| /* |
| * Copyright (c) 2002-2007, Communications and Remote Sensing Laboratory, Universite catholique de Louvain (UCL), Belgium |
| * Copyright (c) 2002-2007, Professor Benoit Macq |
| * Copyright (c) 2001-2003, David Janssens |
| * Copyright (c) 2002-2003, Yannick Verschueren |
| * Copyright (c) 2003-2007, Francois-Olivier Devaux and Antonin Descampe |
| * Copyright (c) 2005, Herve Drolon, FreeImage Team |
| * All rights reserved. |
| * |
| * Redistribution and use in source and binary forms, with or without |
| * modification, are permitted provided that the following conditions |
| * are met: |
| * 1. Redistributions of source code must retain the above copyright |
| * notice, this list of conditions and the following disclaimer. |
| * 2. Redistributions in binary form must reproduce the above copyright |
| * notice, this list of conditions and the following disclaimer in the |
| * documentation and/or other materials provided with the distribution. |
| * |
| * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS `AS IS' |
| * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE |
| * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE |
| * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE |
| * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR |
| * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF |
| * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS |
| * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN |
| * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) |
| * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE |
| * POSSIBILITY OF SUCH DAMAGE. |
| */ |
| |
| #include "opj_includes.h" |
| |
| /** @defgroup BIO BIO - Individual bit input-output stream */ |
| /*@{*/ |
| |
| /** @name Local static functions */ |
| /*@{*/ |
| |
| /** |
| Write a bit |
| @param bio BIO handle |
| @param b Bit to write (0 or 1) |
| */ |
| static void bio_putbit(opj_bio_t *bio, int b); |
| /** |
| Read a bit |
| @param bio BIO handle |
| @return Returns the read bit |
| */ |
| static int bio_getbit(opj_bio_t *bio); |
| /** |
| Write a byte |
| @param bio BIO handle |
| @return Returns 0 if successful, returns 1 otherwise |
| */ |
| static int bio_byteout(opj_bio_t *bio); |
| /** |
| Read a byte |
| @param bio BIO handle |
| @return Returns 0 if successful, returns 1 otherwise |
| */ |
| static int bio_bytein(opj_bio_t *bio); |
| |
| /*@}*/ |
| |
| /*@}*/ |
| |
| /* |
| ========================================================== |
| local functions |
| ========================================================== |
| */ |
| |
| static int bio_byteout(opj_bio_t *bio) { |
| bio->buf = (bio->buf << 8) & 0xffff; |
| bio->ct = bio->buf == 0xff00 ? 7 : 8; |
| if (bio->bp >= bio->end) { |
| return 1; |
| } |
| *bio->bp++ = bio->buf >> 8; |
| return 0; |
| } |
| |
| static int bio_bytein(opj_bio_t *bio) { |
| bio->buf = (bio->buf << 8) & 0xffff; |
| bio->ct = bio->buf == 0xff00 ? 7 : 8; |
| if (bio->bp >= bio->end) { |
| return 1; |
| } |
| bio->buf |= *bio->bp++; |
| return 0; |
| } |
| |
| static void bio_putbit(opj_bio_t *bio, int b) { |
| if (bio->ct == 0) { |
| bio_byteout(bio); |
| } |
| bio->ct--; |
| bio->buf |= b << bio->ct; |
| } |
| |
| static int bio_getbit(opj_bio_t *bio) { |
| if (bio->ct == 0) { |
| bio_bytein(bio); |
| } |
| bio->ct--; |
| return (bio->buf >> bio->ct) & 1; |
| } |
| |
| /* |
| ========================================================== |
| Bit Input/Output interface |
| ========================================================== |
| */ |
| |
| opj_bio_t* bio_create(void) { |
| opj_bio_t *bio = (opj_bio_t*)opj_malloc(sizeof(opj_bio_t)); |
| return bio; |
| } |
| |
| void bio_destroy(opj_bio_t *bio) { |
| if(bio) { |
| opj_free(bio); |
| } |
| } |
| |
| int bio_numbytes(opj_bio_t *bio) { |
| return (bio->bp - bio->start); |
| } |
| |
| void bio_init_enc(opj_bio_t *bio, unsigned char *bp, int len) { |
| bio->start = bp; |
| bio->end = bp + len; |
| bio->bp = bp; |
| bio->buf = 0; |
| bio->ct = 8; |
| } |
| |
| void bio_init_dec(opj_bio_t *bio, unsigned char *bp, int len) { |
| bio->start = bp; |
| bio->end = bp + len; |
| bio->bp = bp; |
| bio->buf = 0; |
| bio->ct = 0; |
| } |
| |
| void bio_write(opj_bio_t *bio, int v, int n) { |
| int i; |
| for (i = n - 1; i >= 0; i--) { |
| bio_putbit(bio, (v >> i) & 1); |
| } |
| } |
| |
| int bio_read(opj_bio_t *bio, int n) { |
| int i, v; |
| v = 0; |
| for (i = n - 1; i >= 0; i--) { |
| v += bio_getbit(bio) << i; |
| } |
| return v; |
| } |
| |
| int bio_flush(opj_bio_t *bio) { |
| bio->ct = 0; |
| if (bio_byteout(bio)) { |
| return 1; |
| } |
| if (bio->ct == 7) { |
| bio->ct = 0; |
| if (bio_byteout(bio)) { |
| return 1; |
| } |
| } |
| return 0; |
| } |
| |
| int bio_inalign(opj_bio_t *bio) { |
| bio->ct = 0; |
| if ((bio->buf & 0xff) == 0xff) { |
| if (bio_bytein(bio)) { |
| return 1; |
| } |
| bio->ct = 0; |
| } |
| return 0; |
| } |