twentytwentwen

macrumors newbie
Original poster
Apr 30, 2014
15
0
Anyone using Home Sharing on a LAN MAC to stream local 4K content in iTunes to ATV4k?

I have an mkv file converted (pass through) to m4v and put in the iTunes library.

On both Windows, Mac, and ATV Home Sharing I get stutter and lag.

If I use Infuse on ATV4K and share/stream from a LAN NFS share - its flawless.

Anyone know why I get stutter with itunes and not infuse?
 

priitv8

macrumors 68040
Jan 13, 2011
3,809
551
Estonia
I do.
What bitrate does your movie have?
In my own tests, it must remain under 50Mbps.
130Mbps and 67Mbps do not play (well), 47Mbps does.
And then there is this codec FourCC problem, but with wrong codec signature (must be hvc1 not hev1 for QuickTime to recognise as HEVC video) aTV would not play it at all.
 
Last edited:

priitv8

macrumors 68040
Jan 13, 2011
3,809
551
Estonia
No. I just use plex. Everything plays wonderfully. No need to mess with conversions.
Plex is still messing with it.
BTW try a 130Mbps bitrate HEVC file. Would be interesting to know how does it play.
I will test on my own server, then we could compare the results.
 

archer75

macrumors 68040
Jan 26, 2005
3,076
1,681
Oregon
Plex is still messing with it.
BTW try a 130Mbps bitrate HEVC file. Would be interesting to know how does it play.
I will test on my own server, then we could compare the results.
Is there any reason to have a file with bitrate that high? That's higher than any of my 4k rips. That would be higher than even 4k on disc. Something that large would really stress your network.
 

priitv8

macrumors 68040
Jan 13, 2011
3,809
551
Estonia
Is there any reason to have a file with bitrate that high? That's higher than any of my 4k rips. That would be higher than even 4k on disc. Something that large would really stress your network.
Most likely, not. Just my initial reaction to OP's problem was to check the bitrate first. As Home Sharing has no inbuilt stuttering problems.
Plex, however, seems to meet it's own decisions. The tvOS client seems to transcode HEVC into AVC no matter what. And my 139Mbps clip is in AVC, but it decides to transcode that into AVC as well. What else but bitrate reduction can it be?
avc2avc.png hevc2avc.png
PS That 44Mbps HEVC clip plays back via Home Sharing without any stuttering, over my wired gigabit network. Served by a Late 2012 Mac Mini, 2,3GHz Quad-Core i7, files on Drobo 5C DAS (USB 3.0).
 
Last edited:

archer75

macrumors 68040
Jan 26, 2005
3,076
1,681
Oregon
Seems the plex client needs an update for HEVC on the ATV. Though I thought it was updated. The 3 things to look at when it's transcoding are container, video and audio. Since your audio is direct streaming and not direct playing this tells me your container is not compatible.
While your video(AVC) should be compatible there may be something about how it's encoded that isn't natively supported by the ATV. Maybe the profile level?

It's also taking a very high bitrate file(139 Mbps) and transcoding on the fly. This is going to use an enormous amount of CPU. I would not expect a mac mini to handle it. I had a 2015? mini and even transcoding one of my movies which is around 12Mbps it was getting damn hot and the fan was at max.
 
Last edited:

priitv8

macrumors 68040
Jan 13, 2011
3,809
551
Estonia
Seems the plex client needs an update for HEVC on the ATV. Though I thought it was updated. The 3 things to look at when it's transcoding are container, video and audio. Since your audio is direct streaming and not direct playing this tells me your container is not compatible.
While your video(AVC) should be compatible there may be something about how it's encoded that isn't natively supported by the ATV. Maybe the profile level?
That AVC I have not touched myself. Could be it's 4096x1714 size. Profile is High@L5.1
Screen Shot 2017-11-29 at 23.34.45.PNG
HEVC encodes I did myself from the above source using HandBrake (x265 library) and HandBrake has been the most solid QuickTime-compatible encoder/muxer so far. Only the FourCC needs to be manually changed afterwards. The proof of that is that the same clip plays back natively in QT on macOS, inside iTunes and on aTV via HomeSharing. Plex tvOS client obviously does not support native HEVC playback. Or has the FourCC issue inverse to QT.
It's also taking a very high bitrate file(139 Mbps) and transcoding on the fly. This is going to use an enormous amount of CPU. I would not expect a mac mini to handle it. I had a 2015? mini and even transcoding one of my movies which is around 12Mbps it was getting damn hot and the fan was at max.
That i7 already has hardware AVC encoder onboard, but Plex taxed it to max anyways and it can not keep up, indeed.
 

archer75

macrumors 68040
Jan 26, 2005
3,076
1,681
Oregon
Profile is too high for AVC. Should be no higher than 4.1 though 4.0 is really all that's needed. That could be the issue. What container is it in?

Your HEVC file is fine as you said. Bitrate is much lower and plex has no problem transcoding this one in real time.
I use handbrake for all my encodes and it works great. H.264 in the past, H.265 now.
 
Last edited:

archer75

macrumors 68040
Jan 26, 2005
3,076
1,681
Oregon
True. But as I've said, that is not my encode. Just re-wrapped it into MP4 and called it a day.
Understood. Though for the purposes of testing, if you so wanted, you could reencode that to a lower profile and see if that resolves it.
 

twentytwentwen

macrumors newbie
Original poster
Apr 30, 2014
15
0
Guys thanks for the replies.... I can say the file I am trying is an m4v that was converted from a mkv by just changing container... Here is the file info:

filescr.png
 

archer75

macrumors 68040
Jan 26, 2005
3,076
1,681
Oregon
ultimately you're getting stutter in itunes and not infuse because something about your encode is not fully supported and infuse uses it's own player. Something with the video file I suspect. Would need more detail on the video file.
This is a 4k file. Just a heads up, the vast majority of 4k out there is fake. Just upconverted 1080p. Not saying this is one of those or where you got it from.
 
  • Like
Reactions: twentytwentwen

twentytwentwen

macrumors newbie
Original poster
Apr 30, 2014
15
0
I feel you.. But I am getting it from other **** thats not 4K..

You guys are definitely right...

Let me find a file... super retarded I may have to scrap itunes
 

archer75

macrumors 68040
Jan 26, 2005
3,076
1,681
Oregon
Are you making these encodes yourself? If so what program and settings are you using?
If you aren't, perhaps try running it through handbrake and then play the resulting file. I could give you my settings.
I'm doing everything through plex and not itunes so i'm not much help there. But I could test a file in itunes if you wanted me to.
 

twentytwentwen

macrumors newbie
Original poster
Apr 30, 2014
15
0
Thanks man.. Yeah give me your settings if you dont mind and I will run through handbrake and test
 

archer75

macrumors 68040
Jan 26, 2005
3,076
1,681
Oregon
Thanks man.. Yeah give me your settings if you dont mind and I will run through handbrake and test
alright i'll get back to you when I get home. The only difference in mine and what you'll have to do is I use MKV and HD audio passthrough but you can easily change those settings. It's the video portion we're really after here.
I'm also using a nightly build of handbrake so I can use a 10bit HEVC profile I found. But itunes supports the MAIN10 profile so we're good there.
 

priitv8

macrumors 68040
Jan 13, 2011
3,809
551
Estonia
Missing encoding profile and interlacing info may be problems.
When I do a re-wrap from MKV to MP4, I also usually do the "optimize" (in HB make sure the "optimized for web playback" checkmark is ticked!) action in Subler. This makes sure all metadata atoms are at the beginnign of the file and aTV can start to decode the stream immediately, without scanning to the end of file first.
PS I do notice with aTV 4K, that the buffering ahead with a HEVC source does not happen as aggressively at all, like it used to.
With AVC movie, you can see the buffer continuously filling until the whole movie has been stored in aTV local storage. With HEVC it ony seems to keep the buffer ahead only by some seconds or minutes (buffer level on screen is only just ahead of the playhead).
 
Register on MacRumors! This sidebar will go away, and you'll see fewer ads.