1/********************************************************************
2 * *
3 * THIS FILE IS PART OF THE OggTheora SOFTWARE CODEC SOURCE CODE. *
4 * USE, DISTRIBUTION AND REPRODUCTION OF THIS LIBRARY SOURCE IS *
5 * GOVERNED BY A BSD-STYLE SOURCE LICENSE INCLUDED WITH THIS SOURCE *
6 * IN 'COPYING'. PLEASE READ THESE TERMS BEFORE DISTRIBUTING. *
7 * *
8 * THE OggTheora SOURCE CODE IS (C) COPYRIGHT 1994-2009 *
9 * by the Xiph.Org Foundation and contributors http://www.xiph.org/ *
10 * *
11 ********************************************************************
12
13 function: packing variable sized words into an octet stream
14 last mod: $Id: bitwise.c 7675 2004-09-01 00:34:39Z xiphmont $
15
16 ********************************************************************/
17#if !defined(_bitpack_H)
18# define _bitpack_H (1)
19# include <stddef.h>
20# include <limits.h>
21# include "internal.h"
22
23
24
25typedef size_t oc_pb_window;
26typedef struct oc_pack_buf oc_pack_buf;
27
28
29
30/*Custom bitpacker implementations.*/
31# if defined(OC_ARM_ASM)
32# include "arm/armbits.h"
33# endif
34
35# if !defined(oc_pack_read)
36# define oc_pack_read oc_pack_read_c
37# endif
38# if !defined(oc_pack_read1)
39# define oc_pack_read1 oc_pack_read1_c
40# endif
41# if !defined(oc_huff_token_decode)
42# define oc_huff_token_decode oc_huff_token_decode_c
43# endif
44
45# define OC_PB_WINDOW_SIZE ((int)sizeof(oc_pb_window)*CHAR_BIT)
46/*This is meant to be a large, positive constant that can still be efficiently
47 loaded as an immediate (on platforms like ARM, for example).
48 Even relatively modest values like 100 would work fine.*/
49# define OC_LOTS_OF_BITS (0x40000000)
50
51
52
53struct oc_pack_buf{
54 const unsigned char *stop;
55 const unsigned char *ptr;
56 oc_pb_window window;
57 int bits;
58 int eof;
59};
60
61void oc_pack_readinit(oc_pack_buf *_b,unsigned char *_buf,long _bytes);
62int oc_pack_look1(oc_pack_buf *_b);
63void oc_pack_adv1(oc_pack_buf *_b);
64/*Here we assume 0<=_bits&&_bits<=32.*/
65long oc_pack_read_c(oc_pack_buf *_b,int _bits);
66int oc_pack_read1_c(oc_pack_buf *_b);
67/* returns -1 for read beyond EOF, or the number of whole bytes available */
68long oc_pack_bytes_left(oc_pack_buf *_b);
69
70/*These two functions are implemented locally in huffdec.c*/
71/*Read in bits without advancing the bitptr.
72 Here we assume 0<=_bits&&_bits<=32.*/
73/*static int oc_pack_look(oc_pack_buf *_b,int _bits);*/
74/*static void oc_pack_adv(oc_pack_buf *_b,int _bits);*/
75
76#endif
77