Thumbnails on trimmed videos

[MadDogDean]

Hello,

I have mp4 videos taken from a DJI Action 3. They are saved in .h264, 1920 x 1080 30fps.

When I trim the videos, I set the beginning to a keyframe and trim it (as needed), etc, etc.

But when I save the video, I no longer have a thumbnail visible in File Explorer (the originals did), now I only see the VLC (or other player) icon. I am using avidemux via the GUI. Is there some setting I am missing to set the new first frame as the thumbnail or do I need to do something else?

Thanks,
MadDogDean

PS. I searched the forum but couldn't find anything for my need

[eumagga0x2a]

Please make sure you use a supported version of Avidemux (preferably the latest available 2.8.2 nightly, else the last 2.8.1 release which means that in case of problems you will be asked to verify against the newest nightly) and provide information which would allow to assess the issue:

1. Output format (muxer) and its settings.

2. Copy mode or re-encoding, and if the latter, which encoder and its configuration.

3. Windows version.

[MadDogDean]

Hello,

I was running ver 2.8.1 and just tried the nightly, both with same results

1. The original file is an MP4, so the muxer is left on MP4, settings are all default.
Format: MP4
Optimize for Streaming: Move index to beginning of file
Rotate video: Do not rotate
Time scale: Auto

2. Copy mode

3. Windows 11 (also same action & results on Win 10) all updated.

Thanks

[eumagga0x2a]

Could you please do the following in order to narrow down the list of possible causes:

1. Please export a (part of) video which had got a proper thumbnail prior to being edited with Avidemux, in copy mode as before but this time using the MKV muxer.

2. Please export (a part of) the same source video using the MP4 muxer, but with the video track re-encoded using the x264 encoder. Then repeat the same with "resample fps" filter inserted.

3. If you have downloaded a MinGW-built nightly (those from the "win64" directory on the server), then please try exporting in copy mode using the MP4v2 muxer (yes, unsupported and obsolete – which can change now as the libmp4v2 library it is based upon is maintained again after many years of being abandonware). Else please download a win64 nightly instead of a Microsoft Visual Studio-generated vsWin64 one first.

4. If nothing of the above results in a video thumbnail being generated, please check whether the outcome in a different Windows user account is different.

I don't have Windows 11 (and until very recently didn't have any Windows-11-compatible hardware), on my Windows 10 system which exists for the sole purpose of being able to test Avidemux, there is no problem with thumbnails for videos exported by Avidemux.

[MadDogDean]

Thanks for all of that. I'll make some time this weekend to check things out.

Cheers