[Feedback Requested] HLS Playback Speed Improvement

[NickM-27]

In fb290c4 which will be part of the 0.16.1 release, HLS was optimized to improve playback startup speed. In manual throttled testing via chrome, this improved the playback start speed from 30 seconds to 8.

In order to get some examples of this, whether a speed up is noticed or not, it would be helpful if users can provide data points with the following provided information:

1. Camera Information
   i. Recording resolution & codec
   ii. Recording bitrate
2. Browser and browser version
3. Screenshot of browser network tab showing HLS segment playback loading

See an example below:

[NickM-27]

1. Dahua 5442 2688x1520 H.265 (6144)
2. Chrome 139

[lpaolini]

Here's a video of my browser's network tab (XHR only, /vod only) after clicking on a clip to review.
The spinner stops and the video starts playing only at the end of the third segment.
https://youtu.be/YyR18NbwMM4

[NickM-27]

So there are a few things to note here:

1. The fix is definitely working in this video. Before the fix you would have had seg-1-v1-a1 load first, which would have roughly doubled the loading time
2. Based on your video, playback should start after 16 seconds. If this is not the same then that could be a browser problem

[NickM-27]

yes, playback starts when the first segment finishes loading

[lpaolini]

At what point in time is playback supposed to start? At the end of the first segment?

[lpaolini]

At this point I'm quite sure my issue is due mostly to the high bandwidth of the record stream (it's a 12Mpixel camera), which translates into huge segments, long loading times and unsustainable streaming when bandwidth to Frigate is lower than bitrate, causing rebuffering. I really wish I could switch to the lower bandwidth stream for reviewing events.

[NickM-27]

Just curious, does the preview not satisfy the need most of the time? I know at least for me if there is any question what happened the preview answers it. I rarely need to open full res recordings

[lpaolini]

Well, often the "stop-motion" preview is enough, but sometimes it's not and I would need to look at an actual video.

I just got an idea... Are the thumbnail.webp files generated on the fly? If so, an interesting upgrade could be to load interleaved frames on the second run (when hovering enough on the clip), taking advantage of cached images from the first run, effectively doubling the framerate of the preview from the second run on.

[NickM-27]

No, they are not generated. And in fact, the webp images only exist for the current hour. Once the hour ends they are compressed to h264 to save on storage space

[lpaolini]

@NickM-27 Is master the most up to date branch?

[NickM-27]

Master is where small fixes are going. Dev has 0.17