/src/FreeImage/Source/LibOpenJPEG/cio.c

  1/*
  2 * Copyright (c) 2002-2007, Communications and Remote Sensing Laboratory, Universite catholique de Louvain (UCL), Belgium
  3 * Copyright (c) 2002-2007, Professor Benoit Macq
  4 * Copyright (c) 2001-2003, David Janssens
  5 * Copyright (c) 2002-2003, Yannick Verschueren
  6 * Copyright (c) 2003-2007, Francois-Olivier Devaux and Antonin Descampe
  7 * Copyright (c) 2005, Herve Drolon, FreeImage Team
  8 * All rights reserved.
  9 *
 10 * Redistribution and use in source and binary forms, with or without
 11 * modification, are permitted provided that the following conditions
 12 * are met:
 13 * 1. Redistributions of source code must retain the above copyright
 14 *    notice, this list of conditions and the following disclaimer.
 15 * 2. Redistributions in binary form must reproduce the above copyright
 16 *    notice, this list of conditions and the following disclaimer in the
 17 *    documentation and/or other materials provided with the distribution.
 18 *
 19 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS `AS IS'
 20 * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 21 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 22 * ARE DISCLAIMED.  IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
 23 * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
 24 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
 25 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
 26 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
 27 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
 28 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
 29 * POSSIBILITY OF SUCH DAMAGE.
 30 */
 31
 32#include "opj_includes.h"
 33
 34/* ----------------------------------------------------------------------- */
 35
 36opj_cio_t* OPJ_CALLCONV opj_cio_open(opj_common_ptr cinfo, unsigned char *buffer, int length) {
 37	opj_cp_t *cp = NULL;
 38	opj_cio_t *cio = (opj_cio_t*)opj_malloc(sizeof(opj_cio_t));
 39	if(!cio) return NULL;
 40	cio->cinfo = cinfo;
 41	if(buffer && length) {
 42		/* wrap a user buffer containing the encoded image */
 43		cio->openmode = OPJ_STREAM_READ;
 44		cio->buffer = buffer;
 45		cio->length = length;
 46	}
 47	else if(!buffer && !length && cinfo) {
 48		/* allocate a buffer for the encoded image */
 49		cio->openmode = OPJ_STREAM_WRITE;
 50		switch(cinfo->codec_format) {
 51			case CODEC_J2K:
 52				cp = ((opj_j2k_t*)cinfo->j2k_handle)->cp;
 53				break;
 54			case CODEC_JP2:
 55				cp = ((opj_jp2_t*)cinfo->jp2_handle)->j2k->cp;
 56				break;
 57			default:
 58				opj_free(cio);
 59				return NULL;
 60		}
 61		cio->length = (unsigned int) (0.1625 * cp->img_size + 2000); /* 0.1625 = 1.3/8 and 2000 bytes as a minimum for headers */
 62		cio->buffer = (unsigned char *)opj_malloc(cio->length);
 63		if(!cio->buffer) {
 64			opj_event_msg(cio->cinfo, EVT_ERROR, "Error allocating memory for compressed bitstream\n");
 65			opj_free(cio);
 66			return NULL;
 67		}
 68	}
 69	else {
 70		opj_free(cio);
 71		return NULL;
 72	}
 73
 74	/* Initialize byte IO */
 75	cio->start = cio->buffer;
 76	cio->end = cio->buffer + cio->length;
 77	cio->bp = cio->buffer;
 78
 79	return cio;
 80}
 81
 82void OPJ_CALLCONV opj_cio_close(opj_cio_t *cio) {
 83	if(cio) {
 84		if(cio->openmode == OPJ_STREAM_WRITE) {
 85			/* destroy the allocated buffer */
 86			opj_free(cio->buffer);
 87		}
 88		/* destroy the cio */
 89		opj_free(cio);
 90	}
 91}
 92
 93
 94/* ----------------------------------------------------------------------- */
 95
 96/*
 97 * Get position in byte stream.
 98 */
 99int OPJ_CALLCONV cio_tell(opj_cio_t *cio) {
100	return cio->bp - cio->start;
101}
102
103/*
104 * Set position in byte stream.
105 *
106 * pos : position, in number of bytes, from the beginning of the stream
107 */
108void OPJ_CALLCONV cio_seek(opj_cio_t *cio, int pos) {
109	cio->bp = cio->start + pos;
110}
111
112/*
113 * Number of bytes left before the end of the stream.
114 */
115int cio_numbytesleft(opj_cio_t *cio) {
116	return cio->end - cio->bp;
117}
118
119/*
120 * Get pointer to the current position in the stream.
121 */
122unsigned char *cio_getbp(opj_cio_t *cio) {
123	return cio->bp;
124}
125
126/*
127 * Write a byte.
128 */
129opj_bool cio_byteout(opj_cio_t *cio, unsigned char v) {
130	if (cio->bp >= cio->end) {
131		opj_event_msg(cio->cinfo, EVT_ERROR, "write error\n");
132		return OPJ_FALSE;
133	}
134	*cio->bp++ = v;
135	return OPJ_TRUE;
136}
137
138/*
139 * Read a byte.
140 */
141unsigned char cio_bytein(opj_cio_t *cio) {
142	if (cio->bp >= cio->end) {
143		opj_event_msg(cio->cinfo, EVT_ERROR, "read error: passed the end of the codestream (start = %d, current = %d, end = %d\n", cio->start, cio->bp, cio->end);
144		return 0;
145	}
146	return *cio->bp++;
147}
148
149/*
150 * Write some bytes.
151 *
152 * v : value to write
153 * n : number of bytes to write
154 */
155unsigned int cio_write(opj_cio_t *cio, unsigned long long int v, int n) {
156	int i;
157	for (i = n - 1; i >= 0; i--) {
158		if( !cio_byteout(cio, (unsigned char) ((v >> (i << 3)) & 0xff)) )
159			return 0;
160	}
161	return n;
162}
163
164/*
165 * Read some bytes.
166 *
167 * n : number of bytes to read
168 *
169 * return : value of the n bytes read
170 */
171unsigned int cio_read(opj_cio_t *cio, int n) {
172	int i;
173	unsigned int v;
174	v = 0;
175	for (i = n - 1; i >= 0; i--) {
176		v += cio_bytein(cio) << (i << 3);
177	}
178	return v;
179}
180
181/* 
182 * Skip some bytes.
183 *
184 * n : number of bytes to skip
185 */
186void cio_skip(opj_cio_t *cio, int n) {
187	cio->bp += n;
188}
189
190
191