Minor Video Stutter

Encoding method, then the iTunes Store must have badly encoded videos as well they exhibit the same behaviour.

Well I explored the sync rate idea and turned off the "Film Mode" (3:2 pull-down) and "Fine Motion Enhanced" settings in my TV's settings menu. This TV is a Sharp Aquos LC-52E77UN 52" 120Hz LCD. I'm a bit hesitant to say the problem is completely solved, but after viewing my test video clips several times again (and toggling those settings on/off a couple of times to compare), it definitely appears to at least be greatly reduced to the point that if/when I see a glitch it's infrequent/minor enough that I'm not even certain that I'm not just imagining it. To put it another way, I think I can actually go back to just enjoying watching my content.

This doesn't explain why the problem did appear to be more frequent/noticeable after the movie has fully loaded to the Apple TV's buffer.

I still do think that there's something not quite right on the Apple TV's side of things. I suspect also that if Apple could add support for additional output sync rates/resolutions (other than just 720p @ 60Hz) then that might alleviate the issue further. Sending out the video at the native sync rate (e.g., 24 or 23.976) would probably be ideal.

I'll do some more testing with other TV's in my house as well as my 720p projector.

Im getting the same with my ATV(2). Network bandwidth isn't an issue and my i7 iMac can transcode the same movies to my PS3 via PS3 Media Server without stutter.

Exactly the same symptoms every minute or so there seems to be dropped frames whether its a handbrake rip or paid for download. I am using a Samsung series 5 TV

Apples QC seems to be going down the pan. My iphone4 required a bumper, I wonder what we will get with the ATV.

I feel that we are experiencing two different issues

Seems like Sony TV's are causing weird behaviour with their motion flow ect.. once turned off then our issue is still there.

It only happens once the movie if fully buffered onto the Apple TV. It's just a quick stutter more like glitch for about a second and happens very infrequently.

I feel this has nothing to do with refresh rates of the tv or Apple TV otherwise it would happen even before it's fully buffered.

As mentioned my issue is with frame drop every minute or so although I am open to the idea that the Sammy TV is causing the problem. However I do not get the issue when I use the transcoding option when using the PS3. However when using the PS3 while streaming m4v files there is quite violent stuttering. But I am led to believe its the PS3's fault.

How can you tell when the buffer is full ? I can see when streaming a You tube movie but not when I am playing a movie from my iMac.

I experienced an almost nauseas level of stutter last night. The source video was not to put to fine a point on it totally crap. Leaving this aside I verified that a computer monitor showed no stutter in the same file. Assuming a display device issue (ie: TV) I checked various options set on Sony 32" TV. I was able to almost entirely remove visible stutter by adjusting the Cinema Mode. It has three options, off/auto 1/auto 2. It supposedly provides 'smoother' picture movement, Auto 1 was the setting causing the problem, supposedly the best for adjusting source to native refresh frequency. Setting to off or Auto 2 seemed to achieve the same good results. Motionflow setting didn't appear to impact on stutter.

I have the same problem with an unusual setup
MacPro via ethernet to AppleTV 2 connected to an S-Video downscaler and finally to my Bang & Olufsen Avant Real Flat 32 (good old fashion CRT TV).
Whats surprising is that I have no stutter streaming wirelessly to my MacBook Pro

Message was edited by: Soosay

People with Sony Tv are seeing a different issue.

This is clearly an Apple TV hopefully Apple will fix it with a firmware update soon.

I can confirm the stutter only starts for me when the buffer is full.

I just bought the ATV2 and noticed this issue on my first HD rental.

My immediate instinct is in agreement with hipnetic, that this is a consequence of the way our TVs deal with a 60hz signal. I have a Pioneer 428XD with three different Film Mode settings, "Standard" "Smooth" or "Advance", none of which seemed right. The only thing I haven't tried is Film Mode off, so I'll try that and report back.

Ok, changing the Pioneer's PureCinema (i.e. Film Mode) settings to standard or off had no effect. Advance seems to be the best compromise, but it's by no means perfect. But there are various advanced settings within the 428XD, so if anyone has any ideas about which combination of settings might be best for 720p at 60hz, I'm eager to hear them! Here's a summary of what the Pioneer settings do:

The Drive Mode setting selects the preferred refresh rate/frequency for displaying 50Hz content only. The settings have no effect for any other content such as NTSC TV, Region 1 DVDs, BR, and other less common HD formats:
• DM1 displays 50Hz content at 75 Hz; best for anything originally shot in 25fps, ie film based material
• DM2 displays 50Hz content at 100 Hz; best for anything originally shot in 50fps, ie video based material
• DM3 displays 50Hz content at 72 Hz; there is never a home use for this setting – avoid it (this advice is fairly new, so watch this space...)

The Purecinema setting is exclusively dedicated to how the TV presents film based material only on the screen, ie 25 fps (films on TV and DVD) and 24fps (BR films):
• Off disables film mode de-interlacing and switches to mode de-interlacing – appropriate for video based material or film based material which has already been de-interlaced, eg by the DVD player or Sky box
• Standard is appropriate for 50Hz film based material originally shot in 25 fps and should be displayed at 75 Hz (DM1). The de-interlacing method is classic 3:2 and 2:2 cadence detection with reverse pulldown
• Smooth is never selected in the real world – whatever it does, it does badly so there is little point in trying to establish what it is attempting to do
• Advance is predominantly used for a BR 1080p24 signal which it will display at 72Hz. It is also used for NTSC DVDs (eg Region 1) when this mode cleverly tries to lock onto the 3:2 cadence to extract a pure 24p signal from it which it then displays at 72Hz.

Message was edited by: Alex T

Just a thought - but the Apple TV couldn't be running at 60Hz output rather than the proper 59.94Hz output that is actually used by broadcasters. (cf 23.976Hz and 29.97Hz being the actual rates rather than 24Hz and 30Hz).

If 29.97Hz and 23.976Hz content is output at 60Hz rather than 59.94Hz you will get a repeated frame every so often to allow the lower refresh rate source to stay in sync.

("60Hz" broadcast TV has been 59.94Hz ever since NTSC colour was introduced in the 50s, to avoid the colour subcarrier interfering with the FM audio carrier. Even though NTSC and subcarrier are a thing of the past, SD and HD video still use 59.94Hz rather than 60Hz to avoid having frame rate issues during up and down conversion. As a result "24Hz" film and video content is also captured at 23.976Hz which is the 3:2 multiple of 59.94Hz. Surprising how many computer video solutions - I'm looking at you Intel - don't get this...)

Don't get me started on the Apple TV v2 in Europe... There is no way of getting it to output a 50Hz 720p signal that I can find (unlike the Apple TV v1 which allowed you to select 50Hz 1080i, 720p, 576p and 576i resolutions manually) This means that any 50Hz content you may have in iTunes (which could be a LOT if you use an Elgato EyeTV or similar to record / play TV, or shoot home videos, which will be 50Hz in Europe) judders appallingy - as 5 frames a second are repeated to get from 25Hz to 30Hz.

And when is the ATV (v1 or v2) going to support native 23.976Hz output - and when are Apple going to support proper 50/59.94Hz full-rate video - I'm fed up watching interlaced shows de-interlaced to half-rate 25/29.97Hz...

Rant over.

Of course the answer to this is that the ATV v2 is only designed for viewing content Apple have sold you... Which will be 29.97Hz or 23.976Hz...

The inability for the aTV2 to output 720p at 50hz is a major problem for me as my PAL DV video clips from my camcorder look awful. A firmware update to enable 50Hz like the old model would be wonderful.

Yep - in an ideal world the ATV v2 would read EDID supported frame-rates from the display - and automatically switch to the best frame rate based on the video file's fps (as indicated by Movie Inspector etc.)

My TV supports 23.976/24/50/59.94/60Hz refresh rates - and in an ideal world the Apple TV would just output at the right frame rate automatically.

Next best would at least be a manual selection of frame rate. Defaulting to 60Hz is just plain lazy - and ignores the large chunk of the world that will have 50Hz content (Europe, much of Asia, Australia, New Zealand, parts of South America etc.)