[FFmpeg-cvslog] avcodec/golomb: get_ur_golomb_jpegls: Fix reading huge k values

Michael Niedermayer git at videolan.org
Thu May 21 21:26:12 CEST 2015


ffmpeg | branch: release/2.5 | Michael Niedermayer <michaelni at gmx.at> | Sun May 17 19:07:17 2015 +0200| [8b95fc6d8dcc6509bd2b3067508c034b0b6effbd] | committer: Michael Niedermayer

avcodec/golomb: get_ur_golomb_jpegls: Fix reading huge k values

Signed-off-by: Michael Niedermayer <michaelni at gmx.at>
(cherry picked from commit c720b9ce9850710e74a103d9626869e397a89faa)

Signed-off-by: Michael Niedermayer <michaelni at gmx.at>

> http://git.videolan.org/gitweb.cgi/ffmpeg.git/?a=commit;h=8b95fc6d8dcc6509bd2b3067508c034b0b6effbd
---

 libavcodec/golomb.h |   12 ++++++++++--
 1 file changed, 10 insertions(+), 2 deletions(-)

diff --git a/libavcodec/golomb.h b/libavcodec/golomb.h
index 81d8aee..a65c17e 100644
--- a/libavcodec/golomb.h
+++ b/libavcodec/golomb.h
@@ -346,8 +346,16 @@ 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;
             }



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