Value 4 (Unknown) is for the time being part of the Matroska spec but not
supported by WebM
Addresses ticket #6176
} else if (display_width_div != 1 || display_height_div != 1) {
put_ebml_uint(pb, MATROSKA_ID_VIDEODISPLAYWIDTH , par->width / display_width_div);
put_ebml_uint(pb, MATROSKA_ID_VIDEODISPLAYHEIGHT, par->height / display_height_div);
- } else
+ } else if (mkv->mode != MODE_WEBM)
put_ebml_uint(pb, MATROSKA_ID_VIDEODISPLAYUNIT, MATROSKA_VIDEO_DISPLAYUNIT_UNKNOWN);
if (par->codec_id == AV_CODEC_ID_RAWVIDEO) {