Video/ audio editing issues

Video/ audio editing issues

I’ve got a ‘free’ whistle - the catch is, i have to record some video clips for the maker’s website. No problem, thought i - i have messed around with video editing before and i’m pretty good at audio mixing/ mastering.
Of course, nothing is going to plan.
Recorded video on my laptop’s camera (because i haven’t anything better) and audo on this nifty little Tascam device. Let both run and figured that i’d only need to sync the audio to the video’s (crap) audio once.
I wish…

Well i’ve been up literally all night, and i can’t get it to sync. It’s a bugger trying to line up the peaks and troughs of the wave-forms, because they’re at different volumes - in fact they look like totally different tracks - and i think there’s a bit of lag in the editing software’s player so i can’t do it by ear. And when i think i’ve got it lined up, i look a bit further in the file and they are clearly not lined up…

Because of this, I also suspect that the video has little glitches in it - when i played the video on its own this appeared to be the case. But as it doesn’t seem to glitch when i’m looking at it in the editing software i can’t be sure. As i don’t know where they are, i can’t correct for them.

Everything of course takes forever because the software is clunky and my computer is dead slow. Any ideas?

Re: Video/ audio editing issues

I would film / record it again and use the clapperboard trick: clap your hands once at the start of the film then pick up the whistle and play. The clap is very easy to sync, then the rest will be in time.

Re: Video/ audio editing issues

while i’m on the subject, any good free alternatives to vegas pro? After a night of faffing i discover it only records 2min clips unless you want to shell out for it. FML

Re: Video/ audio editing issues

Yes! It’s not mindnumbingly user intuitive (ie you do need to sit through a YouTube into video first realistically), but “Da Vinci Resolve” by Black Magic is probably now the standard best free video editor and full scale movies have been made with it.

I use it for all my video projects and it’s worth learning/is fantastic.

It is a full adobe style video editor though, not an iMovie style one (iMovie is actually perfectly acceptable for short basic clips and (I think) free/low cost on an iPad)

Re: Video/ audio editing issues

‘Clapperboard trick’. Yes I realized what they were for the first time I tried matching audio. A dog training ‘clicker’ works well and leaves a hand free. Some come with a wrist loop.

Re: Video/ audio editing issues

Sorry if you’ve thought of this, but are you sure the recordings are at the same bitrate? The times I’ve tried to synch two tracks - one at 44.1kHz and one at 48kHz is ridiculous!

Re: Video/ audio editing issues

For sync just clap your hands before each take. The clap will be very obvious on both tracks. There are a few possible reasons for the video glitching. The first thing is to make sure the frame rate you shoot at matches the frame rate of your project, if the editor has to convert between 25/30 fps there will be irrecoverable glitches. (Use 30fps for both if the end result is going on youtube not TV). The second thing to be aware of is that unless you are using a very high end PC with a very powerful GPU, if you try to edit HD video the editor will make a low quality copy and use that to speed up the edit processing. When you view the video within the editor it will be low quaslity and glitchy, but when you do the final render it will revert to the original HD files, and the video will be miraculously restored to its original quality.

You can edit video within Reaper. If it just needs basic cut and splice that is probably the easiest solution. If you need more complex video processing Da Vinci Resolve is free, Power Director is better but not free, though substantially cheaper than any Adobe product.

Posted by .

Re: Video/ audio editing issues

Just remembered another useful idea - clap at the start and end of each recording. Then you can sync up the first clap, and if the second one is also in sync you can be confident that everything in-between will also be ok.

Re: Video/ audio editing issues

Thanks guys.
This is proving the most time consuming exercise imaginable.
Not to mention i hate hearing myself playing solo! Get 2 minutes into a half-decent take and then get nervous and fluff it. Also there are 101 external things like car alarms and traffic and .. to f--- things up. And then mastering the music takes 4 times longer than playing it because of CPU and then video editing.
---
The clap idea looks do-able - i need effectively to create a -infinity to 0 db instantaneous peak or as near to that as possible. I might get a wooden chopping board and a wooden spoon.

I’d heard about davinci resolve, its good to know that it’s free. And it allows you to make full-length videos? The sign up process looked lengthy, so i didn’t want to go thro that and find out i couldn’t. I use a trial version of soundforge all the time & refresh my pc and reinstall it when the trial runs out! I’d forgot that Vegas had the limitations on output files.

Everything’s at the same bitrate, i checked. 44,100. But i might well record the audio at 48,000 because most of the video codecs seem to go that way. I don’t care much if the video resamples, but i want the audio as good as possible.

Another whistle-specific question. I just left the whistle sound as natural as possible, normalised it up, no compression. That’s what i default to for recording my solo playing. Because i’m going for a video clip that people are going to click on and listen to approx. 30 seconds of, surrounded by other videos which will be louder (usually smartphone footage which is clipping) i’d ideally like to get it louder, but my attempts of using compression haven’t sounded that good. I don’t know if 2:1 is too aggressive a ratio, or how far i want to drag the compressor down into the meat of the waveform (for tin whistle) I know people are going to say ‘use your ears’ but i need a starting-point by eye - i can’t listen during, it takes forever compressing stuff then listening back & i can’t be arsed, especially as the video stuff is taking forever too.

Re: Video/ audio editing issues

Does your compressor have a pre-set for ‘female vocal’ or something similar? I find that works for whistle/flute, and if you normalize the track before you apply the compressor you should find it puts the knee in about the right place (normalize again after compression to bring it back up to the max possible volume). Why can’t you listen as you apply the compressor? Are you trying to do all this in Audacity or something?

Posted by .

Re: Video/ audio editing issues

They say that procrastination is the thief of time but it’s a rank amateur compared to video editing.

Re: Video/ audio editing issues

@Mark M: Audio editing in Sony Sound Forge Pro (+the Izotope plugins). My laptop is a 100 quid P.O.S. thats the main problem. Its crashed numerous times trying to do things. In fact its on the verge of an impromptou flying lesson via my window if it does it again on something that’s nearly finished…
i’ll have to have a look at the ‘female vocals’ thing: wasn’t trying to do anything fancy re compression, (i have found that for this audio recorder it does a nice job of solo whistle sound, except i run a quick filter at 60 hz to get rid of the brown sound at the bottom.) Just bog standard compression without bands. I suppose i could arse around with bands to tame the whistle upper octave, but they are quite close together relatively speaking…
@JoeEvans: Yup. Its the worst.

Re: Video/ audio editing issues

@happycamper: Yes Resolve is completely free and allows you to create full length cinema movies if you want with no restrictions I’m aware of (other than their more professional AI tools which you’d never need).

It is a full video editing suite though = you do need to spend an hour or so understanding it vs. e.g. iMovie or the Windows 11 editor etc…
The plus side is it has a range of tools for sorting audio syncing out, including automatically changing the sampling rate to fit etc, but if you’re already frustrated with the time this has taken… it will take more = prob only worth it if you think you’ll be doing more video editing in the future.

Re: Video/ audio editing issues

The ‘female vocal’, wasn’t a suggestion to do anything fancy, just to use a ready made pre-set to get you into the ball park. TBH if you can’t hear what you are doing there is no way you are going to be able to set up a compressor. If your PC can’t run a DAW with a handful of plugins there is no way it will cope with video, definitely time for that flying lesson! Your 2:1 ratio is quite mild, and probably appropriate for what you are doing. if it doesn’t do enough you could probably go up to about 3 without it becoming noticable. I’d normally be looking for a reduction of about 4-6dB on the peaks, you could do that by noting the original peak value for the track, then adjusting the threshold until it comes down to 4-6 dB less. Attack and release I normally begin with minimum attack and release set to somewhere beween a quaver and a crotchet (250-500mS at 120 bpm) Increase the attack to make it punchier if need be, reduce the release to make it harsher, but those initial settings should usually be about right for maintaining a natural sound.

Posted by .

Re: Video/ audio editing issues

Audio recorded on two different devices over several minutes will often have a little drift, since they’re working off of different clocks. There are a couple ways to fix it. First is to go in and find breaks in the audio (like where you breathed), and break the good audio file up into smaller pieces, and then sync up each piece manually, which can be a lot of work. The other option is to use audio software that will let you stretch/compress the track until you get them to match up. I don’t know what DAW or audio software you’re using, but you might do a quick internet search for “timestretch” or just “stretch audio” for your software. Some applications will even give you a little handle on an audio file that will let you manually stretch it (or compress it) until you can get the audio to match up.

Here’s a video showing this process (he’s using Adobe Audition, but the concept remains the same no matter what you’re using). https://www.youtube.com/watch?v=F1tO_zx4LA8

Re: Video/ audio editing issues

@Reverend: Cheers. You wouldn’t believe how different the audio waveforms looked and there just wasn’t anywhere .. peaks were moot because the video audio clipped and troughs were wider valleys on both sides for the audio track. Utterly frustrating. Spent ages looking for cues.
In the end i’m taking somebody’s advice - creating an artificial instantaneous peaks with a sharp clap. I will see tomorrow if its worked…

Re: Video/ audio editing issues

Generally if you’re mucking about with compression and nothing sounds right, then the problem is probably EQ.

Definitely clap at the beginning and end of a track; the first is for sync, the second tells you if you have clock issues; unlikely on a short track but hey, if you don’t check, you don’t know.

Posted by .

Re: Video/ audio editing issues

just had a truly horrible thought…
What if the video and the video’s audio get increasingly out of sync? Then it doesn’t much matter whether i can line the audio up, and the playback speed in the pro-tools means i won’t be able to be sure until i’ve rendered the video..
Aargh!

video/ audio editing issues part 2

I’ve finally found a decent video editor that sits in the venn diagram overlap of free (trial), intuitive, and not breaking my CPU. Davinci resolve was bad for me (unintuitive and my computer can’t handle it), but thanks whoever suggested it at the time - it was freeware, looks decent, and if i could be arsed to learn how to use it it might be good for me in the future. once i get a half decent computer.

Planxty JoeEvans for the shout out about the clap-board for synicing audio - its genius and one of those things that is only obvious after the fact. You probably saved me half a day faffing about.

Anyway
I’ve got some half-decent clips (god only knows about the playing itself but that’s another story.) Some wierd things that cropped up which i’d like to fix are:
1 - there’s a kind of grunt getting picked up in the audio, (i think its the diaphragm bumps for upper octave because it only happens on the whistle with a stiffer upper octave.) Any idea how to edit that out? I mean specifically. In the past i played around with Izotope RX, (its not a standalone or at least you can’t use the trial version as a standalone because it won’t let you save the files) with which you can do a lot of cleaning-up sorcery but i remember that there were some issues with the trial version and also some issues making RX run in sound forge (i ended up using RX in Adobe’s protools in the end)
2 - Intermittant bumps and bangs from my housemates in other rooms and random traffic noise occasionally. Its not so bad in a set of reels, but it spoils the immersion in a slow air as you might imagine.

Re: video/ audio editing issues part 2

I’ve found on close-miked flute recordings that breath intake can sound intrusive, which may be a similar annoyance to the audio issues you mention, HC. What I’ve done is expand the image of the signal on the screen (I use Cubase) to identify the precise place where the extraneous sound occurs, select it and apply ‘silence’ from the Processes menu. The resulting hiatus is usually so brief that it’s not noticed, though you have to go through the recording phrase by phrase to spot the places where its needed.

That’s fine where the unwanted noise occurs in small gaps between notes (as in breathing). A bit more tricky when it’s a noise that coincides with the music. Maybe there are clever tech systems for filtering out such sounds on the same track, but the only thing I’ve found is to use a graphic equaliser to identify the frequency that sounds most intrusive and take out a notch at that point. Again, if it’s done at exactly the point of most interference, it shouldn’t normally be noticeable. It’s laborious, but it’s possible to set it up so that you can store these adjustments on a sub-track to apply them automatically on replay/mix-down.

Posted by .

Re: Video/ audio editing issues

> What if the video and the video’s audio get increasingly out of sync?

This is happening, yes. Every device has a clock, and that clock is what tells the device that 1/44100 of a second has passed and it is time to collect a new audio sample or that 1/30 of a second has passed and it’s time to grab a new video frame. Although every clock knows how long a second is, they’re not perfectly equal and over time they are drifting. The effect is minimal over a few minutes but on any serious production every piece of audio and video kit will be connected to a master clock that keeps everything in sync. That’s why I said clap at the beginning and end of a track, as it’s the easiest way to catch if you are having a problem with this.Unlikely unless you are doing multiple takes and leaving everything running.

As for extraneous sounds, often the best thing to do is leave them the hell alone. Just because you can hear it with the volume turned up on your high quality system doesn’t mean that it will be there when the rest of us are watching it through headphones on the back of a bus. The human brain doesn’t hear sounds it doesn’t expect to hear unless it’s been trained to listen for them. Breath noises, string squeaks, key noises, grunts, groans, passing traffic, dogs, etc, are all things that exist on commercial recordings. Of course there’s a judgement to be made about what’s intrusive, but I’d honestly walk away from those tracks for 48 hours then come back and listen to them on your car stereo and decide if they really need to be edited in that level of detail.

Posted by .

Re: Video/ audio editing issues

@Calum, think you’re right about the extraneous sounds. In the time it would take me to fix it on some alright-but-honestly-not-amazing playing i could be better spent the time recording new stuff or doing something else. The can’t be ars3d factor is strong here.
I do owe the whistle maker my best effort for a free whistle, but i strongly suspect the other clips on his website weren’t from as many takes as i did, i’ve done a fair amount of playing for it, plus recording and mastering its took a couple of full days at a guess when you add all the time up. (i’m inconsistent and i had a lot of bad days where i recorded nothing worthwhile then 2 days where i played well for 1 hour, stick a fork in it, i’m done. getting towards the point of diminishing returns generally with my level of playing.)
Yea, with the claps between tracks that was enough to keep the sync to acceptable levels, if i was being fussy, 1 frame of the video is quite a substantial time step and you need the video, the video’s audio and the actual audio as close as possible to the frame… Quite often the impact of the clipboard happened between frames… It’ll do lol.