Editing ProRes and XAVC Multicam

[Alpha Video]

I'm considering purchasing a BlackmagicDesign Video Assist recorder, that can record to ProRes. I'm pretty clueless about ProRes but want to know if there are likely to be any issues when doing a multicam shoot and edit using one of my other cameras, that uses the XAVC codec. Sony's spec says it is XAVC HD (1920 x 1080)@59.94p, 50p, 50 Mbps/35 Mbps.

[Ron Evans]

There is no problem. I use a Video Assist in multicam with also XAVC-S files from AX53, AX100 and AX1 all 60P other than the Video Assist which comes from my NX5U so is 60i.

[Alpha Video]

There is no problem. I use a Video Assist in multicam with also XAVC-S files from AX53, AX100 and AX1 all 60P other than the Video Assist which comes from my NX5U so is 60i.

Thanks Ron. Btw, I'm in PAL land, in case this makes a difference. I'm not quite sure what you mean by "all 60P other than the Video Assist which comes from my NX5U so is 60i."

[Ron Evans]

The NX5U only shoots interlace so the SDI output to the Video Assist is also interlace though improved to 4:2:2 from the normal AVCHD internal recording. For you the equivalent would be 50i. All my other cameras are set to record 60P ( 59.94 for purists ) I edit on a 60i timeline as all my outputs go to DVD or Bluray anyway. I like the Video Assist works well. Would be nice if the display had more controls but for my use works great.

[DigitalDave]

I often edit multicam- occasionally up to 16 tracks with ProRes from BM recorders, XAVC-intra 50MB and XAVC-S. Not a problem.

[Alpha Video]

The NX5U only shoots interlace so the SDI output to the Video Assist is also interlace though improved to 4:2:2 from the normal AVCHD internal recording. For you the equivalent would be 50i. All my other cameras are set to record 60P ( 59.94 for purists ) I edit on a 60i timeline as all my outputs go to DVD or Bluray anyway. I like the Video Assist works well. Would be nice if the display had more controls but for my use works great.

Ok, I see what you mean. I would be using the VA to output from a Nikon D5300 to record ProRes onto SD card via HDMI so that I can bypass the Nikon's current max of 10 minutes at highest quality of 1920x1080p 50fps, so could keep the project settings in Edius as 1080 50p

[Ron Evans]

Yes you could edit in a 50P project though bear in mind if you want to output to a Bluray your choices are interlace for 1920x1080 or 1280x720 for 50P.

[Alpha Video]

Yes you could edit in a 50P project though bear in mind if you want to output to a Bluray your choices are interlace for 1920x1080 or 1280x720 for 50P.

I'm not quite sure I get this. Why is the output still interlaced? What then is the point of progressive? Keep in mind that I'm not too technical.

Most of what I do at the moment is 1080 HD downconverted to SD for DVD authoring using cameras shooting interlaced, so haven't really used Progressive before. It's just that, in the future, I will be shooting progressive as I am changing cameras.

My plan is to move to USB pen drive as primary output, but still offering Bluray and DVD as options. When using my interlaced footage in a 1080i Edius project, and exporting an H264 MP4 file, the file when played back on a computer looks ok, but needs to be deinterlaced to get rid of the horizontal lines. Playback on a TV through the USB port looks horrendous as it's all jerky. By contrast, I have found that even 1080i interlaced footage in a 1080p Edius project exported to MP4 gives me smooth playback on TV and on a USB drive without having to deinterlace.

So I don't really understand the technicalities of why a 50p project would only allow interlaced for Bluray.

[Ron Evans]

This is a disc spec issue. https://en.wikipedia.org/wiki/Blu-ray

Bluray spec is only interlaced for 1920x1080 50i or progressive 24P also 1280x720P50. If you are going to just prepare a file for PC or directly to a TV then progressive is the way to go. If you want to make a Bluray you will need to make either an interlaced version or scale to 1280x720 at 50P in your case.

[Alpha Video]

This is a disc spec issue. https://en.wikipedia.org/wiki/Blu-ray

Bluray spec is only interlaced for 1920x1080 50i or progressive 24P also 1280x720P50. If you are going to just prepare a file for PC or directly to a TV then progressive is the way to go. If you want to make a Bluray you will need to make either an interlaced version or scale to 1280x720 at 50P in your case.

Well, I've learnt something today. So is it possible to create an interlaced version from a 50p Edius project?

[Ron Evans]

Not straight forward. You need to export a HQX file of the project then start a new project with interlace settings and place your HQX file in it for export using QS etc or use the file in another software program to encode for Bluray.

For 1280x720P you will just need to change the project settings before going to export Bluray preset.