Adjusting audio volume in batch

[SearchQuality]

Hi Folks. I have mpeg and avi clips where the sound volume varies considerably from clip to clip. Sometimes I replace the original sound with narration or music. In one project I may have 3 to 4 hours of video. Instead of going through every clip I want to do some batch processing of the audio track. What I wish to do is to have a script where I can give the maximum and minimum values of the sound volume and have the program decrease the values greater than maximum. It should also indicate the places where this max and min values occur. I have some experience with Vdub and Avisynch and I use Audacity. Any help will be appreciated. Thanks.

[jagabo]

For MP3 audio:
https://forum.videohelp.com/threads/255147-Mini-Guide-Normalizing-Audio-for-Multiple-AV...ormalize+batch

[SearchQuality]

Thanks a lot. Seems to do what I am looking for. I see 2 problems. Firstly, as far as I can see it does not handle MPEGs and secondly the fact that one has to move all the files to be processed to the folder of the application is a hustle. I wonder if anyone has any solution for that.

[DarrellS]

Did you try the GUI that was listed in the post by nologic?

http://www.mediafire.com/?0hl1zticp5444uc

[SearchQuality]

Yes I looked at that GUI. The tool MP3gain seems to be the best choice.

[Andy_Gee]

Normalizing just pulls the audio to a point where the loudest point hits 0dB. It doesn't do anything after that.

A much better option for this kind of thing is audio mastering. It will make sure that not only the peaks are the same volume, but also the troughs.

If you are having narrative over other music then don't just lower the volume - it's such a cheap effect and really noticeable - look into sidechain compression. This is actually pretty complicated stuff - you're better off hiring an audio engineer to do all your post production audio work. It's easy to tell when someone who doesn't know what they're doing has done the job.

[SearchQuality]

Normalizing just pulls the audio to a point where the loudest point hits 0dB. It doesn't do anything after that.

A much better option for this kind of thing is audio mastering. It will make sure that not only the peaks are the same volume, but also the troughs.

If you are having narrative over other music then don't just lower the volume - it's such a cheap effect and really noticeable - look into sidechain compression. This is actually pretty complicated stuff - you're better off hiring an audio engineer to do all your post production audio work. It's easy to tell when someone who doesn't know what they're doing has done the job.

Last point is a valid suggestion for people who are actually doing professional work. I work in this area as an amateur. Grasping and employing new techniques are targets so valuable to me that I can not leave them to someone else. Well philosophical aspects to one side lets get back to the actual subject. Could you please elaborate on mastering versus normalizing. What tool do I need to do the mastering? As I described in my first posting what I need is the possibility to have an acceptable standard volume throughout the chapters of the DVD no matter what kind of sounds are present in the sound tracks. I may leave the original sounds or overlay them with narration or music or replace them completely by music. Important is that the audience does not have to play with the volume button on the remote control.

[Andy_Gee]

Normalizing just pulls the audio to a point where the loudest point hits 0dB. It doesn't do anything after that.

A much better option for this kind of thing is audio mastering. It will make sure that not only the peaks are the same volume, but also the troughs.

If you are having narrative over other music then don't just lower the volume - it's such a cheap effect and really noticeable - look into sidechain compression. This is actually pretty complicated stuff - you're better off hiring an audio engineer to do all your post production audio work. It's easy to tell when someone who doesn't know what they're doing has done the job.

Last point is a valid suggestion for people who are actually doing professional work. I work in this area as an amateur. Grasping and employing new techniques are targets so valuable to me that I can not leave them to someone else. Well philosophical aspects to one side lets get back to the actual subject. Could you please elaborate on mastering versus normalizing. What tool do I need to do the mastering? As I described in my first posting what I need is the possibility to have an acceptable standard volume throughout the chapters of the DVD no matter what kind of sounds are present in the sound tracks. I may leave the original sounds or overlay them with narration or music or replace them completely by music. Important is that the audience does not have to play with the volume button on the remote control.

Normalizing will raise the volume of any given input until the loudest point reaches 0dB. It wont do more, it wont do less. If you're mixing two audio tracks (let's say for example music and speech over the top) 0dB might be too loud for the audio over the music, or it still might be too quiet. If it's too quiet, or there is too large of a dynamic range between the loudest point (the peak) and the softest point (the trough) normalizing wont help you. A more valuable tool in this instance is either compression or limiting - depends what kind of effect you want. It also depends on what type of compressor you use and the settings. It's very complicated stuff - it's not something you can follow a formula to - that's why audio engineers have valuable ears

Giving all your audio to an audio engineer would ensure that all the audio is mixed perfectly, and all the chapters on the DVD are the exact same volume. That's what mastering is - from music to film, that's what mastering does. It makes all the finished audio tracks the same volume, so you don't have to play with the remote control.

That's all well and good that you want to learn this stuff yourself, but mastering is a seperate profession in itself, so is audio engineering. It's not uncommon for studios to outsource their work to audio engineers for the sound part of the project. This is actually what i do as a living - audio engineering for video editors.

You might pick up the basics after a few years - but you still wont get results as good as a professional audio engineer or mastering engineer - that's just how life goes!

Oh, and mastering engineers generally have audio studios equipped with equipment and software specific to audio mastering. They have suites of tools, not individual tools.