I've converted my audio to ac3, now it sounds softer??

[ButchNapkins]

Hi there.. I've just finished ripping audio from several MP2's and converting it to AC3 format. I was able to mux the ac3 back into the original video, but now the sound is much softer- more quiet. I'm listening to these on just a 2-speaker setup, though I wouldn't figure that mattered.. Anyone have an idea as to why?


Butch

[wwenze]

That is coz when you compress a sound file, you take out some of the audio information. With less information (the 'instruments that plays your music), of course it will sound softer.

[ButchNapkins]

Really? I'd thought that the idea of compression would be to keep the exact same level of quality in a smaller file.. Kinda like a zip or rar file.. They're smaller than the files they hold, but when you decompress them they still output the same (bigger) files.. There's no quality loss then, right?


Butch

[eyrie0]

Zip files are lossless compression. Almost all video and audio compressions are lossy compression algorithms. For instance, if you encode a CD to MP3 and then decode the MP3 back to WAV audio and burn it to a CD, the 2nd CD will be of lesser quality than the original.

[dcsos]

Conversion to AC3 with freeware tools will always result in a loss of level.
This is due to a setting called the DOLBY DIALNORM setting.
This can only be tweaked to equal the level of your input MPEG file(or PCM) in the authoring environment. SCENERIST, CREATOR or FUSION have access to these settings, Ulead and Pinnacle do not.
To do this with freeware, just increase the level of the MPEG sample before conversion.