2009-01-21 16:00:49 -08:00
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/********************************************************************
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* *
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* THIS FILE IS PART OF THE OggTheora SOFTWARE CODEC SOURCE CODE. *
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* USE, DISTRIBUTION AND REPRODUCTION OF THIS LIBRARY SOURCE IS *
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* GOVERNED BY A BSD-STYLE SOURCE LICENSE INCLUDED WITH THIS SOURCE *
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* IN 'COPYING'. PLEASE READ THESE TERMS BEFORE DISTRIBUTING. *
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* *
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2009-09-27 15:14:21 -07:00
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* THE OggTheora SOURCE CODE IS (C) COPYRIGHT 1994-2009 *
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2009-01-21 16:00:49 -08:00
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* by the Xiph.Org Foundation and contributors http://www.xiph.org/ *
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* *
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********************************************************************
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function: packing variable sized words into an octet stream
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last mod: $Id: bitwise.c 7675 2004-09-01 00:34:39Z xiphmont $
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********************************************************************/
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#if !defined(_bitpack_H)
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# define _bitpack_H (1)
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# include <stddef.h>
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# include <limits.h>
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# include "internal.h"
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2009-01-21 16:00:49 -08:00
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2009-09-27 15:14:21 -07:00
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2010-11-07 23:47:34 -08:00
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typedef size_t oc_pb_window;
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typedef struct oc_pack_buf oc_pack_buf;
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2010-11-07 23:47:34 -08:00
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/*Custom bitpacker implementations.*/
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# if defined(OC_ARM_ASM)
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# include "arm/armbits.h"
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# endif
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# if !defined(oc_pack_read)
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# define oc_pack_read oc_pack_read_c
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# endif
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# if !defined(oc_pack_read1)
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# define oc_pack_read1 oc_pack_read1_c
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# endif
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# if !defined(oc_huff_token_decode)
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# define oc_huff_token_decode oc_huff_token_decode_c
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# endif
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2009-09-27 15:14:21 -07:00
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# define OC_PB_WINDOW_SIZE ((int)sizeof(oc_pb_window)*CHAR_BIT)
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/*This is meant to be a large, positive constant that can still be efficiently
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loaded as an immediate (on platforms like ARM, for example).
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Even relatively modest values like 100 would work fine.*/
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# define OC_LOTS_OF_BITS (0x40000000)
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struct oc_pack_buf{
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const unsigned char *stop;
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const unsigned char *ptr;
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oc_pb_window window;
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int bits;
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int eof;
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};
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void oc_pack_readinit(oc_pack_buf *_b,unsigned char *_buf,long _bytes);
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int oc_pack_look1(oc_pack_buf *_b);
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void oc_pack_adv1(oc_pack_buf *_b);
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/*Here we assume 0<=_bits&&_bits<=32.*/
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long oc_pack_read_c(oc_pack_buf *_b,int _bits);
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int oc_pack_read1_c(oc_pack_buf *_b);
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/* returns -1 for read beyond EOF, or the number of whole bytes available */
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long oc_pack_bytes_left(oc_pack_buf *_b);
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/*These two functions are implemented locally in huffdec.c*/
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/*Read in bits without advancing the bitptr.
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Here we assume 0<=_bits&&_bits<=32.*/
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/*static int oc_pack_look(oc_pack_buf *_b,int _bits);*/
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/*static void oc_pack_adv(oc_pack_buf *_b,int _bits);*/
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#endif
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