23.976 Hz video output issue still not fixed in Ivy Bridge?

[Fjodor2001]

Hi,

In the Anandtech review of Sandy Bridge CPU, Intel said that the 23.976 Hz video output issue would be fixed with the new Z77/Z75/H77 chipsets introduced with Ivy Bridge.

However, I just read an article about Ivy Bridge where Intel now says:

While 4K video support is impressive, Intel hasn’t completely fixed the 24fps issue that some people noticed in Sandy Bridge. By not quite getting the frame rate of video playback for this format of video, movies can appear to stutter.

When asked about this, Dr Hong Jiang, senior principal engineer and chief media architect for Intel, said that ‘we’ve improved the clock for Ivy Bridge, so that issue is much reduced. Compared to Sandy Bridge, it’s a major step forward.’ Tom Piazza, Intel senior fellow, chipped in, adding that ‘it’s significantly reduced – you’d have to look real hard to catch it.’

So it seems like Intel will not fix this completely with Ivy Bridge after all! If this is true, I think it's a major disappointment for e.g. those who have waited for Ivy Bridge to build a HTPC with proper 23.976 Hz video output.

 

[gevorg]

This was a deal breaker for me too for my HTPC rig, but if stuttering playback is really reduced and hard to detect like Intel says, then maybe its no big deal anymore. Even with Sandy Bridge, some TVs show the problem pretty badly while other TVs are just fine (I guess the receiver/clock/dejitter or whatever is in TV might make a difference). I wouldn't discount Ivy Bridge for HTPC just yet, lets wait for actual results rather than paper specs. If not, then AMD Fusion APU line is always an option.

 

[Fjodor2001]

Well, either it works or it doesn't. If Intel has improved it with Ivy Bridge so that it stutters for example only every 30 minutes instead of every 5 minutes then I think it's still unacceptable - it will still take focus from the movie and I will be counting the minutes until the next stutter occurs.

Also, apparently the AMD Fusion APUs have the same problem so it does not seem to be an option either, see here. Is the only way to get proper 23.976 Hz video output to buy a discrete AMD graphics card (and only some of their models work as far as I heard)?

Finally, does anyone know why it technically is so hard to produce a proper 23.976Hz video output? Why are so many hardware manufacturers having problems with this?

 

[meatana]

People don't realize what's worse than the occasional video glitch is that every time you get a video glitch you also get a 42ms lip-sync slip as well!!!! To me this is MUCH more annoying than an occasional video glitch.

The audio video relation is slowly slipping until a frame is dropped or repeated at which time is snaps 42ms.

I bought several Clarkdale systems for HTPC before finding out they had this MAJOR hardware bug. Like a fool bought a couple Sandy Bridge systems because it was suppose to be fixed, NOW expecting ivy bridge to fix it, I feel like an idiot 8-O

It sounds like they are just going to stretch the problem farther, maybe the glitch will only happen one every hour, which is still 100% bad.

Someone step up to the plate and fix this already. Here's your window if Intel is not fixing it in Ivy Bridge you have until at least the next series of CPUs to make you money back.

 

[Magic Carpet]

Thanks for bringing this up. Never knew it had any issues. I just have a bad habit using discrete cards whenever I can ;-p

Hope it gets fixed in IB, though.

 

[Khato]

This is one subject that irks me... because the majority of those complaining about this 'issue' don't even have a display capable of accepting a 24p (23.976 fps) output. For those that do actually have everything in the signal path capable of supporting 24p, even ATI and NVIDIA don't always get it right - http://www.avsforum.com/avs-vb/showthread.php?t=1333324 (Note that Intel's -0.003 is currently obtainable on Sandy Bridge with UAC disabled, and that's likely going to be the norm for Ivy Bridge.)

Personally, I don't care about 24p playback because... well, I never liked the 'jerky' look of fast action scenes in the theater that results from the slow fps. I far prefer letting my computer and projector do frame interpolation to give movement a natural fluidity.

 

[Denithor]

People don't realize what's worse than the occasional video glitch is that every time you get a video glitch you also get a 42ms lip-sync slip as well!!!! To me this is MUCH more annoying than an occasional video glitch.

The audio video relation is slowly slipping until a frame is dropped or repeated at which time is snaps 42ms.

I bought several Clarkdale systems for HTPC before finding out they had this MAJOR hardware bug. Like a fool bought a couple Sandy Bridge systems because it was suppose to be fixed, NOW expecting ivy bridge to fix it, I feel like an idiot 8-O

It sounds like they are just going to stretch the problem farther, maybe the glitch will only happen one every hour, which is still 100% bad.

Someone step up to the plate and fix this already. Here's your window if Intel is not fixing it in Ivy Bridge you have until at least the next series of CPUs to make you money back.

Is this an issue when using Clarkdale & integrated GPU or still present on Clarkdale with discrete GPU as well? Because I have this annoying problem where occasionally my video unsyncs from my audio while watching DVDs (from disc or rips on hdd). Not sure if it's related to my software (Media Player Classic - Home Cinema, VLC player, PowerDVD 7) or hardware (i3-550 w/ GT-240 GDDR5).

 

[Fjodor2001]

This is one subject that irks me... because the majority of those complaining about this 'issue' don't even have a display capable of accepting a 24p (23.976 fps) output.

Not true. Most modern HDTVs handle 23.976 Hz playback correctly (assuming the source provides the video in that format). Note that most Blu-ray movies are in 23.976 Hz format.

 

[BenchPress]

Can't you just disable Quick Sync? Ivy Bridge should have plenty of CPU performance for video decoding and the new transistor technology should make it very power efficient.

With Haswell the Quick Sync technology will make even less sense since AVX2 will double the integer SIMD performance.

 

[JAG87]

23.976Hz playback is useless on an HTPC, unless you like your navigation menu also running at 23.976Hz, or you like that nice delay for your TV to re-sync every time you play/stop. NV and AMD don't support 23.976Hz playback either without a custom profile, they run 24Hz which means the FPS needs to be speed up to 24.000 fps (most software like XBMC does this) and then audio then also needs to be adjusted either by re-sampling, duping, or dropping samples.

It's pointless. Stick with 59.97Hz with 3:2 pulldown and you'll have less problems on an HTPC, trust me. Change to 50Hz only when you are playing 25fps content, for everything else use 60Hz (59.97Hz).

 

[Khato]

Not true. Most modern HDTVs handle 23.976 Hz playback correctly (assuming the source provides the video in that format). Note that most Blu-ray movies are in 23.976 Hz format.

True, most modern HDTVs handle it fine, at least above the entry level models. But even going a year back the 'feature' becomes less prevalent, and 2+ years ago it was something that you had to intentionally look for if you wanted it. Hence why I still feel that it's acceptable to state that the majority of those complaining about this issue likely don't even have a display capable of accepting a 24p input signal.

I've subjectively tested 24p content playback on my LG-CF181D projector with and without CFI enabled at both 24p output and 60Hz through an AMD 4890, NVIDIA GT 430, and Intel HD3000 (with UAC disabled.) Using 24p output with CFI disabled was painful on any movement scene, reminded me of one reason I dislike theaters. Meanwhile 24p output with CFI enabled was the same on all three graphics cards. 60Hz output with CFI disabled was intermediate in quality, whereas 60Hz with CFI enabled looked the same as 24p with CFI enabled. I've been doing 60Hz with CFI enabled on the HD3000 because actually using a HTPC set to 24p output is painful, and because the HD3000 was the only one to properly handle duplicating the display without introducing visual artifacts (both AMD and NVIDIA appeared to have occasional frame buffer synchronization problems when duplicating to both projector and the 1080p monitor I use when I don't want to power on the projector.)

 

[Fjodor2001]

23.976Hz playback is useless on an HTPC, unless you like your navigation menu also running at 23.976Hz, or you like that nice delay for your TV to re-sync every time you play/stop.

That's handled automatically by most HTPC software. Normally you press play once and enter 23.976 Hz automatically, then watch the movie (where you can may press fast forward/fast reverse/pause/play while not exiting 23.976 Hz), then press stop and automatically return to non-23.976 Hz video output. I.e. basically it works the same as when you use a normal stand alone Blu-ray player, and I don't think most people find those hard to use?

 

[Fjodor2001]

True, most modern HDTVs handle it fine, at least above the entry level models. But even going a year back the 'feature' becomes less prevalent, and 2+ years ago it was something that you had to intentionally look for if you wanted it.

Sony's mid-range models has had it for more than four years. For example the Sony W3000 had it in 2007 (see "24p True Cinema" in the tech specs):

http://www.hdtvtest.co.uk/Sony-KDL40W3000/

 

[tweakboy]

Aww man that blows goat. My old mans rig is a 2600K and I see the issue with Premiere ,,,,, sighs,, its in Irene I mean Ivy Bridge as well ,,, daz not cool!!!

 

[krumme]

Intel GFX quality and speed problems is always fixed in the next version

 

[tweakboy]

I mean my dad has never complained, but I did see how it was 23.xxxx fps . Intel blows for not even fixing this issue with Ivy, maybe the x80 chipset will fix it, lets go Howard I mean Haswell.

I would think a BIOS upgrade would fix this problem for Sandy people ?

 

[86waterpumper]

I must be blind or something, I have never dealt with this issue once on my 2500k and I watch video on it all the time. I have watched netflix, and various other flash based streaming internet video, plus mpgs, mkvs, avis etc. Which types of video are bothered by this any format? I have had video get out of sync with the audio before but it has been due to bad encoding not the system itself. I don't think intel cares much about it because most people probably won't ever know about it or be bothered by it. My buddy constantly streams hulu and various other video to his tv through his i3 2100 system and he hasnt' noticed anything either.

 

[JAG87]

That's handled automatically by most HTPC software. Normally you press play once and enter 23.976 Hz automatically, then watch the movie (where you can may press fast forward/fast reverse/pause/play while not exiting 23.976 Hz), then press stop and automatically return to non-23.976 Hz video output. I.e. basically it works the same as when you use a normal stand alone Blu-ray player, and I don't think most people find those hard to use?

I would hang myself if I every time I wanted to watch something I had to put in a disk, wait for it to load, and have to watch forced "do not pirate this plz" ads.

My Kuro has a 2-3 second delay when switching modes, and I have a time wasting pet-peeve.

Also, there are BDs mastered at 24.000 fps rather than 23.976Hz (just a few), that wouldn't work too well with 23.976Hz output (audio would have to stay in sync by duping frames).

 

[Phynaz]

Aww man that blows goat. My old mans rig is a 2600K and I see the issue with Premiere ,,,,, sighs,, its in Irene I mean Ivy Bridge as well ,,, daz not cool!!!

WTF? Adobe Premiere is an authoring application, not playback. Are you telling me your old man bought a $600 video editing app to watch DVD's?

 

[Fjodor2001]

I must be blind or something, I have never dealt with this issue once on my 2500k and I watch video on it all the time. I have watched netflix, and various other flash based streaming internet video, plus mpgs, mkvs, avis etc. Which types of video are bothered by this any format?

Any video that is in 23.976 Hz format. And you must make sure the video output of your PC/HTPC is set to match that, and you must have a TV that can handle that video frequency correctly. If you have set your PC to fixed 60 Hz (like many people have), the PC will try to convert the 23.976 Hz video to 60 Hz (or whatever frequency you are using) and then you will not notice the frame drops / duplicate frames and audio sync problems, but then you'll get 3:2 pulldown or similar instead which is not ideal.

 

[Fjodor2001]

I would hang myself if I every time I wanted to watch something I had to put in a disk, wait for it to load, and have to watch forced "do not pirate this plz" ads.

I guess hundreds of millions of people hang themselves when watching BD movies on standard Blu-ray players then.

My Kuro has a 2-3 second delay when switching modes, and I have a time wasting pet-peeve.

Wow, 2-3 seconds delay (about the same as when switching TV channels) when pressing play and then ~2 hours later when pressing stop. Totally unacceptable. I guess you'll have to get another TV with shorter delay.

Also, there are BDs mastered at 24.000 fps rather than 23.976Hz (just a few), that wouldn't work too well with 23.976Hz output (audio would have to stay in sync by duping frames).

Blu-ray players and GFX cards which handle this properly automatically output either 23.976 Hz or 24.000 Hz depending on the source material. So this is not a problem with the correct hardware. I.e. if you play a 23.976 Hz movie you get 23.976 Hz video output, and if you play a 24.000 Hz movie you get 24.000 Hz video output. Also, the TV:s are able to detect the video frequency of the source and display it properly. The problem occurs when the source indicates that the video stream is 23.976 Hz, but in reality does not use exactly that frequency. They you get frame drops or duplicate frames, and audio sync problems. I.e. the problems we are seeing with e.g. Sandy Bridge and possibly Ivy Bridge.

 

[Khato]

Sony's mid-range models has had it for more than four years. For example the Sony W3000 had it in 2007 (see "24p True Cinema" in the tech specs):

http://www.hdtvtest.co.uk/Sony-KDL40W3000/

Which proves my point - you had to look for it if you wanted it.

Regardless, the point still stands that the majority of computer users don't understand what 24p playback actually is/what it actually affects. As well, near every thread railing on Intel for this 'issue' neglects the fact that support by AMD and NVIDIA can be just as 'bad', aka off by a 1-4 thousandths of a fps. I'm now rather curious as to what kind of clocking circuit each design uses for it - what I've seen from most implies that there isn't much filtering/stabilization logic present, resulting in fluctuations corresponding to whatever they're using for a base clock frequency.

 

[Fjodor2001]

Which proves my point - you had to look for it if you wanted it.

I don't agree. It has been mainstream for mid-range HDTVs since around 2007.

I'm now rather curious as to what kind of clocking circuit each design uses for it - what I've seen from most implies that there isn't much filtering/stabilization logic present, resulting in fluctuations corresponding to whatever they're using for a base clock frequency.

On this I do agree. It would be interesting to know why some hardware is having problems displaying 23.976 Hz video correctly. In what lies the technical difficulties? How come a multi billion dollar tech company like for example Intel can't get it right, while even "el-cheapo" blu-ray players can?

 

[IntelUser2000]

This is yet another proof their graphics problems are due to lacking in hardware, rather than on drivers.

Slow hardware T&L/VS = Fixed in Ironlake
Significantly off 24p support = Practically unnoticeable in Ivy Bridge
Anisotropic Angle dependency = Fixed in Ivy Bridge
Compatibility = Every new hardware generation improves it significantly while drivers did almost nothing

 

[JAG87]

I guess hundreds of millions of people hang themselves when watching BD movies on standard Blu-ray players then.

Wow, 2-3 seconds delay (about the same as when switching TV channels) when pressing play and then ~2 hours later when pressing stop. Totally unacceptable. I guess you'll have to get another TV with shorter delay.

Blu-ray players and GFX cards which handle this properly automatically output either 23.976 Hz or 24.000 Hz depending on the source material. So this is not a problem with the correct hardware. I.e. if you play a 23.976 Hz movie you get 23.976 Hz video output, and if you play a 24.000 Hz movie you get 24.000 Hz video output. Also, the TV:s are able to detect the video frequency of the source and display it properly. The problem occurs when the source indicates that the video stream is 23.976 Hz, but in reality does not use exactly that frequency. They you get frame drops or duplicate frames, and audio sync problems. I.e. the problems we are seeing with e.g. Sandy Bridge and possibly Ivy Bridge.

What makes you think all I watch is 2 hour movies? What if I watch 20 minute shows? What if I want to try something out for a few minutes and go back and play something else? That's the whole point of an HTPC, I can flip between things to watch effortlessly.

And no, GPUs from all vendors do not do this seamlessly at all. There's a huge article right here on AT about it. GPUs pretty much suck at outputting the correct frequency, which is another reason why I gave up trying. I used to try custom NV profiles for 23.976Hz

http://www.anandtech.com/show/4380/discrete-htpc-gpus-shootout/5