Apple TV - Video Stutter.

[newagemac]

I always turn all that fancy processing crap off on my HDTVs. My Sony has "motionflow" and "motion enhancer" fancy frame interpolation settings too but I learned that these things are more a gimmick than anything else because they usually cause more problems than it is worth. It's basically different ways to interpolate frames and handle the 3:2 pulldown. If you have a 120hz tv you really should turn all that stuff off and let the tv do a straight frame repeat rather than interpolating and inventing frames out of thin air because that is what causes judder and stuttering like people are posting in this thread.

 

[rkuo]

Well, I want to watch my video clip a dozen more times before I say so for sure, but I think you might have nailed it. If so, I feel like a dope, too, because monkeying around with my Acer Revo w/XBMC settings to replicate what the Apple TV is doing (sending 720 @ 60Hz) is something I had meant to experiment with. I kind of discounted the possibility before because I've seen judder on my XBMC box (same scene) and it was more constant. In that panning space scene, it would happen every second (maybe more), whereas with the Apple TV, I was seeing a glitch more like every 10 seconds (I didn't time it, I'm just pulling that number out of the air).

But based on your comments, I cracked open my Sharp Aquos 120Hz LCD manual and looked to see what options were available. There are three 3:2 film-related settings available. The default was labeled "Low" (whatever that's supposed to mean). There's also a "High" setting, so I tried that. If anything, the glitch seemed a bit worse or more frequent, but I can't say for certain (more testing required). And then there's an "Off" setting. With that option set, I *think* that I'm not seeing any glitches, *BUT* the overall motion seems less smooth. Rather than appearing as an occasional glitch, the overall motion feels like it's running at a reduced framerate or something. I'll have to test this out with other clips to see which of these two evils is more bearable, or if they both drive me crazy.

My TV also has a "Fine Motion" (I think that's what they call it) mode which is supposed to be better for fast action. Not sure what that's doing behind the scenes, but I may toggle that on/off see if I can make out any improvements.

One of my next tests will be to hook up my Apple TV to my Panasonic AE-700U LCD projector which is native 720p, to see if things are any better or worse there.

Maybe I'm just spoiled having seen how things look on my Acer Revo w/XBMC. That sends out the native sync rate (24p in this case), though I believe it is upscaling it to 1080p.

Whoa. If you have Fine Motion on and it is doing 120Hz frame rate interpolation then you absolutely have to turn it off to do any sort of valid testing.

 

[BlackMangoTree]

I still don't buy it being a refresh rate issue. Because the stutter is only there when the movie is fully buffered on the Apple TV.

 

[BlackMangoTree]

Noticed the discussion over at the Apple forums has been deleted.

Apple made a dud or a turn as someone else put it.

 

[hipnetic]

Noticed the discussion over at the Apple forums has been deleted.

Apple made a dud or a turn as someone else put it.

The thread has not been deleted. It's still there. Here's the link:
http://discussions.apple.com/thread.jspa?threadID=2599423

It hasn't been replied to in the last 24+ hours, so it's on page 10 as of this moment.

Regarding the way that it seems to present the problem more frequently when the movie is fully loaded to the buffer, I can't explain that and I do agree that I'm fairly certain that my experience was in line with that. However, unlike some others, I definitely *did* see the problem even when it wasn't fully loaded to the buffer. It did appear to be more frequent when it had, but it still occurred even when it hadn't.

Anyways, here's my update:
1) I played one or two of my video clips a few times with the two TV options I previously described turned on, and a few times with both options turned off. With the options turned off, the problem has either gone away completely or it's so infrequent as to be a non-issue. After the 2nd or 3rd test with the options turned off, I decided to skip ahead and watch a couple of minutes of my movie where there are a couple of people talking to eachother so that I could "just watch" the movie and see if I was bothered by anything once I'd been paying attention to the movie, and not looking for problems. Again, it either wasn't happening, or it was so infrequent/minor so as to not impact my enjoyment of the movie. Switching back to having both options on caused the problem to reappear (every 5-10 seconds, and I played the clip a few times).

2) I might have gotten a bit greedy at that point, as I then decided to try out the 1080p encode I did early on. That played, but there were noticeable dropped frames fairly frequently. It wasn't "horrible" (I've seen worse), but it would certainly be unwatchable for me. If the Apple TV eventually gets totally jailbroken and they can overclock the A4 chip, perhaps it will be up to the task. They'll obviously also need to hack it to output 1080p instead of 720p.

Oh, the only other comments I'll add at this time are that I had a few different clips to test out (different encodes I had done with Handbrake). My 720p, High Profile, RF16, no filters encode looked the best. The iPad (adjusted for 1280 width) encode didn't look as good. If time allows, I'll do some more head-to-head comparisons on those sorts of things so that I can settle down on some specific encoding settings to use.

For now, I'm cautiously calling this a success. Playing this on my projector and 92" screen will be my next test. Wish me luck.

 

[DoFoT9]

so much for backwards compatibility, eh?

so 1080p films actually play? what is the max observable bitrate that the AppleTV can decode?

 

[BlackMangoTree]

Thanks for the update.

The link in your original post was showing Apple forum doesn't exists thats why i thought it was deleted.

I am still at a loss to why it stutters only once the movie is fully buffered and only old encodes of mine, anything i encode with the High Profile Preset does not stutter ever.

I will bring this unit down to my brothers place when i get a chance and try his Tv and see if it's actually a refresh problem.

The original Apple TV plays back all my old encodes perfectly.

This is a very frustrating issue and i am thinking of returning the Apple TV.

 

[hipnetic]

I am still at a loss to why it stutters only once the movie is fully buffered and only old encodes of mine, anything i encode with the High Profile Preset does not stutter ever.

Again, I personally experienced the stutter even before the movie was fully loaded to the buffer, but it did appear to be more frequent/noticeable when fully loaded. FWIW, one of the encodes I made recently was using the old Apple TV preset (albeit, via a recently nightly build of Handbrake). So, I just tried that out and I'm still seeing the same results. Even after fully loading to the buffer, my movie which previously had stutter/judder/glitch issues is now playing back fine (or, if it does have any issues, they're very, very minor). I don't have an old Apple TV, so I can't compare the two, but I'm increasingly confident that the problems are related to the sync rate differences and/or some of the advanced settings that TVs use to "improve" things. I still place most of the blame on Apple, since they would ideally output the video at its native framerate, but it seems (at least for me, so far) that I can diminish/eliminate the issue by toggling some settings on my TV.

As I previously noted, I still need to test out my new Apple TV when plugged into my projector, so we'll see how that goes.

Hopefully Apple will improve things (assuming it's even possible with the current hardware) by issuing a firmware update which allows for sending out some resolutions/sync rates other than just 720p @ 60Hz.

 

[BlackMangoTree]

Hopefully Apple will improve things (assuming it's even possible with the current hardware) by issuing a firmware update which allows for sending out some resolutions/sync rates other than just 720p @ 60Hz.

720p @ 60Hz is what i set my original Apple Tv and don't see the stuttering.

 

[monnelly]

Hi guys, I'm back. After more experimenting with my old Samsung 40" 1080p TV - which has no scaling options and very bare-basic processing - I encountered no stuttering at all. As for my Sony, I never use motion flow or any motion enhancers, as I feel they make the picture look unrealistic. However, you do have separate scaling options, which I do leave active for standard def content because it does make a huge difference. But by changing the scaler settings I managed to alleviate all stutter on my TV. I don't know why it stutters more for some people when the buffer is completely full, but mine used to stutter when the buffer was empty as well; it just always stuttered regardless of how much content was in there, but never did it for standard def content.

This whole problem reminds me of when the first blu ray players came out, with 1080p at 24fps. it caused stuttering and catch-up moments just like what we're seeing here. I think it must be caused by the refresh rate not being perfectly in sync with what TVs are used to, ie. instead of syncing at 60hz at 720p, it might be doing it at 59HZ or 61HZ. But, if everyone who has an issue with stuttering can post what TV they're using, and if it's a pal set or ntsc set - then if we get enough information together, we might be able to figure out the key reason why some sets stutter and others don't.

 

[BlackMangoTree]

Panasonic Plasma Model No. TH-42PX7A

Screen Size (cm viewable) 106
Screen Size (inches viewable) 42
Screen Type Plasma
Panel Type Progressive HD Plasma Panel
Panel Aspect Ratio 16:9 (Widescreen)
Aspect Ratio Control Modes (TV/AV modes) 4:3, 4:3 Full, 14:9, 16:9, DVB-T 16:9 Fixed, Just, Zoom1, Zoom2, Zoom3
Aspect Ratio Control Modes (PC mode) 16:9, 4:3
Comb Filter 3D Digital
100Hz Technology Yes
Progressive Scan Yes
TV Tuner Receiving System DVB (Digital), PAL-B/G (Analogue)
Tuner Type Integrated SD/HD DVB-T 7MHz Australia, PAL B/G
Electronic Program Guide (EPG) Support1 Yes - 7 Day
Channel Preset/s -
Colour System PAL, NTSC
Picture In Picture (PIP) No
Multi-Window -
CATV/Hyperband Tuner No
Stereo PAL 2CS Stereo
Horizontal Resolution (pixels) 1024
Vertical Resolution (pixels) 768
Contrast Ratio:1 - Native 10000
Contrast Ratio:1 - Dynamic TBC
Picture Adjustment Modes / Film Modes Normal, Dynamic, Cinema
Colour Temperature Control Normal, Cool, Warm
Picture Quality Improvement Functions 3D Comb Filter, Picture Noise Reduction, MPEG Noise Reduction
Teletext Yes
Audio Output Power - Total (Watts RMS) 20
Speakers 2
Audio Features Bass/Treble, Balance, Headphone Volume
Auto Timed On/Off Switch Off Only
On Screen Display Languages English
DTV Parental Guidance Info No
Remote Control Standard
SD Card Slot No
Component Video Input x2
Applicable Component Video Input Signals 576i @ 50Hz (15.63KHz), 576p @ 50Hz (31.25KHz), 720p @ 50Hz (37.50KHz), 1,080i @ 50Hz (28.125KHz), 480i @ 60Hz (15.73KHz), 480p @ 60Hz (31.47KHz), 720p @ 60Hz (45KHz), 1,080i @ 60Hz (33.75KHz)
HDMI Input/Output Input Only, x1
Applicable HDMI Video Input Signals 576i @ 50Hz (15.63KHz), 576p @ 50Hz (31.25KHz), 720p @ 50Hz (37.50KHz), 1,080i @ 50Hz (28.125KHz), 480i @ 60Hz (15.73KHz), 480p @ 60Hz (31.47KHz), 720p @ 60Hz (45KHz), 1,080i @ 60Hz (33.75KHz)
S-Video Input 1
Combined I/O Scart Terminal(s) -
PC Input 1x VGA (15 pin Mini-D-Dub)
Applicable PC Input Signals 4:3 ASPECT RATIO:, 640×400 @ 70Hz (31.46KHz), 640×480 @ 60 Hz (31.47KHz), 640×480 @ 75 Hz (37.50KHz), 800×600 @ 60 Hz (37.88KHz), 800×600 @ 75 Hz (46.88KHz), 800×600 @ 85 Hz (53.67KHz), 1,024×768 @ 60 Hz (48.36KHz), 1,024×768 @ 70 Hz (56.48KHz), 1,024×768 @ 75 Hz (60.02KHz), 1,024×768 @ 85 Hz (68.68KHz), 1,280×1,024 @60 Hz (63.98KHz), Macintosh 13 inch 640x480 @66.67Hz (35KHz), Macintosh 16 inch 832x624 @74.54Hz (49.72KHz), Macintosh 21 inch 1152x870 @75.06Hz (68.68KHz)
A/V Input 3 - Rear
A/V 1: Stereo-in L&R [RCA], Video-in [RCA], S-Video-in [S terminal]
A/V 2: Stereo-in L&R [RCA], Video-in [RCA], Component Video Input [Y, Pb, Pr]
A/V 3: Stereo-in L&R [RCA], Video-in [RCA], Component Video Input [Y, Pb, Pr]
Digital Audio Out Optical Terminal, DVB-T Only
Monitor Out Stereo L&R [RCA], Video [RCA]

What is strange i only see this stutter once the movie is fully buffered. It's once every now and then, sometimes it plays fine for 10 mins then a slight stutter for a sec then plays fine again got 5 mins then a slight stutter for a sec.

 

[BlackMangoTree]

Oh well i have tried everything over the last few days to resolve this issue, different handbrake settings different apps different tv's different hdmi cables.

I am giving up.

The Apple Tv is going back to the store for a refund.

 

[jajohns8]

Blackmango, I have a Panasonic 42" plasma too. I forgot the exact model number, but will post later when back home.

Something.... X1 maybe? Bought it last year.

I hate to have to return my Apple TV 2, but I cant deal with the stutter anymore.

Interesting that people have reported the same stutter with rented Itunes HD videos.

I rented an HD version of a Family guy episode and it played ok. Would like to test this out more though.

 

[chriso89]

What is Video stutter?

 

[SonicStomp]

Video Stutter

I am convinced that it is related to TV motion processing features.

I have a Sony KDL40W5500 Bravia 3 - I was noticing stutter regularly, so tried turning off motion flow - no change. Then I tried turning off 'Film Mode'. Hey presto - problem solved!!

'Film Mode' apparently provides "improved picture movement when playing DVD or VCR images taken on film, reducing picture blur and graininess."

Genuinely, this has solved the problem (or improved it to the point when I don't notice it anymore.)

 

[BlackMangoTree]

I think that we are dealing with two different issues.

For some of us we only see the issue arise once the movie has fully buffered onto the Apple TV, then it's only a very minor stutter more like a quick 1 second glitch that happens very infrequently, maybe once every 10 mins.

 

[SonicStomp]

Blackmango - the way in which you have described the problem is exactly how I would have described mine. Except mine is NOT related to buffer at all and has been solved by turning off my tv's motion processing feature.

 

[BlackMangoTree]

I have use 3 Apple TV's on 3 different TVs one TV was a sony turned off all its video enhancers, fixed the issue of stutter but did not get rid of the 1 sec glitch every now and then once the movie is fully buffered.

The way i see it 3 tv's 3 Apple Tv's all have the same issue, this is a Apple fault and needs to be fixed ASAP.

I feel it's bullsiht that Apple release a product with this kinda flaw, not to mention all the other issues. (Freaking subtitles don't work at all)

Whats happened to their QA ?

Maybe they'll release a bumper for the Apple TV.

What a joke. Seriously this is pathetic.

PS. My original Apple TV plays all my movies over HDMI without an issue. (subtitles work)

 

[jajohns8]

FWIW, my tv is a panasonic tcp42x1.

Blackmango, did you take yours back, or are you still testing?

I am curious to read the consensus of the handbrake community. Is this a widespread issue that rears it's ugly head only with HD (particularly with HD handbrake encodes, but has been reported with HD iTunes rentals.) material? Television specific?

One thing is for sure. It's not "just me."

This is definitely a problem with the device or a process unique to Atv2.

My atv1 plays back the same material flawlessly.

 

[BlackMangoTree]

It has been reported to be happening on iTunes rentals too. I have had it happen on SD dvd rips as well. I am 100% sure it is not handbrake related at all.

I think all we can do is wait for Apple to hopefully fix this issue.

 

[elliotclowes]

Lot's of great advice in here for me to try when I get back home. But I think I have a different issue. I don't see occasional stuttering at all, but on certain movies streamed over Home Share, every 10 minutes or so they'll be 10 seconds of 2fps then it will just freeze completely. Exiting the movie and resuming it fixes it, but only for another 10 minutes. I had to do that all the way through Lord of the Rings!

It doesn't occur with rents and as far as I can tell only with longer movies, 90 minute ones are fine, but that that's likely just a coincidence. This might be a known issue with a fix and I've just missed it in the forums, but any help would be greatly appreciated. Thanks!

 

[DoFoT9]

It has been reported to be happening on iTunes rentals too. I have had it happen on SD dvd rips as well. I am 100% sure it is not handbrake related at all.

I think all we can do is wait for Apple to hopefully fix this issue.

it is likely that a a firmware/OS update will fix the issue - at this point in time we dont actually know where the problem lies by the looks of it, as we arent able to debug at the lowest levels.

 

[n0ah87]

Lot's of great advice in here for me to try when I get back home. But I think I have a different issue. I don't see occasional stuttering at all, but on certain movies streamed over Home Share, every 10 minutes or so they'll be 10 seconds of 2fps then it will just freeze completely. Exiting the movie and resuming it fixes it, but only for another 10 minutes. I had to do that all the way through Lord of the Rings!

It doesn't occur with rents and as far as I can tell only with longer movies, 90 minute ones are fine, but that that's likely just a coincidence. This might be a known issue with a fix and I've just missed it in the forums, but any help would be greatly appreciated. Thanks!

This is exactly the same problem that I am having. I thought it might have been because I was using wireless so I ordered an Ethernet cable but it has done exactly nothing. It is extremely irritating and i've considered bringing my at2 back as well. When I get home i'll try out changing the TV settings and some of the encodings on handbrake to see if I have any success and let you know. Hopefully apple puts out a fix for this soon

 

[BlackMangoTree]

This Issue Has Nothing To Do With Handbrake.

 

[JeffLebowski41]

I'm seeing this too. very quick, half second at most stutter every few minutes after the movie has been buffered. Calibrated Panasonic s1 plasma..no motion enhancement or anything like that.