Frame rate

[sub]

There is lots of ways you could potentially end up doing it, from looking in the file's data yourself, using directshow graphs, or running external utilities to examine the file. Yes, you could do these in c# if you wanted to.

[imilne]

Further reading suggests Media Portal's option for doing this uses some open source library called mediainfo.dll.

I have a feeling genuine dynamic refresh rate changing may be impossible though. For example, if you run a DVD, it might play its menus and stuff at 29.97fps, but the main movie itself could be 23.976fps. I'm not sure how we'd be able to tell it had changed once playback was in progress. I assume NPVR has very little to do with it once handed over to DirectShow? This might be where ReClock's detection (and refresh rate switching) will have to be used instead.

Regardless of that little problem though, DVDs might need special treatment (from a variation of the building_graph event) to recognise them, what with real discs, ISOs, folder rips etc all being valid ways of running them. Lots to think about :eek:

[imilne]

sub, if you have the time (and inclination) could you check out this issue for me...

Detection of fps aside, I'm finding that NPVR isn't very happy with having the refresh rate changed while it's running. I've tried changing it in two ways:

- a custom task launched from the menu that uses the 12noon dc.exe to flick between 50hz and 24hz
- a plugin that receives that BUILDING_GRAPH event and then calls dc.exe with the video obviously starting immediately afterwards

The results are unfortunately not consistent, but in the worst case I end up with video that's all jerky even when changing back to the the correct refresh. It happens with recordings, live tv and non-NPVR handled files (eg, mkv). If you exit NPVR and restart then everything is fine. Full-screen suffers much worse than windowed. Only very occasionally does it appear to actually work (ie, a refresh change happens and video remains smooth afterwards).

Is there perhaps something you do to initialize the direct3d stuff when it first starts up? Perhaps we'd need a method of telling NPVR to redo that if a plugin forces a refresh rate change?

I've tried the same stuff with SetDisplayFrequency.exe that ships with AnyDVD and doesn't perform any better, and I'm also looking at how to change the refresh rate directly from code but I doubt it'll help either.

This is all with Windows 7, EVR and the MS decoder.

It's nothing urgent, but I'd be interested in your thoughts on it.

Iain