Compatibility with Nvidia's PureVideo optimized MPEG2 decoder!

[smilingcrow]

I was perusing the forum for an answer to my question and I came across this post by sub, 'GB-PVR doesnt do any playback of video itself. Instead it just asks Microsoft directshow to do the playback (then steps out of the way).'

Does this mean that GB-PVR will pass the MPEG2 decoding off to the selected DirectShow compatible decoder, which will be NVidia's in my case? Can you select which decoder you use from within the program or is that an external choice?
The question is relating to the real-time PVR features and not off-line playback of MPEG2 material which I already have covered.

[sub]

Does this mean that GB-PVR will pass the MPEG2 decoding off to the selected DirectShow compatible decoder, which will be NVidia's in my case?

Yes

Can you select which decoder you use from within the program or is that an external choice?

You can set the video decoder on the 'playback' tab of the config app.

A MPEG2 video decoder (like the PureVideo one) will only be used for live tv if you set the deinterlacing to 'encoder pass through'

[wtg]

A MPEG2 video decoder (like the PureVideo one) will only be used for live tv if you set the deinterlacing to 'encoder pass through'

Can you elaborate on that sub? Is it only a certain kind of decoder that can be used for live tv w/o deinterlacing set to encoder pass-through? What if deinterlacing is set to None? What the heck does encoder pass through mean, anyway?

[sub]

If the deinterlacing is set to none, then directshow just uses the raw YUV video produced by the PVR card's drivers, and displays it using either VMR or Overlay. No actual MPEG2 decoding is required in this case.

If you select to use 'encoder pass through' the MPEG2 video is used instead of raw YUV video, which needs to be decoded by an MPEG2 decoder. This uses a little more CPU power, but does have some advantages (deinterlacing, better audio/video synchronisation etc).

[smilingcrow]

Thanks for the quick reply sub. Just to nail this sucker to the ground, do I then in effect get all the benefits of using the PureVideo decoder when watching live and paused TV, which I also get when playing back MPEG2 files from disk? i.e. the high quality de-interlacing, reduced CPU load and the other fancy stuff that relates to MPEG2. I’m aware that there are many other features within PureVideo that are not related to MPEG2.

[wtg]

Thanks for the explanation... I've always wondered about that. By the way, is the Deinterlacing setting only used for Live TV? It's labelled as if that's the case, but it seems like I've seen others recommend changing the Deinterlacing setting when having playback problems in general.

[sub]

By the way, is the Deinterlacing setting only used for Live TV?

Yes, and only when you're using live preview mode.

but it seems like I've seen others recommend changing the Deinterlacing setting when having playback problems in general

They're wrong.