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Audio Post Workflow - video vs wav

sfoster

Staff Member
Moderator
One of the guys from my weekly trivia night said he has done some audio post work for live theatre and he volunteered to help clean up my dialogue tracks. ( i have some cricket problems )

Is the audio quality lossless and sufficient to give him just the video.. (i.e. prores444) or should I export all the audio to a wave file and provide him with that instead

if wav.. what would i use for kHz rate and Linear PCM Settings? 48kHz and 16bit sample size. is that significant?
 
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Thanks! that was very informative. Too bad about the crickets. I was able to improve it an okay amount by overlaying some other cricket sounds between the dialogue tracks as they switched. I think I did get it to the point of not being a distraction. I won't get my hopes up that he can do any better, thanks.

Ah, in your OP you mentioned the cricket noise and dialogue "clean up", so I assumed you meant you needed to clean the dialogue up (significantly reduce or remove the cricket noise) because it was too distracting and/or making parts of the dialogue difficult to understand. If that's not the case and a possible solution is actually to add more cricket noise then maybe it won't be too difficult to deal with this issue. In future though, definitely avoid this type of background noise when filming. When you get to the filmmaking stage of wanting to commercially distribute or broadcast your films you will need clean dialogue tracks.

Since wav is lossless, I'm thinking there is no advantage of sending him OMF instead

The reason for OMF is not really anything to do with "lossless" because it's assumed however you deliver your sound to the audio post peeps that it will always be lossless. As Alcove said, the main reason for OMF is to have the original edits so you can easily go in and re-edit or replace the edits, and so that the audio can be easily re-organised for mixing, all of which is far more difficult and time consuming if all you've got is a bunch of full length wav files.

Ah yes but then you run into the problem of codec.. I know h264 compresses video, so I have to assume that it compresses audio as well. So then do i have to export in prores for him? etc.. at least i know wav is lossless now

Normally you would supply your video in the format requested by the audio post peeps, with your rough audio mix muxed into the video (which is a useful guide). The audio would then be delivered separately in an OMF (or AAF). I personally prefer a H264 in full HD res, which I then transcode to ProRes, as ProRez is too big to upload. Others may prefer different formats, Alcove for example.

I think for a youtube video it's okay but if I were to really scrutinize I don't think it was good enough to be played in a theatre. if you're listening for it the switches between audio tracks are definitely noticeable.

Cinema sound systems are usually extremely revealing, much more so than any other sound system you are likely to come across. This means that even issues which you cannot hear now will become noticeable in the cinema and those things which are noticeable to you now will likely be extremely noticeable to the point of seriously distracting.

one scene i forgot to turn off the pool heater & filtration so i'm hoping he can clean up the humming. Another scene the line of dialogue I want to use wasn't completely lining up with the actors mouth.

I'm hoping he can fix all of those..

Some electrical hums can be fairly easily dealt with, electrical motors are not so easy because they might initially sound consistent but are actually constantly varying (usually cyclically). Even with experience and the right tools, ADR is often the only real solution. BTW, the "right tools" are relatively expensive, even the cheaper not so great alternatives are still into the 4 figures. It's extremely unlikely your friend has these tools so, again I would warn you not to get your hopes up too high that "he can fix all of those [problems]".

If he's not charging you anything then you've got nothing to loose by letting him have a go but I'm with Alcove, unless you are particularly bad with audio, chances are he's not going to do a much better job than you could.

G
 
Ah, in your OP you mentioned the cricket noise and dialogue "clean up", so I assumed you meant you needed to clean the dialogue up (significantly reduce or remove the cricket noise) because it was too distracting and/or making parts of the dialogue difficult to understand. If that's not the case and a possible solution is actually to add more cricket noise then maybe it won't be too difficult to deal with this issue. In future though, definitely avoid this type of background noise when filming. When you get to the filmmaking stage of wanting to commercially distribute or broadcast your films you will need clean dialogue tracks.

G

In my original post, I was indeed hoping that he could get rid of the crickets altogether. After you said the best have problems with that, I set my sights lower and thought maybe he could disguise the changes better.

The problem is crickets have like 4 different songs, and they change frequencies, so in one track they're playing one beat, then when another character talks it suddenly changes. You can clearly hear the people but I threw a bunch of extra cricket noise on top which took away the abruptness of it. It's still there if you listen for it though.

One of my friends recently has decided that the only way he can get high production quality sound is to ADR everything and match that up. I guess thats possible for a short but is a depressing thought. Seems it would have been mandatory with my location unless I bombed the whole forest with ddt


I think something went wrong with his export, this is the sound file he sent me back
ScreenShot2014-02-02at31100PM.png
 
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The problem is crickets have like 4 different songs, and they change frequencies, so in one track they're playing one beat, then when another character talks it suddenly changes. You can clearly hear the people but I threw a bunch of extra cricket noise on top which took away the abruptness of it. It's still there if you listen for it though.

Yes, the big problem with background sound like cricket noise (and other noises) is that even when it appears to be consistent it isn't and you don't notice that it isn't until you start picture editorial, which juxtaposes different parts of the noise which highlights the inconsistency and all of a sudden it sounds "wrong".

One of my friends recently has decided that the only way he can get high production quality sound is to ADR everything and match that up. I guess thats possible for a short but is a depressing thought. Seems it would have been mandatory with my location unless I bombed the whole forest with ddt

Your friend is in for a nasty shock! There are several issues with ADR'ing everything:

1. An actor's performance is not just visual (their facial expression and body movement), the performance is also largely in exactly how they deliver their lines. Even the very top actors have a great deal of difficulty getting the same quality of performance during ADR recording as they achieved during filming. In other words, while the technical recording quality of ADR is better, almost without exception the artistic quality is poorer. Of course, with actors who have less experience and skill this problem is exacerbated.

2. Matching up ADR is usually not a trivial exercise! Commercial ADR studios make the matching up process easier but are usually well beyond the budgets of most lo/no budget filmmakers. The most common end result is ADR which has a different aural perspective to the visuals and this sensory contradiction will feel "wrong" to an audience and pull them out of the scene/film.

Even in commercial filmmaking ADR is always a last resort. As a general rule, at the lo/no budget level it should be avoided at almost any cost! Good quality production sound recording is essential at every budget level but in some respects it's even more important in lo/no budget filmmaking because with such a limited budget "fixing it in post" either isn't possible at all or virtually always results in at least a compromised, if not extremely compromised film. Obviously, one of the most important aspects of decent quality production sound is consideration of production sound when location scouting.

I think something went wrong with his export, this is the sound file he sent me back.

As Stef stated, that's a pretty badly clipped audio file! Knowledge of general audio, of another branch of audio or even knowledge of audio post itself, is not by itself necessarily of any use or any indicator of whether someone can actually do a half decent audio post job. It's the knowledge combined with experience and the appropriate tools which makes the difference. Due to lack of funds, lo/no budget filmmakers often turn to composers, music producers, audio students or in this case, a theatre sound guy for their audio post needs. Rarely if ever do these audio people have the audio post specific knowledge, experience or tools to do the job significantly better than the filmmaker could themselves. Even though it might appear that they have a proper studio, full of wicked equipment and are far more audio knowledge! In this case, nothing but a day or two of time has been lost but if/when you have a bit of budget for audio post, make sure you spend that budget on an actual audio post guy rather than a wannabe or someone experienced in another audio field!

G
 
The actor performance bit makes a lot of sense. Very much a pleasure talking to you here about these issues.

Obviously right now I'm in the really low budget phase of my career. Maybe I am just being lazy after a really long editing phase and need to get back on that horse for audio. Ugh. I am very happy to have anyone volunteer to help me out though, maybe this guy can help me in production instead. Last project I had to boom and direct at the same time
 
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