avcodec/motionpixels: Use symbols table

If allows us to directly store the deltas in the VLC table and therefore
avoids a level of indirection.

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

libavcodec/motionpixels.c

@@ -192,10 +192,8 @@ static void mp_set_rgb_from_yuv(MotionPixelsContext *mp, int x, int y, const Yuv
 
 static av_always_inline int mp_get_vlc(MotionPixelsContext *mp, GetBitContext *gb)
 {
-    int i;
-
-    i = (mp->codes_count == 1) ? 0 : get_vlc2(gb, mp->vlc.table, mp->max_codes_bits, 1);
-    return mp->codes[i].delta;
+    return mp->vlc.table ? get_vlc2(gb, mp->vlc.table, mp->max_codes_bits, 1)
+                         : mp->codes[0].delta;
 }
 
 static void mp_decode_line(MotionPixelsContext *mp, GetBitContext *gb, int y)
@@ -322,9 +320,14 @@ static int mp_decode_frame(AVCodecContext *avctx,
     if (sz == 0)
         goto end;
 
-    if (mp->codes_count > 1)
-    if (init_vlc(&mp->vlc, mp->max_codes_bits, mp->codes_count, &mp->codes[0].size, sizeof(HuffCode), 1, &mp->codes[0].code, sizeof(HuffCode), 4, 0))
-        goto end;
+    if (mp->codes_count > 1) {
+        ret = ff_init_vlc_sparse(&mp->vlc, mp->max_codes_bits, mp->codes_count,
+                                 &mp->codes[0].size,  sizeof(HuffCode), 1,
+                                 &mp->codes[0].code,  sizeof(HuffCode), 4,
+                                 &mp->codes[0].delta, sizeof(HuffCode), 1, 0);
+        if (ret < 0)
+            goto end;
+    }
     mp_decode_frame_helper(mp, &gb);
     ff_free_vlc(&mp->vlc);