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Apple TV 3 - Stuttering
- Thread starter Daniel97
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Hi Guys,
Just bought an ATV3 so i could airplay my macbook air to my TV screen to watch blu ray rips .. all seems great except for movies seem to be a bit laggy when playing in full screen?
Anybody know why?
Thanks!
What format are they in? The original MKV - that is, basically, you're using the slow and, for video playback, useless direct mirroring? Or, have you remuxed them to MP4's as should be done?
HobeSoundDarryl
macrumors G5
If you've had it for a while, try the old unplug, wait 30 sec, plug it back in. I personally think there is a memory leak bug in the 
TV3 that eventually eats up almost all of the available storage space. I suspect it can't eat it all up (there's probably a minimum buffer) but that's what I think ends up being THE buffer after enough time has passed. The unplug, wait 30, reboot things seems to resolve the problem for a while.
If you haven't had it for a while, you'll need to share more information for good help. Maybe you're feeding it files at a bit rate above what it can handle? Maybe your wifi system is not fast enough to handle 1080p? Maybe others in your household are also taking a slide of your wifi bandwidth while you are trying to airplay? Maybe you've got some wifi interference from neighbors or other stuff in your home? Lots of possibilities.
One suggestion to overcome all of the wifi potential issues: for one of the problematic movies, try a wired connection as a test. See if it continues to play "laggy." If it is smoother with a wired transfer, start hunting for issues in your wifi setup.
TV3 that eventually eats up almost all of the available storage space. I suspect it can't eat it all up (there's probably a minimum buffer) but that's what I think ends up being THE buffer after enough time has passed. The unplug, wait 30, reboot things seems to resolve the problem for a while.If you haven't had it for a while, you'll need to share more information for good help. Maybe you're feeding it files at a bit rate above what it can handle? Maybe your wifi system is not fast enough to handle 1080p? Maybe others in your household are also taking a slide of your wifi bandwidth while you are trying to airplay? Maybe you've got some wifi interference from neighbors or other stuff in your home? Lots of possibilities.
One suggestion to overcome all of the wifi potential issues: for one of the problematic movies, try a wired connection as a test. See if it continues to play "laggy." If it is smoother with a wired transfer, start hunting for issues in your wifi setup.
HobeSoundDarryl
macrumors G5
MKVs retain maximums for everything (like bitrate). TV3 can't play BD maximums (like bitrate). Instead, it will struggle to cut things down to what it can play while also trying to play it as fluidly as possible. You will likely be much happier with TV3 if you convert the MKV to an TV3 (native) version. Handbrake is your friend.
Also, internet connection speed has nothing to do with airplay or wifi. It's all kept in-house. I'd try a temporary wired option if you choose not to heed the above (convert) to rule out wifi interference, internal wifi bandwidth pinches (by others in your house), etc.
TV3 can't play BD maximums (like bitrate). Instead, it will struggle to cut things down to what it can play while also trying to play it as fluidly as possible. You will likely be much happier with TV3 if you convert the MKV to an TV3 (native) version. Handbrake is your friend.Also, internet connection speed has nothing to do with airplay or wifi. It's all kept in-house. I'd try a temporary wired option if you choose not to heed the above (convert) to rule out wifi interference, internal wifi bandwidth pinches (by others in your house), etc.
HobeSoundDarryl
macrumors G5
I assume you're in the UK as a previous post of yours uses the word 'bollox'
So you're probably having the same problem as most of us in the UK, the Apple TV stutters a bit on moving video. Not too sure what the problem is (though I think it's to with 50/60hz & 25/24 frames per second - though I'm no video expert and I'm happy to be proven wrong).
It's a bit crap to be honest, I'm hoping one day it'll get sorted (or I get a TV that sorts it).
So you're probably having the same problem as most of us in the UK, the Apple TV stutters a bit on moving video. Not too sure what the problem is (though I think it's to with 50/60hz & 25/24 frames per second - though I'm no video expert and I'm happy to be proven wrong).
It's a bit crap to be honest, I'm hoping one day it'll get sorted (or I get a TV that sorts it).
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MKV's? That's the problem. You will want to remux them first with Subler, Smart Converter or MP4Tools.
As I've explained above, MKV's aren't played back in hardware by the ATV, only via streaming - hence the stuttering. The same video stream inside an MP4 (mov / m4v) container surely won't stutter, unless it has some extreme bitrate.
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Before embarking on some lenghty reencoding with HB, try remuxing the MKV's to MP4 files to see whether it fixes the problem. I think it will.
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MKVs retain maximums for everything (like bitrate).
Are you sure? I've tested the ATV3 with high-bitrate videos like the 40 Mbps (!!) one at http://www.auby.no/files/video_tests/h264_1080p_hp_4.1_40mbps_birds.mkv (after remuxing it with Subler). Absolutely no problems during playback. BTW, not even the A4 CPU (one-generation less than the one in the ATV3) in the iPad 1 / iPhone 4 stutters while playing back the same video.
It's only the iPhone 3GS that does have problems with this video - but even it's watchable to some degree. (Even earlier (1st and 2nd gen) small-screened iOS devices can't play back the footage at all.)
I haven't encountered stutters or dropped frames with regular, uncompressed BD rips I've made either; for example, an Iron Sky rip at 22 Mbps (24 fps) - that's at least twice the bitrate most people use for 24 fps 16:9 1080p.
My understanding is that the aTV will play bitrates higher than it's spec just fine. However, the people that have success doing this are using ethernet as wifi will not reliably carry that amount of data. I have tried using uncompressed BR files over wifi and I do not get smooth playback.
Doesn't matter whether wifi-N or ethernet. Sure you'll get less dropouts hard-wired but still, check the network data information under activity monitor while a movie is playing. The AppleTV can't write the data fast enough to the internal memory. The max I'm getting with wifi N is 4 MB/s and it's the same with ethernet 4 MB/s. The player will spit out high bitrate movies with 4.1 profile easily, it just has a serious problem with buffering any content. Anyone hard-wired to the player should be seeing transfer rates of 12.5 MB/s. That's not happening. Unless my player is faulty I see no mechanism for improving data transfer.
HobeSoundDarryl
macrumors G5
TV3 specs say up to 25Mbps so those latter 2 make perfect sense. Typical of apple: I can get things to smoothly play at a bit above 25Mbps. However, there is a cap but it's not a simple number. TV3 will seem to try to play just about anything we throw at it as long as it is in the appropriate container. For example, it will try to play 1080p60fps and it will even seem to look fine until the camera pans and thus lots of pixels are changing on screen at the same time. Then, it's going to stutter.I didn't look at that birds clip you reference but if it is 40Mbps,
TV may be trying to play it. If it's not very demanding- that is, not many pixels are changing on screen- it might work just like 1080p60fps seems to work when the camera is not moving. The test would be to try something at 40Mbps with a lot of action (such as a camera moving left or right so that most of the pixels on the screen are changing). I bet it stutters in that scenario. Unfortunately, most(?) movies will have a panning camera in them. So if you test that out and discover stutter, it would yield the same stutter for most(?) movies.The solution: process it down with the
TV3 preset in Handbrake so that the resulting file works at the specs Apple intended. Then, it should play great.Going back to my quote you referenced, there is a perceptual error. I said "
TV3 can't play BD maximums (like bitrate)" and what I meant in that is BD maximum bit rates. If a BD happens to be encoded at a rate of around 25Mbps or less, then it is encoded at TV3 bitrate specs. That's not BD maximum specs and not all- or even- many BDs will be encoded at maximum specs. Some will be encoded at specs compatible with TV3. When that's the case, the subler conversion should work well (assuming a few other variables such as the video is already h.264, etc).Update: I downloaded that birds file and see that there is some slow pan to the left with a slow reverse zoom showing more and more birds in the frame. If that clip is 40Mbps, I have no idea why it's able to play on
TV3. I would expect it to drop frames or stutter. Maybe when you convert it for TV3, your method is compressing it a bit more and/or reducing the bit rate to a lower level? Maybe the lack of audio frees up some extra horses? I tried it with Subler and it yielded a 40Mbps file. I'll test it on my
TV3 a little later.
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Update: I downloaded that birds file and see that there is some slow pan to the left with a slow reverse zoom showing more and more birds in the frame. If that clip is 40Mbps, I have no idea why it's able to play on
Unfortunately, that clip is a re-encode. BBC's Planet Earth utilizes the VC-1 codec which is not playable on the
TV.
HobeSoundDarryl
macrumors G5
Update to post #13: I tried the birds video converted to .m4v with Subler (still showing about 40Mbps). What I noticed is that when I tried to play it on TV3 (wired ethernet), it had a prolonged delay and wouldn't start even when about half of the progress bar was full (showing about half of the file streamed over).
That's different than any other video media I've got. Usually the latter will start playing when only a minor bit of the progress bar is full.
Since the birds .m4v is so small (<120Mb), I would have expected it to stream over in just a few seconds at worst. Instead, it took a long time.
My suspicions:TV3 recognized that it could not play it and was internally downconverting it to something it could play (probably re-doing it at around 25Mbps or less). It was probably using most of it's horsepower to do the conversion leading to the slow transfer of the stream. But that's just a guess based on the experience relative to playing any other 1080p video I've got in my library.
I'm guessing if I waited it out, it would have eventually played. If the guess is right, it should have looked about the same as the original but I think it would have been a copy of the original, not the 40Mbps version actually playing onTV3. The prior generation would accept 1080p video and then dynamically downconvert it to 720p, so there's certainly code in the little box for accepting something it can't handle and converting it to something it can. Maybe that is occurring with this 40Mbps file too?
That's pure speculation on my part. I have no way to know what was actually happening in thatTV3. I just noticed how different this file behaved vs. any others properly encoded per TV3 specs.
TV3 (wired ethernet), it had a prolonged delay and wouldn't start even when about half of the progress bar was full (showing about half of the file streamed over). That's different than any other video media I've got. Usually the latter will start playing when only a minor bit of the progress bar is full.
Since the birds .m4v is so small (<120Mb), I would have expected it to stream over in just a few seconds at worst. Instead, it took a long time.
My suspicions:
TV3 recognized that it could not play it and was internally downconverting it to something it could play (probably re-doing it at around 25Mbps or less). It was probably using most of it's horsepower to do the conversion leading to the slow transfer of the stream. But that's just a guess based on the experience relative to playing any other 1080p video I've got in my library.I'm guessing if I waited it out, it would have eventually played. If the guess is right, it should have looked about the same as the original but I think it would have been a copy of the original, not the 40Mbps version actually playing on
TV3. The prior generation would accept 1080p video and then dynamically downconvert it to 720p, so there's certainly code in the little box for accepting something it can't handle and converting it to something it can. Maybe that is occurring with this 40Mbps file too?That's pure speculation on my part. I have no way to know what was actually happening in that
TV3. I just noticed how different this file behaved vs. any others properly encoded per TV3 specs.
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Update to post #13: I tried the birds video converted to .m4v with Subler (still showing about 40Mbps). What I noticed is that when I tried to play it on
Check your connections. It played fine on my
TV 3, started after a few seconds, and played through with no hiccups. And this was over wifi. No on-the-fly transcoding is occurring, the
TV can play high bitrate content. Like I said earlier, the problem lies with the system being slow at buffering the movie, basically the system is slow at writing to it's internal memory.I'll also check this out by comparing the blockiness at the end of the video when the image turns black. (Blocks are certainly visible even with the original file played in desktop VLC; a lower-bitrate video should show even worse blockiness.)
Update: I downloaded that birds file and see that there is some slow pan to the left with a slow reverse zoom showing more and more birds in the frame. If that clip is 40Mbps, I have no idea why it's able to play on
I've both made it much longer (by joining the same file to itself several times) and added two audio tracks (AC3 + AAC) to it. I've started uploading it to https://dl.dropbox.com/u/81986513/0...4.1_40mbps_birds copy 7.mp4.joined.2audio.m4v (it'll take a while for it to be transferred - at least 5-6 hours from now (see the timestamp of this post). That is, the link, for the moment, is still useless.)
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Unfortunately, that clip is a re-encode. BBC's Planet Earth utilizes the VC-1 codec which is not playable on the
Is there any fundamental difference between the BD H.264 and that of HB (if HB was used for reencoding)?
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Yup, wired connections are so much better than Wi-Fi ones. The ATV might have a particularly weak Wi-Fi unit.
There is no fundamental problem with my Wi-Fi network: while my late 2009 17" MBP (2.8 GHz c2d, Vertex 4, ML) can download files off the Internet with 2.5 Mbyte/s in exactly the same location as the ATV3, the wired connection's speed is "only" five time of that (around 12 Mbyte/s).
That is, - prolly it's the ATV3 that is this bad.
HobeSoundDarryl
macrumors G5
H.264 is H.264.
However, there is a fundamental difference: Handbrake will be decoding the "master" and then re-encoding a second generation. As such there will be some loss (always is when going from one generation to the next).
Secondly, if you are using the preset to yield an
TV version, it's going to be compressing the file to fit what the specs can handle. Not only will this typically reduce a BD's video Mbps but this also affects sound quality (typically dropping it from uncompressed DTS or Dolby to compressed Dolby Digital).All that said, HB does a great job. File sizes drop considerably and video looks great. Experiment with a chapter at various settings and blind test one against another to see if you can see the difference. You might be surprised.
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No on-the-fly transcoding is occurring, the
How sure are you of this? I've seen an awful lot of people griping about Mbps much above 25. Technically one could call that "high bitrate" but we're talking about 40Mbps, which, as I understand it, is beyond what
TV can do. See for example, post #2 here: https://forums.macrumors.com/threads/1351739/ or read this: http://appleinsider.com/articles/12...n_1080p_apple_tv_and_software_update_5/page/7My system is wired and I never have problems with speed of the stream. In this test, I tried the birds video and it behaved differently than other videos. To rule out a coincidental system issue, I immediately tried one of my other movies and it shot over as usual (without the odd happenings I described).
If "3" can handle 40Mbps, just about all BDs could be simply repackaged by Subler (no Handbrake required). So again, are you sure about what you wrote up there or by "high bitrate" did you mean around 25Mbps and less... not 40Mbps? An awful lot of people are using Handbrake for BD conversions.
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"Birds" is a really action-packed video - no wonder it needed to be encoded at extreme bitrates, equaling BD's maximal allowed video bitrate (see http://en.wikipedia.org/wiki/Blu-ray_Disc#Bit_rate ). Few BD's go over 30 Mbps, I'd say.
BTW, the Norwegian test page states the Birds video is "Direct bluray (or hddvd) remux" - that is, it might not have been reencoded.
How sure are you of this? I've seen an awful lot of people griping about Mbps much above 25. Technically one could call that "high bitrate" but we're talking about 40Mbps, which, as I understand it, is beyond what
My system is wired and I never have problems with speed of the stream. In this test, I tried the birds video and it behaved differently than other videos. To rule out a coincidental system issue, I immediately tried one of my other movies and it shot over as usual (without the odd happenings I described).
If "3" can handle 40Mbps, just about all BDs could be simply repackaged by Subler (no Handbrake required). So again, are you sure about what you wrote up there or by "high bitrate" did you mean around 25Mbps and less... not 40Mbps? An awful lot of people are using Handbrake for BD conversions.
I'm almost positive no on the fly transcoding is occurring. Too much horsepower needed. But I would love to be proven wrong. As for my movies, they're all re-muxed bluray titles with an extremely high bitrate. Most play without a problem after an initial 20 second buffer. And that includes a 40GB Avatar file. I don't like Handbrake and don't use it. Subler and makemkv are all I use.
As for your network, just open up Activity Monitor under Applications, click Network, and observe the transfer rate from your computer running iTunes to your
TV while you play a movie. Take note of your transfer rate and compare it to wifi. You'll be hard pressed to see any significant difference. The TV tops out at a 4MB/s transfer rate whether your running ethernet or wifi. Sure ethernet is more consistent, but it's not faster according to the numbers I'm reading. Just so you know, a 10/100 ethernet connection should yield 12.5MB/s transfer between devices. I haven't seen those transfer rates since the 1st gen TV. the buffer is slow, hence the small file sizes on iTunes.----------
MediaInfo clearly shows the codec being x264. BBC encoded Planet Earth utilizing the VC-1 codec (Microsoft). Someone re-encoded the file somewhere.
HobeSoundDarryl
macrumors G5
My guess about the lack of sound seems irrelevant with Jlassoon's response to me in post #20. He says he's not even using Handbrake- just subler- which means he's simply putting an TV3 wrapper around the original BD rip. I assume he wouldn't do that without sound. Since some of those rips are huge (and very likely above 25Mbps) and since he says they play flawlessly, apparently the collective and well-published concept of TV3 spec cap at 25Mbps is wrong.
And, if it can handle any Mbps rate BD can handle, then the only significant specs advantage BD has overTV3 will be the sound licenses (better than Dolby Digital).
Given how much is out there about people having trouble over 25Mbps and written information pinning it down as the maximum spec, I still find it hard to believe... and I can't explain my own experience with that Subler-converted Birds video at 40Mbps (when Menneisyys2 says it plays fine). Nevertheless, if he says it works fine at much higher bitrates, all we can do is break out Subler and do some tests, make some >25Mbps files and see how they play.
I may be biased to history, meaning I'm used to Apple specs being near what Apple stuff can really do. For example,TV1 specs seemed to be about 80-85% of the actual max. Maybe that bias has made me assume something about TV3 that- apparently- is not true?
TV3 wrapper around the original BD rip. I assume he wouldn't do that without sound. Since some of those rips are huge (and very likely above 25Mbps) and since he says they play flawlessly, apparently the collective and well-published concept of TV3 spec cap at 25Mbps is wrong.And, if it can handle any Mbps rate BD can handle, then the only significant specs advantage BD has over
TV3 will be the sound licenses (better than Dolby Digital).Given how much is out there about people having trouble over 25Mbps and written information pinning it down as the maximum spec, I still find it hard to believe... and I can't explain my own experience with that Subler-converted Birds video at 40Mbps (when Menneisyys2 says it plays fine). Nevertheless, if he says it works fine at much higher bitrates, all we can do is break out Subler and do some tests, make some >25Mbps files and see how they play.
I may be biased to history, meaning I'm used to Apple specs being near what Apple stuff can really do. For example,
TV1 specs seemed to be about 80-85% of the actual max. Maybe that bias has made me assume something about TV3 that- apparently- is not true?
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HobeSoundDarryl
macrumors G5
Update: I gave "birds" another try. This time, I opened it in QT7, copied the whole thing, pasted it onto the end and repeated this again. This yielded about a 1:09 version of the movie (same video running 3 times back-to-back). Saved. Subler to make it an m4v. Optimize. Put it in iTunes.
Then, to cover a few other bases, unpluggedTV3, waited 30, plugged it back in. Shut down iTunes & reopened.
Selected a "short" film <25Mbps at about 5 minutes long. The buffering bar showed, the bar filled to about 4% and it started to play. Total time for playback to begin- about 4 seconds at most.
Selected the birds video (nearly 40Mbps) at 1:09 long. The buffering bar showed, the bar had to fill to nearly 33% or more and then it did play... and appeared to play smoothly this time. Total time for playback to begin- about 60+ seconds.
From this, I continue to suspect that eitherTV or the computer to which it is linked is dynamically creating a copy of the birds video that TV can play. The assumption is based on one like-sized HD video starting in <4 seconds while the next one taking a minute or longer to start playing.
Unless there is some way to know what is happening within theTV, it would be easy to assume that no such conversion is occurring but then we would need to explain the 4 seconds vs. 60+. I do know that the "2" used to receive 1080p files and dynamically downscale them to 720p so I know that at least that kind of conversion programming to fit spec limits existed within the "2".
So I'm not sure what to make of the dual beliefs within in this thread. There is an argument thatTV3 can smoothly play high BD bitrates well above 25Mbps and there is a counter that it can't. If there is some definitive way for someone to test this, it would be good to know for sure.
I'm pretty sure I don't have transfer rate problems as this test was 2 like-sized files. Why would I have a transfer rate issue with only the birds video?
Then, to cover a few other bases, unplugged
TV3, waited 30, plugged it back in. Shut down iTunes & reopened. Selected a "short" film <25Mbps at about 5 minutes long. The buffering bar showed, the bar filled to about 4% and it started to play. Total time for playback to begin- about 4 seconds at most.
Selected the birds video (nearly 40Mbps) at 1:09 long. The buffering bar showed, the bar had to fill to nearly 33% or more and then it did play... and appeared to play smoothly this time. Total time for playback to begin- about 60+ seconds.
From this, I continue to suspect that either
TV or the computer to which it is linked is dynamically creating a copy of the birds video that TV can play. The assumption is based on one like-sized HD video starting in <4 seconds while the next one taking a minute or longer to start playing.Unless there is some way to know what is happening within the
TV, it would be easy to assume that no such conversion is occurring but then we would need to explain the 4 seconds vs. 60+. I do know that the "2" used to receive 1080p files and dynamically downscale them to 720p so I know that at least that kind of conversion programming to fit spec limits existed within the "2".So I'm not sure what to make of the dual beliefs within in this thread. There is an argument that
TV3 can smoothly play high BD bitrates well above 25Mbps and there is a counter that it can't. If there is some definitive way for someone to test this, it would be good to know for sure.I'm pretty sure I don't have transfer rate problems as this test was 2 like-sized files. Why would I have a transfer rate issue with only the birds video?
My guess about the lack of sound seems irrelevant with Jlassoon's response to me in post #20. He says he's not even using Handbrake- just subler- which means he's simply putting an
And, if it can handle any Mbps rate BD can handle, then the only significant specs advantage BD has over
I should have elaborated a little bit, I also use a program called Remux to convert the DTS-HD Master track to AC3. But I do keep the lossless track within the MP4 file. The
TV just doesn't play the DTS track. I simply do this to future-proof my movies. For large movie files, I simply allow the
TV to buffer more content by pausing the movie before it actually starts playing. I have no problems with movies <20GB, but anything over is asking for trouble as the ethernet capabilities of the system are limited. And with that being said, I have yet to see any of my movies stutter because of bitrate. The only problems I have ever encountered were as a result of a Handbrake encode. That's why I don't use it. The current gen TV is a very capable product, but extremely limited as-well. We're talking 20 year old audio capabilities. As for video, well the system is quite capable. Here's a screenshot of my latest remux within iTunes. Look at the size of the file as-well as the bitrate. 
I played the movie last night with a significant buffer and it was fine. looked the same as playing it through my much more expensive BluRay player. No transcoding at all happening on my MacPro. Heck the system was completely idle.
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And, if it can handle any Mbps rate BD can handle, then the only significant specs advantage BD has over
Yep, I use my
TV quite bit more than my BluRay player. Comes down to ease of use and on-demand playback. But I do have a very capable system, and the TV is just not up to snuff on the audio end of things.