Netflix 24 fps / 30 fps content being converted/displayed at 50Hz (25 fps)

edited 6 March 2017, 10:48PM in Archived Posts
YouView hardware: TalkTalk DN370T (the same problem exists with the DN360T and DN372T).

Most Netflix video content is 24 or 30 frames per second.  The TalkTalk YouView device only outputs a 50Hz video signal (25 frames per second).  The result is that most of Netflix's content does not play-back smoothly.

In the case of 24 fps content every 24th frame is duplicated, so the video effectively freezes every second (for 1/25th of a second).

In the case of 30 fps content I really don't know what is done, but my guess is that it drops (does not show) every 6th frame.

Is there anybody that can shed some light on this situation?  Is all YouView hardware limited to 50Hz (25 fps) video output?  Is the Netflix app. converting the video to 25 frames per second or is it the YouView hardware?

I admit that this is very much a first-world problem, but I was very surprised to see it nonetheless  in this day and age.

Any help/knowledge would be appreciated,

Steve
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Comments

  • jasonr2000jasonr2000 Posts: 85Member
    edited 19 February 2015, 11:32AM
    I don't have this issue on my humax box so I'm guessing its the low hardware in the huawei box
  • edited 14 February 2016, 10:52PM
    Thanks for the reply Jason.  But to be honest I'm not 100% sure that what you say is accurate.  Are you saying that when watching an American show on Netflix (Breaking Bad for example), your Humax YouView box is outputting a 60Hz video signal?  Can I ask how you verified this?

    Thanks,

    Steve

    Here's an image of the A-Team playing on Netflix - pressing the Info button on the (Samsung) TV remote shows that the YouView box is outputting a 50Hz signal - which is incorrect in order to display the A-Team/Breaking Bad/most Netflix content properly (i.e. without stutter).

    image
  • RoyRoy Posts: 13,655Member ✭✭✭
    edited 6 March 2017, 10:48PM
    Conversely, Steve, what is your source for the duplication of every 24th frame? The usual way to handle 24fps material at 25fps is just to run it 4% faster, to get 25 frames into each second.
    ‘Does television exist for us to watch, or do we exist to watch television?’ - Noah Hawley
  • Mark MccamleyMark Mccamley Posts: 59Member
    edited 19 October 2015, 7:16PM
    I have huawei box and it shows netflix fine. No stuttering.
  • VisionmanVisionman Posts: 8,696Member ✭✭✭
    edited 26 February 2017, 2:39PM
    Multicast packet loss? 

    Though 50Hz and 60Hz is usually the difference between PAL (UK TV) and NTSC (the USA version).
  • edited 5 March 2017, 2:28PM
    Roy, I cannot verify the precise way in which the 24fps material is being converted to 25fps.  I agree that one method is to increase the speed of the source material by 1/24th.  This method produces perfectly smooth video with a potential side-effect of higher-pitched audio unless pitch-shifting is used.  However, due to the fact that the resultant video (on American shows) is not smooth (it IS if you watch a British show - e.g. Peep Show), I have concurred that the YouView hardware is performing a more crude conversion.

    It's easiest to see if you watch a camera pan on a British show and then a camera pan on a US show.  The British video is smooth and the US one is not.

    If you took 5-10 minutes of your time, Roy, you could probably verify this - after which you might be a bit less condescending.  The introduction to the very first episode of Sons of Anarchy is a good 24fps test video.  The video is not smooth and the reason is that the 24fps video is being shoe-horned into 25fps.

    The fact is that on some or all YouView hardware/software, 60Hz output does seem to be possible, which is a bigger problem (in my opinion) since the introduction of Netflix, as most content is 24fps.

    If possible I would like somebody in the know at YouView to comment on this.  The problem is clearly nothing to do with packet-loss.  The video stutter I am talking about is well-documented on the internet.  I'm not doing something wrong at my end.

    Let's make the question more simple: Does the YouView software/hardware (in general) officially support 60Hz output?  There must be somebody out there who knows the answer to this simple question.

    Many thanks,

    Steve

    P.S. With all due respect to the people who are saying 'works fine for me', in my opinion either your YouView hardware supports 60Hz or your eyes simply do not notice the not-quite-smooth quality of the video.  I'm glad for you whether it's the latter or former reason.  However, until somebody provides evidence that some YouView hardware supports 60Hz output, I will assume such hardware does not exist.
  • VisionmanVisionman Posts: 8,696Member ✭✭✭
    edited 26 February 2017, 2:39PM
    IPTV uses a different delivery system to UK OTA broadcasting. And Roy was being helpful.
  • RoyRoy Posts: 13,655Member ✭✭✭
    edited 6 March 2017, 10:48PM
    Thank you Visionman.

    Steve, you use the expression 'perhaps not 100% accurate' to cast doubt on what jasonr reports he is seeing with his own eyes, and then the giveaway 'with all due respect' to suggest that other people's eyes are, or perhaps their discernment is, inferior to yours?

    And then I post a perfectly sensible and genuine enquiry, based on some knowledge of the subject, and you have the brass neck to call me condescending?

    When you point the finger at someone, you have three fingers pointing back at yourself.

    It would, by the bye, take me a little more than 5-10 minutes to position myself in front of my YouView box, as I am watching it remotely via SCART into a Slingbox accessed via an iPod Touch which passes it to an Apple TV plugged into a Samsung TV with the vertical resolution jiggered to counteract the incorrect vertical aspect that the Slingbox software produces, and it's 1500 miles away.

    Which you might know, if you had been in this Community longer than a dogwatch. Oh, and welcome, by the way.

    But it does mean that my chances of seeing what you reckon most people can't see anyway when they are right in front of their sets are round about zero given the amount of video reprocessing going on before I get my picture here :-)

    I'm also a little confused as to why you think 24 fps runs at 60 Hz. Wouldn't it need to run at 48 Hz?
    ‘Does television exist for us to watch, or do we exist to watch television?’ - Noah Hawley
  • Michael GMichael G Posts: 876Member
    edited 25 February 2017, 9:03PM
    I've no idea what any of this stuff means. Most of my other functions are declining rapidly, but my eyes are still good at detecting any issues on our Samsung 46 HD panel in our small living room. We're just re-running Breaking bad on Netflix whilst we wait for Better Call Saul and the picture is perfect via either the YV version (Humax) or (more frequently, admittedly) via the app on my phone and chromecast. Same Netflix UK service. No settings changed on TV or service. It just works. No stuttering . Unless essential to the plot dialogue of course. 
  • DaveG1DaveG1 Posts: 39Member
    edited 25 February 2017, 9:03PM
    We use Netflix all the time on our YouView box without any problems whatsoever
  • Mark MccamleyMark Mccamley Posts: 59Member
    edited 6 March 2017, 8:32AM
    I'm realy concerntrating on trying to see this stutter but no matter how hard I look I can't see it. Not saying it's not there. And to the trained eye assumr IT must be annoying.
    But for my layman view point. It's of an except able quality.
    Been waiting long enough for it !!!
    I tried to see a difference by playing though app on sammy tv. And then you view. Still couldn't.
  • jimbjimb Posts: 945Member ✭✭
    edited 6 March 2017, 10:48PM
    I am really surprised that no one else is seeing this problem.
    I have the new BT box (G4) and fibre broadband.
    On any slow panning camera shot it is immediately obvious.
    The same content viewed with the Netflix app on my Samsung TV is completely smooth.
  • RoyRoy Posts: 13,655Member ✭✭✭
    edited 7 December 2016, 8:39AM
    jimb said:

    I am really surprised that no one else is seeing this problem.
    I have the new BT box (G4) and fibre broadband.
    On any slow panning camera shot it is immediately obvious.
    The same content viewed with the Netflix app on my Samsung TV is completely smooth.

    jim

    While playing each, can you press the Info button on your Samsung remote, and see what resolution and Hz (or p) is reported in each case?
    ‘Does television exist for us to watch, or do we exist to watch television?’ - Noah Hawley
  • alal Posts: 1,270Member ✭✭
    edited 8 December 2016, 12:01PM
    jimb said:

    I am really surprised that no one else is seeing this problem.
    I have the new BT box (G4) and fibre broadband.
    On any slow panning camera shot it is immediately obvious.
    The same content viewed with the Netflix app on my Samsung TV is completely smooth.

    I also have the BT box and, although can confirm it's running at 50Hz, I can't see any conversion problems on a 50" screen. I usually can so the yv box is doing a much better job than I am used to. Have you checked that any picture enhancements on the youview input in your Sammy are set correctly? My tv has a reduced number of picture mutating options on the netflix app ;)

    I will take a second look at some point though as I haven't spent a lot of time checking - Until the youview offers 5.1 I'm not going to spend the time necessary to fix the terrible audio delay.
  • Michael GMichael G Posts: 876Member
    edited 21 December 2016, 12:29PM
    jimb said:

    I am really surprised that no one else is seeing this problem.
    I have the new BT box (G4) and fibre broadband.
    On any slow panning camera shot it is immediately obvious.
    The same content viewed with the Netflix app on my Samsung TV is completely smooth.

    One of the reasons I mainly use Netflix via a chromecast in my AV receiver. Frees up that DD+ 5.1 nicely. 
  • alal Posts: 1,270Member ✭✭
    edited 8 December 2016, 12:01PM

    Roy, I cannot verify the precise way in which the 24fps material is being converted to 25fps.  I agree that one method is to increase the speed of the source material by 1/24th.  This method produces perfectly smooth video with a potential side-effect of higher-pitched audio unless pitch-shifting is used.  However, due to the fact that the resultant video (on American shows) is not smooth (it IS if you watch a British show - e.g. Peep Show), I have concurred that the YouView hardware is performing a more crude conversion.

    It's easiest to see if you watch a camera pan on a British show and then a camera pan on a US show.  The British video is smooth and the US one is not.

    If you took 5-10 minutes of your time, Roy, you could probably verify this - after which you might be a bit less condescending.  The introduction to the very first episode of Sons of Anarchy is a good 24fps test video.  The video is not smooth and the reason is that the 24fps video is being shoe-horned into 25fps.

    The fact is that on some or all YouView hardware/software, 60Hz output does seem to be possible, which is a bigger problem (in my opinion) since the introduction of Netflix, as most content is 24fps.

    If possible I would like somebody in the know at YouView to comment on this.  The problem is clearly nothing to do with packet-loss.  The video stutter I am talking about is well-documented on the internet.  I'm not doing something wrong at my end.

    Let's make the question more simple: Does the YouView software/hardware (in general) officially support 60Hz output?  There must be somebody out there who knows the answer to this simple question.

    Many thanks,

    Steve

    P.S. With all due respect to the people who are saying 'works fine for me', in my opinion either your YouView hardware supports 60Hz or your eyes simply do not notice the not-quite-smooth quality of the video.  I'm glad for you whether it's the latter or former reason.  However, until somebody provides evidence that some YouView hardware supports 60Hz output, I will assume such hardware does not exist.

    I gave it a go and have no idea what part of Sons Of Anarchy you are referring to. It all looks hand held to me.

    Knowing Tarantino goes a bit wayward for pans I put the opening to Django Unchained on (Dang its US, can you check that?), just after the "Big Daddy" credit there is a pan and yes, there is the slightest glitch which isn't seen on my tv app.

    tbh I doubt that many people are going to notice this. Firstly most people can live with it, secondly those with a big enough screen to be bothered by it and an interest in seeing it flawlessly, probably have additional netflix equipment to watch it on.
  • edited 14 February 2016, 11:00PM
    I'm SO glad that Jim weighed-in here.  I was a hair's breadth from committing myself to the local sanitarium.

    I'm not particularly intelligent, but it is not difficult to understand that when altering the framerate of a video - unless the new framerate is a multiple of the original framerate - it is not possible to reproduce the smoothness of the original video.

    Of course not everybody will/can notice the 'judder', but I'm surprised, because a 24 fps to 25 fps conversion (not speed-up) is actually the worst possible, because the two frame rates are so close (yet so far).

    The two questions are:

    1) Is the YouView Netflix app. converting the 24 fps videos to 25 fps and then passing that to the YouView box, or is the YouView box doing the conversion (I guess the latter)?

    2) Does the YouView 'platform' support 60Hz video output?  I.e., if I were to manufacture a YV box and I wanted to allow 60Hz output, would YouView allow this?

    Note, I'm not asking anybody to fix anything (at the moment).  I just want to understand the situation.  The irritating thing is that there are many people out there that know the answers to all of these questions.  The hard part is reaching these people.

    Maybe it's rude or condescending, but it really isn't helpful for someone to say that they don't have this problem (if they are using the same equipment), because it is a fact that the problem exists.  The 24fps vs 25fps problem is not something I have invented - why would I do that?

    If a person does not perceive the problem, that's fair enough and I'm glad for them.  But the correct response would be to state 'I don't perceive this problem, although I accept that it exists'.

    Of course I'm glad that Netflix is finally on YV (it's why I finally bought two boxes), but given the amount of time that the relevant parties have had to think about this, one could be forgiven for expecting that they would have considered this potential problem and thought about solving it.  But maybe they did and simply concluded - 'ah sod it'.  Either way it would be nice to know.

    Am I asking a lot to know these few pieces of information?  Is it bad to seek this information.  In my opinion - no.
  • edited 19 February 2015, 11:32AM

    I'm realy concerntrating on trying to see this stutter but no matter how hard I look I can't see it. Not saying it's not there. And to the trained eye assumr IT must be annoying.
    But for my layman view point. It's of an except able quality.
    Been waiting long enough for it !!!
    I tried to see a difference by playing though app on sammy tv. And then you view. Still couldn't.

    "I'm not saying it's not there.".

    Here's the simple way to know if it's there (it being the 24 vs 25fps problem):

    1) Play Breaking Bad (any US show will suffice - but hey BB is great) via YouView Netflix.
    2) Whilst it is playing press the 'INFO' button on your Samsung TV remote.
    3) Observe the on-screen information which should appear, telling you the resolution and refresh rate of the current video source (the YouView box).

    If it says 1920x1080 50Hz, the problem exists (whether your eyes perceive it or not).
    If it says 1920x1080 60Hz, the 24 vs 25fps problem does not exist.  Your video will be smoother.  A 'problem' still exists (24 vs 30fps), but that problem is much less severe.

    If you try this same experiment but this time using your Samsung Smart TV's Netflix app., I can all but guarantee that you will see "1920 x 1080 60Hz".  Unlike the YouView box, the Samsung TV ('s internal video processing) is not artificially limited to outputting 50Hz video to the screen.

    Thanks for any time you spend doing anything related to this thread - it is most-certainly not necessary.
  • edited 19 February 2015, 11:32AM
    DaveG1 said:

    We use Netflix all the time on our YouView box without any problems whatsoever

    It's possible that you are not perceiving the problem, which factually exists (assuming you are using a YouView box which is not able to output at 60Hz, or that you only watch British content on Netflix - this content will be perfectly smooth).
  • redchizredchiz Posts: 4,475Member ✭✭✭
    edited 20 December 2016, 1:57PM

    I'm realy concerntrating on trying to see this stutter but no matter how hard I look I can't see it. Not saying it's not there. And to the trained eye assumr IT must be annoying.
    But for my layman view point. It's of an except able quality.
    Been waiting long enough for it !!!
    I tried to see a difference by playing though app on sammy tv. And then you view. Still couldn't.

    What if one doesn't have a Samsung TV?
  • Mark MccamleyMark Mccamley Posts: 59Member
    edited 19 October 2015, 7:16PM

    I'm realy concerntrating on trying to see this stutter but no matter how hard I look I can't see it. Not saying it's not there. And to the trained eye assumr IT must be annoying.
    But for my layman view point. It's of an except able quality.
    Been waiting long enough for it !!!
    I tried to see a difference by playing though app on sammy tv. And then you view. Still couldn't.

    Any brand of smart tv has netflix app
  • edited 19 February 2015, 11:32AM
    jimb said:

    I am really surprised that no one else is seeing this problem.
    I have the new BT box (G4) and fibre broadband.
    On any slow panning camera shot it is immediately obvious.
    The same content viewed with the Netflix app on my Samsung TV is completely smooth.

    Jim, thanks for bringing some sanity to the thread.  The video is smooth on your Smart TV app. because the TV's internal video processing is outputting 60Hz video.  The YouView box seems locked to 50Hz - this is a design fault in my view.

    al, it's possible that your TV is performing frame interpolation (video smoothing).  If the BT box is outputting 50Hz, I'm pretty sure that the box is not doing anything to help you.  It's the TV if anything.  For a fair test you should turn off these functions in your TV menu, if possible.  However there really is no need for you to test anything - if you're happy then continue to live your life and view your content.
  • edited 19 February 2015, 11:32AM

    I'm realy concerntrating on trying to see this stutter but no matter how hard I look I can't see it. Not saying it's not there. And to the trained eye assumr IT must be annoying.
    But for my layman view point. It's of an except able quality.
    Been waiting long enough for it !!!
    I tried to see a difference by playing though app on sammy tv. And then you view. Still couldn't.

    redchiz, what do you mean?  I was replying to a person who has stated that he has a Samsung TV.

    You can perform the same experiment on any Smart TV with a Netflix app.  All you must do differently is press the appropriate TV remote button to show you the resolution and refresh rate of the current video source (step 2).

    Good luck.
  • edited 14 February 2016, 10:56PM
    Michael G said:

    I've no idea what any of this stuff means. Most of my other functions are declining rapidly, but my eyes are still good at detecting any issues on our Samsung 46 HD panel in our small living room. We're just re-running Breaking bad on Netflix whilst we wait for Better Call Saul and the picture is perfect via either the YV version (Humax) or (more frequently, admittedly) via the app on my phone and chromecast. Same Netflix UK service. No settings changed on TV or service. It just works. No stuttering . Unless essential to the plot dialogue of course. 

    Funnily enough (whether you perceive it or not), the opposite-ish problem exists with the chromecast device - it can only output 60Hz video.

    If you watch UK content (e.g. Peep Show) using the chromecast, the chromecast must change the 25fps content such that it has 30fps - i.e. it must duplicate 5 frames of the source video.

    1 second of UK content in its unaltered form looks like this (a frame is a still image):

    Frame: 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15. . .25 - 25 frames in total, no duplicates.
    Time:   0s                       0.4s                               1s

    The chromecast will take this UK source content and essentially output this to your TV:

    Frame 1 2 3 4 5 5 6 7 8 9 10 10 11 12 13 14 15 15. . .25 25 - 30 frames in total.
    Time:  0s                                0.4s                                         1s

    If you don't understand this just don't worry about it - ignore it and enjoy your viewing.  This thread is only really here for people who understand and agree that the problem exists (whether person A, B or C perceives it or not), and who want to discuss the matter/talk to YouView about a potential solution.
  • redchizredchiz Posts: 4,475Member ✭✭✭
    edited 20 December 2016, 1:57PM

    I'm realy concerntrating on trying to see this stutter but no matter how hard I look I can't see it. Not saying it's not there. And to the trained eye assumr IT must be annoying.
    But for my layman view point. It's of an except able quality.
    Been waiting long enough for it !!!
    I tried to see a difference by playing though app on sammy tv. And then you view. Still couldn't.

    I meant the bit about interrogating the refresh rate, my TV doesn't reveal that information. Nor is it smart. So I can't do either of your tests. Luckily my eyesight must be so poor that I can't see a problem.
    
  • edited 19 February 2015, 11:32AM
    Roy1 said:

    Thank you Visionman.

    Steve, you use the expression 'perhaps not 100% accurate' to cast doubt on what jasonr reports he is seeing with his own eyes, and then the giveaway 'with all due respect' to suggest that other people's eyes are, or perhaps their discernment is, inferior to yours?

    And then I post a perfectly sensible and genuine enquiry, based on some knowledge of the subject, and you have the brass neck to call me condescending?

    When you point the finger at someone, you have three fingers pointing back at yourself.

    It would, by the bye, take me a little more than 5-10 minutes to position myself in front of my YouView box, as I am watching it remotely via SCART into a Slingbox accessed via an iPod Touch which passes it to an Apple TV plugged into a Samsung TV with the vertical resolution jiggered to counteract the incorrect vertical aspect that the Slingbox software produces, and it's 1500 miles away.

    Which you might know, if you had been in this Community longer than a dogwatch. Oh, and welcome, by the way.

    But it does mean that my chances of seeing what you reckon most people can't see anyway when they are right in front of their sets are round about zero given the amount of video reprocessing going on before I get my picture here :-)

    I'm also a little confused as to why you think 24 fps runs at 60 Hz. Wouldn't it need to run at 48 Hz?

    Roy, I've seen a few of your other posts in this community.  One that stands out for me is where you destroyed a guy who was simply asking if a SmartDNS service worked with the YouView box to enable the Netflix app. to serve the US (and other countries) library instead of the UK one.

    You were quite arrogant and, most-importantly, wrong in what you were saying (ranting about VPNs and trying to show a superior level of knowledge).  Smart DNS works perfectly with the YouView boxes and VPNs have nothing to do with it.

    I have never stated that 24fps video 'runs at 60Hz'.  Ideally, as you say, 24fps video content should be displayed at 24, 48, 72, 96 (ETC).  The fact is that the most common (in the future hopefully it will change) way to display 24p content (barring PAL DVDs which usually speed it up - producing good results) is using 3:2 pulldown.  It produces judder in the resultant video but it is not as noticeable as 24 -> 25 judder.

    The speeding-up of 24p content is NOT common in the IPTV age.  PAL DVDs and UK terrestrial broadcasting - yes, but clearly we are not dealing with either of those things here.

    Long story short, you have not provided any useful information in this thread.  I don't understand what your first post was supposed to achieve:

    "Conversely, Steve, what is your source for the duplication of every 24th frame? The usual way to handle 24fps material at 25fps is just to run it 4% faster, to get 25 frames into each second."

    Presumably it was an attempt at show-boating.  The YouView box is clearly not speeding up the content - if it were the video would be smooth and the content would last 24/25ths the original play-time.  The YouView box is adding 1 frame per second to the original content.

    Given your strange set-up, maybe it is best that you don't contribute to this thread..

    Note: I get the sense that you consider yourself important due to the fact that you joined this forum a long time ago.  I'm sorry, but that is not how it works.  You're no more important that anyone else, even if you use a SlingBox to view UK terrestrial content from 1500 miles away.  Both of those things are completely irrelevant.
  • edited 14 February 2016, 10:51PM

    I don't have this issue on my humax box so I'm guessing its the low hardware in the huawei box

    Well, the question is 'does your Humax box output at 50Hz or 60Hz?'.  'High' hardware is not required to output 24fps video content at 60Hz.  Nice attempt at knocking the perfectly good Huawei boxes, though.
  • redchizredchiz Posts: 4,475Member ✭✭✭
    edited 28 February 2017, 3:05PM
    Could it be some of the "enhancement" settings in the TV, many of which are of dubious benefit at the best of times, not interacting nicely with the Netflix stream? Perhaps experiment by turning off Dynamic Picture Balustrading, Super Playflow Gherkin Mode etc. and see if that has any effect?
  • edited 14 February 2016, 10:53PM
    Visionman said:

    Multicast packet loss? 

    Though 50Hz and 60Hz is usually the difference between PAL (UK TV) and NTSC (the USA version).

    Suggesting that the problem is packet-loss seems a bit strange.  Why would UK content play smoothly but US content not play smoothly?  Packet-loss would affect everything.  You are right about PAL and NTSC using 50Hz and 60Hz respectively, this is why the problem exists today.  The US uses frame rates which play nicely with 60Hz (23.976, 24fps, 29.98fps and 30fps) and Europe uses ones which play nicely with 50Hz (25fps).
  • KeithKeith Posts: 2,382Member ✭✭✭
    edited 4 March 2017, 10:29AM
    Hi Steve - as you say above, the/your basic questions
    1) Is the YouView Netflix app. converting the 24 fps videos to 25 fps and then passing that to the YouView box, or is the YouView box doing the conversion (I guess the latter)?

    2) Does the YouView 'platform' support 60Hz video output?  I.e., if I were to manufacture a YV box and I wanted to allow 60Hz output, would YouView allow this?
    are broadly very straight forward matters of fact, just not ones none of us customers here have so far been able to state as absolute fact.

    Sanj or Phil (YouView employees covering the forum amongst other things) should be able to pick up on this straight forward query tomorrow morning when YouView is once again open for business, have a word with Piers or other suitable technical person and report back to us all.

    As you say, once we have a clear understanding of the basic facts it may well demonstrate some inadequacy in the current implementation that in turn may spawn discussion of how it could be adjusted and in turn a plea/request/idea/suggestion from customers that such adjustments be made :)

    Sanj/Phil - here's hoping you can provide the supporting/underpinning facts for this discussion/observation sometime in the week :)
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