Positively glacial FPS on a (very) old ISO

Well this surprised me …

Tried to play an ISO rip of a very, very old DVD (usual disclaimer: We own physical copies of all our media; we have taken a rip as a backup and to use so we can preserve the original optical media) - “The Lost Boys” - it’s so old it’s in an original style plastic-and-cardboard case :slight_smile: (anyone else remember the DVD case wars?).

The playback was visually so slow, entire continents could have risen and fallen between frames … OK, that’s (obviously) an exaggeration … but not much of one - the debug overlay reports it at ~16fps but subjectively it was considerably slower than that.

The rip itself is absolutely fine (and so is the network server providing it) - when we couldn’t watch the film on our “Vero 2”, we watched exactly the same rip (also NFS mounted from exactly the same server) on a Dune “Base 3D”, which played it with absolutely no problems whatsoever.

You’ll see from the logs what all the actual figures are, but when I looked at the debug information on-screen, what struck me most was quite a few drops, but mainly a skips counter that was just constantly incrementing. So there was something about the video which something on the “Vero 2” really did not like. My first thought was that it could be because the video is such poor quality (those early DVDs were often quick scans of often very old film stock and in some places are little, if any, better quality than VHS - I wonder whether the “Vero 2” just can’t easily handle that much video noise?), but that’s pure speculation - hopefully something in the logs will let someone come up with a more informed opinion :slight_smile:

Thanks folks! :slight_smile:

This is because the DVD is being pushed to software decode. It’s a bug that was brought to my attention yesterday, I’ll find out what’s causing it. I suspect the decoder is choosing to ignore anything below <800p.

If you press the context menu symbol, and see ‘ffmpeg-mpeg2’, this will confirm software decode.

Sam

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Errr, the “dc:” (decode?) says “ff-mpeg2video” - that close enough, or am I looking in the wrong place?

But what you’re saying makes perfect sense - nice to know you already have a handle on the issue :slight_smile:

Thanks @sam_nazarko!

Yep, just need to find a DVD ISO from somewhere to test, as I don’t have any at hand

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[And thank you very much to whoever just moved this thread into the correct category :slight_smile:]

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I can confirm this issue.

It is currently a Kodi 16 (Jarvis) ‘feature’ to play DVDs in software on all platforms. This is likely due to issues with still frames. Still frames (often found in DVD menus) can be a bit problematic, as a lot of hardware decoder implementations don’t yet offer a way of extracting single frames.

In Kodi 17, this will change. VideoPlayer, which replaces dvdplayer has support for ‘draining’ which is where a codec will empty its frames.

I can force hardware decoding of DVD. The image looks much better, but the stuttering still persists. I suspect the frame rate tracking is off.

Sam

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Sadly only implemented for DXVA, VDPAU and VAAPI, Raspberry Pi, it is still ignored on IMX and AML.