diff options
Diffstat (limited to 'converter/other/jbig/libjbig/include/jbig_ar.h')
-rw-r--r-- | converter/other/jbig/libjbig/include/jbig_ar.h | 53 |
1 files changed, 53 insertions, 0 deletions
diff --git a/converter/other/jbig/libjbig/include/jbig_ar.h b/converter/other/jbig/libjbig/include/jbig_ar.h new file mode 100644 index 00000000..d58b1ae0 --- /dev/null +++ b/converter/other/jbig/libjbig/include/jbig_ar.h @@ -0,0 +1,53 @@ +/* + * Header file for the arithmetic encoder and decoder of + * the portable JBIG compression library + * + * Markus Kuhn -- http://www.cl.cam.ac.uk/~mgk25/jbigkit/ + */ + +#ifndef JBG_AR_H +#define JBG_AR_H + +/* + * Status of arithmetic encoder + */ + +struct jbg_arenc_state { + unsigned char st[4096]; /* probability status for contexts, MSB = MPS */ + unsigned long c; /* register C: base of coding intervall, * + * layout as in Table 23 */ + unsigned long a; /* register A: normalized size of coding interval */ + long sc; /* number of buffered 0xff values that might still overflow */ + int ct; /* bit shift counter, determines when next byte will be written */ + int buffer; /* buffer for most recent output byte != 0xff */ + void (*byte_out)(int, void *); /* function that receives all PSCD bytes */ + void *file; /* parameter passed to byte_out */ +}; + +/* + * Status of arithmetic decoder + */ + +struct jbg_ardec_state { + unsigned char st[4096]; /* probability status for contexts, MSB = MPS */ + unsigned long c; /* register C: base of coding intervall, * + * layout as in Table 25 */ + unsigned long a; /* register A: normalized size of coding interval */ + unsigned char *pscd_ptr; /* pointer to next PSCD data byte */ + unsigned char *pscd_end; /* pointer to byte after PSCD */ + int ct; /* bit-shift counter, determines when next byte will be read; + * special value -1 signals that zero-padding has started */ + int startup; /* boolean flag that controls initial fill of s->c */ + int nopadding; /* boolean flag that triggers return -2 between + * reaching PSCD end and decoding the first symbol + * that might never have been encoded in the first + * place */ +}; + +void arith_encode_init(struct jbg_arenc_state *s, int reuse_st); +void arith_encode_flush(struct jbg_arenc_state *s); +void arith_encode(struct jbg_arenc_state *s, int cx, int pix); +void arith_decode_init(struct jbg_ardec_state *s, int reuse_st); +int arith_decode(struct jbg_ardec_state *s, int cx); + +#endif /* JBG_AR_H */ |