Builds 2.8.1 and 2.8.2 blur video

[Aabyhoj]

It appears that Avidemux builds 2.8.1 and 2.8.2 (but not 2.8.0) blur video. The effect is associated with opening and rendering of the original video by Avidemix viewing system and not by its following compression. The recompression simply reproduces the viewed image ("correct" of "faulty"). The below images present a capture from 2.8.0 (where the beard of an officer is reproduced very well) and a capture from 2.8.2 (where the beard is blurred). The compressed files give the results in accordance with a "correct" viewing of 2.8.0 and a "faulty" viewing by 2.8.2. The effects were observed on Alienware 18', Windows 10, Nvidia graphic card.

[eumagga0x2a]

Please ensure post-processing is  completely disabled in Avidemux preferences.

Post-processing was broken for a long time and fixed a couple of years ago, so that settings inherited from very old Avidemux versions (in current Avidemux, post-processing defaults to "off") take effect.

[Aabyhoj]

Thank you, but I do not think that the postprocessing is the reason. Avidemux 2.8.0 I am currently using (and which renders video absolutely correctly) has two functions in Default Postprocessing enabled: (i) Horizontal deblocking and (ii) Vertical deblocking, while Deringing is disabled. Yet, 2.8.0 gives no blurring in contrast to 2.8.1 and 2.8.2. The two latter versions also have a somewhat unsharp appearance of their buttons (which have different icons in comparison to 2.8.0). I suspect that there is some incompatibility between GUI of 2.8.1 and 2.8.2 and my graphic card (Nvidia 8.1.940.0) or some setups. Do you have any comments?

[szlldm]

Default Postprocessing enabled: (i) Horizontal deblocking and (ii) Vertical deblocking

This is exactly what causes the blurring.
In 2.8.0 (and prior) the postprocessing settings are ignored, and disabled.

[Aabyhoj]

Yes, I got what you mean. The menu of 2.8.0 has two post processing options checked "on", but they are disabled by internal codes, while in 2.8.1 and 2.8.2 they are both checked and enabled. Indeed, when all post processing of 2.8.2 was removed, everything fall in place and the video became OK. Thank you for a very useful comment! But this means that it should be stated in very large letters: DISABLE ALL POST PROCESSING IN 2.8.2 !!!! unless you want to spoil your video. Thanks again!

[Geo_log]

... But this means that it should be stated in very large letters: DISABLE ALL POST PROCESSING IN 2.8.2 !!!! unless you want to spoil your video.

- I support this. It would be good if program asked (one time, only if post processing is ON): "Are you sure you whant to spoil your video with POST PROCESSING ?".  Because a lot of old users are spoiling their videos rigth now...

[nobby23]

Yes, I got what you mean. The menu of 2.8.0 has two post processing options checked "on", but they are disabled by internal codes, while in 2.8.1 and 2.8.2 they are both checked and enabled. Indeed, when all post processing of 2.8.2 was removed, everything fall in place and the video became OK. Thank you for a very useful comment! But this means that it should be stated in very large letters: DISABLE ALL POST PROCESSING IN 2.8.2 !!!! unless you want to spoil your video. Thanks again!

Does the need for disabling the post processing in 2.8.1 and 2.8.2 apply to non-windows versions of Avidemux? (I noticed this is a Windows thread)
I am running Ubuntu 22.04.2 LTS on a Macmini7,1 with Avidemux 2.8.1 installed from the ubuntu repositories. Should I also disable all the post processing options including the HDR options in the bottom section, or just the horizontal and vertical deblocking?

[szlldm]

or just the horizontal and vertical deblocking

deblocking and deringing should be disabled