avcodec/h263, mpeg(picture|video): Only allocate mbskip_table for MPEG-4

It is the only user of said table and doing so is especially
important given that this buffer is zeroed every time.

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

libavcodec/h263.c

@@ -56,7 +56,8 @@ void ff_h263_update_motion_val(MpegEncContext * s){
     const int wrap = s->b8_stride;
     const int xy = s->block_index[0];
 
-    s->current_picture.mbskip_table[mb_xy] = s->mb_skipped;
+    if (s->current_picture.mbskip_table)
+        s->current_picture.mbskip_table[mb_xy] = s->mb_skipped;
 
     if(s->mv_type != MV_TYPE_8X8){
         int motion_x, motion_y;

libavcodec/mpegpicture.c

@@ -138,10 +138,11 @@ static int alloc_picture_tables(BufferPoolContext *pools, Picture *pic,
     if (!pic->name ## buf_suffix idx_suffix) \
         return AVERROR(ENOMEM); \
 } while (0)
-    GET_BUFFER(mbskip_table,,);
     GET_BUFFER(qscale_table, _base,);
     GET_BUFFER(mb_type, _base,);
     if (pools->motion_val_pool) {
+        if (pools->mbskip_table_pool)
+            GET_BUFFER(mbskip_table,,);
         for (int i = 0; i < 2; i++) {
             GET_BUFFER(ref_index,, [i]);
             GET_BUFFER(motion_val, _base, [i]);

libavcodec/mpegvideo.c

@@ -594,6 +594,12 @@ int ff_mpv_init_context_frame(MpegEncContext *s)
 
     s->mb_index2xy[s->mb_height * s->mb_width] = (s->mb_height - 1) * s->mb_stride + s->mb_width; // FIXME really needed?
 
+#define ALLOC_POOL(name, size, flags) do { \
+    pools->name ##_pool = ff_refstruct_pool_alloc((size), (flags)); \
+    if (!pools->name ##_pool) \
+        return AVERROR(ENOMEM); \
+} while (0)
+
     if (s->codec_id == AV_CODEC_ID_MPEG4 ||
         (s->avctx->flags & AV_CODEC_FLAG_INTERLACED_ME)) {
         /* interlaced direct mode decoding tables */
@@ -608,12 +614,16 @@ int ff_mpv_init_context_frame(MpegEncContext *s)
                 tmp += mv_table_size;
             }
         }
-        if (s->codec_id == AV_CODEC_ID_MPEG4 && !s->encoding) {
+        if (s->codec_id == AV_CODEC_ID_MPEG4) {
+            ALLOC_POOL(mbskip_table, mb_array_size + 2,
+                       FF_REFSTRUCT_POOL_FLAG_ZERO_EVERY_TIME);
+        if (!s->encoding) {
             /* cbp, pred_dir */
             if (!(s->cbp_table      = av_mallocz(mb_array_size)) ||
                 !(s->pred_dir_table = av_mallocz(mb_array_size)))
                 return AVERROR(ENOMEM);
         }
+        }
     }
 
     if (s->msmpeg4_version >= 3) {
@@ -642,13 +652,6 @@ int ff_mpv_init_context_frame(MpegEncContext *s)
         return AVERROR(ENOMEM);
     memset(s->mbintra_table, 1, mb_array_size);
 
-#define ALLOC_POOL(name, size, flags) do { \
-    pools->name ##_pool = ff_refstruct_pool_alloc((size), (flags)); \
-    if (!pools->name ##_pool) \
-        return AVERROR(ENOMEM); \
-} while (0)
-
-    ALLOC_POOL(mbskip_table, mb_array_size + 2, FF_REFSTRUCT_POOL_FLAG_ZERO_EVERY_TIME);
     ALLOC_POOL(qscale_table, mv_table_size, 0);
     ALLOC_POOL(mb_type, mv_table_size * sizeof(uint32_t), 0);