How can i publish video podcasts

You can submit a video podcast in exactly the same way you submit an audio one: the format must be m4v, .mov or .mp4 (not Windows Media, RealMedia,  Flash or YouTube).

You may find my 'get you started' page on podcasting helpful: http://wilmut.uk/pc

See also https://podcasters.apple.com/support/825-how-to-create-an-episode

Apple Podcasts fully supports Episodes that are Audio, Video and PDF format. BUT - you need to make sure you are using a podcast host that ALSO supports those formats. Most podcasts hosts do NOT support Video - and only Libsyn and maybe one other support PDF content. But short answer is - Apple already supports it - you just need to pick a podcast host that also supports video.