Intel Haswell: finally true 23.976p (not 24.000p or 23.972p)

[flashandpan007]

Hi,
I want to build a new computer so I can watch 23.976 movies and videos in MPC HC in true 23.976.

So I just read about true 23.976 fps with the Intel HD 4600 of the new Haswell (Generation 4) processors. I definitly want this. At the moment I have a Nvidia card which only supports 23.972 instead of 23.976. Older Intel HD graphics had a 24p bug which played 23,976p as 24,000p. Then they "fixed" it to 23,972p. But now in Haswell it should work properly:

http://www.anandtech.com/show/7007/intels-haswell-an-htpc-perspective/4

Has someone already tested it in this forum?

Thanks

PS: I had 23.976p with ATI-cards but both of them (a 2010 Sapphire 5770 and a 2013 Asus 7790) had tearing with two monitors at 1920x1080 which I couldn't solve like many others

[jagabo]

You really think you'll notice one dropped or duplicate frame every four minutes? Will that ruin your viewing experience?

[flashandpan007]

Hi,
no it doesn't ruin my viewing experience, but I need a new computer and the new Intel graphics should do 23.976 perfectly. Why not give it a try?

[jagabo]

I see no reason to doubt Anandtech's report. I'm waiting to see what Haswell based i3 CPUs bring to the table for my next HTPC build.

[flashandpan007]

So do you think there is no tearing issue like ATI with this intel graphics in clone mode of two displays?

What do you have in your HTPC?

Had the "old" Intel graphics tearing problems? I never had one

[jagabo]

So do you think there is no tearing issue like ATI with this intel graphics in clone mode of two displays?

What do you have in your HTPC?

Had the "old" Intel graphics tearing problems? I never had one

I have no idea about tearing problems in clone mode using Haswell. Right now I have an AMD x2 255 in my HTPC (integrated Radeon HD 4200 GPU). I have no tearing problems but I'm not using clone mode (just one HDTV hooked up via HDMI). I've used clone mode in the past with NVidia and ATI graphics cards and there was always tearing on one of the displays. I just made the TV the main display (without tearing).

[flashandpan007]

With my Nvidia GTX 660 there is no tearing (I tested it with tearing option of MPC HC). But I have to use D3D-mode. In ATI models I had always got tearing on at least one display. That was shit


Is there anybody who already tested a haswell processor?

[flashandpan007]

@ jagabo: What cooler do you use in your HTPC?

[jagabo]

@ jagabo: What cooler do you use in your HTPC?

It's running the stock AMD cooler. It (and the PSU and 120mm case fan) isn't silent but once the TV is on it's not really audible.

[smrpix]

The irony here is that 24 is correct. 23.976 was the accommodation for NTSC.

[flashandpan007]

Yes,
NTSC:
23.976 -> 24.000 : 1001 = 23.9760239760239760239760239760...
29.970 -> 30.000 : 1001 = 29.9700299700299700299700299700...
59.940 -> 60.000 : 1001 = 59.9400599400599400599400599400...

correct me if I'm wrong

I also tried 24p in PAL setting of my EOS 650D, but here also 23,976 like in NTSC 24p setting. MediaInfo Lite told me that (I don't use MediaInfo because of the strange toolbars. One time I wasn't asked to install this crap and it was installed! Very strange)
If you want to try it, simple but all you need if you're honest:
http://www.codecguide.com/download_other.htm#mediainfo

So, does anyone already tested true 23.976 with Haswell.
But they had trouble with 25/50Hz in the test. I hope nothing serious.

[hello_hello]

If the refresh rate isn't exactly what it should be (is it ever?) then maybe using ReClock is the solution? According to ReClock my PC is currently connected to my TV using a refresh rate of 50.002Hz (Nvidia video card). In an ideal world I guess it should be exactly 50Hz. Depending on the renderer being used ReClock can also make VSync adjustments in order to (hopefully) fix tearing problems.

[jagabo]

According to ReClock my PC is currently connected to my TV using a refresh rate of 50.002Hz (Nvidia video card).

That 0.002 error isn't all that much better than the difference between 23.972 and 23.976 (0.004).

I certainly wouldn't spend hundreds of dollars upgrading to Haswell just for the frame rate fix -- unless that was causing my TV to lose sync.

[flashandpan007]

23.972 instead of real 23.976 (NTSC 24p/23Hz) you can see that sync is drifting away and must be synced (-> drop or double a frame) but in 50Hz mode this isn't the case. You can't compare that two things.
Here you can see the little the steps I don't want to have in 23.976

To avoid that and also needing a second computer this year I think getting a Haswell with hopefully perfect 23.976 refresh rate handling would be a great thing. But that needs to be tested in detail when I have one.

[hello_hello]

23.972 instead of real 23.976 (NTSC 24p/23Hz) you can see that sync is drifting away and must be synced (-> drop or double a frame) but in 50Hz mode this isn't the case. You can't compare that two things.

I'm not sure why.... assuming you're playing a 25fps video.

For fun I thought I'd try connecting to my TV using a few different refresh rates. The first is what it should be, the second is the actual refresh rate (according to ReClock). My 24Hz refresh rate is less accurate than yours.

60Hz - 60.003
50Hz - 50.002
30Hz - 29.989
25Hz - 25.001
24Hz - 23.951

Connected to second display (CRT PC Monitor).

85Hz - 84.985

I checked the second PC here. Same video card, connected to an identical CRT PC monitor and also to the same TV via VGA.

85Hz - 84.984
60Hz - 60.002

If I find the motivation I might swap the video card in this PC for a different one to see if the results are any different, but can anyone connect their PC to a monitor or TV and have it connect at exactly the specified refresh rate?

I guess ultimately you've either got to change refresh rate according to the frame rate of each video you play or adjust the frame rate as applicable and use a constant refresh rate. As it's common for video to be either 23.976fps or 24fps these days, there's not a "one refresh rate fits all" refresh rate anyway, even if you could connect at exactly 23.976Hz or 24Hz.
In my case as I live in PAL-Land I tend to leave the TV at 50Hz and use ReClock to play everything at 25fps. Or to be 100% accurate, I guess I'm watching everything at 25.001fps. I probably should switch between 24Hz and 25/50Hz accordingly but doing it the other way around seems easier.

If these mean more to you than they do to me, below are a couple of screenshots using a refresh rate of 24Hz (real refresh rate 23.951) while playing a 23.976fps video. The first is without ReClock doing it's thing, the second with it.





There's lots of stuff I don't understand when it comes to refresh rates, such as how the actual refresh rate is negotiated between the TV and a connected device such as a PC or hardware player. Does the player/video card determine the refresh rate or is it decided by the TV and the player/video card adjusts it's refresh rate accordingly? I guess if it's the latter the refresh rate would always be the same regardless of the video card but I can't say I've done any video card swapping in order to test it.
And what about when using a hardware player and/or TV only capable of 23.976Hz while playing video with a 24fps frame rate? Are frames dropped or can hardware players make slight adjustments to the speed at which the video is played to match the refresh rate.... as happens when using ReClock while playing video with a PC?

[hello_hello]

As a side note, even the way the frame rate of the video is saved can make a slight difference. When remuxing video and setting the frame rate to 23.967, some programs round it to a single frame duration while some use slightly different frame durations in some sort of repeating pattern. For example VirtualDubMod uses a constant 41.708ms frame duration while I think VirtualDub uses 41.7083ms and 41.7084ms in a repeating 3:2 pattern (or something similar). MKVMergeGUI seems to use 41ms and 42ms frame durations in some sort of 3:2, 2:1 type pattern. I've also seen a constant 41.7084ms frame duration used, which some programs round to 23.976 while others round it to 23.975. And of course true 24fps video has a constant frame duration of 41.666666666667ms. which is "fudged" using similar methods.

As an example, here's three screen shots. The same video each time. The first remuxed with VirtualDubMod while setting the frame rate to 23.976, the second remuxed with MKVMergeGUI. The third is the same as the second, except ReClock is being used. The TV refresh rate was 23.951Hz (24Hz).

[flashandpan007]

I'm not sure why.... assuming you're playing a 25fps video.

No you can see in the pic that the video is a 23.976 file which is played at 23.972 Hz in 23Hz mode setting. 24 Hz setting is only for 24.000p files but these are quite rare.

[hello_hello]

I'm not sure why.... assuming you're playing a 25fps video.

No you can see in the pic that the video is a 23.976 file which is played at 23.972 Hz in 23Hz mode setting. 24 Hz setting is only for 24.000p files but these are quite rare.

If I'm playing a 25fps video and the refresh rate is not exactly 25Hz or 50Hz, I'm not sure how the result would be any different to playing a 23.976fps video when the refresh rate and frame rate differ by a similar percentage.

24fps is not uncommon for Bluray. I've got many 24fps encodes.
Using a PC, the options are to switch between refresh rates accordingly while hoping while you can use exactly 23.976Hz and 24Hz refresh rates (which it seems is very unlikely), or pick the closest refresh rate and adjust the frame rate accordingly. Or a combination of both. Have you tried using ReClock?

I don't know whether it's the TV, the video card or the version of Windows I'm running (XP), but I can only select a 24Hz refresh rate (which is really 23.951Hz). I'm pretty sure when I set up my other half's PC/TV I could choose between 23Hz and 24Hz, or at least 59.8Hz and 60Hz (my only option there is 60Hz). How accurate those refresh rates were, I can't remember. When I get a chance I'll check, and I might borrow her laptop to test with my TV to see if the refresh rate choices are different to those I have using my PC etc.

[flashandpan007]

Hi,
you're right 24.000fps should be common in Blu-rays but I only have one (maybe two) with 24.000fps. Strange but all 100+ others are 23.976fps, 50i or 60i.
50Hz/59Hz/60Hz is not drifting away tried that with several ATI and nVidia cards.

ReClock is not a option for me. Tried that for several weeks. Not what I'm looking for.

I'm looking a new computer with perfect (!) native 23.976 fps support so I'm hopefully happy for the next time

Thanks for your help