Nextcloud talk recording causes very high CPU usage

[!TIP]

How to use GitHub

• Please use the 👍 reaction to show that you are affected by the same issue.
• Please don't comment if you have no relevant information to add. It's just extra noise for everyone subscribed to this issue.
• Subscribe to receive notifications on status change and new comments.

Steps to reproduce

1. Start a video call in Nextcloud Talk (even with a sigle participant)
2. Start recording (with camera activated or sharing the desktop)
3. Server CPU usage will jump to 100%

Expected behaviour

I am running a Nexcloud instance on a fairly powerfull machine (12 cores), at most 2-4 should be processing the recording, not all of them.

When not recording performace is OK for video calls.

Actual behaviour

All the cores in the server jump to 100% usage.

Talk app

Using with nextcloud AIO, nextcloud version 33.0.3 (Nextcloud Hub 26)

Talk app version: 23.04

Custom Signaling server configured: no

Custom TURN server configured: no

Custom STUN server configured: no

Browser

Microphone available: yes

Camera available: yes

Operating system: Ubuntu

Browser name: Brave Browser (Chrome)

Browser version: 1.89.143

Browser log

Server configuration

Operating system: Ubuntu

Web server: Apache

Database: PostgreSQL

PHP version: 8.1/8.2/8.3

Nextcloud Version: 33.0.3

List of activated apps:

If you have access to your command line run e.g.:
sudo -u www-data php occ app:list
from within your server installation folder

Nextcloud configuration:

If you have access to your command line run e.g.:
sudo -u www-data php occ config:list system
from within your Nextcloud installation folder

Server log (data/nextcloud.log)

Insert your server log here

Start by reproducing the issue with a single-participant Nextcloud Talk call and recording enabled, then inspect the server CPU usage and the available nextcloud.log output. The issue is resolved when recording no longer drives every server core to 100% under the described setup.