Camera w/H265 main and H264 sub, record main but use sub for event page?

[transplier]

Howdy, finally upgraded beyond my 0.8.4 installation. I'm having some trouble with the event viewer if someone has a moment to point me in a direction.

My cameras provide 2 streams, a 4k H.265 main stream and a low resolution H.264 sub stream. I cannot change the codec.

My intent is to record main to disk for archival purposes (I view it with other tools) and use the sub stream for detection and clips. This worked well because the Frigate clips UI got the H.264 stream which is playable in the browser. This worked fine in 0.8.4.

Now that "clips" are gone, it appears to me that it is no longer possible to use the sub stream for event display while also recording the main stream to disk. Is this true? Is there another way of restoring video playback capability to the event page that doesn't involve re-encoding on the fly? My machine would definitely not keep up reencoding multiple 4k streams to H.264, not to mention the power use.

One workaround I was thinking is defining each camera twice - one using the sub stream just for detection and events with zero retain_days, and another using the main stream with no detection role. Maybe there's a better way?

[blakeblackshear]

You can setup a duplicate camera and use ffmpeg to generate a low-res black stream as the detect stream. This should use minimal CPU.

cameras:
  duplicate_for_record_only:
    ffmpeg:
      inputs:
        - path: /dev/zero
          input_args: -re -s 640x480 -f rawvideo -pix_fmt rgb24 -r 1
          roles:
            - detect
        - path: rtsp://<high_res>
          roles:
            - record
    detect:
        enabled: False
        height: 480
        width: 640
        fps: 1

[transplier]

Thanks! Gotta love the FOSS ecosystem's flexibility. I'll give this a shot. Perhaps in this situation I'd be better off using another software for just the recording part to avoid having a bunch of extra cameras in the UI. But I love frigate so maybe not :) I'm thankful every day (and still a little astounded) that great software like this and Home Assistant exist!

[ceandraka]

I have a question on this approach. Does this then support saving recordings only during events, or does it result in 24/7 recordings at high res? If the latter, is the detect portion really needed, or can you just set up the rtsp high res path and record 24/7?

I have the same issue as the OP. But what I am wanting is for Frigate to save the "clip" recording (30 seconds around the event) at both the substream (detect, display on mobile) level and on the high resolution level. So basically the "primary" entry for the camera would be substream, detect and record. The "duplicate camera" would record high def, but would keep recordings based on the trigger of the substream camera.

Maybe that is what this does? Does Frigate keep all cameras when one detects a trigger?

I suppose I could set up the duplicate camera to also detect on substream, but then the detection is duplicated (twice the CPU) for each camera.

Thanks!

[blakeblackshear]

It would result in 24/7 recording of the high res stream. It's not possible to only record the duplicated stream during events without duplicating the detection work. The only way I can think of would be to use an automation in homeassistant to enable and disable the recording switch.

It may be better to use the low res stream in the duplicate camera for 24/7 and the high res in the primary to reduce disk usage.

[ceandraka]

Thanks again for following this and commenting. If you look at the OP's post, he ahs the same issue as I do. If the clips, or recording, is the high res camera, then the mobile app and mobile browsers, in our case, won't display them.

An alternative solution in my mind would be to detect and record on the high res stream, but add a feature in Frigate API that would allow application of ffmpeg to the streaming of clips. Then the notification could have several choices, one filtered by ffmpeg (re-encoded at a lower res for review), and a link to the high res clip for review on a PC or archival downloading for the police report.

This approach would only store one set of recordings at high res, and would re-encode as needed on the fly.

Is this possible with current Frigate, HA, and ffmpeg? Or coudl it be added? The CPU usage would go up in that review period, but that is minimal.

[ceandraka]

Oops, I see you saw that on my feature request.