iPhone XS Max Choppy video playback on iPhone XS and XS Max.

[Ritte]

Ok so that seems like a relief that it’s not a gpu problem and that it’s ios12 issue with software decoding of Dolby vision.....seems to fit with the evidence
Kind of begs the question why do Netflix and native video player in iOS use software decoding , while apps like infuse are using HW??

It’s not only a problem with Dolby Vision, the file I played in Plex/Infuse is SDR 1080p with a high bitrate (>30Mbps). Seems that there is stutter when the cpu is decoding demanding videos not matter sdr/hdr or 1080p/4K.

It’s actually a bit worrying that the Xs can not play a SDR 1080p.

Yesterday the Xs crashed when I tried to play that specific 1080p in Plex (SW-decoding). I actually think it maybe thermal related. Maybe not a throttle, but the thermal management doesn’t seem to be proper. Only my theory.

 

[UKapple73]

It’s not only a problem with Dolby Vision, the file I played in Plex/Infuse is SDR 1080p with a high bitrate (>30Mbps). Seems that there is stutter when the cpu is decoding demanding videos not matter sdr/hdr or 1080p/4K.

It’s actually a bit worrying that the Xs can not play a SDR 1080p.

Yesterday the Xs crashed when I tried to play that specific 1080p in Plex (SW-decoding). I actually think it maybe thermal related. Maybe not a throttle, but the thermal management doesn’t seem to be proper. Only my theory.

Do you think this is fixable within iOS? And how come more people aren’t complaining, must be lots of folk playing the iTunes and Netflix stuff

 

[Ritte]

Do you think this is fixable within iOS? And how come more people aren’t complaining, must be lots of folk playing the iTunes and Netflix stuff

Both iTunes and Netflix 1080p SDR are realitivly low bitrate. The file I played was a 1:1 copy of a blue ray 1080p. I can play 1080p with a 12Mbps just fine.

So demanding video files will trigger the stutter.

 

[LordJames]

It’s not only a problem with Dolby Vision, the file I played in Plex/Infuse is SDR 1080p with a high bitrate (>30Mbps). Seems that there is stutter when the cpu is decoding demanding videos not matter sdr/hdr or 1080p/4K.

It’s actually a bit worrying that the Xs can not play a SDR 1080p.

Yesterday the Xs crashed when I tried to play that specific 1080p in Plex (SW-decoding). I actually think it maybe thermal related. Maybe not a throttle, but the thermal management doesn’t seem to be proper. Only my theory.

Definitely not and HDR issue, more of a high nitrate issue: just tried and watch the latest “Better Call Saul” episode on Netflix.

Stuttering made it practically unwatchable.

I want to report the issue to Apple myself: anyone knows how can I talk to someone on the phone, without an AppleCare?

 

[Ritte]

Let's make this a little bit more scientific.
Do this guys:

• Download VLC and toggle off HW-decoding in the settings. We want to use SW-decoder.
• Go in here: jell.yfish.us
• Download the SDR h264 file, raise the bitrate (but keep the file to SDR h264).

Here's a url to the 40mbps h264 SDR:
jell.yfish.us/media/jellyfish-40-mbps-hd-h264.mkv

It's increasing by 5, so to download. 45 it's:
jell.yfish.us/media/jellyfish-45-mbps-hd-h264.mkv

Let's see if we can hit the limit of the XS cpu.

Woule be great to repeat this with a non-XS phone.

 

[0014]

Let's make this a little bit more scientific.
Do this guys:

• Download VLC and toggle off HW-decoding in the settings. We want to use SW-decoder.
• Go in here: jell.yfish.us
• Download the SDR h264 file, raise the bitrate (but keep the file to SDR h264).

Here's a url to the 40mbps h264 SDR:
jell.yfish.us/media/jellyfish-40-mbps-hd-h264.mkv

It's increasing by 5, so to download. 45 it's:
jell.yfish.us/media/jellyfish-45-mbps-hd-h264.mkv

Let's see if we can hit the limit of the XS cpu.

Woule be great to repeat this with a non-XS phone.

This is for a 64Gb iPhone X on 12.1 Beta 1

It will play all the way to 200mbps. At 250mbps it stutters with SW decoding. With HW decoding all play fine.

I didn’t try any of the HEVC 10bit files.

 

[Ritte]

This is for a 64Gb iPhone X on 12.1 Beta 1

It will play all the way to 200mbps. At 250mbps it stutters with SW decoding. With HW decoding all play fine.

I didn’t try any of the HEVC 10bit files.

Great, now we need some reports from XS. I'll do this when I'm back from work.
Would be nice to do the same with 6s, 7 and 8. To identify if this is a problem specific for XS.

Remember to use the SDR h264-file, so we all compare the same files.

 

[Stevejr]

Great, now we need some reports from XS. I'll do this when I'm back from work.
Would be nice to do the same with 6s, 7 and 8. To identify if this is a problem specific for XS.

Remember to use the SDR h264-file, so we all compare the same files.

I tried with xs max 256gb. HW decoding off, smooth video all the way to 200mbps, but a very very mild (almost unnoticed) stuttering at 200mbps, but stutter badly at 250mbps. With HW decode turned on, all played well.

 

[Ritte]

I tried with xs max 256gb. HW decoding off, smooth video all the way to 200mbps, but a very very mild (almost unnoticed) stuttering at 200mbps, but stutter badly at 250mbps. With HW decode turned on, all played well.

Interesting. Have you had any problems with stuttering before? On Netflix or other site?

 

[Stevejr]

Interesting. Have you had any problems with stuttering before? On Netflix or other site?

Yes stuttering happened intermittent on netflix. Luke cage, iron fist, etc...

 

[Ritte]

Yes stuttering happened intermittent on netflix. Luke cage, iron fist, etc...

Can you try the HDR 4K samples on that site, and see how good they play? They are marked with “10-bit”
[doublepost=1537979667][/doublepost]I could play 10,20 and 40MB/s HDR-files (10-bit) with SW-decoding only. So it seems to be able to play some files just fine. I wonder what triggers the stuttering.

Edit: 60mbps 10-bit(HDR) started to stutter with SW-decoder. So the limit for SW-decoding seems to be between 40-60mbps 1080p 10-bit HDR.

 

[WilliamG]

I tried with xs max 256gb. HW decoding off, smooth video all the way to 200mbps, but a very very mild (almost unnoticed) stuttering at 200mbps, but stutter badly at 250mbps. With HW decode turned on, all played well.

Sounds like a software issue to me.

 

[Stevejr]

Can you try the HDR 4K samples on that site, and see how good they play? They are marked with “10-bit”
[doublepost=1537979667][/doublepost]I could play 10,20 and 40MB/s HDR-files (10-bit) with SW-decoding only. So it seems to be able to play some files just fine. I wonder what triggers the stuttering.

Lol HW off, 250, 300 and 400 mbps 10bit totally hang during the first second of each video. HW on, all these 3 video playing well.

 

[Macalway]

Netflix looks fine. YouTube stutters on my Max. (not sure what that's about)

 

[ValO]

@Stevejr
Yes, to me too. Hdr seems to be enabled on YouTube now for the xs max(at 1080p max, though).
I just played 40 min of 4K hdr clips on YouTube in a loop, no stutters at all.
So that kind of rules out the thermal throttling for me. Switched back an forth between the 4khdr YouTube clips and Netflix.
And at the moment Netflix begins to stutter for a while on lost in space, I immediately switched to YouTube 4K hdr, and no stutters, very smooth. That kind of rules out a thermal issue for me.
[doublepost=1537981641][/doublepost]

Netflix looks fine. YouTube stutters on my Max. (not sure what that's about)

That is strange, for me it is the other way around.

People that test the Netflix issues, make sure you have a premium account, so you are able to play 4k(and hdr/Dolby vision), if you don’ t, my guess is you won’ t see stutters , judder, because it seems to manifest itself in Dolby vision/hdr content on Netflix. Regular videos are fine.

 

[Stevejr]

@Stevejr
Yes, to me too. Hdr seems to be enabled on YouTube now for the xs max(at 1080p max, though).
I just played 40 min of 4K hdr clips on YouTube in a loop, no stutters at all.
So that kind of rules out the thermal throttling for me. Switched back an forth between the 4khdr YouTube clips and Netflix.
And at the moment Netflix begins to stutter for a while on lost in space, I immediately switched to YouTube 4K hdr, and no stutters, very smooth. That kind of rules out a thermal issue for me.
[doublepost=1537981641][/doublepost]
That is strange, for me it is the other way around.

People that test the Netflix issues, make sure you have a premium account, so you are able to play 4k(and hdr/Dolby vision), if you don’ t, my guess is you won’ t see stutters , judder, because it seems to manifest itself in Dolby vision/hdr content on Netflix. Regular videos are fine.

Great to hear youtube enabled hdr videos. My netflix is premium account, now chances getting stuttering issues in netflix seems to be lesser but still happen sometimes. I believe apple or maybe netflix teams are doing some tweak on their backend source that we wouldn’t know, if not youtube won’t enable the hdr for xs quietly, haha.

 

[ValO]

Great to hear youtube enabled hdr videos. My netflix is premium account, now chances getting stuttering issues in netflix seems to be lesser but still happen sometimes. I believe apple or maybe netflix teams are doing some tweak on their backend source that we wouldn’t know, if not youtube won’t enable the hdr for xs quietly, haha.

Could be that Netflix is fixing their backend source. But if that is true, apple would also be fixing hdr/Dolby vision from iTunes, which also have stutters and judder.
Someone could test that ?

 

[Stevejr]

Could be that Netflix is fixing their backend source. But if that is true, apple would also be fixing hdr/Dolby vision from iTunes, which also have stutters and judder.
Someone could test that ?

I never bought any movie from iTunes, thus need someone else to update us on this. Finger crossed, hopefully all those issues can get it fixed soon.

 

[UKapple73]

I used the Dolby vision demo that Ritte posted. With nPlayer, HW decoding was fine. With SW, a jittery mess. But that could be the app software being crap I guess
I also tried ready player one off iTunes, downloaded. This also stuttered....tres confused
Netflix haven’t changed anything it’s still stuttering.

 

[rdillon2008]

https://apple.news/AIeL3mujQQpagUM8hYV2BbQ

 

[Furifo]

@Stevejr
Yes, to me too. Hdr seems to be enabled on YouTube now for the xs max(at 1080p max, though).
I just played 40 min of 4K hdr clips on YouTube in a loop, no stutters at all.
So that kind of rules out the thermal throttling for me. Switched back an forth between the 4khdr YouTube clips and Netflix.
And at the moment Netflix begins to stutter for a while on lost in space, I immediately switched to YouTube 4K hdr, and no stutters, very smooth. That kind of rules out a thermal issue for me.
[doublepost=1537981641][/doublepost]
That is strange, for me it is the other way around.

People that test the Netflix issues, make sure you have a premium account, so you are able to play 4k(and hdr/Dolby vision), if you don’ t, my guess is you won’ t see stutters , judder, because it seems to manifest itself in Dolby vision/hdr content on Netflix. Regular videos are fine.

To add to this, I have just tried a variety of videos on YouTube, all HDR, higest resolution possible and most of them at 60fps back to back. Screen brightness on max too.

No stutter, no dropped frames, extremely smooth.

 

[ValO]

To add to this, I have just tried a variety of videos on YouTube, all HDR, higest resolution possible and most of them at 60fps back to back. Screen brightness on max too.

No stutter, no dropped frames, extremely smooth.

No, but at the beginning of this thread, the only problem with YouTube was that it didn’ t have hdr support. It does now, so we can cross that of our list.
The biggest problem starting this thread is that there is a great amount of judder and stutter playing Dolby vision content on Netflix and iTunes . That is still an issue, so let us concentrate on that.

 

[Ritte]

No, but at the beginning of this thread, the only problem with YouTube was that it didn’ t have hdr support. It does now, so we can cross that of our list.
The biggest problem starting this thread is that there is a great amount of judder and stutter playing Dolby vision content on Netflix and iTunes . That is still an issue, so let us concentrate on that.

Dolby vision is not a problem as long as it’s HW-decoded. Download the sample I posted and try it yourself. Probably Netflix hasn’t fixed their HW-decoding for Dolby Vision and it doesn’t kick in for XS.
[doublepost=1537988385][/doublepost]I can confirm that YouTube HDR does not stutter.

 

[ValO]

Dolby vision is not a problem as long as it’s HW-decoded. Download the sample I posted and try it yourself. Probably Netflix hasn’t fixed their HW-decoding for Dolby Vision and it doesn’t kick in for XS.
[doublepost=1537988385][/doublepost]I can confirm that YouTube HDR does not stutter.

Yes, but it is very strange that the same decoding issue occurs with movies streaming and downloaded of apple’ s own iTunes.
They should have tested or fixed this.

 

[Apple_Robert]

YouTube has added HDR support for the new iPhones. I am watching 1080p 60fps. I do get some buffering on LTE while I am watching right now (cellular) but haven't experienced any stuttering.