There are a lot of HDMI IP encoders available on Amazon these days, under brand names like URayCoder and iseevy
These have been discussed a bit in the past here:
I picked one up to try it out, and it works quite well. You can choose between H264/H265, select the bitrate and a lot of other options. It exposes a simple url
http://x.x.x.x/0.ts which can be fed directly into a Custom Channel for streaming into Channels DVR.
There are even models available with 4 HDMI inputs: https://www.szuray.com/h-pd-115.html
@boukmandutty has been using a few of these with Android TV devices attached to record from YouTube TV. By enabling ADB on the Android TV devices, they can be controlled to tune into specific channels automatically.
I've put together a little helper program here that can be used with Channels DVR:
This is a work in progress, but if anyone is interested in trying something similar the pieces are all available and work pretty well together.