@@ -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;