Avidemux Forum

I've been struggling with the same issue from my old Panasonic camcorder. The explanation about SAR vs DAR finally makes sense now.
One thing I've noticed: when dealing with dozens of clips from the same camera, the aspect ratio detection becomes tedious. I recently experimented with using LoraAI fine-tuning on a small vision model to automatically flag which of my archived videos have this anamorphic encoding. It's not perfect, but saves me from opening each file individually in MediaInfo or ffprobe.
The model basically learned to recognize the pattern: "1440x1080 + specific codec metadata = needs DAR attention". Now I can batch-scan folders and get a quick report before importing into Avidemux.
For the actual editing though, your solution is spot-on - keeping "Copy" mode and just ensuring the MP4 muxer forces 16:9 is the cleanest approach. Re-encoding just to preview correctly would be wasteful.
Quick tip for others: If you're on Windows, you can add this to your right-click context menu to quickly check aspect ratio without opening the file:
ffprobe -v error -select_streams v:0 -show_entries stream=width,height,display_aspect_ratio-of compact "%1"

You can  achieve this in Avidemux, but it's a bit buggy. The first and last frames/images will usually have the wrong duration.
You could add blank frames/images at the beginning and end, but personally I would do this with FFmpeg.

Here are the steps for Avidemux.

If you want your images to display for 3 seconds each and an output of 25fps, apply the following steps:

Import images and set Video Output of choice.

In Filters dialogue select Change FPS filter and set Destination frame rate: to 1

Add Resample FPS filter and set New frame rate: to 75.
This is set to 3 x output frame rate (3 × 25).

Add a second Change FPS filter and set New frame rate: to 25.
The output frame rate.

Filters must be applied in above order.

Sark

Quote from: DRWin on February 14, 2026, 02:26:42 PMHow can I keep 25fps (for TV compatibility) while "slowing down" the video

Have you tried the "Resample FPS" filter ?

I made a video using a couple of hundred images, with output set to 1fps so that each image had a duration of several seconds.  The video works perfectly on my laptop, but the TV would not play the video due to "unsupported video format".  The problem is the 1fps output. (I know this because I ran a test video with 25fps output, which displayed perfectly on TV but each image lasted only a fraction of a second.)
How can I keep 25fps (for TV compatibility) while "slowing down" the video so that each image remains displayed for a few seconds?  Can Avidemux do this?

I'm sorry for a very late reply. Which build of Avidemux are you using?

I'm not sure about the exact version of NVIDIA Video Codec SDK headers (nv-codec-headers) various Avidemux 2.8.2 nighties are built against, but if it is 12, then the minimum driver version that SDK requires (522.25) is newer than the last one that still supports GTX 660 (475.xx).

In doubt, if your were using the last release (Avidemux 2.8.1) please try the latest available 2.8.2 build from https://avidemux.org/nightly/vsWin64/

Hello. I've been using Mpeg4 AVC for a while now, and it's taking me all night and most of the day to render a 45-minute movie to 4K. A friend of mine's Nvidia H264 option significantly reduces the video conversion time. However, I'm getting this error. Could this be a problem with a faulty graphics card? I struggled with installing the drivers for a long time, and at one point, they weren't visible in Device Manager. Now they are. However, I keep getting the same error. What could be causing this?




My graphic is Nvidia Geforce GTX 660 2GB.
CPU I5 3550S
16GB RAM DDR3

Dies ist allein die Sache des Clients (also Avidemux, ffmpeg usw.), der die libav*-Bibliotheken nutzt.

Falls es sich um die Unterstützung von Intel Quick Sync zum Kodieren von Videos als HEVC (oder H.264) in Avidemux geht, ist sie nur unter Linux mittels gebündelter libavutil Library via VA-API-Schnittstelle verfügbar.

Je nachdem wie FFmpeg kompiliert wurde, könnte die entsprechende Unterstützung über Windows-spezifische Schnittstellen verfügbar sein. Fragen zu FFmpeg bitte auf den Mailingslisten des FFmpeg-Projekts oder in entsprechenden Foren stellen ;-)

Quote from: Gloster on February 01, 2026, 10:40:09 PMIch speichere öfter via Avidemux meine TS-Dateien im Kopier-Modus ab. Der TS-Stream der von der Schüssel kommt verwendet ein 192 Byte Ts-Container Protokoll, Avidemux macht daraus ein 188 Byte Ts-container Protokoll, die 4-Byte Präambel wird entfernt (warum auch immer).

Man kann den M2TS-Modus in den Einstellungen des MpegTS-Muxers erzwingen, falls aus irgendwelchen Gründen gewünscht.

Füll-NALUs (falls solche unter "Null-Bytes" gemeint sind) werden von Avidemux aus MPEG-TS immer dann entfernt, wenn im Kopiermodus aus MPEG-TS als MP4 oder MKV (also nicht als MPEG-TS) gespeichert wird. Beim Speichern als MPEG-TS kann man im Gegenteil vom MpegTS-Muxer verlangen, Füllmaterial hinzuzufügen, um eine konstante Bitrate zu erreichen, nützlich für Übertragungen über eine Verbindung mit fest vorgegebener Bandbreite.

Danke für die Info.

Es ist ja ein TS vom Sat-Receiver. Ist da bei der Ausstrahlung an sich schon was falsch gelaufen? Beim Ansehen des Film war der Ton nicht auffällig und Avidemux hat den Stream ohne aktivierten Kompressor ja auch klaglos verarbeitet