Adjust mp4 audio volume

[mcramer]

I have an mp4 video file, where the audio is too loud in comparison to most of my avi's and mpgs, I've had no problem in the past adjusting audio levels and am reasonably familiar with VirtualDub, but don't have anything in my toolbox to handle an mp4 video file.

Yamb says this about the file:

* Movie Info *
Timescale 1000 - Duration 00:46:12.706
Fragmented File no - 2 track(s)
File Brand mp42 - version 1
Created: GMT Sat Sep 30 03:15:56 2006

File has no MPEG4 IOD/OD

Track # 1 Info - TrackID 1 - TimeScale 2997 - Duration 00:46:12.706
Media Info: Language "Undetermined" - Type "vide" - Sub Type "avc1" - 83098 samples
MPEG-4 Config: Visual Stream - ObjectTypeIndication 0x21
AVC/H264 Video - Visual Size 320 x 240 - Profile Baseline @ Level 1.3
Pixel Aspect Ratio 220:219 - Indicated track size 320 x 240
Self-synchronized

Track # 2 Info - TrackID 2 - TimeScale 44100 - Duration 00:46:12.485
Media Info: Language "Undetermined" - Type "soun" - Sub Type "mp4a" - 119401 samples
MPEG-4 Config: Audio Stream - ObjectTypeIndication 0x40
MPEG-4 Audio AAC LC - 2 Channel(s) - SampleRate 44100
Synchronized on stream 1

Can anyone point me at a tool that would be able to adjust the audio gain on this file?

Or a pointer to a guide or faq that would cover this topic.

Thank you

Mark

[Baldrick]

Extract the aac audio with Yamb and then convert it to wav and adjust the volume in an audio tool. Convert back to aac and add back it to the mp4 using Yamb again.

Google for "aac to wav" or "aac normalize" or similiar for aac converters tools.

[celtic_druid]

Could also try aacgain once you have extracted.

[mcramer]

I downloaded BeSweet and BeLight, pulled the Nero DLLs off the Nero disk I received with my burner, spent ages browsing the net trying to find some of the other dlls BeLight seems to require.

Extracted track2 using Yamb and tried to use BeLight 0.2.2.0 beta 9 to convert to Wav, BeLight crashed after writing a 36k Wav, the mp4 audio is 42M.

Tried using Mp3GainGui after renaming Aacgain and I get:

24/02/2007 18:31:06 Error while analyzing: C:\Data\Movies\Track2.mp4 is not a valid mp4/m4a file.

Vlc has no problem playing the original file or the extracted Audio mp4.

Any pointers as to what to try next?

[celtic_druid]

BeSweet I don't think can handle aac decoding, only encoding.
aacgain requires one audio track with track id 1. Probably when you demux with yamb you get a different track id.

[Soopafresh]

What about:

ffmpeg -i myfile.mp4 -an -vcodec copy -y video1.mp4
ffmpeg -i myfile.mp4 -vn -y audio1.wav
wavegain -r -n -y audio1.wav
ffmpeg -i video1.mp4 -i audio1.wav -vcodec copy -acodec aac -ab 128 -y ouput.mp4

[mcramer]

Thanks Soopafresh, that did exactly what I wanted.

Much appreciated.

Mark

[Soopafresh]

Thank celtic_druid . He probably compiled the ffmpeg you used!

http://tirnanog.fate.jp/mirror/ffmpeg/

[mcramer]

In that case to celtic_druid

Now I just have to understand what the options do

Thanks.