how to raise the volume of a movie by using audacity

[cns00]

i have a movie which has low volume and i have to increase the volume of the tv by a lot so i can properly understand what they are saying. i saw this tutorial https://www.youtube.com/watch?v=7K_6E9C7WjA on how to increase the loudness by using audacity. it said that i can move the gain slider or i can use amplify

amplify doesnt work for that movie and the volume is still low. i moved the gain slider to the right to the max to +36db. it became much louder and it made the laptop speakers vibrate. also in vlc player the volume is still loud between volume level 100 and 200 and the volume is not becoming less when i lower from 200 to 100. i think i overdid it and i made the movie very loud

is it ok if i raise the gain to something like +15? will the audio of the movie get distorted and spoil if i move the gain slider to the right?

[ProWo]

You have to normalize your audio.
Seek in tne audacity menu for normalize.
You could also use clever Ffmpeg-GUI, audio conversion section and seek the max possible gain with the volume detect function and recode the audio with the db gain you found.

[johns0]

clever Ffmpeg-GUI is easier to use than audacity,you dont have to save and process.

[cns00]

ok thanks. i just want to know is it ok if i move the gain slider to the right in audacity?

[jagabo]

ok thanks. i just want to know is it ok if i move the gain slider to the right in audacity?

By default the Amplify filter in Audacity increases the volume so that the loudest part of the audio will not clip (distort). My guess is that there are some parts of your video that are very loud already (this could be even a single sample) so the default amplification isn't very much. If you move the slider to the right (more amplification) those loud parts will become distorted. If those loud parts are just a small part of the full audio you can manually exclude them and crank up the volume for the rest.

Here's an example. The track has a very loud section at the very end. If you use Amplify to increase the volume of the entire track:


[Attachment 65613 - Click to enlarge]

it defaults to 0.0 dB (no amplification). But if you select only the quite part:


[Attachment 65614 - Click to enlarge]

it defaults to 11.351 dB of amplification. The soft part will become as loud as the loud part:


[Attachment 65615 - Click to enlarge]

Or you could use the Compressor (dynamic range compression) filter which will automatically increase the volume of the soft parts but not the loud parts (though it may sound un-natural at times as the volume pumps). If you're dealing with a 5.1 (or higher) source you can try just amplifying the center channel (where most of the dialog is).

[cornemuse]

I am very interested!

How does one mount a movie in audacity? Can you mount an iso? Must it be hdd folders? Have to extract audio first?

-c-

[johns0]

Just load a video file as you would an audio file.No iso or folders.

[jagabo]

Although Audacity (with the ffmpeg source filter) can import audio from A/V files , it cannot remux the new audio with the video. You have to export the audio from Audacity, then remux with another program. MkvToolNix, ffmpeg, VirtualDub2, etc.