* Copyright (c) 2003 Fabrice Bellard
* Copyright (c) 2006 Konstantin Shishkov
*
- * This file is part of FFmpeg.
+ * This file is part of Libav.
*
- * FFmpeg is free software; you can redistribute it and/or
+ * Libav is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation; either
* version 2.1 of the License, or (at your option) any later version.
*
- * FFmpeg is distributed in the hope that it will be useful,
+ * Libav is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
- * License along with FFmpeg; if not, write to the Free Software
+ * License along with Libav; if not, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
*/
/**
- * @file lzw.c
+ * @file
* @brief LZW decoding routines
* @author Fabrice Bellard
- * Modified for use in TIFF by Konstantin Shishkov
+ * @author modified for use in TIFF by Konstantin Shishkov
*/
#include "avcodec.h"
+#include "bytestream.h"
#include "lzw.h"
+#include "libavutil/mem.h"
#define LZW_MAXBITS 12
#define LZW_SIZTABLE (1<<LZW_MAXBITS)
};
struct LZWState {
- const uint8_t *pbuf, *ebuf;
+ GetByteContext gb;
int bbits;
unsigned int bbuf;
if(s->mode == FF_LZW_GIF) {
while (s->bbits < s->cursize) {
if (!s->bs) {
- s->bs = *s->pbuf++;
+ s->bs = bytestream2_get_byte(&s->gb);
}
- s->bbuf |= (*s->pbuf++) << s->bbits;
+ s->bbuf |= bytestream2_get_byte(&s->gb) << s->bbits;
s->bbits += 8;
s->bs--;
}
s->bbuf >>= s->cursize;
} else { // TIFF
while (s->bbits < s->cursize) {
- s->bbuf = (s->bbuf << 8) | (*s->pbuf++);
+ s->bbuf = (s->bbuf << 8) | bytestream2_get_byte(&s->gb);
s->bbits += 8;
}
c = s->bbuf >> (s->bbits - s->cursize);
return c & s->curmask;
}
-const uint8_t* ff_lzw_cur_ptr(LZWState *p)
+int ff_lzw_size_read(LZWState *p)
{
- return ((struct LZWState*)p)->pbuf;
+ struct LZWState *s = p;
+ return bytestream2_tell(&s->gb);
}
void ff_lzw_decode_tail(LZWState *p)
struct LZWState *s = (struct LZWState *)p;
if(s->mode == FF_LZW_GIF) {
- while(s->pbuf < s->ebuf && s->bs>0){
- s->pbuf += s->bs;
- s->bs = *s->pbuf++;
+ while (s->bs > 0 && bytestream2_get_bytes_left(&s->gb)) {
+ bytestream2_skip(&s->gb, s->bs);
+ s->bs = bytestream2_get_byte(&s->gb);
}
}else
- s->pbuf= s->ebuf;
+ bytestream2_skip(&s->gb, bytestream2_get_bytes_left(&s->gb));
}
av_cold void ff_lzw_decode_open(LZWState **p)
/**
* Initialize LZW decoder
- * @param s LZW context
+ * @param p LZW context
* @param csize initial code size in bits
* @param buf input data
* @param buf_size input data size
if(csize < 1 || csize >= LZW_MAXBITS)
return -1;
/* read buffer */
- s->pbuf = buf;
- s->ebuf = s->pbuf + buf_size;
+ bytestream2_init(&s->gb, buf, buf_size);
s->bbuf = 0;
s->bbits = 0;
s->bs = 0;
* NOTE: the algorithm here is inspired from the LZW GIF decoder
* written by Steven A. Bennett in 1987.
*
- * @param s LZW context
+ * @param p LZW context
* @param buf output buffer
* @param len number of bytes to decode
* @return number of bytes decoded