MultiCamera-Edit (two angles) with help of Size and position filter?

Hello folks.

I am trying to make a multi camera edit with two angles.
I’ve found multiple suggestions for such approach (as here: Multi camera editing).

I like the suggestions, but my issue is, that I would like to have a preview of all (in my case two) angles in the preview window to make better/faster decisions as where to switch between angles/cameras.

Any suggestions?

I did try to approach this by applying a “size and position” filter to Video track 1+2 (not the clips itself), so that I can easily remove the filter after I’m done with my multi camera edit. It seems to use very much CPU if I play both clips with the filter applied in the previe window. I get maybe 2-4 fps and very lagging audio, to a point, where I do not really have any usability to make the cuts.

Here is an example picture of my setup, which I thought would be a great idea:

I think it’s a good idea as well, but your computer maybe the culprit.
What are the specs?

You have other alternatives:

  1. Use your idea but first export the “multi-view” clip as a single video, then bring it back and add it as another video track whilst the other two are beneath it.
    Since it’s no longer trying to scale two videos at the same time, your CPU useage may come down to a point where it’s OK to edit.
    This approach may or may not work depending on how long your videos are and if you have the time to export and HDD space to store the extra clip.

  2. Don’t use the “multi-view” approach but rather switch the top video track on or off using the eye symbol.
    This will reveal the track under it.
    Not as elegant but may just do the trick.

  3. Export lower res (and bit rate) versions of your cameras then bring them in and try your idea again.
    Make sure that in all cases the frame rates are the same as your originals or your timings will be off.
    Make the cuts as required then save your project and close SC.
    Now replace the lower version clips with the full version ones and open your project again.
    Export.
    Search around on this forum for workarounds that others have tried for Proxy use.

The idea being that the lower res proxies don’t bring your computer to it’s knees.

Sorry - I forgot to add the necessary information/specs in this post, because I did address a related issue/question here.

The current setup is:
Win 8.1 64bit, 8GB Ram, I7-4500U CPU, Shotcut-Version 19.06.15.
Current try is with H.264-Files (I am considering re-encoding to other formats as mentiones in the other post) prior editing.

Now I’ll read trough the rest of your post.

I do like your idea #1. Will give it a try. Alternatively I will work/explore idea #3.

Any thought on what file format (and maybe resolution) for idea #1 with a minimum CPU requirement during editing? Is it ProRES or something else?

Any thoughts on the capability of my hardware?

Make sure that only one audio track at a time makes it onto your final cut (assuming the same audio is present on more than one track). If you try to combine the audio from both of your cameras I don’t think you’ll be happy.

Nothing wrong with those specs.

As to codec, all “I” frame (no B or P) is always best but it’s a trade off between size and bit rate.
All “I” frame codecs lighten the CPU load but the price you pay is huge file sizes.
It also does not help if the bit rate is near 100Mb/s, or higher, as that could cause bottle necks else where, although your hardware looks pretty decent.

You will have to experiment.
Prores is certainly a candidate, look at the different Prores settings like plain 422, LT, proxy and so on.
I think DNxHD is also all “I” frame, have a look at DNxHD36.
AVCintra is also a good candidate but it’s 100Mb/s and don’t know if SC supports it.

You can also try H.264 Baseline Profile @ 1280X720 and reduce the GOP size to something like 12 or 15.
I think it defaults to 125 which means loads of “B” and “P” frames before the next “I” arrives 125 frames later.

The I-Frame ist certainly a thought. I did re-encode with handbrake and there I could not find I-Frame-settings. I found B-Frame however and did set them to “2”. Thought, that’s plenty low, performance wise. Reading your post, I assume, that “0” B-Frames would result in I-frames only.

Any suggestions on a ProRes encoder for Windows? I could not find anything (open-source) and thought I might re-encode with Shotcut. Shotcut however does not seem to have the ProRes candidates, as mentioned in Your post.

Not quite that simple, it could still have P frames.
B frames are bi-directional P frames, best is to try it out and see.

Prores is rather mac-centric and hence not very Windows friendly.
You could try ffmpeg to generate the Prores clips, or try DNxHD which is more supported under Windows.

You can use SC to create different Prores standards.
Select Prores and make sure in the “Codec” tab it shows prores_ks.
Then in the “Other” tab, you will see a line with something like vprofile=2
Change the 2 to what you need from the list below:

35%20PM

The corresponding bit-rates as follows:

2 Likes

Thank You!

Great information.

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