WHY?: 100% CPU while watching select IPTV streams

[Pete (NZ)]

I loaded http://i.mjh.nz/nzau/kodi.m3u8 into an IPTV device (NPVR 5.14), and am playing channels via Kodi v19.1, all on a single Windows 10/4GB/Intel i5 laptop, from Martinborough, NZ, via 4G mobile internet.

The NZ channels seem to play fine with around 15-25% CPU (Kodi specs displayed on screen via pressing "o" key), mostly 720p at the time.

However, I'd enabled a couple of Aus channels, and found that while playing them, e.g. ABC channel (also 720p), I was getting significant caching/buffering happening while watching in Kodi.

While the Kodi stream specs were onscreen (I was checking to see if there was a resolution/bitrate difference), I noticed the CPU was at 100% when playing the Aus stream.

Further investigation with "Process Hacker" revealed that Kodi was using around 5% and ffmpeg.exe, under the NPVR service, was maxing out the CPU. So I'm presuming that was the cause of the caching, not the internet stream bitrate/connection. (?)

I verified no recording was scheduled at the time.

I changed channel to TVNZ (720p), and CPU went down to the usual 20-25%, with ffmpeg showing little CPU use.
Switched back to ABC channel, and back up went ffmpeg's CPU use.

So what is the role of ffmpeg here? Why doesn't NPVR just pass the stream on to Kodi, without any transcoding? (...if that is indeed what it's doing to the ABC stream?). If it is transcoding, why doe NPVR think it's required? Is it a situation that is fixable?
The "Inputstream FFMPEG direct" plugin is enabled in Kodi, but I'm not sure exactly what that does, or if it's related.
(BTW, I have "Prefer no trancoding" set in Settings.)


Again, in advance, thanks for your generous help!
Pete


I

[Pete (NZ)]

Here's the details when watching the TVNZ stream:
   
   

[Pete (NZ)]

...vs when playing the ABC stream:
   
   

[mvallevand]

You should have uploaded the logs but when NextPVR can't detect the file type of an IPTV file it will use ffmpeg to transcode it. When you play the Oz stream in Kodi you are giving the wrong page from the o key (NextPVR doesn't populate that info) what does it show on the other tab "Player Process Info" or better what about the bottom when you hit i during video playback.

Edit: No point in hitting the o in Kodi since the transcoded files will always be h264/aac.

Martin

[sub]

As Martin says above, basically NextPVR will try to handle the stream natively if possible. Unfortunately there is lots of different types of IPTV streams out there, and they behave lots of different ways, often complicated by the source trying to protect their stream. If NextPVR can't understand the stream, it falls back to asking ffmpeg to handle the stream.

I've spent the last couple of hours looking at the ABC stream to determine why NextPVR doesn't like it. I found a couple of causes. I'm working through some changes now to hopefully get it handling this stream natively without having to fallback to ffmpeg.

[sub]

This is fixed for the next build.

[sub]

(ignore the picture - I guess that doesn't tell you that ffmpeg isn't needed )

[sub]

It was definitely a bug worth looking into. The changes fixes a compatibility issue with a pile of streams running on Akamai, and it's nice to be able to stream these without having to rely on ffmpeg to convert them.

[Pete (NZ)]

Geez, Sub... you're bloody impressive. And soooo appreciate your ongoing generousity.

I'm in Wellington too, and if there's a couple of hours of building/joiney/handyman work (that's my profession) that I can do for you sometime -- pro bono -- I'd love to be able to do that for you. Or perhaps if you'd ever like to use a joinery workshop (I'm in Karori) or a tool or machine for making or breaking anything, I'd be happy to share. Mobile is 0Two9-nine7three-6triple1

[sub]

Cheers for the offer. Not in need of anything at this stage, but I appreciate the offer.

I'm actually in Kelburn, so not far from you.