mpeg12enc: check dimension validity

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

libavcodec/mpeg12enc.c

@@ -180,6 +180,19 @@ static av_cold int encode_init(AVCodecContext *avctx)
         }
     }
 
+    if ((avctx->width & 0xFFF) == 0 && (avctx->height & 0xFFF) == 1) {
+        av_log(avctx, AV_LOG_ERROR, "Width / Height is invalid for MPEG2\n");
+        return AVERROR(EINVAL);
+    }
+
+    if (s->strict_std_compliance > FF_COMPLIANCE_UNOFFICIAL) {
+        if ((avctx->width & 0xFFF) == 0 || (avctx->height & 0xFFF) == 0) {
+            av_log(avctx, AV_LOG_ERROR, "Width or Height are not allowed to be multiplies of 4096\n"
+                                        "add '-strict %d' if you want to use them anyway.\n", FF_COMPLIANCE_UNOFFICIAL);
+            return AVERROR(EINVAL);
+        }
+    }
+
     s->drop_frame_timecode = s->drop_frame_timecode || !!(avctx->flags2 & CODEC_FLAG2_DROP_FRAME_TIMECODE);
     if (s->drop_frame_timecode)
         s->tc.flags |= AV_TIMECODE_FLAG_DROPFRAME;