avcodec/mpegvideo_enc, vc1dec: Remove always-false check

Mpeg1EncContext.droppable is only nonzero for the FLV decoder.

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

libavcodec/mpegvideo_enc.c

@@ -1658,8 +1658,7 @@ static int frame_start(MpegEncContext *s)
 
     if (s->pict_type != AV_PICTURE_TYPE_B) {
         s->last_picture_ptr = s->next_picture_ptr;
-        if (!s->droppable)
-            s->next_picture_ptr = s->current_picture_ptr;
+        s->next_picture_ptr = s->current_picture_ptr;
     }
 
     if (s->last_picture_ptr) {

libavcodec/vc1dec.c

@@ -862,7 +862,7 @@ static int vc1_decode_frame(AVCodecContext *avctx, void *data,
     s->current_picture.f->key_frame = s->pict_type == AV_PICTURE_TYPE_I;
 
     /* skip B-frames if we don't have reference frames */
-    if (!s->last_picture_ptr && (s->pict_type == AV_PICTURE_TYPE_B || s->droppable)) {
+    if (!s->last_picture_ptr && s->pict_type == AV_PICTURE_TYPE_B) {
         av_log(v->s.avctx, AV_LOG_DEBUG, "Skipping B frame without reference frames\n");
         goto end;
     }