avcodec/mjpegdec: improve decoding of DNG files

That have unused symbols coded in DHT.

1 files changed, 2 insertions, 13 deletions

diff --git a/libavcodec/jpegtables.c b/libavcodec/jpegtables.c
index fa5c6f9fc5..e44bc7a22a 100644
--- a/libavcodec/jpegtables.c
+++ b/libavcodec/jpegtables.c
@@ -130,25 +130,14 @@ void ff_mjpeg_build_huffman_codes(uint8_t *huff_size, uint16_t *huff_code,
 {
     int i, j, k,nb, code, sym;
 
-    /* Some badly encoded files [1] map 2 different codes to symbol 0.
-       Only the first one is valid, so we zero-initialize this here and
-       make sure we only set it once (the first time) in the loop below.
-
-       [1]: Embedded JPEGs in "X7 RAW" and "X7 CinemaDNG" samples here:
-            https://www.dji.com/gr/zenmuse-x7/info#downloads
-     */
-    huff_size[0] = 0;
-
     k = 0;
     code = 0;
     for(i=1;i<=16;i++) {
         nb = bits_table[i];
         for(j=0;j<nb;j++) {
             sym = val_table[k++];
-            if (sym != 0 || huff_size[sym] == 0) { /* see comment above */
-                huff_size[sym] = i;
-                huff_code[sym] = code;
-            }
+            huff_size[sym] = i;
+            huff_code[sym] = code;
             code++;
         }
         code <<= 1;