How to record only part of the window?

[Skfrd]

I hold alt and click with the left to circle the part I want, but when I record, once in a while just record the part that interests me it records the black part all around

i don't want to record the black part (circled in yellow) how can i do that? it should be something so simple ...

 

[carlmmii]

Change your canvas size to match your source size.

 

[Skfrd]

Change your canvas size to match your source size.

is there no other easier way? adjust in real time for example

 

[carlmmii]

No. Video files have a set resolution. They do not change over time, so you cannot change the canvas size over the course of a recording.

This is not a standard use case you're asking for.

 

[Skfrd]

No. Video files have a set resolution. They do not change over time, so you cannot change the canvas size over the course of a recording.

This is not a standard use case you're asking for.

I don't want to change during, just before as I did in the middle of the image without the black parts

 

[carlmmii]

Changing canvas size is the only way if you're looking to match the file's output resolution with the actual size of your source. There's no quick interface for this because this is a non-standard operation that is only changed for the specific reason of rebuilding your composition/layout.