avcodec/rl: Don't pretend ff_rl_init() initializes a RLTable twice

It can't any longer, because all users of ff_rl_init() are now
behind ff_thread_once() or the global codec lock. Therefore
the check for whether the RLTable is already initialized can be removed;
as can the stack buffers that existed to make sure that nothing is ever
set to a value different from its final value.
Similarly, it is not necessary to check whether the VLCs associated
with the RLTable are already initialized (they aren't).

Signed-off-by: Andreas Rheinhardt <andreas.rheinhardt@outlook.com>

libavcodec/rl.c

@@ -27,16 +27,13 @@
 av_cold void ff_rl_init(RLTable *rl,
                         uint8_t static_store[2][2 * MAX_RUN + MAX_LEVEL + 3])
 {
-    int8_t  max_level[MAX_RUN + 1], max_run[MAX_LEVEL + 1];
-    uint8_t index_run[MAX_RUN + 1];
     int last, run, level, start, end, i;
 
-    /* If rl->max_level[0] is set, this RLTable has already been initialized */
-    if (rl->max_level[0])
-        return;
-
     /* compute max_level[], max_run[] and index_run[] */
     for (last = 0; last < 2; last++) {
+        int8_t *max_level  = static_store[last];
+        int8_t *max_run    = static_store[last] + MAX_RUN + 1;
+        uint8_t *index_run = static_store[last] + MAX_RUN + 1 + MAX_LEVEL + 1;
         if (last == 0) {
             start = 0;
             end = rl->last;
@@ -45,8 +42,6 @@ av_cold void ff_rl_init(RLTable *rl,
             end = rl->n;
         }
 
-        memset(max_level, 0, MAX_RUN + 1);
-        memset(max_run, 0, MAX_LEVEL + 1);
         memset(index_run, rl->n, MAX_RUN + 1);
         for (i = start; i < end; i++) {
             run   = rl->table_run[i];
@@ -58,12 +53,9 @@ av_cold void ff_rl_init(RLTable *rl,
             if (run > max_run[level])
                 max_run[level] = run;
         }
-        rl->max_level[last] = static_store[last];
-        memcpy(rl->max_level[last], max_level, MAX_RUN + 1);
-        rl->max_run[last]   = static_store[last] + MAX_RUN + 1;
-        memcpy(rl->max_run[last], max_run, MAX_LEVEL + 1);
-        rl->index_run[last] = static_store[last] + MAX_RUN + MAX_LEVEL + 2;
-        memcpy(rl->index_run[last], index_run, MAX_RUN + 1);
+        rl->max_level[last] = max_level;
+        rl->max_run[last]   = max_run;
+        rl->index_run[last] = index_run;
     }
 }
 

libavcodec/rl.h

@@ -72,15 +72,12 @@ void ff_rl_init_vlc(RLTable *rl, unsigned static_size);
 
 #define INIT_VLC_RL(rl, static_size)\
 {\
-    int q;\
     static RL_VLC_ELEM rl_vlc_table[32][static_size];\
 \
-    if(!rl.rl_vlc[0]){\
-        for(q=0; q<32; q++)\
-            rl.rl_vlc[q]= rl_vlc_table[q];\
+    for (int q = 0; q < 32; q++) \
+        rl.rl_vlc[q] = rl_vlc_table[q]; \
 \
-        ff_rl_init_vlc(&rl, static_size);\
-    }\
+    ff_rl_init_vlc(&rl, static_size); \
 }
 
 #define INIT_FIRST_VLC_RL(rl, static_size)              \