X-Git-Url: https://git.creatis.insa-lyon.fr/pubgit/?a=blobdiff_plain;f=src%2Fjpeg%2Flibijg%2Fjdhuff.h;h=907465628a0fc9f20b6a00c44702016d4101e4d7;hb=c4220b95e9d5e902a7468e408435bf6dea4950eb;hp=ae19b6cafd7e81f94499d92876a6cf88bcafda86;hpb=a26e6f06a76ec85504cf65288e7c47f2cd728641;p=gdcm.git diff --git a/src/jpeg/libijg/jdhuff.h b/src/jpeg/libijg/jdhuff.h index ae19b6ca..90746562 100644 --- a/src/jpeg/libijg/jdhuff.h +++ b/src/jpeg/libijg/jdhuff.h @@ -1,33 +1,34 @@ /* * jdhuff.h * - * Copyright (C) 1991-1997, Thomas G. Lane. + * Copyright (C) 1991-1998, Thomas G. Lane. * This file is part of the Independent JPEG Group's software. * For conditions of distribution and use, see the accompanying README file. * * This file contains declarations for Huffman entropy decoding routines - * that are shared between the sequential decoder (jdhuff.c) and the - * progressive decoder (jdphuff.c). No other modules need to see these. + * that are shared between the sequential decoder (jdhuff.c), the + * progressive decoder (jdphuff.c) and the lossless decoder (jdlhuff.c). + * No other modules need to see these. */ /* Short forms of external names for systems with brain-damaged linkers. */ #ifdef NEED_SHORT_EXTERNAL_NAMES -#define jpeg_make_d_derived_tbl jMkDDerived -#define jpeg_fill_bit_buffer jFilBitBuf -#define jpeg_huff_decode jHufDecode +#define jpeg_make_d_derived_tbl jMkDDerived +#define jpeg_fill_bit_buffer jFilBitBuf +#define jpeg_huff_decode jHufDecode #endif /* NEED_SHORT_EXTERNAL_NAMES */ /* Derived data constructed for each Huffman table */ -#define HUFF_LOOKAHEAD 8 /* # of bits of lookahead */ +#define HUFF_LOOKAHEAD 8 /* # of bits of lookahead */ typedef struct { /* Basic tables: (element [0] of each array is unused) */ - INT32 maxcode[18]; /* largest code of length k (-1 if none) */ + INT32 maxcode[18]; /* largest code of length k (-1 if none) */ /* (maxcode[17] is a sentinel to ensure jpeg_huff_decode terminates) */ - INT32 valoffset[17]; /* huffval[] offset for codes of length k */ + INT32 valoffset[17]; /* huffval[] offset for codes of length k */ /* valoffset[k] = huffval[] index of 1st symbol of code length k, less * the smallest code of length k; so given a code of length k, the * corresponding symbol is huffval[code + valoffset[k]] @@ -47,8 +48,8 @@ typedef struct { /* Expand a Huffman table definition into the derived format */ EXTERN(void) jpeg_make_d_derived_tbl - JPP((j_decompress_ptr cinfo, boolean isDC, int tblno, - d_derived_tbl ** pdtbl)); + JPP((j_decompress_ptr cinfo, boolean isDC, int tblno, + d_derived_tbl ** pdtbl)); /* @@ -69,8 +70,8 @@ EXTERN(void) jpeg_make_d_derived_tbl * necessary. */ -typedef INT32 bit_buf_type; /* type of bit-extraction buffer */ -#define BIT_BUF_SIZE 32 /* size of buffer in bits */ +typedef INT32 bit_buf_type; /* type of bit-extraction buffer */ +#define BIT_BUF_SIZE 32 /* size of buffer in bits */ /* If long is > 32 bits on your machine, and shifting/masking longs is * reasonably fast, making bit_buf_type be long and setting BIT_BUF_SIZE @@ -79,43 +80,43 @@ typedef INT32 bit_buf_type; /* type of bit-extraction buffer */ * because not all machines measure sizeof in 8-bit bytes. */ -typedef struct { /* Bitreading state saved across MCUs */ - bit_buf_type get_buffer; /* current bit-extraction buffer */ - int bits_left; /* # of unused bits in it */ +typedef struct { /* Bitreading state saved across MCUs */ + bit_buf_type get_buffer; /* current bit-extraction buffer */ + int bits_left; /* # of unused bits in it */ } bitread_perm_state; -typedef struct { /* Bitreading working state within an MCU */ +typedef struct { /* Bitreading working state within an MCU */ /* Current data source location */ /* We need a copy, rather than munging the original, in case of suspension */ const JOCTET * next_input_byte; /* => next byte to read from source */ - size_t bytes_in_buffer; /* # of bytes remaining in source buffer */ + size_t bytes_in_buffer; /* # of bytes remaining in source buffer */ /* Bit input buffer --- note these values are kept in register variables, * not in this struct, inside the inner loops. */ - bit_buf_type get_buffer; /* current bit-extraction buffer */ - int bits_left; /* # of unused bits in it */ + bit_buf_type get_buffer; /* current bit-extraction buffer */ + int bits_left; /* # of unused bits in it */ /* Pointer needed by jpeg_fill_bit_buffer. */ - j_decompress_ptr cinfo; /* back link to decompress master record */ + j_decompress_ptr cinfo; /* back link to decompress master record */ } bitread_working_state; /* Macros to declare and load/save bitread local variables. */ #define BITREAD_STATE_VARS \ - register bit_buf_type get_buffer; \ - register int bits_left; \ - bitread_working_state br_state + register bit_buf_type get_buffer; \ + register int bits_left; \ + bitread_working_state br_state #define BITREAD_LOAD_STATE(cinfop,permstate) \ - br_state.cinfo = cinfop; \ - br_state.next_input_byte = cinfop->src->next_input_byte; \ - br_state.bytes_in_buffer = cinfop->src->bytes_in_buffer; \ - get_buffer = permstate.get_buffer; \ - bits_left = permstate.bits_left; + br_state.cinfo = cinfop; \ + br_state.next_input_byte = cinfop->src->next_input_byte; \ + br_state.bytes_in_buffer = cinfop->src->bytes_in_buffer; \ + get_buffer = permstate.get_buffer; \ + bits_left = permstate.bits_left; #define BITREAD_SAVE_STATE(cinfop,permstate) \ - cinfop->src->next_input_byte = br_state.next_input_byte; \ - cinfop->src->bytes_in_buffer = br_state.bytes_in_buffer; \ - permstate.get_buffer = get_buffer; \ - permstate.bits_left = bits_left + cinfop->src->next_input_byte = br_state.next_input_byte; \ + cinfop->src->bytes_in_buffer = br_state.bytes_in_buffer; \ + permstate.get_buffer = get_buffer; \ + permstate.bits_left = bits_left /* * These macros provide the in-line portion of bit fetching. @@ -123,37 +124,37 @@ typedef struct { /* Bitreading working state within an MCU */ * before using GET_BITS, PEEK_BITS, or DROP_BITS. * The variables get_buffer and bits_left are assumed to be locals, * but the state struct might not be (jpeg_huff_decode needs this). - * CHECK_BIT_BUFFER(state,n,action); - * Ensure there are N bits in get_buffer; if suspend, take action. + * CHECK_BIT_BUFFER(state,n,action); + * Ensure there are N bits in get_buffer; if suspend, take action. * val = GET_BITS(n); - * Fetch next N bits. + * Fetch next N bits. * val = PEEK_BITS(n); - * Fetch next N bits without removing them from the buffer. - * DROP_BITS(n); - * Discard next N bits. + * Fetch next N bits without removing them from the buffer. + * DROP_BITS(n); + * Discard next N bits. * The value N should be a simple variable, not an expression, because it * is evaluated multiple times. */ #define CHECK_BIT_BUFFER(state,nbits,action) \ - { if (bits_left < (nbits)) { \ - if (! jpeg_fill_bit_buffer(&(state),get_buffer,bits_left,nbits)) \ - { action; } \ - get_buffer = (state).get_buffer; bits_left = (state).bits_left; } } + { if (bits_left < (nbits)) { \ + if (! jpeg_fill_bit_buffer(&(state),get_buffer,bits_left,nbits)) \ + { action; } \ + get_buffer = (state).get_buffer; bits_left = (state).bits_left; } } #define GET_BITS(nbits) \ - (((int) (get_buffer >> (bits_left -= (nbits)))) & ((1<<(nbits))-1)) + (((int) (get_buffer >> (bits_left -= (nbits)))) & ((1<<(nbits))-1)) #define PEEK_BITS(nbits) \ - (((int) (get_buffer >> (bits_left - (nbits)))) & ((1<<(nbits))-1)) + (((int) (get_buffer >> (bits_left - (nbits)))) & ((1<<(nbits))-1)) #define DROP_BITS(nbits) \ - (bits_left -= (nbits)) + (bits_left -= (nbits)) /* Load up the bit buffer to a depth of at least nbits */ EXTERN(boolean) jpeg_fill_bit_buffer - JPP((bitread_working_state * state, register bit_buf_type get_buffer, - register int bits_left, int nbits)); + JPP((bitread_working_state * state, register bit_buf_type get_buffer, + register int bits_left, int nbits)); /* @@ -190,12 +191,39 @@ EXTERN(boolean) jpeg_fill_bit_buffer nb = HUFF_LOOKAHEAD+1; \ slowlabel: \ if ((result=jpeg_huff_decode(&state,get_buffer,bits_left,htbl,nb)) < 0) \ - { failaction; } \ + { failaction; } \ get_buffer = state.get_buffer; bits_left = state.bits_left; \ } \ } /* Out-of-line case for Huffman code fetching */ EXTERN(int) jpeg_huff_decode - JPP((bitread_working_state * state, register bit_buf_type get_buffer, - register int bits_left, d_derived_tbl * htbl, int min_bits)); + JPP((bitread_working_state * state, register bit_buf_type get_buffer, + register int bits_left, d_derived_tbl * htbl, int min_bits)); + + +/* Common fields between sequential, progressive and lossless Huffman entropy + * decoder master structs. + */ + +#define huffd_common_fields \ + boolean insufficient_data; /* set TRUE after emmitting warning */ \ + /* These fields are loaded into local variables at start of each MCU. \ + * In case of suspension, we exit WITHOUT updating them. \ + */ \ + bitread_perm_state bitstate /* Bit buffer at start of MCU */ + +/* Routines that are to be used by any or all of the entropy decoders are + * declared to receive a pointer to this structure. There are no actual + * instances of huffd_common_struct, only of shuff_entropy_decoder, + * phuff_entropy_decoder and lhuff_entropy_decoder. + */ +struct huffd_common_struct { + huffd_common_fields; /* Fields common to all decoder struct types */ + /* Additional fields follow in an actual shuff_entropy_decoder, + * phuff_entropy_decoder or lhuff_entropy_decoder struct. All four structs + * must agree on these initial fields! (This would be a lot cleaner in C++.) + */ +}; + +typedef struct huffd_common_struct * huffd_common_ptr;