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