avcodec/golomb: get_ur_golomb_jpegls: Fix reading huge k values

Signed-off-by: Michael Niedermayer <michaelni@gmx.at>
10 years ago · c720b9ce98
parent 4f2fcac290
commit c720b9ce98
1 changed files with 10 additions and 2 deletions
--- a/libavcodec/golomb.h
+++ b/libavcodec/golomb.h
@ -334,8 +334,16 @@ static inline int get_ur_golomb_jpegls(GetBitContext *gb, int k, int limit,

        if (i < limit - 1) {
            if (k) {
-                buf = SHOW_UBITS(re, gb, k);
-                LAST_SKIP_BITS(re, gb, k);
+                if (k > MIN_CACHE_BITS - 1) {
+                    buf = SHOW_UBITS(re, gb, 16) << (k-16);
+                    LAST_SKIP_BITS(re, gb, 16);
+                    UPDATE_CACHE(re, gb);
+                    buf |= SHOW_UBITS(re, gb, k-16);
+                    LAST_SKIP_BITS(re, gb, k-16);
+                } else {
+                    buf = SHOW_UBITS(re, gb, k);
+                    LAST_SKIP_BITS(re, gb, k);
+                }
            } else {
                buf = 0;
            }