Commercial detection suddenly too slow to be useful

Channels DVR Server
#1

Haven't had issues w/ commercial detection that I can recall since starting to use Channels years ago ... have always had a mix of OTA and TVE content, currently mostly watching football. Have never had an issue joining a live recording and having comskip sort out the commercials in short enough order to be useful.

Not now. Not sure what's changed, but watching the TVE recording of the Wisconsin/Rutgers game from BTN (YTTV) and I'm at the end of the 1st half and there's no commercials detected yet. Channels status says it's running. I can confirm from tailing the video.log. The mpg is just h264 as near as I can tell from ffmpeg.

Hardware is, and has been forever, a Synology DS920+. Running Channels via Docker w/ /dev/dri mapped. comskip is pegging one CPU 100%, beyond that, the NAS is pretty idle.

Cheers and thanks for any tips!

#2

If you have this setting enabled, it's known to be problematic.
Settings > Live TV & DVR > Commercial Detection > Start live detection when watching in-progress recording

#3

I agree, Live commercial skipping has never worked correctly. It would be wonderful if it did. The developers seem to ignore questions about making it work properly. That's probably because it's ffmpeg that dose the skipping which is not there product.

#4

comskip (which uses ffmpeg)

#5

If I’m understanding right, these problems are with accuracy (drift), which I have noticed, but the behavior I saw today was new for me. No commercials detected for a very long time (they did eventually get detected). I’ve never seen the performance this bad.

#6

Most likely timestamp issues with TVE channels. That will throw off comskip for sure.
You'll see them in the comskip log (video.log) if you search for jump and strange
Like these

Strange audio pts step of 2959.04642 instead of 0.00000 at frame 509
Jump in base apts from 17.52342 to 2976.56930, delta=2959.04588
Strange audio pts step of -2959.17342 instead of 0.00000 at frame 512
Jump in base apts from 2976.56930 to 17.39537, delta=-2959.17392
Strange video pts step of 2959.16028 instead of 0.03387 at frame 512
Strange audio pts step of -2959.17342 instead of 0.00000 at frame 514
Jump in base apts from 2976.56932 to 17.39540, delta=-2959.17392
Strange video pts step of -2959.10738 instead of 0.03387 at frame 514
Strange video pts step of 2959.16028 instead of 0.03387 at frame 514
Strange video pts step of -2959.10738 instead of 0.03387 at frame 516

pts means presentation time stamp (in seconds), what you would see for the current playhead time when playing the video