[FFmpeg-cvslog] lzw: switch to bytestream2
Anton Khirnov
git at videolan.org
Sun Jan 12 16:13:01 CET 2014
ffmpeg | branch: release/1.1 | Anton Khirnov <anton at khirnov.net> | Thu Nov 28 10:54:35 2013 +0100| [ffa83bcc49375a7760ff9cbc889ce7171e8afe4a] | committer: Reinhard Tartler
lzw: switch to bytestream2
Found-by: Mateusz "j00ru" Jurczyk and Gynvael Coldwind
CC:libav-stable at libav.org
(cherry picked from commit e89aa4bf56e5b5c45f569eb12733519789e057da)
Signed-off-by: Reinhard Tartler <siretart at tauware.de>
> http://git.videolan.org/gitweb.cgi/ffmpeg.git/?a=commit;h=ffa83bcc49375a7760ff9cbc889ce7171e8afe4a
---
libavcodec/lzw.c | 27 +++++++++++----------------
1 file changed, 11 insertions(+), 16 deletions(-)
diff --git a/libavcodec/lzw.c b/libavcodec/lzw.c
index 0167140..fae5687 100644
--- a/libavcodec/lzw.c
+++ b/libavcodec/lzw.c
@@ -28,6 +28,7 @@
*/
#include "avcodec.h"
+#include "bytestream.h"
#include "lzw.h"
#include "libavutil/mem.h"
@@ -43,7 +44,7 @@ static const uint16_t mask[17] =
};
struct LZWState {
- const uint8_t *buf_start, *pbuf, *ebuf;
+ GetByteContext gb;
int bbits;
unsigned int bbuf;
@@ -73,9 +74,9 @@ static int lzw_get_code(struct LZWState * s)
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--;
}
@@ -83,7 +84,7 @@ static int lzw_get_code(struct LZWState * s)
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);
@@ -95,7 +96,7 @@ static int lzw_get_code(struct LZWState * s)
int ff_lzw_size_read(LZWState *p)
{
struct LZWState *s = p;
- return s->pbuf - s->buf_start;
+ return bytestream2_tell(&s->gb);
}
void ff_lzw_decode_tail(LZWState *p)
@@ -103,17 +104,12 @@ void ff_lzw_decode_tail(LZWState *p)
struct LZWState *s = (struct LZWState *)p;
if(s->mode == FF_LZW_GIF) {
- while (s->bs > 0) {
- if (s->bs >= s->ebuf - s->pbuf) {
- s->pbuf = s->ebuf;
- break;
- } else {
- 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)
@@ -141,8 +137,7 @@ int ff_lzw_decode_init(LZWState *p, int csize, const uint8_t *buf, int buf_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;
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