XBMC PVR demux

[mvallevand]

I think that part of the channel switching speed issue is a basic flaw in the way the xbmc pvr demux works which is outside sub's control. Here is a demo comparison of xbmc pvr vs x-newa both using pretty he same web server backend http://youtu.be/ptuuDKzrV4M Fundamentally a python addon should be much slower than the integrated cpp plugin yet the plugin consistantly takes twice as long (8 seconds vs 4) This is networked via wifi with beta1 but since the http streaming is the same I think it is a valid test. I have timeshifting off in case that was slowing things down.

Edit: This is compiled with the 'faster' ffmpeg switch reference on the XBMC forums.

Martin

[KaraokeStu]

Wow... good find - have you tried mentioning this on the XBMC forums to see if they'd change the way that the PVR demux works?

[mvallevand]

The PVR devs seem to deflect this and push sub to use another delivery model instead of sending raw ts from the card, so I am not sure it will help. Certainly there doesn't seem to be any general developer support for improving overall XBMC support for growing files. Since ub may even be working on the backend so I personally don't want to get into the debate which is why I posted here fro general information.

Martin

[KaraokeStu]

Furry muff - personally I agree that XBMC should be able to directly handle the .TS stream as it has all the codecs to just play it without messing around with FFMPEG etc.

[sub]

It certainly a frustrating experience.

In my tests with a DVB-S tuner, the NextPVR addon is delivering data to XBMC in around than a second, but it usually takes XBMC another 5 seconds or so before it'll display anything. The bulk of this seems to be in ffmpeg analysing the stream. Unfortunately there doesn't seem to be any good way around this.

There is some options, like implementing your own demux, but this seems to still be undergoing changes. It can give fast channel changes, but requires a huge amount of effort in either the addon or backend. Alternatively I can switch to playback of files, which ffmpeg seems to handle slightly quicker than http stream, but it makes things pretty ugly with configuration (requiring samba shares etc to be setup). I just wish XBMC would be optimised to improve the startup time when playing an http stream.

The playback of in-progress recordings also shows XBMC infrastructure provided to PVR addons needs more work. Politics may be factor in why it isn't being done.

At this stage, I'm not worrying about it too much and just waiting for things to settle down.

[KaraokeStu]

I'd be happy with an option to use the network stream option, as my XBMC and NextPVR are on the same box.