avformat: add vc2 as an allowed rawenc Dirac extension

Signed-off-by: Rostislav Pehlivanov <atomnuker@gmail.com>

libavformat/rawenc.c

@@ -115,7 +115,7 @@ AVOutputFormat ff_data_muxer = {
 AVOutputFormat ff_dirac_muxer = {
     .name              = "dirac",
     .long_name         = NULL_IF_CONFIG_SMALL("raw Dirac"),
-    .extensions        = "drc",
+    .extensions        = "drc,vc2",
     .audio_codec       = AV_CODEC_ID_NONE,
     .video_codec       = AV_CODEC_ID_DIRAC,
     .write_header      = force_one_stream,