Avidemux Forum

Avidemux => MacOSX => Topic started by: fugueink on July 17, 2024, 04:24:50 PM

Title: Slow down audio
Post by: fugueink on July 17, 2024, 04:24:50 PM
I am trying to slow down the audio of something by 15 percent. I am willing to slow down the video as well, but the goal is a 15 percent slower audio file.

I found how to slow down the video, but I can find no place to do that with the audio, not even a stay-synced-with-video option.

Is there any way to do this in Avidemux? I really don't want to have to try to compile Ffmpeg for Audacity again, for such a tiny task. I spent two or three hours on it a few months ago and had to give up in the end.

Sorry, forgot system info: MacOS 10.15.7 (Catalina), Avidemux 2.8.1 (220209_588c8f3e649-fflibs 4.4.1)

Thank you.
Title: Re: Slow down audio
Post by: szlldm on July 17, 2024, 04:49:44 PM
Add the "Change FPS" video filter, set the desired new fps.
Then go to audio filters, change "Frame rate change" to Custom. The Tempo multiplier should be automatically filled to the desired value.
Title: Re: Slow down audio
Post by: fugueink on July 17, 2024, 05:58:05 PM
There is no "Custom" in the pull-down menu next to "Frame rate change".

The choices are: None, Film to PAL, and PAL to Film.

I did double check that I had the video filter correct.

Thank you.
Title: Re: Slow down audio
Post by: szlldm on July 17, 2024, 09:55:46 PM
Try the latest 2.8.2 nightly build. It could be that custom audio frame rate change was integrated after the 2.8.1 release. It was a long time ago...
Title: Re: Slow down audio
Post by: eumagga0x2a on July 17, 2024, 11:37:59 PM
Audio stretcher with custom frame rate is definitely present in 2.8.1 release, but not in a pre-release 2.8.1 nightly fugueink is using.

Quote from: szlldm on July 17, 2024, 09:55:46 PMTry the latest 2.8.2 nightly build.

There are none compatible with the ancient macOS version installed, fugueink would have to build it locally from source. Doing this on a system not officially supported by Homebrew is untested, but is worth a try.

A much easier solution would be installing Windows 10 as a second operating system and using an official 2.8.2 nightly for Windows there.
Title: Re: Slow down audio
Post by: fugueink on July 18, 2024, 12:44:53 PM
Yikes. . . .

None of those are possible for me. I guess I am out of luck.

Thank you for telling me, though!