CLI to set volume levels (Not normalize)

[VideoGuruDude]

Ive been examining and experimenting with normalize, and this is not what I want to do.

I have a video, from which the audio volume levels are sometimes so weak you have to turn the volume of the TV way up, then when an explosion goes off... it is WAAAY too loud.

Id like to process the audio file so I can ENJOY the video at ONE volume level... so the quite is the same audio level as the loud.

I do hope I am making sense...

Id prefer a CLI that I can wrap into a Win32 BAT file during processing... and I can do any video with this method.

If I am making sense, and you can advise, I am looking forward to your reply.

Thanks,
Andrew

[nic2k4]

The function you are looking for is dynamic range compression.

[budwzr]

AKA "Brick Wall" compression.

[Cornucopia]

Not really budwzr, "BrickWall" compression is more used as Peak Limiting. DRC like nic2k4 mentioned has a really low threshold and basically the whole dynamic range is adjusted.

So, (going from loudest to softest) the range would be:
0dB__-1.5__-3__-4.5__-6__-7.5__-9__-10.5__-12...
instead of:
0dB__-3__-6__-9__-12__-15__-18__-21__-24...

dbx used to make a common analog compressor that did just that (though it was meant to be used paired with a complementary expander on playback, the 2 known as a "compander" for use with media that had bad dynamic range, such as slow-moving consumer reel-to-reels & cassettes).

I'm sure there are (or ought to be) DirectX and probably VST plugins that can do that for you in realtime during playback on a PC...

Scott

[jagabo]

Many TVs and other set-top players have such filters too. Usually labeled something like Volume Leveling, Night Mode, etc.

[poisondeathray]

Maybe try compand in SoX

http://sox.sourceforge.net/sox.html

[budwzr]

Not really budwzr, "BrickWall" compression is more used as Peak Limiting.

EDIT: I looked it up on Wiki. Seems like DRC is what the "Loudness" button on a car stereo does. I get it. I think. Whereas BrickWall is concerned with specific frequencies prior to mixing, like kick drums or transients.

My Faux-Paux (Pardone Moi) (Hoity Toity)

[budwzr]

Maybe try compand in SoX

http://sox.sourceforge.net/sox.html

Man, to use that software you need a PhD is musicology. That's a tough gig. I don't know where you guys get the time to do this scripting stuff. On a DAW it's ALL visual, you don't have to know nada, just let your ears and brain go-to-town.

[budwzr]

I have a video, from which the audio volume levels are sometimes so weak you have to turn the volume of the TV way up, then when an explosion goes off... it is WAAAY too loud.

What probably happened is a poor conversion from 5.1 to stereo. AutoGK isn't a CLI, but I think you can batch. It has some great audio processing.

From the description you give, I would use a Multi-Band Compressor, 3-band, and just compress the lower band in RMS mode.

I suspect that if you reduce the whole dynamic range, you're going to lose the quieter (normal) parts.

[Cornucopia]

Sorry to raz on you again, budwzr, but that's still not quite right. "Loudness", as used by most devices, is an EQ that boosts low frequencies and high frequencies at low volume levels so that it roughly matches the freq balance as PERCEIVED at higher volume levels.
It is also sometimes used to refer to automatic level adjustment based on surrounding/ambient levels. Also, brickwall peak limiting is primarily full bandwidth, not focusedon specific frequencies.

No, DRC brings the low volumes up and the high volumes down. My previous example used as the pivot point the 0dB fullsignal peak, but you could just as easily use -24 or -30dB midpoints as the pivot (where input level = output level), or even use a low level such as -75, Then all levels above that still grow, but not by as much as normal.

Scott

[vhelp]

i thought the term was 'normalize'. there is a guide and recent activity on this subject.

https://forum.videohelp.com/threads/255147-Mini-Guide-Normalizing-Audio-for-Multiple-AVI-files

otherwise, do what i do, use your remote with strong batteries.

[budwzr]

Normalize is the idea, ways of accomplishing it are the discussion.

[nic2k4]

Normalize is the reason why the booms in his movies are the right volume, but the dialogue is too low. Normalize adjusts the audio level of the selected range so that the loudest part never exceeds the level you choose.

AGK can downmix DD5.1 to stereo and while doing so will also do some DRC adjustment (unless you use the original AC3 audio in your AVI), then AGK does a normalize just before converting to MP3.

Besweet can do DRC, read/write AC3 and has a batch mode. Check out the wonderful guides just above the comments on the tool page.

[aedipuss]

op's complaint reminds me of many dvd dts tracks. meant to be that way and played LOUD. if i had to work on it i'd bring it into an audio editor as 6 channels of wav. bump up the center channel, lower the surrounds and lfe until it sounded ok. export back to 5.1

[budwzr]

I wish we had a sample file to work with. There's more than one way to skin a cat. Anybody have a phucked up file we can play with?

If I provide one, it might get shot down as a ringer.

[jagabo]

In my experience most people who complain about too much dynamic range have their system set up improperly. Or they want to watch movies late at night without waking others. Or they're trying to listen to classical music in a car!

[Cornucopia]

Still, those last 2 can be valid reasons. Though this is best accomplished by a switchable feature on the audio receiver/amp.

Scott

[budwzr]

Sorry to raz on you again, budwzr, but ...

Yeah, DRC does accomplish the task quite handily. Thanks for the Razz.

I didn't think about it, but the OP's problem is too wide dynamic range, not peaks. No fancy tools required, just push it all together. Hahaha.

[VideoGuruDude]

I started researching SOX a while back... used it previously to combine 6 WAV files to a single 5.1 wav, then encode to AC3.

Anywho... I played with the normalize function, didnt do what I wanted.

Then I started looking at the comp function, and found a sample setting I tried, and it seamed to work great!

Heres the line:

sox audio.wav audio-sox.wav compand 0.3,1 6:-70,-60,-20 -5 -90 0.2

I cannot in this limited time expand on what it means, the info is out there... and yes, its kinda like a CLI DNSd, a "black art magic"...

Andrew