451 int i_caller_offset_backup = 0, i_match;
453 /* Find the right place */
454 i_size = *pi_offset + p_bytestream->i_offset;
455 for( p_block = p_bytestream->p_block;
456 p_block != NULL; p_block = p_block->p_next )
458 i_size -= p_block->i_buffer;
459 if( i_size < 0 ) break;
464 /* Not enough data, bail out */
469 * We first look for an occurrence of the 1st startcode byte and
470 * if found, we do a more thorough check. */
471 i_size = p_block->i_buffer + i_size;
472 *pi_offset -= i_size;
474 for( ; p_block != NULL; p_block = p_block->p_next )
476 for( i_offset = i_size; i_offset < p_block->i_buffer; i_offset++ )
478 if( p_block->p_buffer[i_offset] == p_startcode[i_match] )
482 p_block_backup = p_block;
483 i_offset_backup = i_offset;
484 i_caller_offset_backup = *pi_offset;
487 if( i_match + 1 == i_startcode_length )
490 *pi_offset += i_offset - i_match;
499 p_block = p_block_backup;
500 i_offset = i_offset_backup;
501 *pi_offset = i_caller_offset_backup;
507 *pi_offset += i_offset;
510 *pi_offset -= i_match;
514 #endif /* VLC_BLOCK_HELPER_H */