avcodec/cfhd, cfhddata: Simplify check for escape

cfhd.c checked for level being equal to a certain codebook-
dependent constant and to run being two. The first check is
actually redundant, as all codebooks contain only one (real)
entry with run == 2 (as is usual with VLCs, this one real entry
has several corresponding entries in the table). But given
that no entry has a run of zero (except incomplete entries
which just signal that one needs to do another round of parsing),
one can actually use that as sentinel. This patch does so.

Reviewed-by: Paul B Mahol <onemda@gmail.com>
Signed-off-by: Andreas Rheinhardt <andreas.rheinhardt@outlook.com>

libavcodec/cfhd.c

@@ -819,7 +819,7 @@ static int cfhd_decode(AVCodecContext *avctx, AVFrame *pic,
                                    VLC_BITS, 3, 1);
 
                         /* escape */
-                        if (level == 64 && run == 2)
+                        if (!run)
                             break;
 
                         count += run;
@@ -850,7 +850,7 @@ static int cfhd_decode(AVCodecContext *avctx, AVFrame *pic,
                                    VLC_BITS, 3, 1);
 
                         /* escape */
-                        if (level == 255 && run == 2)
+                        if (!run)
                             break;
 
                         count += run;

libavcodec/cfhddata.c

@@ -72,7 +72,7 @@ static const uint16_t table_9_vlc_run[NB_VLC_TABLE_9] = {
     1,    1,    1,    1,    1,    1,    1,    1,
     1,    1,    1,    1,    1,    1,    1,    1,
     1,    1,    1,    1,    1,    1,    1,    1,
-    1,    2,
+    1,    0,
 };
 
 static const uint8_t table_9_vlc_level[NB_VLC_TABLE_9] = {
@@ -226,7 +226,7 @@ static const uint16_t table_18_vlc_run[NB_VLC_TABLE_18] = {
      1,    1,    1,    1,    1,    1,    1,    1,
      1,    1,    1,    1,    1,    1,    1,    1,
      1,    1,    1,    1,    1,    1,    1,    1,
-     1,    1,    1,    1,    1,    1,    1,    2,
+     1,    1,    1,    1,    1,    1,    1,    0,
 };
 
 static const uint8_t table_18_vlc_level[NB_VLC_TABLE_18] = {