Dvd playback refresh rate issues
#1
Question 
I've searched though what seem like endless threads trying to understand why this is happening, but I can't seem to find an answer. My problem/question is from playing back dvds from the disc. I haven't tried playback from a dvd ripped to the hard drive, so I can't comment on that. Many dvds being played with xbmc, with the "adjust display refresh rate to match video" enabled, play back at 24hz just fine. The resolution on my tv is switched and it's super smooth and perfect. (My tv smoothes out content better when it's a 24hz source.) Some dvds play the entire length of the disc with no problems at all.

However, some dvds will get choppy and I have dropped frames for certain chapters, then another chapter will be fine. I've noticed that when it's playing back at 24hz and then goes jumpy, if I stop playback and resume, it will then play back at 60hz instead, and the reported fps in the info is no longer 23.976, but now 29.976. I assume this is a problem with the dvds themselves. Please correct me if I'm wrong.

Is it a problem with flags in the dvd video that will screw up ivtc within xbmc? Even when the playback will work the way I want it to (at 24hz), the video starts out for a few seconds showing it's 29.976 fps before switching the display to 24hz and then showing the fps of the video is 23.976.

I will admit I do not understand exactly how the conversion process to get a 29.976 fps source converted to 23.976 works, but I still want to ask what is going on that the playback is changing? I don't understand why, if the dvd video's frame rate did not change, the display refresh rate needs to be? I would like to also note that I know 23.976fps is not the same thing as 24hz, I'm just attempting to make my post easier to understand......attempting mind you.

I've had this issue with all versions I've ever had of xbmc. I tried the babylon releasese, camelot, dharma, and even nightlies. Same thing.
I'm running Windows 7 x64, amd 1090t processor, and a radeon 5970.
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#2
XBMC detects that the dvd is in fact 23.976 fps by looking at the video timestamps, it sounds like some chapters on the dvd have broken timestamps, please play one of those chapters for a few minutes then post the debug log on pastebin (don't forget to turn on debug logging).
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#3
This is the log from when I started playback from one of the "problem" chapters that was listed as 29.976fps.
http://pastebin.com/Wi5Khxe8

This is the log from when I started playback from a chapter that was listed as 23.976fps and went into a chapter that caused stuttering and frame drops.
http://pastebin.com/KZ5QfidX

As a note, I don't have remote control problems that I'm aware of, so I don't know why it shows all of those errors.
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#4
Ok, the problem is that one chapter is 23.976 fps, then the chapter where it drops is 29.97 fps, we currently don't recalculate the fps there.
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#5
So with DVDs like this one there is no way to get consistent 24p playback? Also, thank you for the help and quick responses!
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#6
Thanks for the help! I was hoping it was the DVDs. I think that's so weird though.
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#7
amvolante Wrote:So with DVDs like this one there is no way to get consistent 24p playback? Also, thank you for the help and quick responses!

Well, if the track is 29.97 fps, you won't be getting any 23.976 fps playback.
I should fix the fps calculation to take these things into account.
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Dvd playback refresh rate issues0