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Diffstat (limited to 'media/libtheora/lib/bitpack.h')
-rw-r--r-- | media/libtheora/lib/bitpack.h | 76 |
1 files changed, 76 insertions, 0 deletions
diff --git a/media/libtheora/lib/bitpack.h b/media/libtheora/lib/bitpack.h new file mode 100644 index 0000000000..237b584055 --- /dev/null +++ b/media/libtheora/lib/bitpack.h @@ -0,0 +1,76 @@ +/******************************************************************** + * * + * THIS FILE IS PART OF THE OggTheora SOFTWARE CODEC SOURCE CODE. * + * USE, DISTRIBUTION AND REPRODUCTION OF THIS LIBRARY SOURCE IS * + * GOVERNED BY A BSD-STYLE SOURCE LICENSE INCLUDED WITH THIS SOURCE * + * IN 'COPYING'. PLEASE READ THESE TERMS BEFORE DISTRIBUTING. * + * * + * THE OggTheora SOURCE CODE IS (C) COPYRIGHT 1994-2009 * + * by the Xiph.Org Foundation and contributors http://www.xiph.org/ * + * * + ******************************************************************** + + function: packing variable sized words into an octet stream + last mod: $Id: bitwise.c 7675 2004-09-01 00:34:39Z xiphmont $ + + ********************************************************************/ +#if !defined(_bitpack_H) +# define _bitpack_H (1) +# include <stddef.h> +# include <limits.h> +# include "internal.h" + + + +typedef size_t oc_pb_window; +typedef struct oc_pack_buf oc_pack_buf; + + + +/*Custom bitpacker implementations.*/ +# if defined(OC_ARM_ASM) +# include "arm/armbits.h" +# endif + +# if !defined(oc_pack_read) +# define oc_pack_read oc_pack_read_c +# endif +# if !defined(oc_pack_read1) +# define oc_pack_read1 oc_pack_read1_c +# endif +# if !defined(oc_huff_token_decode) +# define oc_huff_token_decode oc_huff_token_decode_c +# endif + +# define OC_PB_WINDOW_SIZE ((int)sizeof(oc_pb_window)*CHAR_BIT) +/*This is meant to be a large, positive constant that can still be efficiently + loaded as an immediate (on platforms like ARM, for example). + Even relatively modest values like 100 would work fine.*/ +# define OC_LOTS_OF_BITS (0x40000000) + + + +struct oc_pack_buf{ + const unsigned char *stop; + const unsigned char *ptr; + oc_pb_window window; + int bits; + int eof; +}; + +void oc_pack_readinit(oc_pack_buf *_b,unsigned char *_buf,long _bytes); +int oc_pack_look1(oc_pack_buf *_b); +void oc_pack_adv1(oc_pack_buf *_b); +/*Here we assume 0<=_bits&&_bits<=32.*/ +long oc_pack_read_c(oc_pack_buf *_b,int _bits); +int oc_pack_read1_c(oc_pack_buf *_b); +/* returns -1 for read beyond EOF, or the number of whole bytes available */ +long oc_pack_bytes_left(oc_pack_buf *_b); + +/*These two functions are implemented locally in huffdec.c*/ +/*Read in bits without advancing the bitptr. + Here we assume 0<=_bits&&_bits<=32.*/ +/*static int oc_pack_look(oc_pack_buf *_b,int _bits);*/ +/*static void oc_pack_adv(oc_pack_buf *_b,int _bits);*/ + +#endif |