Multi-Camera editing technique

[Davidk]

My video class is about to do a project in multi-camera editing and like most tutors I'm trying to stay ahead of the students, just a little bit. This query is about technique using the MCE functions of Vs 2018 and 2019 (class uses these about 50% for each version).
1. The recording has been done: a subject with several concurrent cameras recording wide-angle face on, side on and close up shots including sound in-camera, and a separate (single) external audio recording of the whole proceeding, including clapper board for any repeats. The recording duration is about 20 minutes.
2. The students will have copies of all the camera and audio files, and be required to edit the files from the cameras and audio recorder to produce a reasonable video clip of the event that's about 5-8 minutes long demonstrating a grasp of using MCE within VideoStudio.

So, the question about technique is about editing any of the video files and the related audio recording, specifically about maintaining sync when doing that, noting that that MCE has provisions for cameras and audio files in the MCE panel
- synching the video and sound at the start of each clip is easy enough - the clapper board is there for that
- maintaining video and external sound synch when editing the video clips - generally to reduce the time/length of clip - is a possible problem. Editing the video clips in MCE is highly likely (?) to get out of sych with the external audio: cut n trim of a video clip is usually effected independently of other tracks inc audio. Would it be better to:
a. edit in MCE, and if so how to maintain sync with external audio files when trimming discrete clips; or
b. edit each clip separately and maintain audio sync manually;, render and then insert the result into MCE
c. ignore the external audio and rely on the integral audio in each video clip, which would result in editing audio at the same times/places as any edits made to the video

[lata]

Hi David
This is my approach
1 / Add all clips to the library, create a new library folder for the clips
1a /if you believe Smart Proxy files will be required to improve normal editing then do that now.
2 / add one of the clips to the timeline choosing the main camera, this will activate the show messages to set the project properties.
I find this best to do now, delete the clip from the timelines as it is not required.
3 / select the clips within the library, including the audio clip, the video clips will be used by MCE in order, so the first video clip will be camera 1
4 / right click the selection for MCE to open the Source Manager, here you can select / rearrange your clips, but if you managed the library then the clips will be in order
But check them - then OK to open the MCE
5 / your clips will occupy the camera angles + audio
6 / Top Left for Cogwheel will allow you to Save As, this will allow you to choose a suitable name, otherwise VS will use its default name MultiCam01.vsp etc
7 / Immediately above the timelines to the left are the audio settings, change Camera 1 to audio 1, that is the audio stream that will be used for the project.
8 / To the left is the sync option, default to Audio, this is what you need, when pressing the Sync icon ( the circular arrow disc) will scan all clips to sync all audio streams.
You can of course use other methods to sync, Markers etc, but if your audio recordings are good enough, sync will be successful.
9/ Below the Audio option is the wave form icon setting the timeline to view the wave form, useful.
10 / Providing all are in sync you simply choose which camera / clip you wish to use, click one of the two / four/six panels to select
If you wish to remove all video hit the black or transparent panel, shows to the right on my 4 camera view.
The black will add a black clip, the other will delete the selection.
11 / I do find it a little tricky if I select the wrong points, but we can adjust by dragging the appropriate yellow trim handles, top timeline select a clip.
12 / If things are a little slow we can use Smart proxy, top left Cogwheel settings, although I prefer to do that before going to the MCE.
13 / When complete Ok will close the MCE and return to VS timelines, the project file being placed in the library
14 / Drag this to the top timelines to continue editing. Notice all Video clips are muted with the audio file being used, all should be in sync.
Project Properties are set correctly as #2
15 / the MCE VSP is a little different to normal VSP’s , if you try to change the cut / trim points the adjacent clip will fill the space with additional frames, the project duration remaining the same.

[Davidk]

Thanks Trevor.
All useful stuff, several points I had not thought of, and I read it several times carefully. But maybe you missed the point about trimming the video to suit the desired time result, and the effect that has on synched audio.

1. Being a bit more explicit:
- the overall recording time is (say) 20 minutes, with 3 cameras covering that time, each having saved 20 minutes of video imagery, and the recorded audio is also 20 minutes.
- but the desired clip time result is 5-8 minutes (flexible enough so a desirable sequence can be allowed to finish, rather than just cut it off), covering everything with switches between wide face on (camera 1), side-on (camera 2) and close -up (camera 3) shots, and running audio which means that the video clips will have to be trimmed (in total) by about 2/3rds or more: some clips inevitably more than others to get that result.
- so if camera 1 is trimmed to 4 minutes in several slices, with parts removed, how does the separate audio maintain sync with the video during editing in MCE? and so on for the other cameras.

2. Or doesn't it? Reading your description, it seems that the approach needed may well be to use MCE to edit the camera video and external audio to get the camera sequencing desired, to match with only 20 minutes of audio.
- Using MCE to choose the desired camera shots for the duration of the recorded audio should be achievable and this ensures that the audio is correctly synched to match the visuals (correct if I am wrong).
- then transfer the 20 minutes of video and synched audio MCE result to the main VS timeline.
- And here use the edit features of VS to cut n trim the sequenced result from MCE down to the overall time of 5-8 minutes, the desired result.
- because when in the VS main timeline the audio is integrally synched with the timeline result so removing any video visuals should also remove any related audio as well.

[lata]

Hi David
No I did not miss that reference to trimming the video, although I did not understand why you would want to do that as MCE can select any frames to use in the final output, and that includes removing frames, effectively trimming the video. Maybe I should expand on 10 regarding the transparent panel.

MCE can trim your recordings from 20 minutes down to 8 minutes and select which camera to use with the audio in sync from the audio file.

Basically MCE is a Multi Trim tool that works over several clips, whereas Multi Trim Video only trims one clip at a time.
In addition MCE syncs the audio streams before we choose the camera angles

[Davidk]

Hi Trevor,
I had not realised that MCE was also a multi-trim tool as well: all the tutorials focus on choosing the video sequence required, not a word (in any tut I saw) about trimming video and audio together, as well as choosing the video sequence.

That certainly calms m concerns at the moment. I'm sure that when the students get into it in a few weeks (term starts next wednesday, 1st day will be copying all the video/audio clips to everyone and reviewing the tutorials), and I'm sure I'll have more when the questions start coming in.

Thanks,
David

[lata]

The image I showed has sections cut out
When we return to the main timelines those gaps will be closed, all video clips will be next to each other
The audio clip will be cut removing the same unwanted frames, then shuffled together to sync with the top track
The Multi trim video tool cuts a single clip into pieces, saving the good bits
MCE does much the same but on several video clips, effectively it’s a trimming tool

[Davidk]

So, I experimented a bit using gallery clips: 2 video, 1 audio in the 2019 (-433version) MCE panel.
My assumption was that to cut out a section of a clip, and it's related audio file, one would move the time marker to the sections of the video clip and cut it - thus marking the start and end of the part to be removed. BUT no way could I get the scissors to be usable with the time market moved any position on a clip any camera. They are there - just greyed out. The technique may be right but I haven't got to 1st base with the scissors. So, what am I missing or not doing?

[lata]

Hi David
After syncing the video clips
Move the cursor along the timeline to the desired start point, you can do by playing or clicking the timeline rule.
Choosing camera1 will add that to the top timeline (Multi Camera)
Reposition the cursor a little to the right, the cursor being at the begging of your next selection
Choose another Camera, If you do not need these frames choose the “O” panel (transparent)
If you need to retain the gap choose the “B” (Black Clip)
Otherwise continue down the timeline choosing your camera angles

Your top timeline now shows various clips
If you wish to split a selection, click a clip, then position the cursor from the top timeline rule to activate the scissors
It appears you have to select the clip and the top timeline rule in any order will activate the Scissors.
This will cut the clip retaining the same camera, select any and choose another camera,
To delete remove frames, select a clip and hit delete, or select the “O” (transparent Panel)
To add frames, drag the ends of any clip, will adjust the cut point.

David do you have your camera recordings available and can you upload them so I can try?
Nick did provide us with some camera test files, I think with Beta X8 when MCE was first introduced, called Jazz, do you have those

[Davidk]

Hi Trevor,
No, no special clips; I was just using gallery clips to make sure I was doing it right before the actual recordings become available in a few days time. What I did not do was sync the clips; they looked sync'd on time so did not bother, but it looks like there's a brake in the software to ensure this is done.

About the time of X8 and the 1st release of MCE, I stayed with doing it manually for 3 cameras. The audio used then was the sound the cameras recorded, so editing the camera video automatically edited the related audio as well. And it was doable but fiddly fiddly. And the lesson then was that I would not want to do it for any higher number of cameras. Fast forward several years to now, the bugs should be out of MCE, and the students are advanced enough to try this on and one of them is more of a movie/sound buff than normal, so now we have 3 cameras and a separate sound track: time to dip toes in MCE water.

I'll repeat my experiment and sync them up and see what happens.

Update
Attached is a screenshot of the experiment, and I'll explain what I was trying to do. Also, learned a bit in the process, and solved one isuue and raised several others.

The clips are randomly selected, inserted and sync'd to the marker when it was at time zero.
In the camera panel, selecting camera 1 first, play/insert for a period, then switch to camera 2: selections shows in the time line.
Now, whilst camera 2 is selected to play, what I was trying to do was edit the clip from camera 1. No matter what I did, the scissors did not activate, but I kept getting orange marker triangles in a camera clip display. At first, I thought that setting markers would enable the scissors, but no, that did not happen and what the markers are for in this context, I have no idea.

Eventually I deduced that editing the camera clips was not required, simply switching from one to another camera in play selection effectively does that. Also learned the normal end-trimming functions (select, click-n-drag) are available to shorten clips. In this case to match the clips to the duration of the external sound track, being careful not to remove the audio sync items.

So, the 1st query as a result of this is what are the markers for, and how do you use them?
Second, with an external sound track available, how do you mute the sound-in-clip in the MCE panel to avoid clashing with the external sound track? Leaving that to the main VS timeline after MCE OK (because now it's all one track selection) would mute everything.

[lata]

David
There is information on MCE in the help guides, press F1, good section on MCE
OK
Showing on your image the sync type has “Marker” selected
The Marker and other options here are means of syncing the clips
In your image I would choose to sync to the longest clip Camera 2, for your class probably use Audio as you indicated as having a separate audio recording.
Only one marker can be placed on the camera angles, position curser, select a camera angle clip, icon next to scissors becomes available, repeat for other tracks.
Then hit the circular sync icon, all markers line up.
Using a flashgun or clapper board are ideal to set a mark whilst recording, but any similar wave form will do.

End trimming function between two clips does not remove frames, it re-positions the cut point between cameras, so as you drag to shorten the first clip, frames are added to the second clip, this retains the sync.
This feature also works the same when returning to vs edit timelines

External sound track
First you would normally choose to sync to the Audio track, change the “Marker” selection to Audio
To the right of that you have Camera 1 selected, that will use Camera 1 audio, change that to the Audio track
Now the sound source will be the audio clip.
When you return to the timelines all video will have its sound muted, a sound clip/s are placed on the music track from Audio1. In sync of course

Scissors
Your image shows camera 2 selected
The scissors cut clips on the top track, click the PinP grey timeline to deselect the camera angles and the scissors should work along with A/B transition

[Davidk]

And the clips are distributed, 1st lessons and queries coming in.
Learnings 1. Before recording, make sure all the cameras used have the same date/time set.
I experimented with some results of the shoot and audio sync just did not take; at that point I realised that all the clips had different times on them even if we used them at the shoot. And if audio sync did not work, then with the clip times all over the place the only real option remaining for sync was to use the marker.
Learnings 2. Selecting and playing the video/camera clips in the MCE tracks has a really nasty buzz to the sound. Took me some time and cross checking between 2018 and 2019 to realise that the MCE audio and timeline did not have that, and the buzz was a reflection of the clip muting in favour of the common audio track.

Query 1. Using the sync by 'selected area' option. This is an item in the pull-down sync list in the MCE panel, but does not get a mention in the user guide. And I've noted that in some clips audio sync did did not work, even tho there was a clapper sound done for sync purposes. So, my thought was that an area of each camera clip could be marked or selected in which a sync sound existed, and only those areas were searched and used to audio sync. However, I can't find anything that might match this concept or otherwise describe how the selected area thing works.

Does anyone have any idea of just what that sync on selected area means?

Moving on, Query 2.
This image is of the MCE panel with 3 camera clips and a common audio recording.

Playing/selecting a camera for shot etc has a significant lag between the sound and the images. All the clips are HD (all 1920x1080 and mp4 files, but the variance between cameras is 25fps and 22kbps, thru 50fps and 25kbps to 50fps and 49kbps), and that video lagging audio would normally (in main VS) be an indication that smart proxy is needed; and while it's enabled in the main program and the MCE panels settings list displays those enabled settings, there is no icon indication in MCE that smart proxy files are in use, even after some time in which the proxy files should have been created and put in use. A check of the proxy file location shows them to have been created (the clip.upx files exist), but the MCE panel does not seem to use them.

Has anyone else noticed this and is it a bug or something else?

[lata]

Hi
You seem to be saying that your recordings are using 25fps and 50 fps
I am unsure what effect that will have on MCE and whether syncing would be effected
The MCE timeline can only be set to one rate, same as main timelines using one rate
Please note afaik the Camera 1 clip fps are used to set the frame rate of the MCE timeline.
If you then add camera 2 using 50 fps the frames have to be dropped, 50% every alternate frame will be removed
If Camera 1 used 50fps with other cameras using 25fps then frames will be added.
I do not know what effect that will have using MCE nor the effect in finally editing the MCE.VSP on the main timelines,
Maybe its ok but worth a mention

Smart proxy
MCE does appear to use smart proxy as I notice a remarked improvement in response when using SP, yep an indication within MCE would be good.
I did mention in my first reply#12 that I prefer to apply SP before going to MCE.

Selected area
Where the video recordings may be repetitive it could confuse the auto sync as it scans the entire clip. I think.
If we choose selected area the camera angles show a green shaded selection
We can resize / position that selection on each clip, (click and drag the mouse anywhere on a clip) then that area will be used to sync the recordings.

Audio playback lagging
Difficult to say why that should be, are all students seeing the same?
I assume all clips have Smart Proxy applied, make sure the main VS library shows Smart Proxy being used
If all are seeing this lag then maybe 25 re 50 fps, but I do not know?

[Davidk]

Hi Trevor,
No, the video was lagging the audio: speaking audio well in advance of fixed face image in the video. Normally an indication that smart proxy is needed.

But smart proxy is enabled, and there are proxy upx files for the clips in the specified folder. The smart proxy icon in the clip thumbnail would be a good indicator, but if the video clips in MCE are acting like SP does not exist, then what?
As a matter of workflow:
1. - Initially, I did not open any clips in the main UI, but opened the MCE panel with a virgin timeline and then imported clips to the various camera/audio items in the opening panel, clicked OK then to get the MCE workspace. Saved the file after some work, but the edit was not complete.
2. - after VS close/open, next opened the project in the MCE workspace by selecting the MCE thumbnail in the library, rt-clk, choose MCE and the MCE UI appeared with files etc as closed. After some more work I noted that the video was lagging the audio . . . .

So, following up your recommendation to do Smart Proxy on clips before inserting into MCE, how would you do 3 clips this way?

[lata]

I have updated my original reply to include
1a /if you believe Smart Proxy files will be required to improve normal editing then do that now.
Right click the clips within the library for Create Smart Proxy Files.
If my video clips require SP when editing in the normal timeline, the same will be when using MCE, in which case I usually know that I need smart proxy and apply before going to MCE, this has always improved my MCE experience.

I always play my video on the main timeline before going MCE. This also ensures that the project settings match the video files properties.
Doing so not only checks SP but gives me an understanding of the video content which helps when working with MCE.

If Smart Proxy files are created as indicated within the library and playback is still a problem then I can only suspect the video files.
Back to the main timelines to make sure they play ok there.
Are all your students having this problem?

You did mention using mixed video some using 25P others 50P, this may affect MCE, saying that I don’t know as I have never used MCE with different frame rates?
Camera 1 files determine the frame rate as set in MCE, if that is 25fps then other video using 50P will have frames removed, I do not know what effect that will have on playback

Could you upload your video samples to One Drive, because of size - one at a time

[Davidk]

Hi Trevor,
Re Onedrive - separate PM about that. The discussion here is about a file set that's too large for the normal 'free' onedrive user allocation.

Using camera 1 to set the MCE properties - noted.

Regarding the use of main VS to set the project properties etc OK, but from there to MCE - I am mystified. Importing camera video to the main timeline and getting the proxy file done (icon in thumbnail) is a normal process, but there seems to be no mechanism to transfer the upx files from the main timeline to the MCE panel and in particular to a specific camera track.

Update
After a lot of fiddling the MCE video in the cameras seems to have become smooth/normal, but even with the MCE timeline track selected, the audio has an irritating buzz in it.