Increase audio on a mp4....

[pinetop]

What freeware would allow me to increase the audio of a mp4, without re-encoding the video?

[Baldrick]

https://forum.videohelp.com/threads/359418-Raise-volume-on-an-Mp4?highlight=mp4+increase+audio

[enim]

In addition to Baldrick suggestion, you may try, ffmpeg -i foo.vid (no video) (only audio) -f wav - | sox normalize wav - | neroAacEnc -ignorelength -q 0.5 -if - -of foo2.m4a If you post mediainfo details, someone here will help you with proper command line. m4a (normalized) you can remux back with h264 into mp4.

[Selur]

btw. it would be better to use -f sox when piping from ffmpeg to sox,...

[enim]

@Selur
Thanks for correcting.

[pinetop]

In addition to Baldrick suggestion, you may try, ffmpeg -i foo.vid (no video) (only audio) -f wav - | sox normalize wav - | neroAacEnc -ignorelength -q 0.5 -if - -of foo2.m4a If you post mediainfo details, someone here will help you with proper command line. m4a (normalized) you can remux back with h264 into mp4.

I'm grateful for the help, but "-i foo, -i way" i have no idea what that means?

[DarrellS]

This is kinda tricky but what I use.

Download and install MP3Gain. Download AACGain, rename AACGain.exe to mp3gain.exe and place in the MP3Gain folder. It will over write the mp3gain.exe file and allow you raise or lower the volume of mp3 or mp4 audio to the correct dB (89.0) or you can set it louder (up to 110 I believe) if you wish.


You could also use VideoGain which is listed in the link that Baldrick posted.

[enim]

@pinetop

I'm grateful for the help, but "-i foo, -i way" i have no idea what that means?

Selur might help you with working command-line coz Selur is master of SoX command-lines.

ffmpeg -i foo.vid (no video) (only audio) -f wav - | sox normalize wav - | neroAacEnc -ignorelength -q 0.5 -if - -of foo2.m4a

If you are not familiar with sox, you can simply use qaac encoder instead of sox and neeroAAc.

ffmpeg -i foo.vid (no video) (only audio) -f wav - | qaac -c 160 -q 100 --normalize -o "normalized.aac" -.

Baldrick might help you with ffmpeg batch commands or he may put up a small guide in guide section with a working and tested command-lines,on
ffmpeg -i foo.vid (no video) (only audio) -f wav - | qaac -c 160 -q 100 --normalize -o "normalized.aac" -

[Selur]

here's an example for ffmpeg->sox->neroAacEnc

ffmpeg -y -threads 8 -v -10 -i "path to input" -f sox - | sox --multi-threaded --ignore-length --buffer 524288 -S -t sox - -t wav - gain -n | neroAacEnc  -q 0.7 -ignorelength -if - -of "path to output file"

here's an example for ffmeg->sox->qaac

ffmpeg -y -threads 8 -v -10 -i "path to input" -f sox - | sox --multi-threaded --ignore-length --buffer 524288 -S -t sox - -b 16 -t raw - gain -n | qaac --no-delay --threading --raw-channels 2 --raw-rate 48000 --tvbr 75 --raw - -o "path to output file"

for qaac I use raw as piping format since it's best supported by qaac

also https://forum.videohelp.com/threads/352067-normalizing-audio-volume-using-new-ffmpeg-options might be interesting to read.

and if your playback device supports gain flags, you could simply use MP3Gain (which also supports aac audio).

[enim]

@Selur
Normally I introduce delay of 2 frames @ 29.97 = 67ms approx. at the time of mp4 muxing.
Is it possible to introduce 67ms delay by --delay parameter in qaac at the time of encoding?
If so, how you correspond to 67ms to the total number of audio samples (sample. freq x sec ?)?

[Selur]

Normally I introduce delay of 2 frames @ 29.97 = 67ms approx. at the time of mp4 muxing.

aac encoder delay should not be present if qaac with '--no-delay' is used

Is it possible to introduce 67ms delay by --delay parameter in qaac at the time of encoding?

--delay <[[hh:]mm:]ss[.ss..]|ns>
Specify delay either by time or number of samples.
When positive value is given, prepend silence at the
begining to achieve delay of specified amount.
When negative value is given, specified length is
dropped from the beginning.
Example:
--delay -2112s : trim 2112 samples at beginning
--delay 1.234 : prepend 1.234 seconds silence

-> "--delay 0.067" would be 67ms

so, how you correspond to 67ms to the total number of audio samples (sample. freq x sec ?)?

-> https://forum.videohelp.com/threads/357644-Encoding-AC3-to-AAC-with-NeroAAC-Encoder might be interesting, I posted there how I calculate the the aac encoder delay
(also about the subject: http://forum.doom9.org/showthread.php?t=156200 and http://forum.doom9.org/showthread.php?t=164363

Cu Selur

[enim]

@Selur
You owe me Weihenstephan!
I am sharpening a bit more!

But, still you did not disclose recipe or ingredients? Ha..Ha..
Thanks!

[pinetop]

Thanks for the help. I used VideoGain, Its was very easy to use. And believe it didn't re-encode my file.