Avidemux Forum

**OS and Version (please complete the following information):**
 - Operating System: windows 64bit (Intel(R) Core(TM) i7-8700 CPU @ 3.20GHz   3.19 GHz)
 - Software Version: latest version

**Describe the bug**
for Snapdragon 8 Gen 2 & 8 Gen3 based mobile phones， all 4K HEVC 60fps mp4 recorded by build-in Camera App，
does not play smoothly and stutters in this software. it seems a common case.

**Steps To Reproduce**
1. Start Shotcut
2. Load the mp4 file (you may record by any model of such mobile phones which equipped above SoCs)
3. Playback

**Expected behavior**
A smooth playback

**Screenshots**
n/a

Quote from: Luc77600 on November 09, 2026, 02:14:50 PMHowever—and I'm not sure why—the first time I launch Avidemux, I have to wait several minutes before I can actually use it.

Please see the recent topic "Question about updates" starting with https://avidemux.org/smif/index.php?msg=98741 (Windows Defender screwing up Avidemux and similar modular software is not new though).

I'm running the same Windows version and load time is about 2 seconds. If I drag a video file onto the Avidemux shortcut on my desktop, it still only take about 2 seconds to load. The video file may of course take longer to open, depending on its size.

I'm running an older system with Win 10 installed, but it is completely offline, so I have no security running. My guess is your security somewhere is causing the issue.

Hello,
I use the latest portable versions of Avidemux.
I don't encounter any particular issues with how I use the software.
However—and I'm not sure why—the first time I launch Avidemux, I have to wait several minutes before I can actually use it. Furthermore, if I close Avidemux during a Windows session and then relaunch it later, I once again have to wait a long time before I can use the program.
It feels as though numerous components need to be "loaded" each time, and that these components are discarded after Avidemux has been left unused for a certain period...
I am running Windows 11 Pro 26H2.
This issue was already present in Avidemux 2.8.2 (from Dec 12, 2024), though the startup time was much faster in that version.
Are you aware of this issue, and do you know what might be causing it?
Thank you for your help.

One other question...Did you make it Keyframe only to satisfy your own needs, or was it a technical limitation. Just curious!

(1) Find on the official site : Up to 256 kbit/s per channel. So it is relevant.
https://www.iis.fraunhofer.de/en/ff/amm/broadcast-streaming/aaclc.html

(2) It works !

Thanks for the solution.

Impressive. Well done... I don't use subs myself, but I've more than once read requests here for subtitle support in Avidemux. This should satisfy the needs of those Avidemux users.

Before posting this I did a quick test with a short file with subs and all worked well. I'm being pedantic I know but, it would be nice if the intermediate file was automatically deleted. No big deal though.

Overall, a nice project that should be of use to other Avidemux users.

Quote from: NXYZ on November 08, 2026, 04:01:28 AMWhy are not proposed 320 and 256 kbit/s ?

Probably some copy and paste from older to newer AAC audio encoder plugins in action here. Higher bitrates with AAC make sense only with 6 (up to suppoted max value of eight) channels. I don't think this is relevant in any way to "fill the gaps" in the bitrate menus, but less than 64 kbit/s per channel may be undesirable regarding quality.

Quote from: NXYZ on November 08, 2026, 04:01:28 AMIs there a setting or trick, to restore these bitrates ?

Create a project script for your encode (prior to exporting = saving the output, use "File" --> "Project Script" --> "Save As Project..." to generate the .py file), modify the value matching the bitrate in the script to your liking, run the script via "File" --> "Projekt Script" --> "Run Project...", do not open audio codec configuration dialog, save / export the video.

Hello everyone !

About AAC codecs.

Why are not proposed 320 and 256 kbit/s ?
Is there a setting or trick, to restore these bitrates ?

Thanks in advance.

First, thanks to the developer of this app, I think it's the best MKV editor on the planet!

To download the files, head to my Proton Drive: https://drive.proton.me/urls/JNHHJPAG2M#f7ZP0FwujNB8

The file names are fairly self-explanatory as to what they are. If you have any questions or problems, let me know. The Linux builds are self-contained AppImage files and the Windows ZIP is a portable version of Avidemux.

Once you're done editing your media file and save it.... you can leave Avidemux open or close it but shortly after saving your file, in that same folder, you'll eventually see a file named '.subs'. That will be the FINISHED file with your edits AND time synced and retained subtitles!

Example, say you're editing a file named 1.mkv. Make your changes and hit save and it will default to naming it 1_edit.mkv. A few seconds later (depending on the speed of your disk sub-system) this modified version of Avidemux will produce 1_edit.subs.mkv.

While it's creating the .subs file, it's normal to see a weirdly named mkv file for a short time. This is just a temp file so don't panic.

I hope you all find this modified version of Avidemux as useful as I do.