[PanMaster]

I've been exploring ways of solving the Clarkdale (corei3/i5) 23.976fps problem. Sandybridge is said to suffer the problem too.
For those that don't know, Clarkdale doesn't support 23.976hz and only supports 24hz. 24p material is actually 23.976fps and as a result goes out of sync with the refresh rate thus a frame is repeated every 41.7 seconds which is awful.
To solve this the optimal solution would be to get a refresh rate of 23.976hz working but according to info from 2010 clarkdale doesn't support it at the driver level so using a program such as powerstip to create a custom refresh rate won't work - http://www.avsforum.com/avs-vb/showthread.php?t=1241833. Intel couldn't care less about it.

The current solution XBMC uses is to speed up the 23.976fps by 0.1% to 24fps. With A/V sync set to audio clock the audio is slightly out of sync, particularly during dialogue. Audio resampling distorts the audio too much.
The alternative solution is to use 59.94hz refresh with 3:2 pulldown but that's what I had before and want to get proper 24p going.

All the info I can find on the internet is almost a year old. Surely there must be a fix by now?

best Regards
Panmaster

[PanMaster]

Surely there must be a fix by now?

Replies: 0

Obviously not.

(or no-one has the foggiest clue what I'm going on about and this forum isn't aimed at detailed technical questions, in which case this will be my last post)

[avus m3]

I am using 530's in my 2 HTPC's and so I am familiar with this problem. I just don't have xbmc set to adjust display to source and it's fine although not ideal.

[bobo1on1]

Obviously not.

(or no-one has the foggiest clue what I'm going on about and this forum isn't aimed at detailed technical questions, in which case this will be my last post)

I know what you mean
If you don't want to use the resample sync method, then your only option probably is to patch the intel drivers to make 23.976 hertz work.

[dan1son]

People here are capable of the detailed technical discussions you seek, but your description did a fine job of explaining you're out of luck until Intel fixes their drivers. I suggest you wait, or drop $40 on a fanless Nvidia geforce 210 card.

[PanMaster]

I might have found something:

Set using DTD Calculator.

Also, here are the custom timings I used to get smooth playback at 23.976 with my core i3


This is for 1920x1080 output

The proper timing info that I found to get 23.976 playback is as follows:

active pixels horizontal: 1920 vertical: 1080
front porch horizontal: 638 vertical: 4
sync width horizontal: 44 vertical: 5
total pixels horizontal: 2750 vertical: 1124
polarity horizontal: positive vertical: positive
refresh rate: 23.978

for 59.94:
front porch horizontal: 88 vertical: 4
sync width horizontal: 44 vertical: 5
total pixels horizontal: 2200 vertical: 1124
refresh rate: 59.942

for 29.97:
unverified (my projector cannot output at this refresh rate)
front porch horizontal: 638 vertical: 4
sync width horizontal: 44 vertical: 5
total pixels horizontal: 2750 vertical: 1124
polarity horizontal: positive vertical: positive
refresh rate: 29.972