ffmpeg from pan to only 1 audio monotrack and monochannel

[marcorocchini]

Hi

I'm a cat, please patience.

ffmpeg64bit2014.exe -y -i input.avi -vn -map_channel 0.1.0 -map_channel 0.1.1 -af "pan=stereo:c0<c0+c1:c1<c0+c1,volume=1.5" -c:a pcm_s24le gat.wav

from this commandline I get an audio wav file with 2 channels, can I generate the mix of pan into one single track and one channel (not 2 channel)?

my input is a stereo L+R file

[cholla]

This works for me:

[The_Doman]

This can probably help you out?

FFMpeg: Manipulating audio channels

[cholla]

This works for me:

ffmpeg64bit2014.exe -y -i input.avi -vn -af "pan=mono|c0=0.5*c0+0.5*c1,volume=1.5" -c:a pcm_s24le gat.wav

[marcorocchini]

wow

[Attachment 92634 - Click to enlarge]

it works ***

so

ffmpeg64bit2014.exe -y -i input.avi -vn -af "pan=mono|c0=0.5*c0+0.5*c1,volume=1.5" -c:a pcm_s24le gat.wav

is it the same of using

ffmpeg64bit2014.exe -y -i input.avi -vn -af "pan=stereo:c0<c0+c1:c1<c0+c1,volume=1.5" -c:a pcm_s24le -ac 1 gat.wav

?

[cholla]

This is the simplest code that does what you are trying:

ffmpeg64bit2014.exe -y -i input.avi -vn -af "pan=mono|c0=c0+c1,volume=1.5" -c:a pcm_s24le output.wav

If you get clipping remove the volume=1.5.

Or this code will normalize but same as the above if you get clipping.

ffmpeg64bit2014.exe -y -i input.avi -vn -af "pan=mono|c0<c0+c1,volume=1.5" -c:a pcm_s24le output.wav

Adding gain requires different coding if that is what you want instead of volume increase.

Basically the equal sign = adds their volume levels directly for each channel.
The less than sign means "Normalize" & calculates the total gain coefficient (1 + 1 = 2) and divides each individual channel's gain by that total.

[jagabo]

Simple stereo to mono mix, (L+R)/2,

https://trac.ffmpeg.org/wiki/AudioChannelManipulation#stereomonostream

ffmpeg -i stereo.flac -ac 1 mono.flac

[cholla]

Simple stereo to mono mix, (L+R)/2,

ffmpeg -i stereo.flac -ac 1 mono.flac

jagabo your code will work except the OP wants to remove the video so it needs -vn added.

I had never worked with the Pan settings in ffmpeg before.
They are to control the levels. So a mono does not get the full level of each track.
If the full level is used a lot of conversions get clipping.

This one should resist clipping

ffmpeg64bit2014.exe -y -i input.avi -vn -af "pan=mono|c0=0.5*c0+0.5*c1" -c:a pcm_s24le output.wav

If you leave this out of the code c:a pcm_s24le it will usually do 16-bit .

[jagabo]

Simple stereo to mono mix, (L+R)/2,

ffmpeg -i stereo.flac -ac 1 mono.flac

jagabo your code will work except the OP wants to remove the video so it needs -vn added.

I was just showing a simple command line that converts stereo to mono. The OP can adapt it to his circumstances for himself.

[dannyboy48888]

Jagabo solution is what I do instead I pump to wav then run normalize-audio on it. That is the Linux command, dunno the windows cli equivalent