[raid517]

Hi I am using Gotham on a dedicated Windows HTPC system. I am using MediaPortal as my back end.

However I have noticed that there are significant differences in the quality and performance of DVB playback between using XBMC/Kodi (still XBMC as of Gotham I assume) and using MediaPortal natively/on its own.

In particular the image quality and degree of stuttering is much less favourable in XBMC than in MP. In MP for example with the default LAV filters enabled, the image quality in both SD and HD modes is much sharper , much crisper and much clearer than in XBMC. In XBMC there is also intermittent 'stuttering' or 'smearing' of the digital image. This happens particularly in HD mode and occurs on average about once a minute, sufficient to make it annoying and to make HD TV watching a little pointless. (Given that HD is supposed to be all about image quality). In MP with the default LAV decoders enabled there is still some (very) occasional 'smearing', but it is much reduced.

More interestingly however is that when I change the default LAV DVB decoders in MP for the Microsoft DVB decoders, I get faultless performance from these, with no stuttering, smearing or glitches at all. They also seem rock solid.

As a compromise therefore I have disabled Live TV support in XBMC and am using Advanced Launcher to launch an instance of Media Portal, exclusively for TV viewing. There are simply things that XBMC does better (Local Media PlayBack and scripts) and things that MP does better, which at this juncture is TV, TV recording and EPG.

Of course the ideal scenario would be to have the best of both worlds. Great DVB and EPG performance in XBMC and no need for this rough hack to begin with.

So my question is, how likely is this to happen? How likely is it that the deficiencies in DVB playback/EPG in Kodi will be addressed? Also is there anything I can do in the interim? Can I for example tell XBMC to use the native Microsoft DVB decoders (which I think are the same as those in Microsoft Media Centre) and get great performance, without having to launch any third party software? I can't use Microsoft Media Centre, as I have Windows 8.1 pro which was supplied by my school and for whatever reason the licensing forbids me to use MC with this version of Windows. I can however still use the MC DVB decoders it seems.

For the record I am using two Astrometa USB DVB-T2 tuners and a Zoltac EN760+ (basically a steambox, but with Windows on it) as my dedicated HTPC.

[nickr]

I must say that this is not a universal experience. My DVB-T works fine. Perhaps Mediaportal is the problem - I use MythTV.

[raid517]

I can't use MyTV, nor is it useful in my circumstances. I have built a fully 'tricked out' HTPC with full HTPC and modern 3D PC game playing functionality too. I have about 30 PC games (so far) and am not keen on the compromise that using Linux would involve. (Maybe I can get some of my games to work in Wine, maybe I can't). Media portal is not the issue, if you read what I said you will recall that I am using MediaPortal as my standalone DVB app without issues.

I am launching this via 'Advance Launcher' whenever I want to switch to watching TV because XBMC DVB playback in Windows is generally quite poor (in my experience).

I think really we are comparing apples and oranges when assessing the relative merits of Linux DVB playback and Windows DVB playback.

On a side note, since DVB playback in MediaPortal seems rock solid (especially when using the native Windows 8.1 DVB decoders) is there any way to get XBMC/Kodi to use the same Microsoft DVB filters that MediaPortal uses, so that maybe I can eliminate the need to use the MediaPortal front end entirely?

[nickr]

I think perhaps you could do with some debug log (wiki)s and we try and work out what the problem is.

XBMC uses all it's own video playback libraries, nothing external. It is based on ffmpeg. I haven't seen any other complaints about DVB performance (although I don't by any means read every post of course). However given that your probelm seems rare, it may be some problem with your setup.

So far we haven't heard anything other than the barest details about your setup.

What codec is being broadcast?
Where in the world are you/who provides your DVB service?
Are you deinterlacing?
Are you using hardware acceleration of playback?

[raid517]

There are loads of people with loads of complaints about PVR performance in XBMC. http://forum.xbmc.org/showthread.php?tid=173319 is just one of many threads that exist. I could grab more, but I'm not trying to prove a point. I know you are genuinely trying to help and I really do appreciate this, but it's just a little frustrating when someone implies that no one other than you has this issue and that the problem is 'rare'.

It's not my set up that's the issue, as I said in Mediaportal, with MS DVB decoders enabled (rather than the default LAV decoders) I get rock solid top quality performance.

As I said maybe it's different in Linux. I suspect it may well be. Linux is after all a totally different beast.

That said, in answer to your questions

I believe DVB-T in the UK (SD) uses MPEG-2 and it seems MPEG-2 codecs, while DVB-T2 (HD) uses MPEG-4: H.264 for video and most likely AAC for audio.(This is the best information I can find)

I live in the UK. Our over the air DVB provider is Freeview

Yes and no to interlacing. I have tried all interlacing settings, both with and without to no effect.

Yes Hardware acceleration seems sensible given that I have a fairly decent graphics card and good overall set up in the form of a Zotan Zbox EN760 plus: http://www.pcworld.com/article/2455207/z...power.html

http://www.zotac.com/products/mini-pcs/z...tions.html

But since this is FFMPEG as you say, perhaps there is some setting somewhere in this that can be tweaked? Again sorry for any frustration. It's not a nice feeling to be told 'you are the only one'. There are loads of guys usind advanced launcher to launch different DVB apps, including WMC and others to try to overcome the DVB limitations in XBMC. I have really read rather a lot about this.

[negge]

Open the video settings OSD and tell us what value you have set in "Deinterlace", "Deinterlace mode" and "Video scaling method". Those are the ones that control how well the video looks. If you get stuttering from time to time it sounds like your refresh rate doesn't match the frame rate of whatever you're watching, you can fix that by enabling "adjust refresh rate to match video" in System -> Video -> Playback. You may want to enable "Sync playback to display too", look in the wiki for what these different options actually do.

[negge]

There are loads of guys usind advanced launcher to launch different DVB apps, including WMC and others to try to overcome the DVB limitations in XBMC

90% of the people who do this (from what I've gathered) are those who 1) need to be able to schedule recurring recordings directly from XBMC (something that will be possible in future versions regardless of backend) or 2) people who gave up instantly when their wife/girlfriend said something negative about it. People like you who have actual video/playback performance problems are seemingly in the minority.

[nickr]

There are loads of people with loads of complaints about PVR performance in XBMC. http://forum.xbmc.org/showthread.php?tid=173319 is just one of many threads that exist. I could grab more, but I'm not trying to prove a point. I know you are genuinely trying to help and I really do appreciate this, but it's just a little frustrating when someone implies that no one other than you has this issue and that the problem is 'rare'.

No one in that thread is complaining about playback quality. It is mainly about channel change speed and series recording abilities.

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How about you provide a debug log and a sample stream that you are having trouble with, so others can try and replicate the problem you are having.

[raid517]

There are loads of people with loads of complaints about PVR performance in XBMC. http://forum.xbmc.org/showthread.php?tid=173319 is just one of many threads that exist. I could grab more, but I'm not trying to prove a point. I know you are genuinely trying to help and I really do appreciate this, but it's just a little frustrating when someone implies that no one other than you has this issue and that the problem is 'rare'.

No one in that thread is complaining about playback quality. It is mainly about channel change speed and series recording abilities.

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How about you provide a debug log and a sample stream that you are having trouble with, so others can try and replicate the problem you are having.

Dude I think we have gotten off on the wrong footing? Maybe we should just leave it alone? I read through dozens of threads with people having DVB performance issues. I simply do not have the time to post them all here. I don't get why this is such a big deal to you and why you don't just prefer to suggest possible ways to fix it, instead of attempting to imply that any problem cannot exist? If this is what you really believe, or if you wish to believe my problem is completely unique, then fair enough. Good luck to you. I still would like to find a way to resolve it though.

For the record, before anyone gets ahead of themselves, I am going to try the Argus DVB back end. There are good reports of this in Windows - and if this works it might demonstrate that there can sometimes be little glitches with various DVB set ups in Windows. Maybe less so in Linux? I confess I have no idea. I have an old Ubuntu install around somewhere - and beyond a decent file server, it doesn't get used for much.

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"How about you provide a debug log and a sample stream that you are having trouble with, so others can try and replicate the problem you are having"

How about I try a different back end first (Argus TV) and see how I get along with that - and then report back in an hour or two on whether or not this solved the problem?

[negge]

Changing backends will not help with your problem since the stream that is played by XBMC is the same. Look at the settings I told you about.