Increasing volume level of audio

[Enchanter]

How does that differ from normalisation?

[zoli]

Normalization is to find the peak volume in your audio, see how much it can be amplified without problems (errors, etc.) and pull up the volume level of the rest of it by multiplying with this gain factor (or whatever it's called), retaining the relative difference between soft and loud parts.

Dynamic range compression, however, deals with the difference between soft and loud parts. Practically, it amplifies soft audio more than already loud ones. So, you gonna get the dynamic range decreased and hopefully when there's a dialogue in your movie, the next gunshot won't blow up your hifi.

z.

[engramic]

Hmm Just to define some of what Zoli said... normalisation is about finding the highest peak in the sound and amplifying the whole wave file so that the peak is at 0dB. With digital audio, as soon as anything goes over 0dB you get clipping; there is no tolerance for this. You get distortion straight away. Additionally, it isn't really accurate to say that when using compression the soft bits are brought up. Rather, the loud bits are brought down allowing you to raise amplitude of the waveform as a whole.

[Enchanter]

Thanks for input, guys.

Now, I'm most interested in getting Cooledit and would like to know where I can find it. Can I just go over to www.downloads.com and get it? Or is there anywhere else I can get it? Thanks again!

[UncasMS]

http://www.cooledit.com/

+
astalavista

[Enchanter]

Thanks.

Got it at CNet Downloads. Now going to get the crack.

[Enchanter]

CoolEdit working beautifully, thanks to you all, guys!

[Enchanter]

By the way, can CoolEdit increase the volume of an existing MP3 track without having to reencode the final result into MP3 again? I hate to think of reencoding a 128kbps MP3 into a 128kbps MP3 (A louder version). There's bound to a loss of quality, even if it's slight.

[Enchanter]

Also, another thing. I tried increasing the audio volume of a music video, encoded in divx and MP3 format. Extracted the MP3 track, amplified the volume by 10dB and saved it into an MP3 of the same bitrate (256kbps). Then I joined the audio and video together using nandub (which accepts MP3 without any complaints).

However, the final result, being satisfactory indeed, took much much more CPU power required to play. On a PIII-800, the original file required about 50-60% of CPU cycles on average. However, the new file, with amplified sound, requires 100% of the CPU cycles and that's still not enough (periodic skipping and stuttering every few seconds of playback).

Anyone has an idea on why this is so and how I can fix it? Thanks!