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      1 /*
      2  * The copyright in this software is being made available under the 2-clauses
      3  * BSD License, included below. This software may be subject to other third
      4  * party and contributor rights, including patent rights, and no such rights
      5  * are granted under this license.
      6  *
      7  * Copyright (c) 2002-2014, Universite catholique de Louvain (UCL), Belgium
      8  * Copyright (c) 2002-2014, Professor Benoit Macq
      9  * Copyright (c) 2001-2003, David Janssens
     10  * Copyright (c) 2002-2003, Yannick Verschueren
     11  * Copyright (c) 2003-2007, Francois-Olivier Devaux
     12  * Copyright (c) 2003-2014, Antonin Descampe
     13  * Copyright (c) 2005, Herve Drolon, FreeImage Team
     14  * Copyright (c) 2008, 2011-2012, Centre National d'Etudes Spatiales (CNES), FR
     15  * Copyright (c) 2012, CS Systemes d'Information, France
     16  * All rights reserved.
     17  *
     18  * Redistribution and use in source and binary forms, with or without
     19  * modification, are permitted provided that the following conditions
     20  * are met:
     21  * 1. Redistributions of source code must retain the above copyright
     22  *    notice, this list of conditions and the following disclaimer.
     23  * 2. Redistributions in binary form must reproduce the above copyright
     24  *    notice, this list of conditions and the following disclaimer in the
     25  *    documentation and/or other materials provided with the distribution.
     26  *
     27  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS `AS IS'
     28  * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
     29  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
     30  * ARE DISCLAIMED.  IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
     31  * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
     32  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
     33  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
     34  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
     35  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
     36  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
     37  * POSSIBILITY OF SUCH DAMAGE.
     38  */
     39 
     40 #include "opj_includes.h"
     41 
     42 /* ----------------------------------------------------------------------- */
     43 
     44 
     45 /* ----------------------------------------------------------------------- */
     46 
     47 void opj_write_bytes_BE (OPJ_BYTE * p_buffer, OPJ_UINT32 p_value, OPJ_UINT32 p_nb_bytes)
     48 {
     49 	const OPJ_BYTE * l_data_ptr = ((const OPJ_BYTE *) &p_value)+sizeof(OPJ_UINT32)-p_nb_bytes;
     50 
     51 	assert(p_nb_bytes > 0 && p_nb_bytes <=  sizeof(OPJ_UINT32));
     52 
     53 	memcpy(p_buffer,l_data_ptr,p_nb_bytes);
     54 }
     55 
     56 void opj_write_bytes_LE (OPJ_BYTE * p_buffer, OPJ_UINT32 p_value, OPJ_UINT32 p_nb_bytes)
     57 {
     58 	const OPJ_BYTE * l_data_ptr = ((const OPJ_BYTE *) &p_value) + p_nb_bytes - 1;
     59 	OPJ_UINT32 i;
     60 
     61 	assert(p_nb_bytes > 0 && p_nb_bytes <= sizeof(OPJ_UINT32));
     62 
     63 	for	(i=0;i<p_nb_bytes;++i) {
     64 		*(p_buffer++) = *(l_data_ptr--);
     65 	}
     66 }
     67 
     68 void opj_read_bytes_BE(const OPJ_BYTE * p_buffer, OPJ_UINT32 * p_value, OPJ_UINT32 p_nb_bytes)
     69 {
     70 	OPJ_BYTE * l_data_ptr = ((OPJ_BYTE *) p_value);
     71 
     72 	assert(p_nb_bytes > 0 && p_nb_bytes <= sizeof(OPJ_UINT32));
     73 
     74 	*p_value = 0;
     75 	memcpy(l_data_ptr+sizeof(OPJ_UINT32)-p_nb_bytes,p_buffer,p_nb_bytes);
     76 }
     77 
     78 void opj_read_bytes_LE(const OPJ_BYTE * p_buffer, OPJ_UINT32 * p_value, OPJ_UINT32 p_nb_bytes)
     79 {
     80 	OPJ_BYTE * l_data_ptr = ((OPJ_BYTE *) p_value) + p_nb_bytes-1;
     81 	OPJ_UINT32 i;
     82 
     83 	assert(p_nb_bytes > 0 && p_nb_bytes <= sizeof(OPJ_UINT32));
     84 
     85 	*p_value = 0;
     86 	for (i=0;i<p_nb_bytes;++i) {
     87 		*(l_data_ptr--) = *(p_buffer++);
     88 	}
     89 }
     90 
     91 void opj_write_double_BE(OPJ_BYTE * p_buffer, OPJ_FLOAT64 p_value)
     92 {
     93 	const OPJ_BYTE * l_data_ptr = ((const OPJ_BYTE *) &p_value);
     94 	memcpy(p_buffer,l_data_ptr,sizeof(OPJ_FLOAT64));
     95 }
     96 
     97 void opj_write_double_LE(OPJ_BYTE * p_buffer, OPJ_FLOAT64 p_value)
     98 {
     99 	const OPJ_BYTE * l_data_ptr = ((const OPJ_BYTE *) &p_value) + sizeof(OPJ_FLOAT64) - 1;
    100 	OPJ_UINT32 i;
    101 	for	(i=0;i<sizeof(OPJ_FLOAT64);++i) {
    102 		*(p_buffer++) = *(l_data_ptr--);
    103 	}
    104 }
    105 
    106 void opj_read_double_BE(const OPJ_BYTE * p_buffer, OPJ_FLOAT64 * p_value)
    107 {
    108 	OPJ_BYTE * l_data_ptr = ((OPJ_BYTE *) p_value);
    109 	memcpy(l_data_ptr,p_buffer,sizeof(OPJ_FLOAT64));
    110 }
    111 
    112 void opj_read_double_LE(const OPJ_BYTE * p_buffer, OPJ_FLOAT64 * p_value)
    113 {
    114 	OPJ_BYTE * l_data_ptr = ((OPJ_BYTE *) p_value) + sizeof(OPJ_FLOAT64)-1;
    115 	OPJ_UINT32 i;
    116 	for (i=0;i<sizeof(OPJ_FLOAT64);++i) {
    117 		*(l_data_ptr--) = *(p_buffer++);
    118 	}
    119 }
    120 
    121 void opj_write_float_BE(OPJ_BYTE * p_buffer, OPJ_FLOAT32 p_value)
    122 {
    123 	const OPJ_BYTE * l_data_ptr = ((const OPJ_BYTE *) &p_value);
    124 	memcpy(p_buffer,l_data_ptr,sizeof(OPJ_FLOAT32));
    125 }
    126 
    127 void opj_write_float_LE(OPJ_BYTE * p_buffer, OPJ_FLOAT32 p_value)
    128 {
    129 	const OPJ_BYTE * l_data_ptr = ((const OPJ_BYTE *) &p_value) + sizeof(OPJ_FLOAT32) - 1;
    130 	OPJ_UINT32 i;
    131 	for	(i=0;i<sizeof(OPJ_FLOAT32);++i) {
    132 		*(p_buffer++) = *(l_data_ptr--);
    133 	}
    134 }
    135 
    136 void opj_read_float_BE(const OPJ_BYTE * p_buffer, OPJ_FLOAT32 * p_value)
    137 {
    138 	OPJ_BYTE * l_data_ptr = ((OPJ_BYTE *) p_value);
    139 	memcpy(l_data_ptr,p_buffer,sizeof(OPJ_FLOAT32));
    140 }
    141 
    142 void opj_read_float_LE(const OPJ_BYTE * p_buffer, OPJ_FLOAT32 * p_value)
    143 {
    144 	OPJ_BYTE * l_data_ptr = ((OPJ_BYTE *) p_value) + sizeof(OPJ_FLOAT32)-1;
    145 	OPJ_UINT32 i;
    146 	for	(i=0;i<sizeof(OPJ_FLOAT32);++i) {
    147 		*(l_data_ptr--) = *(p_buffer++);
    148 	}
    149 }
    150 
    151 opj_stream_t* OPJ_CALLCONV opj_stream_create(OPJ_SIZE_T p_buffer_size,OPJ_BOOL l_is_input)
    152 {
    153 	opj_stream_private_t * l_stream = 00;
    154 	l_stream = (opj_stream_private_t*) opj_calloc(1,sizeof(opj_stream_private_t));
    155 	if (! l_stream) {
    156 		return 00;
    157 	}
    158 
    159 	l_stream->m_buffer_size = p_buffer_size;
    160 	l_stream->m_stored_data = (OPJ_BYTE *) opj_malloc(p_buffer_size);
    161 	if (! l_stream->m_stored_data) {
    162 		opj_free(l_stream);
    163 		return 00;
    164 	}
    165 
    166 	l_stream->m_current_data = l_stream->m_stored_data;
    167 
    168 	if (l_is_input) {
    169 		l_stream->m_status |= opj_stream_e_input;
    170 		l_stream->m_opj_skip = opj_stream_read_skip;
    171 		l_stream->m_opj_seek = opj_stream_read_seek;
    172 	}
    173 	else {
    174 		l_stream->m_status |= opj_stream_e_output;
    175 		l_stream->m_opj_skip = opj_stream_write_skip;
    176 		l_stream->m_opj_seek = opj_stream_write_seek;
    177 	}
    178 
    179 	l_stream->m_read_fn = opj_stream_default_read;
    180 	l_stream->m_write_fn = opj_stream_default_write;
    181 	l_stream->m_skip_fn = opj_stream_default_skip;
    182 	l_stream->m_seek_fn = opj_stream_default_seek;
    183 
    184 	return (opj_stream_t *) l_stream;
    185 }
    186 
    187 opj_stream_t* OPJ_CALLCONV opj_stream_default_create(OPJ_BOOL l_is_input)
    188 {
    189 	return opj_stream_create(OPJ_J2K_STREAM_CHUNK_SIZE,l_is_input);
    190 }
    191 
    192 void OPJ_CALLCONV opj_stream_destroy(opj_stream_t* p_stream)
    193 {
    194 	opj_stream_private_t* l_stream = (opj_stream_private_t*) p_stream;
    195 
    196 	if (l_stream) {
    197 		if (l_stream->m_free_user_data_fn) {
    198 			l_stream->m_free_user_data_fn(l_stream->m_user_data);
    199 		}
    200 		opj_free(l_stream->m_stored_data);
    201 		l_stream->m_stored_data = 00;
    202 		opj_free(l_stream);
    203 	}
    204 }
    205 
    206 void OPJ_CALLCONV opj_stream_set_read_function(opj_stream_t* p_stream, opj_stream_read_fn p_function)
    207 {
    208 	opj_stream_private_t* l_stream = (opj_stream_private_t*) p_stream;
    209 
    210 	if ((!l_stream) || (! (l_stream->m_status & opj_stream_e_input))) {
    211 		return;
    212 	}
    213 
    214 	l_stream->m_read_fn = p_function;
    215 }
    216 
    217 void OPJ_CALLCONV opj_stream_set_seek_function(opj_stream_t* p_stream, opj_stream_seek_fn p_function)
    218 {
    219 	opj_stream_private_t* l_stream = (opj_stream_private_t*) p_stream;
    220 
    221 	if (!l_stream) {
    222 		return;
    223 	}
    224 	l_stream->m_seek_fn = p_function;
    225 }
    226 
    227 void OPJ_CALLCONV opj_stream_set_write_function(opj_stream_t* p_stream, opj_stream_write_fn p_function)
    228 {
    229 	opj_stream_private_t* l_stream = (opj_stream_private_t*) p_stream;
    230 
    231 	if ((!l_stream )|| (! (l_stream->m_status & opj_stream_e_output))) {
    232 		return;
    233 	}
    234 
    235 	l_stream->m_write_fn = p_function;
    236 }
    237 
    238 void OPJ_CALLCONV opj_stream_set_skip_function(opj_stream_t* p_stream, opj_stream_skip_fn p_function)
    239 {
    240 	opj_stream_private_t* l_stream = (opj_stream_private_t*) p_stream;
    241 
    242 	if (! l_stream) {
    243 		return;
    244 	}
    245 
    246 	l_stream->m_skip_fn = p_function;
    247 }
    248 
    249 void OPJ_CALLCONV opj_stream_set_user_data(opj_stream_t* p_stream, void * p_data, opj_stream_free_user_data_fn p_function)
    250 {
    251 	opj_stream_private_t* l_stream = (opj_stream_private_t*) p_stream;
    252 	if (!l_stream)
    253 		return;
    254 	l_stream->m_user_data = p_data;
    255   l_stream->m_free_user_data_fn = p_function;
    256 }
    257 
    258 void OPJ_CALLCONV opj_stream_set_user_data_length(opj_stream_t* p_stream, OPJ_UINT64 data_length)
    259 {
    260 	opj_stream_private_t* l_stream = (opj_stream_private_t*) p_stream;
    261 	if (!l_stream)
    262 		return;
    263 	l_stream->m_user_data_length = data_length;
    264 }
    265 
    266 OPJ_SIZE_T opj_stream_read_data (opj_stream_private_t * p_stream,OPJ_BYTE * p_buffer, OPJ_SIZE_T p_size, opj_event_mgr_t * p_event_mgr)
    267 {
    268 	OPJ_SIZE_T l_read_nb_bytes = 0;
    269 	if (p_stream->m_bytes_in_buffer >= p_size) {
    270 		memcpy(p_buffer,p_stream->m_current_data,p_size);
    271 		p_stream->m_current_data += p_size;
    272 		p_stream->m_bytes_in_buffer -= p_size;
    273 		l_read_nb_bytes += p_size;
    274 		p_stream->m_byte_offset += (OPJ_OFF_T)p_size;
    275 		return l_read_nb_bytes;
    276 	}
    277 
    278 	/* we are now in the case when the remaining data if not sufficient */
    279 	if (p_stream->m_status & opj_stream_e_end) {
    280 		l_read_nb_bytes += p_stream->m_bytes_in_buffer;
    281 		memcpy(p_buffer,p_stream->m_current_data,p_stream->m_bytes_in_buffer);
    282 		p_stream->m_current_data += p_stream->m_bytes_in_buffer;
    283 		p_stream->m_byte_offset += (OPJ_OFF_T)p_stream->m_bytes_in_buffer;
    284 		p_stream->m_bytes_in_buffer = 0;
    285 		return l_read_nb_bytes ? l_read_nb_bytes : (OPJ_SIZE_T)-1;
    286 	}
    287 
    288 	/* the flag is not set, we copy data and then do an actual read on the stream */
    289 	if (p_stream->m_bytes_in_buffer) {
    290 		l_read_nb_bytes += p_stream->m_bytes_in_buffer;
    291 		memcpy(p_buffer,p_stream->m_current_data,p_stream->m_bytes_in_buffer);
    292 		p_stream->m_current_data = p_stream->m_stored_data;
    293 		p_buffer += p_stream->m_bytes_in_buffer;
    294 		p_size -= p_stream->m_bytes_in_buffer;
    295 		p_stream->m_byte_offset += (OPJ_OFF_T)p_stream->m_bytes_in_buffer;
    296 		p_stream->m_bytes_in_buffer = 0;
    297 	}
    298 	else {
    299     /* case where we are already at the end of the buffer
    300        so reset the m_current_data to point to the start of the
    301        stored buffer to get ready to read from disk*/
    302 		p_stream->m_current_data = p_stream->m_stored_data;
    303 	}
    304 
    305 	for (;;) {
    306 		/* we should read less than a chunk -> read a chunk */
    307 		if (p_size < p_stream->m_buffer_size) {
    308 			/* we should do an actual read on the media */
    309 			p_stream->m_bytes_in_buffer = p_stream->m_read_fn(p_stream->m_stored_data,p_stream->m_buffer_size,p_stream->m_user_data);
    310 
    311 			if (p_stream->m_bytes_in_buffer == (OPJ_SIZE_T)-1) {
    312 				/* end of stream */
    313 				opj_event_msg(p_event_mgr, EVT_INFO, "Stream reached its end !\n");
    314 
    315 				p_stream->m_bytes_in_buffer = 0;
    316 				p_stream->m_status |= opj_stream_e_end;
    317 				/* end of stream */
    318 				return l_read_nb_bytes ? l_read_nb_bytes : (OPJ_SIZE_T)-1;
    319 			}
    320 			else if	(p_stream->m_bytes_in_buffer < p_size) {
    321 				/* not enough data */
    322 				l_read_nb_bytes += p_stream->m_bytes_in_buffer;
    323 				memcpy(p_buffer,p_stream->m_current_data,p_stream->m_bytes_in_buffer);
    324 				p_stream->m_current_data = p_stream->m_stored_data;
    325 				p_buffer += p_stream->m_bytes_in_buffer;
    326 				p_size -= p_stream->m_bytes_in_buffer;
    327 				p_stream->m_byte_offset += (OPJ_OFF_T)p_stream->m_bytes_in_buffer;
    328 				p_stream->m_bytes_in_buffer = 0;
    329 			}
    330 			else {
    331 				l_read_nb_bytes += p_size;
    332 				memcpy(p_buffer,p_stream->m_current_data,p_size);
    333 				p_stream->m_current_data += p_size;
    334 				p_stream->m_bytes_in_buffer -= p_size;
    335 				p_stream->m_byte_offset += (OPJ_OFF_T)p_size;
    336 				return l_read_nb_bytes;
    337 			}
    338 		}
    339 		else {
    340 			/* direct read on the dest buffer */
    341 			p_stream->m_bytes_in_buffer = p_stream->m_read_fn(p_buffer,p_size,p_stream->m_user_data);
    342 
    343 			if (p_stream->m_bytes_in_buffer == (OPJ_SIZE_T)-1) {
    344 				/*  end of stream */
    345 				opj_event_msg(p_event_mgr, EVT_INFO, "Stream reached its end !\n");
    346 
    347 				p_stream->m_bytes_in_buffer = 0;
    348 				p_stream->m_status |= opj_stream_e_end;
    349 				/* end of stream */
    350 				return l_read_nb_bytes ? l_read_nb_bytes : (OPJ_SIZE_T)-1;
    351 			}
    352 			else if (p_stream->m_bytes_in_buffer < p_size) {
    353 				/* not enough data */
    354 				l_read_nb_bytes += p_stream->m_bytes_in_buffer;
    355 				p_stream->m_current_data = p_stream->m_stored_data;
    356 				p_buffer += p_stream->m_bytes_in_buffer;
    357 				p_size -= p_stream->m_bytes_in_buffer;
    358 				p_stream->m_byte_offset += (OPJ_OFF_T)p_stream->m_bytes_in_buffer;
    359 				p_stream->m_bytes_in_buffer = 0;
    360 			}
    361 			else {
    362 				/* we have read the exact size */
    363 				l_read_nb_bytes += p_stream->m_bytes_in_buffer;
    364 				p_stream->m_byte_offset += (OPJ_OFF_T)p_stream->m_bytes_in_buffer;
    365 				p_stream->m_current_data = p_stream->m_stored_data;
    366 				p_stream->m_bytes_in_buffer = 0;
    367 				return l_read_nb_bytes;
    368 			}
    369 		}
    370 	}
    371 }
    372 
    373 OPJ_SIZE_T opj_stream_write_data (opj_stream_private_t * p_stream,
    374 								  const OPJ_BYTE * p_buffer,
    375 								  OPJ_SIZE_T p_size,
    376 								  opj_event_mgr_t * p_event_mgr)
    377 {
    378 	OPJ_SIZE_T l_remaining_bytes = 0;
    379 	OPJ_SIZE_T l_write_nb_bytes = 0;
    380 
    381 	if (p_stream->m_status & opj_stream_e_error) {
    382 		return (OPJ_SIZE_T)-1;
    383 	}
    384 
    385 	for (;;) {
    386 		l_remaining_bytes = p_stream->m_buffer_size - p_stream->m_bytes_in_buffer;
    387 
    388 		/* we have more memory than required */
    389 		if (l_remaining_bytes >= p_size) {
    390 			memcpy(p_stream->m_current_data, p_buffer, p_size);
    391 
    392 			p_stream->m_current_data += p_size;
    393 			p_stream->m_bytes_in_buffer += p_size;
    394 			l_write_nb_bytes += p_size;
    395 			p_stream->m_byte_offset += (OPJ_OFF_T)p_size;
    396 
    397 			return l_write_nb_bytes;
    398 		}
    399 
    400 		/* we copy data and then do an actual read on the stream */
    401 		if (l_remaining_bytes) {
    402 			l_write_nb_bytes += l_remaining_bytes;
    403 
    404 			memcpy(p_stream->m_current_data,p_buffer,l_remaining_bytes);
    405 
    406 			p_stream->m_current_data = p_stream->m_stored_data;
    407 
    408 			p_buffer += l_remaining_bytes;
    409 			p_size -= l_remaining_bytes;
    410 			p_stream->m_bytes_in_buffer += l_remaining_bytes;
    411 			p_stream->m_byte_offset += (OPJ_OFF_T)l_remaining_bytes;
    412 		}
    413 
    414 		if (! opj_stream_flush(p_stream, p_event_mgr)) {
    415 			return (OPJ_SIZE_T)-1;
    416 		}
    417 	}
    418 
    419 }
    420 
    421 OPJ_BOOL opj_stream_flush (opj_stream_private_t * p_stream, opj_event_mgr_t * p_event_mgr)
    422 {
    423 	/* the number of bytes written on the media. */
    424 	OPJ_SIZE_T l_current_write_nb_bytes = 0;
    425 
    426 	p_stream->m_current_data = p_stream->m_stored_data;
    427 
    428 	while (p_stream->m_bytes_in_buffer) {
    429 		/* we should do an actual write on the media */
    430 		l_current_write_nb_bytes = p_stream->m_write_fn(p_stream->m_current_data,
    431 														p_stream->m_bytes_in_buffer,
    432 														p_stream->m_user_data);
    433 
    434 		if (l_current_write_nb_bytes == (OPJ_SIZE_T)-1) {
    435 			p_stream->m_status |= opj_stream_e_error;
    436 			opj_event_msg(p_event_mgr, EVT_INFO, "Error on writing stream!\n");
    437 
    438 			return OPJ_FALSE;
    439 		}
    440 
    441 		p_stream->m_current_data += l_current_write_nb_bytes;
    442 		p_stream->m_bytes_in_buffer -= l_current_write_nb_bytes;
    443 	}
    444 
    445 	p_stream->m_current_data = p_stream->m_stored_data;
    446 
    447 	return OPJ_TRUE;
    448 }
    449 
    450 OPJ_OFF_T opj_stream_read_skip (opj_stream_private_t * p_stream, OPJ_OFF_T p_size, opj_event_mgr_t * p_event_mgr)
    451 {
    452 	OPJ_OFF_T l_skip_nb_bytes = 0;
    453 	OPJ_OFF_T l_current_skip_nb_bytes = 0;
    454 
    455 	assert( p_size >= 0 );
    456 
    457 	if (p_stream->m_bytes_in_buffer >= (OPJ_SIZE_T)p_size) {
    458 		p_stream->m_current_data += p_size;
    459 		/* it is safe to cast p_size to OPJ_SIZE_T since it is <= m_bytes_in_buffer
    460 		which is of type OPJ_SIZE_T */
    461 		p_stream->m_bytes_in_buffer -= (OPJ_SIZE_T)p_size;
    462 		l_skip_nb_bytes += p_size;
    463 		p_stream->m_byte_offset += l_skip_nb_bytes;
    464 		return l_skip_nb_bytes;
    465 	}
    466 
    467 	/* we are now in the case when the remaining data if not sufficient */
    468 	if (p_stream->m_status & opj_stream_e_end) {
    469 		l_skip_nb_bytes += (OPJ_OFF_T)p_stream->m_bytes_in_buffer;
    470 		p_stream->m_current_data += p_stream->m_bytes_in_buffer;
    471 		p_stream->m_bytes_in_buffer = 0;
    472 		p_stream->m_byte_offset += l_skip_nb_bytes;
    473 		return l_skip_nb_bytes ? l_skip_nb_bytes : (OPJ_OFF_T) -1;
    474 	}
    475 
    476 	/* the flag is not set, we copy data and then do an actual skip on the stream */
    477 	if (p_stream->m_bytes_in_buffer) {
    478 		l_skip_nb_bytes += (OPJ_OFF_T)p_stream->m_bytes_in_buffer;
    479 		p_stream->m_current_data = p_stream->m_stored_data;
    480 		p_size -= (OPJ_OFF_T)p_stream->m_bytes_in_buffer;
    481 		p_stream->m_bytes_in_buffer = 0;
    482 	}
    483 
    484 	while (p_size > 0) {
    485 		/* we should do an actual skip on the media */
    486 		l_current_skip_nb_bytes = p_stream->m_skip_fn(p_size, p_stream->m_user_data);
    487 		if (l_current_skip_nb_bytes == (OPJ_OFF_T) -1) {
    488 			opj_event_msg(p_event_mgr, EVT_INFO, "Stream reached its end !\n");
    489 
    490 			p_stream->m_status |= opj_stream_e_end;
    491 			p_stream->m_byte_offset += l_skip_nb_bytes;
    492 			/* end if stream */
    493 			return l_skip_nb_bytes ? l_skip_nb_bytes : (OPJ_OFF_T) -1;
    494 		}
    495 		p_size -= l_current_skip_nb_bytes;
    496 		l_skip_nb_bytes += l_current_skip_nb_bytes;
    497 	}
    498 
    499 	p_stream->m_byte_offset += l_skip_nb_bytes;
    500 
    501 	return l_skip_nb_bytes;
    502 }
    503 
    504 OPJ_OFF_T opj_stream_write_skip (opj_stream_private_t * p_stream, OPJ_OFF_T p_size, opj_event_mgr_t * p_event_mgr)
    505 {
    506 	OPJ_BOOL l_is_written = 0;
    507 	OPJ_OFF_T l_current_skip_nb_bytes = 0;
    508 	OPJ_OFF_T l_skip_nb_bytes = 0;
    509 
    510 	if (p_stream->m_status & opj_stream_e_error) {
    511 		return (OPJ_OFF_T) -1;
    512 	}
    513 
    514 	/* we should flush data */
    515 	l_is_written = opj_stream_flush (p_stream, p_event_mgr);
    516 	if (! l_is_written) {
    517 		p_stream->m_status |= opj_stream_e_error;
    518 		p_stream->m_bytes_in_buffer = 0;
    519 		return (OPJ_OFF_T) -1;
    520 	}
    521 	/* then skip */
    522 
    523 	while (p_size > 0) {
    524 		/* we should do an actual skip on the media */
    525 		l_current_skip_nb_bytes = p_stream->m_skip_fn(p_size, p_stream->m_user_data);
    526 
    527 		if (l_current_skip_nb_bytes == (OPJ_OFF_T)-1) {
    528 			opj_event_msg(p_event_mgr, EVT_INFO, "Stream error!\n");
    529 
    530 			p_stream->m_status |= opj_stream_e_error;
    531 			p_stream->m_byte_offset += l_skip_nb_bytes;
    532 			/* end if stream */
    533 			return l_skip_nb_bytes ? l_skip_nb_bytes : (OPJ_OFF_T)-1;
    534 		}
    535 		p_size -= l_current_skip_nb_bytes;
    536 		l_skip_nb_bytes += l_current_skip_nb_bytes;
    537 	}
    538 
    539 	p_stream->m_byte_offset += l_skip_nb_bytes;
    540 
    541 	return l_skip_nb_bytes;
    542 }
    543 
    544 OPJ_OFF_T opj_stream_tell (const opj_stream_private_t * p_stream)
    545 {
    546 	return p_stream->m_byte_offset;
    547 }
    548 
    549 OPJ_OFF_T opj_stream_get_number_byte_left (const opj_stream_private_t * p_stream)
    550 {
    551   assert( p_stream->m_byte_offset >= 0 );
    552   assert( p_stream->m_user_data_length >= (OPJ_UINT64)p_stream->m_byte_offset);
    553   return p_stream->m_user_data_length ?
    554 				(OPJ_OFF_T)(p_stream->m_user_data_length) - p_stream->m_byte_offset :
    555 				0;
    556 }
    557 
    558 OPJ_OFF_T opj_stream_skip (opj_stream_private_t * p_stream, OPJ_OFF_T p_size, opj_event_mgr_t * p_event_mgr)
    559 {
    560 	assert(p_size >= 0);
    561 	return p_stream->m_opj_skip(p_stream,p_size,p_event_mgr);
    562 }
    563 
    564 OPJ_BOOL opj_stream_read_seek (opj_stream_private_t * p_stream, OPJ_OFF_T p_size, opj_event_mgr_t * p_event_mgr)
    565 {
    566 	OPJ_ARG_NOT_USED(p_event_mgr);
    567 	p_stream->m_current_data = p_stream->m_stored_data;
    568 	p_stream->m_bytes_in_buffer = 0;
    569 
    570 	if( !(p_stream->m_seek_fn(p_size,p_stream->m_user_data)) ) {
    571 		p_stream->m_status |= opj_stream_e_end;
    572 		return OPJ_FALSE;
    573 	}
    574 	else {
    575 		/* reset stream status */
    576 		p_stream->m_status &= (~opj_stream_e_end);
    577 		p_stream->m_byte_offset = p_size;
    578 
    579 	}
    580 
    581 	return OPJ_TRUE;
    582 }
    583 
    584 OPJ_BOOL opj_stream_write_seek (opj_stream_private_t * p_stream, OPJ_OFF_T p_size, opj_event_mgr_t * p_event_mgr)
    585 {
    586 	if (! opj_stream_flush(p_stream,p_event_mgr)) {
    587 		p_stream->m_status |= opj_stream_e_error;
    588 		return OPJ_FALSE;
    589 	}
    590 
    591 	p_stream->m_current_data = p_stream->m_stored_data;
    592 	p_stream->m_bytes_in_buffer = 0;
    593 
    594 	if (! p_stream->m_seek_fn(p_size,p_stream->m_user_data)) {
    595 		p_stream->m_status |= opj_stream_e_error;
    596 		return OPJ_FALSE;
    597 	}
    598 	else {
    599 		p_stream->m_byte_offset = p_size;
    600 	}
    601 
    602 	return OPJ_TRUE;
    603 }
    604 
    605 OPJ_BOOL opj_stream_seek (opj_stream_private_t * p_stream, OPJ_OFF_T p_size, struct opj_event_mgr * p_event_mgr)
    606 {
    607 	assert(p_size >= 0);
    608 	return p_stream->m_opj_seek(p_stream,p_size,p_event_mgr);
    609 }
    610 
    611 OPJ_BOOL opj_stream_has_seek (const opj_stream_private_t * p_stream)
    612 {
    613 	return p_stream->m_seek_fn != opj_stream_default_seek;
    614 }
    615 
    616 OPJ_SIZE_T opj_stream_default_read (void * p_buffer, OPJ_SIZE_T p_nb_bytes, void * p_user_data)
    617 {
    618 	OPJ_ARG_NOT_USED(p_buffer);
    619 	OPJ_ARG_NOT_USED(p_nb_bytes);
    620 	OPJ_ARG_NOT_USED(p_user_data);
    621 	return (OPJ_SIZE_T) -1;
    622 }
    623 
    624 OPJ_SIZE_T opj_stream_default_write (void * p_buffer, OPJ_SIZE_T p_nb_bytes, void * p_user_data)
    625 {
    626 	OPJ_ARG_NOT_USED(p_buffer);
    627 	OPJ_ARG_NOT_USED(p_nb_bytes);
    628 	OPJ_ARG_NOT_USED(p_user_data);
    629 	return (OPJ_SIZE_T) -1;
    630 }
    631 
    632 OPJ_OFF_T opj_stream_default_skip (OPJ_OFF_T p_nb_bytes, void * p_user_data)
    633 {
    634 	OPJ_ARG_NOT_USED(p_nb_bytes);
    635 	OPJ_ARG_NOT_USED(p_user_data);
    636 	return (OPJ_OFF_T) -1;
    637 }
    638 
    639 OPJ_BOOL opj_stream_default_seek (OPJ_OFF_T p_nb_bytes, void * p_user_data)
    640 {
    641 	OPJ_ARG_NOT_USED(p_nb_bytes);
    642 	OPJ_ARG_NOT_USED(p_user_data);
    643 	return OPJ_FALSE;
    644 }
    645