Avidemux Forum

Quote from: sark on May 11, 2025, 07:52:48 PMFirstly though, I strongly recommend you try the latest 2.8.2 (241212) version of Avidemux. 2.8.1 is very old.

Exactly, 2.8.1 is ancient. All reported issues must be verified against latest 2.8.2 developer builds.

Quote from: FMartin on May 11, 2025, 07:33:34 PMMy normal process would be to add my saved preset with filters through the Custom tab, that involves a cropping to 16:9, then to get half-speed with blend, first Resample FPS to 60 fps with Blend on, then Change FPS from 60.000 to 30.000

Always add "Resample FPS" after "Change FPS" to the filter chain (a second instance, if necessary).

With this condition follwed, please verify that the issue persists with the latest available 2.8.2 nightly build. The last known good official cross-compiled build, as sark said, is r241212. I didn't have time to test the latest VC++ nightly build from May 9 yet, the previous one was still missing some features and suffered from the upstream Qt installer bug which broke uninstallation via Windows Settings (to uninstall it, run the uninstaller in the program directory).

Hi again.

Hopefully eumagga, who currently maintains Avidemux, will be able to help. Firstly though, I strongly recommend you try the latest 2.8.2 (241212) version of Avidemux. 2.8.1 is very old.

https://www.avidemux.org/nightly/win64

Hi! Again, thank you for this wonderful and efficient little tool, I've used it for many years to compile timelapses of the night skies or auroras so even those can enjoy who can't travel there or can't tolerate the cold.
 
Lately unfortunately I've noticed a bug: the output framerate is not precise, there is a slight variation, e.g. instead of 30.000 fps, I randomly get 30.01, 30.02, ... even up to 30.28 fps.

I'm using Avidemux 2.8.1 on Windows 10

When I open the first jpg, this is the Info / Properties window:

=====================================================
Video
=====================================================
Codec 4CC:         MJPG
Image Size:         3840 x 2558
Aspect Ratio:         1:1 (1:1)
Frame Rate:         25.000 fps
Average Bitrate:      408672 kbps
Total Duration:         00:00:04.240
Pixel format:         YUV 4:2:2, 8-bit
Color range:         Full (JPEG)
Color primaries:      BT.709
Transfer characteristics:   BT.709
Color space:         BT.470 System B/G

=====================================================

This is just a hundred photos for a quick test, but I've go the same issue even with 6-700 photo timelapses.

My normal process would be to add my saved preset with filters through the Custom tab, that involves a cropping to 16:9, then to get half-speed with blend, first Resample FPS to 60 fps with Blend on, then Change FPS from 60.000 to 30.000; then some Eq2 and Denoise3DHQ - this results in files that are close to 30 fps, but always a fraction over: 30.01, 30.02, .. even up to 30.28 fps.
I've tried it also with the Resample and Change FPS filters, but the issue persists.

I still had the old 2.7.8 installed, unfortunately that doesn't have the Blend option in Resample FPS, and I can't find how to set the project default to 30 fps, but at least there the output is a clean 30.000 fps.

Let me know if you have any ideas what might be causing it.
Thanks!

Thanks for the reply and thanks for taking the time to try to replicate!
Yes, the default is 25 fps - I think I changed it in Edit / Preferences / Import - Assign following standard frame rate: 30.
I will open a new thread then.

I cannot reproduce the issue. If I import a group of images they default to 25fps. I can use "Change fps" to adjust to 30fps. Alternatively, I can use "Change fps" to 12.5fps with "Resample fps" set to 30fps and Blend enabled. In both cases output is exactly as set.

I would suggest you do indeed open a new topic, with a precise example of the workflow that is causing the issue.... Good luck.

Thanks for the reply! I've already been using custom presets for some time
With Resample (+blend) and Change fps I can get what I need but the framerate is still an issue, and a bigger one. Maybe I should open a new topic for it?...

The input is jpg files.

I've also tried just turning jpgs into a timelapse, without any Resample and Change fps speed-up or slow-down, and even this way the resulting framerate was 30.28 fps...

If you are always working with 30fps input, you can create a custom script to instantly apply both filters (and the configuration settings), and apply from the Custom menu with a single click.
No scripting skills are required. If this is of interest I will happily post a simple "how to".

Not sure about your odd framerates, 30.02 and 30.02 etc. Possibly an input with "variable" framerate? Just a guess.

Glad it works for you now, but what was the key for success – using VC++ nightly from Mai 1 or turning hw decoder on (or off?)?

Now, it works perfectly! Thank you very much! JK

Hi, first of all, thank you for this wonderful and efficient little tool!

I've started using Avidemux a long time ago (probably over a decade) to compile timelapse videos from photos. Many of these are astrophotography, shooting stars or northern lights timelapses, shot in conditions so dim that I have to take longer exposures than I'd like - the solution was to use the Change FPS filter's blend option in the old versions, so it would generate an intermediate frame between real frames, and I could have a 30 fps video from just 15 frames - double the duration, not as hectic movement in the skies.

However, this feature was removed in later versions. There is now a separate filter called Blend, but it only combines existing frames to speed up a timelapse - I need the opposite.
I've tried using the Change FPS, from 60 to 30 (like I did many years ago, when the Blend was still there), but that now just results in making the 30 fps project a 15.0x (randomly 15.01 or 15.02 or 15.04 etc) fps file. Here's one of the videos on Yt - since it's slow movement, it's not so apparent that it's just 15 fps, but if you click stats for nerds, you'll see it.

As a workaround, I've also tried combining it with the Resample FPS filter as that still has the Blend option:
Project of 30 fps -> Resample FPS to 60 with Blend enabled -> Change FPS 60 to 30 fps: and the end result is 30.0x fps (again randomly 30.01 or 30.02 or something similar).
Now this workaround works, but it's not very elegant - it would be nice if the slowing-down Blend could be added back. Or is there a better way to do this?

And these random fps numbers, I wish the set fps was better enforced. These are short clips (10-30s), maybe there's not enough granularity, but still. When I found out I'm only getting 15 fps, I resorted to DaVinci Resolve, and it could make it a clean 30.00 fps (however, Resolve is just overkill for this task, way too complicated, resource-hungry and wasteful, I don't like using it). It's kinda close enough, but before I start recompiling a few dozen timelapses, I thought I'd ask Should I open a separate topic for the fps issue?

Thanks!