memory leak when run with --v4l2_sink=

[cadadr]

• I have read the FAQ.
• I have searched in existing issues.

Environment

• OS: Debian Buster
• scrcpy version: dev branch, commit 41a0383
• installation method: manual build
• device model: HTC Desire 728G Dual Sim
• Android version: 5.1

Describe the bug

I built and ran scrcpy as such:

ADB=/home/g/Android/Sdk/platform-tools/adb ./run x --v4l2_sink=/dev/video0

It worked as expected but the memory usage began to increase rapidly, consuming all of 16GB of available memory eventually.

It increases way faster when a camera app is open on the phone (tried both stock app and OpenCamera, the same).

When I do the same without v4l2-loopback integration,

 ADB=/home/g/Android/Sdk/platform-tools/adb ./run x

the memory increase does not happen, scrcpy consumes suprisingly low memory actually.

[rom1v]

This is the kind of bug report which is very useful to detect problems introduced on the dev branch, thank you very much! 👍

The memory leak is fixed by 1cde68a.
An additional (small) memory leak on error is fixed by 84f17fd.

--v4l2_sink

Oops, it seems I failed something in my rebase. Renamed to --v4l2-sink by 45e7280.

[cadadr]

You're very welcome and thank you sooo much!! I had a zoom meeting for tomorrow, this is literally godsend 😸

Tested standalone and with an OBS v4l2 connection and both memory usage and CPU usage are stable (maybe somewhat noticably higher than without v4l2 tho, at 18.8% CPU [went down to ~5% in a space of 5-10min] at 3.6/9GHz and 7.2%mem w/ 16GB mem, I can test and report back on Thursday if that's unexpected).