Macbook - Stutter recording video

[Beresford]

A relative has a seven year old Macbook.
When she records video (songs for locked down community choirs, about 10 mins each) they are often ok, but about a third of them lose video sync after a few minutes, then the video lags by 3-4 seconds. Happens even when she restarts the laptop. She uses Apple supplied software.

Any suggestions?

Probably she has quite a lot of obsolete stuff on it - but how to clear it out?

I have no experience of Macs, but plenty on Windows. On Windows I would restart, up the priority of the video software, stop anything irrelevant using Task Manager and Startup, and maybe use Ccleaner and Defrag to tidy up, but I don't know how to do anything similar on a Mac.

[MrGongGong]

She uses Apple supplied software.
.

I think this might be the problem
Particularly on an "older" machine

[Dave2002]

She uses Apple supplied software.

Any suggestions?

Probably she has quite a lot of obsolete stuff on it - but how to clear it out?

A few.

1. Use Force Quit (from the top left Apple menu) to close down programs that are running which are not needed.

2. Use Activity Monitor (from the Utilities menu) to identify processes which may be taking up resources.

3. Check the memory on the machine. Ideally there should be sufficient spare while running, otherwise there can be problems.

4. How were the videos produced? Maybe they are made at too high a resolution. Nothing particularly wrong with that, but they might not work well on that machine. Apple has a tool called Compressor which can make the videos smaller, by recording them. However there is a tool called Handbrake (free) which usually does a very good job of reducing the video file size with hardly any loss of video quality. If the videos were recorded using a modern video camera, the resolution may be too high for an older MacBook to process. The video frame size can be reduced.

Often just running the video file through Handbrake will reduce the file size, and the problems will likely disappear, even if the frame dimensions are not reduced. Chances are that Apple’s Compressor program won’t do a better job for this problem than Handbrake.

[Beresford]

I didn't make it clear that she is recording video with sound by singing into her Macbook, probably using the Apple equivalent of Camera.
Thanks for the other hints. It is behaving like a memory problem, having to write video to a pagefile or similar, then failing to sync with sound.

[MrGongGong]

I didn't make it clear that she is recording video with sound by singing into her Macbook, probably using the Apple equivalent of Camera.
Thanks for the other hints. It is behaving like a memory problem, having to write video to a pagefile or similar, then failing to sync with sound.

I would investigate getting a different bit of software to make the video.
Not sure what the free/cheap options are at the moment

Worth doing the usual turning everything else off etc

Today I did a rehearsal online with a similar aged mac
I ran a live stream video, audio processing, 3 other bits of software all at the same time
and had forgotten to shut down a few other things I was using before

A few slowing down issues but the machine should be more than able to cope

[Dave2002]

I didn't make it clear that she is recording video with sound by singing into her Macbook, probably using the Apple equivalent of Camera.
Thanks for the other hints. It is behaving like a memory problem, having to write video to a pagefile or similar, then failing to sync with sound.

I've never done things that way before. I've always used a separate camera up to now. Most modern cameras can record video to a memory card. Then I've put the result into a video editor. I also have used a separate sound track, which I then synchronise and merge with the camera sound track.

However, prompted by this thread, I tried several options just now. The ones I tried were:

PhotoBooth
iMovie
Final Cut Pro
and Quicktime Player

The only one I couldn't figure out was Final Cut Pro - I couldn't see a record button, though it did seem to be aware of the inbuilt laptop camera.
I simply clapped a few times while recording the video. I couldn't get Final Cut Pro to work, but I did succeed with all the others. I'm surprised that it took 10 minutes or so in the recordings your relative made for problems to show up. It was clear within seconds that the video and the sound track of my clapping were well out of sync - in all the software tools which actually worked. It is probably not too difficult to realign the video and audio tracks using a tool such as iMovie. What would be more problematic would be if there were drift between the video and audio tracks, as then it wouldn't just be a fairly simple matter of slipping the audio and making the claps line up with the video frames.

I agree that it might be good if there could be a tool to directly input into the computer, which is possible with audio, but I don't think there is such a thing - or not a good one, anyway. All of the ones I've tried do have the problem mentioned. I suggest that the way round this is to do the recording using a camera - running in video mode, then import the file from the camera. The audio and video should be in sync. If concerned about the audio quality, then record audio at the same time, and then synchronise the audio and video files - which isn't actually too difficult to do with a bit of practice.

Sorry not to have been able to help more, but the delay thing does seem to be an inherent problem.

I also found this video - https://youtu.be/qByUQj71YfQ which gives a possible explanation of why there might be issues, and suggests fixes using Handbrake, which I mentioned earlier. Maybe I'll try that on the few clips I've done already.

I did try that quickly - but not a great improvement if any. I did try to force constant framerate as suggested in that video.
If that doesn't work, then slipping the audio and video tracks is the way to go, but I really think that using an external camera and recording to memory card should avoid the problem altogether.

[Beresford]

.... I really think that using an external camera and recording to memory card should avoid the problem altogether.

Do you think recording on an iPhone camera, then transfering to the laptop, would achieve the same result?

Also could the sync problem be in the playback system, rather than embedded in the recording?

Thanks for all the testing.

[MrGongGong]

Do you think recording on an iPhone camera, then transfering to the laptop, would achieve the same result?

Also could the sync problem be in the playback system, rather than embedded in the recording?

Thanks for all the testing.

I would try making the recording on a phone
then seeing if it stays in sync

In my experience this should be ok
Though the audio quality won't be as good as using an external soundcard and computer / ipad /iphone etc

[Dave2002]

Do you think recording on an iPhone camera, then transfering to the laptop, would achieve the same result?

Also could the sync problem be in the playback system, rather than embedded in the recording?

Thanks for all the testing.

I'm not sure about the iPhone option. I can check that later, perhaps. Regarding the recording vs the playback issue, the problem is pretty definitely in the recorded file. I checked this by loading one of the videos into Final Cut Pro X, then looked for the audio claps which were easy to pick out in the soundtrack. My hands didn't get close together until maybe 3-6 1/100s of a second later. Let's take a guess and say it was 50 milliseconds (5/100 of a seond). It's unlikely that the processing I did would have introduced any extra significant slippage between the audio and video.

[Beresford]

Sync problem seems to be solved by buying a new Macbook pro 13 inch.
Thanks for all the suggestions.