Avidemux Forum

Quote from: eumagga0x2a on December 17, 2025, 05:16:47 PM

Quote from: Faiakes on December 17, 2025, 04:07:05 PMI go this and a crash from, I suspect, a malformed video file.

This is entirely possible as the size of a compressed frame is supplied by the demuxer used to load the specific file. If the size calculated by the demuxer doesn't fit into the allocated buffer, we safely call it quit.

It might be interesting to analyze the presumably malformed file to understand whether we should have rejected opening it in the first place, but, in general, a safe termination of the application is likely to be the second most sensible way to deal with such an issue.

Well, idiot me I deleted the file but I think I can find it again.
Would you want me to?
(It was an old foreign language film. I have found a different version, so I don't need anything per se)

Quote from: Faiakes on December 17, 2025, 04:07:05 PMI go this and a crash from, I suspect, a malformed video file.

This is entirely possible as the size of a compressed frame is supplied by the demuxer used to load the specific file. If the size calculated by the demuxer doesn't fit into the allocated buffer, we safely call it quit.

It might be interesting to analyze the presumably malformed file to understand whether we should have rejected opening it in the first place, but, in general, a safe termination of the application is likely to be the second most sensible way to deal with such an issue.

Hi

I go this and a crash from, I suspect, a malformed video file.

Thanks for the minimize option...

I really don't know why I didn't even consider running it in a Virtual Desktop... I'm getting old, my brain is worn out.

Thanks for script option and the obvious (for most) the Virtual Desktop option.
Cheers

You can try re-muxing the file with mkvtoolnix.

Note that this is re-muxing, not re-encoding, the process should be very quick, as in seconds or maybe a minute or two.

You can even change the framerate to 25.000 fps, 24.000 fps, whatever you want.

Load your file, then select the default duration of 24000/1001, which equals 23.976 fps, the audio will remain unchanged.

If the resulting re-muxed file is of a different length or the audio becomes de-synced, further investigation would be required.

https://mkvtoolnix.org/

I dunno if this helps, or if it is still relevant some 8 years later(?), but, if you have a video that is in 25fps, the only option is to re-encode at 23.98, AND modify the audio filter to resample the audio "From PAL to FILM". This will keep the sync, but it will also extend the video a little and may sound "slower" - but in my experience with anything encoded in 25 fps, that is not the proper pitch for the audio anyway, and if you have a sharp ear, you can tell anything in 25 fps sounds a little "chipmunky" when compared to a proper 24 fps file.

Anyway, by the sounds of it, you have a perfectly good 23.98 fps video, but the audio tracks are somehow encoded to be in sync with a 25 fps speed, making them OUT of sync with your video, correct?

If so, try half of what I suggested, and COPY your video (as MKV or MP4) as you would, but use the AUDIO FILTER to change audio from "PAL to FILM"  and hopefully that will sync everything up without having to re-encode the video.

Alternatively, if you want to speed up the video to match 25fps audio, then you're looking at re-encoding the video.
I dunno why you would want to speed it up anyway? That "chipmunk" pitch is annoying and ruins a good movie.

I also recommend making sure the sample rate is set to 48 kHz (48000 Hz), if it isn't already, as I have had horrible results with 44kHz after copying/converting. 44kHz is great for audio music (CD) tracks, but not movie audio.

I posted about this in another thread, but let me try presenting this problem again, a different way :

Is there ANY WAY to MODIFY the FPS in a HEVC (H265) MP4 file, to a more specific rate (from 23·976215 to 23·976023)?   (Those last 3 digits have proven to make a crucial difference.)

I want to FIX my HEVC files that were somehow encoded with a 23·976215 framerate, causing defective results when trying to convert to AVC/H264. This framerate gets screwed up (whether converting to AVC/H264 or HEVC/H265) where it is automatically slashed to half (between 12 and 15 fps).

I tried doing the conversion in Freemake, but the video would not even be recognized and was automatically replaced with "visualizations". (Red flag right there!)

I tried doing conversions in VLC, but NOTHING ever works in VLC except playback. I even tried the "record" function while the file played, but the output was an MP4 with NO VIDEO, just audio.

I tried a Video Converter from NCH Software, but that cheap crap made the video look pixely and turned it into garbage.

Avidemux is the only program that does a decent job on most conversions (despite taking forever) - EXCEPT for this HEVC framerate issue.

While attempts to circumvent this problem in Avidemux have been futile, I came close with using the video filter to "Change FPS" from "23.98 Custom (default)" to "23.98 (Film)" - while the framerate correctly changes to 23.976023, the picture is now a bit stuttery/choppy. It's not as bad as other results, but it's noticeable enough to be annoying.

Why will the smoothness not be retained?
Why does this "215" value in the framerate cause ANY/ALL conversions to screw up the framerate so badly?
Why does modifying "215" to "023" still cause a slight stutter/choppy playback of the video?
In short : HOW DO I FIX THIS?

I know Avidemux is probably loaded with all kinds of settings, but they are in "proper editor terms" I don't understand, and I cannot find anything to "translate" them into layman's terms, so I can figure out what might fix these damn files that were encoded so poorly.

If there is a setting that will correct this discrepancy in the framerate and finally yield a smooth, quality AVC/H264 conversion output at a proper 23.98 (23.976023) fps without stuttering or jerking during playback, I would like to know.

Even if I have to convert the "bad" HEVC/H265 to a "good" HEVC/H265 before converting to AVC/H264 after, as long as I do not lose quality, I'll endure that extra step (despite more countless hours wasting my days away, cos these processes take so damn long).

I also use Windows XP, so my "conversion tool" software options are already limited.


PS :
Please don't get on me about why I still use XP. I have my reasons.
Let's stay on point with the topic, thanks.

Let me try this again, a different way :

Is there ANY WAY to MODIFY the FPS in a HEVC (H265) MP4 file, to a more specific rate (from 23·976215 to 23·976023)?   (Those last 3 digits have proven to make a crucial difference.)

I want to FIX my HEVC files that were somehow encoded with a 23·976215 framerate. This framerate results in screwy conversions (whether to AVC/H264 or HEVC/H265) where the framerate is automatically slashed to half (between 12 and 15 fps).

I tried doing the conversion in Freemake, but the video would not be recognized and was automatically replaced with "visualizations".

I tried doing conversions in VLC, but NOTHING ever works in VLC except playback.

I tried a Video Converter from NCH Software, but that cheap crap made the video look pixely and turned it into garbage.

Avidemux is the only program that does a decent job on most conversions (despite taking forever) - EXCEPT for this HEVC issue (this is why I despise HEVC and any compression formats).

While attempts to circumvent this problem in Avidemux have been futile, I came close with using the video filter to "Change FPS" from "23.98 Custom (default)" to "23.98 (Film)" - while the framerate correctly changes to 23.976023, the picture is now a bit stuttery/choppy. It's not as bad as other results, but it's noticeable enough to be annoying.

Why will the smoothness not be retained?
Why does this "215" value in the framerate cause any conversions to screw up the framerate so badly?
Why does modifying "215" to "023" still cause a slight stutter/choppy playback?
HOW DO I FIX THIS?

I know Avidemux is probably loaded with all kinds of settings, but they are in "proper editor terms" I don't understand, and I cannot find anything to "translate" them into layman's terms, so I can figure out what might fix these damn files that were encoded so poorly.

If there is a setting that will correct this discrepancy in the framerate and finally yield a smooth, quality AVC/H264 conversion output at a proper 23.98 fps without stuttering or jerking during playback, I would like to know.

Even if I have to convert the "bad" HEVC/H265 to a "good" HEVC/H265 before converting to AVC/H264 after, as long as I do not lose quality, I'll endure that extra step (despite more countless hours wasting my days away, cos these processes take so damn long).

I also use Windows XP, so my "conversion tool" software options are already limited.


PS :
Please don't get on me about why I still use XP. I have my reasons.
Let's stay on point with the topic, thanks.

CleanTalk was standing in alexstorm's way trying to post the following text he sent to me via PM:

================= (begin of quote) =================

Thanks RH, that is interesting that CleverFFMPEG_gui software works. There are several different subtitles types that can be embedded or as separate files.  Does this software work for all subtitles?

If this was requested in Post Production house, all edits would use a time code list that has all edit removal or additional drop in inserts, The editor would give the time code list to a subtitle person and they would also use separate software, like you mentioned, to fix the subtitle timing. Does it qualify as a new feature when you are the only person, I've ever seen to ask for it?

I think AVIDemux would need to first support Time Code lists.  Does that happen somewhere with a plug in?

Search for video edit timecode list online to find more info on how to work with timecodes.

================= (end of quote) =================

On my part, I explained it multiple times on many occasions what is required to add support for subtitle tracks in Avidemux – high quality patches are welcome (yes, I know that a few good pull requests in other areas are currently rotting awaiting merge, my fault due to lack of time and task overload).

If you absolutely cannot use the CLI application, e.g. because you need hw accel features (hw video decoders or encoders, OpenGL video filters), you can minimize the window of the graphical application using QtGuiWindowMinimize() method in Gui() class, e.g.

gui = Gui()
gui.QtGuiWindowMinimize()
There is no way to script default zoom value.

By the way, why not running Avidemux on a separate workspace / on another virtual desktop? At least on Windows. On Linux it will impertinently pop up on your current workspace right in your face when encoding is finished, at least with gnome-shell, unfortunately.