[FFmpeg-devel] [PATCH 2/5] mlpenc: fix huff offset calculation

Jai Luthra me at jailuthra.in
Tue Jul 9 23:18:58 EEST 2019


huff offset wasn't always within the bounds before, which lead to
corrupt encoding that didn't always trigger lossless check failures

Signed-off-by: Jai Luthra <me at jailuthra.in>
---
 libavcodec/mlpenc.c | 6 +-----
 1 file changed, 1 insertion(+), 5 deletions(-)

diff --git a/libavcodec/mlpenc.c b/libavcodec/mlpenc.c
index f4948451f1..1cee38c82f 100644
--- a/libavcodec/mlpenc.c
+++ b/libavcodec/mlpenc.c
@@ -1699,7 +1699,7 @@ static inline void codebook_bits(MLPEncodeContext *ctx,
     offset_min = FFMAX(min, HUFF_OFFSET_MIN);
     offset_max = FFMIN(max, HUFF_OFFSET_MAX);
 
-    for (;;) {
+    while (offset <= offset_max && offset >= offset_min) {
         BestOffset temp_bo;
 
         codebook_bits_offset(ctx, channel, codebook,
@@ -1718,12 +1718,8 @@ static inline void codebook_bits(MLPEncodeContext *ctx,
 
         if (direction) {
             offset = temp_bo.max + 1;
-            if (offset > offset_max)
-                break;
         } else {
             offset = temp_bo.min - 1;
-            if (offset < offset_min)
-                break;
         }
     }
 }
-- 
2.22.0



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