Feature request: Make syncing videos frames more easy please!!

[921j]

When comparing videos, I often encounter that the starting frame and frame rate of two videos are different. Therefore, I really need the hotkey to quickly adjust the left and right video's frames separately.
Previously, I used a tool named "VCmpTool", whose open source URL is
https://github.com/ronnielige/ffmpeg-4.2.3-VCmpTool
some hotkey description:
q, ESC quit
f fullscreen
p, space Play/pause
s next frame

F1                           left video next frame

F2                           right video next frame

It is important that F1 and F2 support long press to continue to the next frame

Unfortunately, it seems that this tool has stopped development.
Today I accidentally discovered that your tool is also very useful, but the only thing that makes it difficult for me to adapt is the lack of F1 and F2 functions similar to it. I hope your tool can also achieve similar functions, now attached is the Windows version of VCmpTool:

VCmpTool.z01.zip
VCmpTool.z02.zip
VCmpTool.zip

PS: Download the above three files, change VCmpTool.z01.zip and VCmpTool.z02.zip to VCmpTool.z01 and VCmpTool.z02, extract and run on CMD:
VCmpTool video1 video2

I am looking forward to it and thank you!

[jonfryd]

Sounds to me like the time-shifting features (press + and - from the UI and the -t command-line option) we have already cover this (i.e., adjust videos which are slightly out of sync).

[921j]

I've already read the relevant posts you mentioned, also tried using the + and - hotkeys, It can only adjust the right frame and does not support long press. As a beginner, it took me a while to figure it out.
Why not use two more hotkeys that can adjust the left and right frames respectively, and can go forward and backward, including long press not "auxiliary hotkeys"? Isn't this operation more logical?
I believe that when you compare videos, everyone are looking for and comparing the same frame. I wish the process of syncing frames could be more intuitive, faster, and easier.
Thanks!

[jonfryd]

OK, fair enough. Thanks for the suggestion.

Personally, I'm not going to work on this, but if someone wants to implement it and send me a PR, please feel free to do so. The solution must integrate well with the existing synchronization mechanism.

[RealSting]

Hi jonfryd!
It's a must have :)

[jonfryd]

Hi jonfryd! It's a must have :)

Hey, @RealSting. Think you’re up for the challenge of a PR? 😉