File MPlayer-fix-dvd-crash.patch of Package MPlayer

--- a/libmpcodecs/vd_ffmpeg.c
+++ b/libmpcodecs/vd_ffmpeg.c
@@ -176,7 +176,10 @@ static enum AVDiscard str2AVDiscard(char
 // to set/get/query special features/parameters
 static int control(sh_video_t *sh, int cmd, void *arg, ...){
     vd_ffmpeg_ctx *ctx = sh->context;
-    AVCodecContext *avctx = ctx->avctx;
+    AVCodecContext *avctx;
+    
+    if (!ctx) return CONTROL_UNKNOWN;
+    avctx = ctx->avctx;
     switch(cmd){
     case VDCTRL_QUERY_FORMAT:
     {