Merge commit 'a72d93daa09ffbad2771f1450820941055eaf210'

* commit 'a72d93daa09ffbad2771f1450820941055eaf210':
  mpegvideo_enc: Check AVCodecContext allocation

Conflicts:
	libavcodec/mpegvideo_enc.c

Merged-by: Michael Niedermayer <michaelni@gmx.at>

libavcodec/mpegvideo_enc.c

@@ -1283,6 +1283,8 @@ static int estimate_best_b_count(MpegEncContext *s)
     int64_t best_rd  = INT64_MAX;
     int best_b_count = -1;
 
+    if (!c)
+        return AVERROR(ENOMEM);
     av_assert0(scale >= 0 && scale <= 3);
 
     //emms_c();