ffmpeg transcoding of mjpeg stream used for homekit cameras has very low quality due to low bitrate

[duhanebel]

The problem

I've added a mjpeg camera to home assistant, and then shared it as a homekit accessory from the UI. When I look at the ffmpeg process that is generating the h264 stream for homekit I can see the max bitrate has been set to a very low number: ffmpeg -i http://[server]/stream -hide_banner -nostats -map 0:v:0 -an -c:v libx264 -profile:v high -tune zerolatency -pix_fmt yuv420p -r 30 -b:v 299k -bufsize 299k -maxrate 299k ...

I've looked at the code and I found this line that contains the ffmpeg parameters.

I tried hardcoding a high number (9999k) instead of v_max_bitrate and that seems to produce a way better stream on homekit. Unfortunately I couldn't understand where v_max_bitrate comes from, as it seems to be passed to start_stream in the dictionary stream_config here.

Is this something that is configurable from configuration.yaml? If I knew where stream_config is coming from I might be able to fix this myself. Can anybody help me?

Thanks!

What version of Home Assistant Core has the issue?

core-2023.9.1

What was the last working version of Home Assistant Core?

No response

What type of installation are you running?

Home Assistant Container

Integration causing the issue

homekit

Link to integration documentation on our website

https://www.home-assistant.io/integrations/homekit/

Diagnostics information

No response

Example YAML snippet

No response

Anything in the logs that might be useful for us?

No response

Additional information

No response

[home-assistant[bot]]

Hey there @bdraco, mind taking a look at this issue as it has been labeled with an integration (homekit) you are listed as a code owner for? Thanks!

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[issue-triage-workflows[bot]]

There hasn't been any activity on this issue recently. Due to the high number of incoming GitHub notifications, we have to clean some of the old issues, as many of them have already been resolved with the latest updates. Please make sure to update to the latest Home Assistant version and check if that solves the issue. Let us know if that works for you by adding a comment 👍 This issue has now been marked as stale and will be closed if no further activity occurs. Thank you for your contributions.

[codyc1515]

Still current. It's not at all clear to me why that HomeKit cameras are deliberately downgrade in quality.

[issue-triage-workflows[bot]]

There hasn't been any activity on this issue recently. Due to the high number of incoming GitHub notifications, we have to clean some of the old issues, as many of them have already been resolved with the latest updates. Please make sure to update to the latest Home Assistant version and check if that solves the issue. Let us know if that works for you by adding a comment 👍 This issue has now been marked as stale and will be closed if no further activity occurs. Thank you for your contributions.

[codyc1515]

Current

[bdraco]

iOS is going to request a lower bit rate based on the connection. While you can override it and force a better bitrate its likely going to break streaming for users with slower connections if we did that.

[duhanebel]

That makes sense.. but in my experience with other cameras, the streaming starts on a low bitrate and slowly improves (if there's bandwidth). I don't see the same behaviour with HA.

[issue-triage-workflows[bot]]

There hasn't been any activity on this issue recently. Due to the high number of incoming GitHub notifications, we have to clean some of the old issues, as many of them have already been resolved with the latest updates. Please make sure to update to the latest Home Assistant version and check if that solves the issue. Let us know if that works for you by adding a comment 👍 This issue has now been marked as stale and will be closed if no further activity occurs. Thank you for your contributions.

[codyc1515]

Current