Need to Increase Audio Level in Video

[subpar]

Windows 7
Audacity 2.1.2 .exe
FFmpeg Library Version: F(55.33.100), C(55.52.102), U(52.66.100)

I have an AVI video and the audio plays at an average of -15 for the first 45 seconds. The video is 6:22 (min:sec) long. After the initial 45 seconds the audio decreases to almost inaudible - call it a 1.5 on a scale of 1-10 in home theater DVD player terms. My goal is to play the video on my home theater DVR's HDD without manually increasing the volume by roughly 45%.

I have tried extracting the audio using VLC (2.2.4) but it only extracts approx. 45 seconds. To be clear, the audio IS audible on my home theater speakers, I just need to increase it after the initial, normal, 45 seconds.

How should I proceed?

[kozikowski]

If you have the proper FFMpeg installed and working, the video sound should just open in Audacity. Edit your brains out. What kills you is putting the corrected sound back in the video. You're on your own there.

Koz

[subpar]

I opened the AVI file with Audacity and "highlighted" the low audio part (45 seconds to End). Someone at the VideoHelp forum said to:

mark the low volume section and use Effect -> Amplify to increase its volume [Note: Amplify is grey at this point]. Then use File -> Export Audio to save the result.

Then you'll need to mux the video from the original file with the new audio with an appropriate muxing tool.

Is it even possible to amplify this section of the video or am I just wasting time?

[DVDdoug]

Yeah... You'll need a video editor to re-combine the edited audio with the video. And, most video editors can do some limited audio editing so you probably don't need Audacity.

You can try Windows Movie Maker (I've never used it) or there are some other free video editors. I'm currently using Cyberlink Power Director (~$60 USD) and in the past I've used Corel Video Studio (~$60).

[steve]

[Note: Amplify is grey at this point].

Most effects are greyed out during Play, Record and Pause. Ensure that playback is stopped (click the Stop button) and not just paused.

[Gale Andrews]

You'll need a video editor to re-combine the edited audio with the video.

Avidemux is worth trying. If the audio is compatible with the video format, it can "mux" the replacement audio into a copy of the original video, so avoiding re-encoding the video which will almost certainly degrade it.

Movie Maker cannot do that - it must re-encode the video.


Gale

[mwhelm]

I have found it relatively easy to reload audio with avidemux,
but *usually* there are audio synchronization problems afterwards.

There are also many combinations of audio & video that really don't
work at all in avidemux, particulary on re-importing audio. There's some hint in log
files that they aren't doing anything, but no warnings that I've seen.
I haven't studied it systematically. The avidemux forum was no
help.

I'd benefit from better advice or a better system, frankly.
It seems like everyone sets audio levels too low and many of them
need to be boosted.

[Gale Andrews]

I have found it relatively easy to reload audio with avidemux,
but *usually* there are audio synchronization problems afterwards.

I suspect AVI format will be more prone to that than other formats.

I'd benefit from better advice

There are many excellent specialised forums online like http://forum.videohelp.com/ or Doom9.

Or are you asking how to level out the audio in Audacity?


Gale

[mwhelm]

I think a better solution for simple audio fixups for video is needed.
Just thinking of my case, the main problem is impromptu videos
(something interesting is going on & it's not a properly set up shooting
situation). Audio levels are off, either no way to set them or the
controls are buried deep in menus, no time. A little background noise.

Audacity doesn't do video directly, and most of the video editors I've
seen are useless for this. avidemux will sometimes boost levels,
sometimes boost levels and de-synch. I don't think it can do anything
else.

[kozikowski]

think a better solution for simple audio fixups for video is needed.

I agree completely.

Maybe one of the higher-end video editors is called for. Ripping a video show apart and correcting individual parts of it generally calls for more talents than anyone is prepared to design. Final Cut can correct sound sync issues—or it could until the last version.

Audacity is not a video editor. The developers have a hard enough time keeping up with audio production. We try not to stress them. You know how they get.

Koz