Avidemux Forum

Avidemux currently doesn't understand that codec tag "hev1" means HEVC.

(More precisely, only the MP4 demuxer supports that tag. This is why a placeholder, invalid decoder is chosen when opening this video stored in an AVI container, while an MP4 works.)

Thank you, HEVC in MP4 is accepted by ADM.

However who's the culprit?

Does OpenCV writes HEVC in MP4 errornous?
(There would be a bug in OpenCV)
Is ADM unable to read HEVC in AVI?
(That would be bug or restriction of ADM)

Quote from: guju on April 09, 2024, 12:54:22 PMwhat is going wrong here

- container .avi
Save the output of OpenCV to .mp4 container. 

Recently I needed to edit a HEVC video that was generated
by standard HEVC output of OpenCV (ffmpeg 5.0.1).

Opening gives no error message but only a black screen.
(Opening it with VirtualDub2 (2020), ffmpeg CLI or MPC-HC: no problem).

Can you tell what is going wrong here?
Is it a bug of ADM? (Or maybe of HEVC-type generated?)

https://c.gmx.net/@1155842887640945833/bJH2qPQ-Tm279HnSREF4SA

EDIT:
It is lossless HEVC.

Quote from: szlldm on April 08, 2024, 04:44:26 PMThat is the right URL. When the next nightly build will be built, you will find it there.

Great! Can't wait. Best regards!

That is the right URL. When the next nightly build will be built, you will find it there.

I will check it out, thank you! Only one thing: I know about https://www.avidemux.org/nightly/win64/ - where I can find a feature builds?

What MP4 got to do with my post? The file is MKV. It is Star Trek series where it was filmed in 23.976 and the cgi part in 29.970. The timestamp correctly uses both so the audio is in sync. As my first post avidemux created a weird timestamp that was not compatible with the mkv file.

Seriously why can't avidemux just use the original mkv timestamp and not change it.

Bonjour, j'ai bien lu vos consignes. Je n'ai pas l'ordinateur en question sous la main.
Donc j'essaierai dès que je pourrai, peut-être le week-end prochain, de relancer un encodage avec une version plus récente d'Avidemux, et je vous enverrai les fichiers de log.

Merci à vous

Avidemux tries to restore original timestamps in specific cases when variable frame rate in MKV is an artifact of timestamps being not precisely representable with 1 millisecond resolution in MKV: remuxing a MP4 with a CFR video track at 30000/1001 fps (time base 1001/30000) to a MKV and back to MP4 using Avidemux results in a CFR video like the original. Performing this roundtrip with ffmpeg creates a VFR MP4, the CFR property is lost.

In some rare circumstances, guessing the original timing may go wrong. Please provide a sample MKV then, thank you.

Official releases which are older than a couple of weeks are only useful to verify that an issue found in a nightly build is not a recent regression.