Created attachment 120529 [details]
Video rendered vs project window monitor

Compared side by side, at the left, playing the rendered video in SMPlayer. On the right, KDEnlive (kdenlive-19.04.2-e782377-x86_64.appimage) as it was composed in project window.

It happens in various cropped videos ("Edge crop" effect)

Created attachment 120579 [details]
demo

I don't know man looks fine to me.

19.04 1c appimage

I keep trying different way to replicate the issue, without success. However, when I was just creating a little version of my projecto to send here, I thoght that could be related to the automatic proxy. And that is!!!! The problem happens after KDEnlive had quietly proxied the clip. If I uncheck in "Clip properties" the "Proxy clip" option (or click on "Delete proxy file" button, the clip is cropped and correctly aligned in monitor. If enable again "Proxy clip" for this clip, the problem appears again, showing in screen a different crop than the real that will be done (see attached files). 
On the other hand, I don't understand why the control box to enable/disable the "Proxy clip" in "Clip properties" some times looks like "half filled" and when I enable it manually, it looks like "Full filled".

Created attachment 120601 [details]
Clip proxied: Not showed correctly in screen

Created attachment 120602 [details]
Clip not proxied: Showed correctly in screen

Still present in kdenlive-19.04.2c-x86_64.appimage

No one can confirm this issue? I continue seeing the problem in latest AppImages. The only workaround is to disable proxy for cropped videos.

I have the exact same problem. Steps to reproduce:

1. start kdenlive-19.08.0a-x86_64.appimage on Debian testing
2. add a 720p video clip and drag it into the timeline
3. add an "edge crop" effect, set "top" so some value
4. enable / disable proxy clip for the video

Result: https://imgur.com/a/sypYT7T

Created attachment 122357 [details]
Demo project with short "video" (5 seconds per frame) demonstrating the problem.

The tool "extract frame" shows the same behaviour, the crop effect changes when proxy clip is enabled / disabled.

I took screenshots from the title clip and compared them to the extracted frames and I found out that while the project (and the original video) has 720p resolution the proxy clip has a lower resolution (721x406) but the crop is applied without taking the scale factor into account, in my example both the proxy and the original clip gets the top 120px removed.

Thank you Alexander. I don't understand why developers can't reproduce the problem.

Created attachment 122358 [details]
Reproducing the problem with the latest git version

I was able to reproduce the problem using the latest git version (3a2cce33f1d74e11b46c7578a53ff697b9e7233a). I made a debug build using qtcreator and ran kdenlive in debug mode.

(In reply to Rafael Linux User from comment #11)
> Thank you Alexander. I don't understand why developers can't reproduce the
> problem.

The bug doesn't show when the original clip has a low enough resolution.

I did the following test:

1. Copy the proxy clip from ~/.cache/kdenlive/proxy/...........mkv to my video directory and rename it proxy.mkv
2. Create a new session and use this video file.
3. Apply the crop.
4. The bug does not show, the proxy clip for the proxy clip has exactly the same resolution as the "original proxy clip".

When I detected the issue, I was using FHD videos. I didn't try with lower video resolutions.

*** Bug 411040 has been marked as a duplicate of this bug. ***

I made more tests and found that

a) The problem disappears when I check "use project resolution"
b) The problem does not affect the effect "Crop, scale and tilt"

Just tried that and workaround a) works for me.

Thank you!

Is the issue still there with the current Kdenlive AppImage version 20.08.1?

Yes, as anyone can check trying with demo attached by Alexander in comment https://bugs.kde.org/show_bug.cgi?id=408235#c10 , issue is not solved at all.
As he wrote, as soon as project is loaded you can test:
- Disable video proxy
- Move project monitor play pointer and watch image in project monitor ("edge crop" effect is not applied)
- Enable video proxy
- Move project monitor play pointer and watch image in project monitor ("edge crop" effect is applied)

Checked with last version

Dear Bug Submitter,

This bug has been in NEEDSINFO status with no change for at least
15 days. Please provide the requested information as soon as
possible and set the bug status as REPORTED. Due to regular bug
tracker maintenance, if the bug is still in NEEDSINFO status with
no change in 30 days the bug will be closed as RESOLVED > WORKSFORME
due to lack of needed information.

For more information about our bug triaging procedures please read the
wiki located here:
https://community.kde.org/Guidelines_and_HOWTOs/Bug_triaging

If you have already provided the requested information, please
mark the bug as REPORTED so that the KDE team knows that the bug is
ready to be confirmed.

Thank you for helping us make KDE software even better for everyone!

The behaviour is still present.

As mentioned before the issue does not appear when checking "use project resolution". I think it would be nice if that was checked by default.

I agree with Alexander, that could be a workaround.

Obviously, "Bug Janitor" is not considering my Comment #19, cause I checked (and anyone can do it) that bug is still not fixed.

I can confirm the bug still happens in 21.08.1 from ArchLinux with MLT 7.01, followed steps (original video 1080p H264, proxied) and what I see is not what I get, remove proxy and what I see is what I get.

Yes, I can confirm this issue with 21.08.1. Put a 1080p50 clip into the timeline; add "Edge Crop", move bottom slider. 

Enable proxy: on that clip: Crop bottom get doubled. 

Disable proxy: crop get back to the initial value.

Can you try checking the "Use project resolution" option in the Edge crop effect ? It should fix inconsistencies between proxy and full resolution clips. Maybe we should check it by default...

Enabling "Use project resolution" solves the problem. Enabling/disabling proxy, the crop keeps the size. 

Enable "Use project resolution" by default would solve the problem.

Git commit dcb71b2dd8d54bf82e883640c4c7c846f9cc4cab by Jean-Baptiste Mardelle.
Committed on 11/09/2021 at 14:29.
Pushed by mardelle into branch 'master'.

Crop effect: use project resolution by default(solves proxy issue).

M  +1    -1    data/effects/crop.xml

https://invent.kde.org/multimedia/kdenlive/commit/dcb71b2dd8d54bf82e883640c4c7c846f9cc4cab

Git commit 8aff4a1469c50ad1a127a15ead3b74494ae6d9a1 by Jean-Baptiste Mardelle.
Committed on 11/09/2021 at 15:37.
Pushed by mardelle into branch 'release/21.08'.

Crop effect: use project resolution by default(solves proxy issue).

M  +1    -1    data/effects/crop.xml

https://invent.kde.org/multimedia/kdenlive/commit/8aff4a1469c50ad1a127a15ead3b74494ae6d9a1