Video judder for 23.976p videos (often called 24p videos = cinema movie frame rate) — Oculus
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Video judder for 23.976p videos (often called 24p videos = cinema movie frame rate)

DocStevenDocSteven Posts: 1
NerveGear
When watching movies on the Quest I experience a lot of judder with the built in player Oculus Galery, Oculus Browser, Skybox and Youtube. Only Netflix seems to display movies without jumping frames: flying in logos, like Universal, seem to have no "jumping frames" in the Netflix App.

You can test this for yourself with the file "ft-23.mp4" from these test videos (https://fotovideotec.de/frameraten/downloads/ft-standard.zip)
Take a look at the cars driving from left to right after the stripes (starting at 00:20). Here's the same clip on Youtube for testing in the Youtube App: https://youtu.be/o80pN7zLhIQ

Unfortunately this effects 99% of all movies since 23.976p is the standard frame rate on Blu-rays (because it the standard for cinema movies).

It seems that the standard Quest player (not the Netflix) tries to display 23.976p on a 72p display without proper conversion. Normally the player should speed up the video a tiny bit to 24p so that every frame is displayed 3 times. The player then also has to speed up the audio and sometimes drop audio frames (which is not noticible) - not playing audio faster and altering it with a higher pitch (which some people would hear that, because music pitch sounds off). This speedup is unnoticable and leads to smooth playback. All reasonable players on PC do it like that.

Can you confirm the judder on your Quest? I'm wondering why I didn't find any discussions about that, because it is really obvious judder which is not something only movie buffs will see and it decreases quality sooo much ...

Comments

  • h.r.gargih.r.gargi Posts: 57
    Hiro Protagonist
    Same effect here. Noticed it at Skybox and the standard video player.
  • shamo42shamo42 Posts: 6
    NerveGear
    Noticed this immediately too. Very distracting. Any updates on this? Is it maybe possible to change the frequency of the Quest to 71.928‬ Hz?
  • SpuzzumSpuzzum Posts: 311
    Trinity
    edited June 15
    From my understanding, it's running at 72 fps, so anything that doesn't divide equally into 72, will be jerky. They've mentioned they're working on a 60 fps playback for videos though...but not sure about support for 23.976.
  • DaftnDirectDaftnDirect Posts: 4,804 Volunteer Moderator
    My Blu-rays are encoded as H264 mkv files with AC3 audio and 23.976 frame rate (same as source), with approx 10000kbps bit rate.

    I get slight judder in Skybox but perfectly smooth in Gallery. Same result whether the files are streamed from NAS or stored on the Quest.
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  • shamo42shamo42 Posts: 6
    NerveGear
    DaftnDirect said:
    I get slight judder in Skybox but perfectly smooth in Gallery. Same result whether the files are streamed from NAS or stored on the Quest.
    Oculus Gallery or Android System Gallery?
  • DaftnDirectDaftnDirect Posts: 4,804 Volunteer Moderator
    shamo42 said:
    DaftnDirect said:
    I get slight judder in Skybox but perfectly smooth in Gallery. Same result whether the files are streamed from NAS or stored on the Quest.
    Oculus Gallery or Android System Gallery?
    As far as I know @shamo42 Oculus Gallery is the only gallery app on the Quest.
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  • shamo42shamo42 Posts: 6
    NerveGear
    edited June 20
    Oculus Gallery or Android System Gallery?
    As far as I know @shamo42 Oculus Gallery is the only gallery app on the Quest.
    The native Android Gallery app is installed on every Quest. It's just more difficult to open. You have to use something like SideQuest.

    For me the Oculus Gallery app has judder too. Only the native Android Gallery App plays it more or less without judder.

    Here is a short sample clip for judder testing purposes:
    https://mega.nz/#!qpsQSaAQ!hDGKa_tH8wLogGg4DIVcIX6LKHLDfJsKbBQEo0XGzEY

    My observations so far are that it doesn't matter if it's 23.976p or 24p. They both suffer from the same judder (about every 1 to 2 seconds) in Skybox and Oculus Gallery.
  • DaftnDirectDaftnDirect Posts: 4,804 Volunteer Moderator
    shamo42 said:
    Oculus Gallery or Android System Gallery?
    As far as I know @shamo42 Oculus Gallery is the only gallery app on the Quest.
    The native Android Gallery app is installed on every Quest. It's just more difficult to open. You have to use something like SideQuest.

    For me the Oculus Gallery app has judder too. Only the native Android Gallery App plays it more or less without judder.

    Here is a short sample clip for judder testing purposes:
    https://mega.nz/#!qpsQSaAQ!hDGKa_tH8wLogGg4DIVcIX6LKHLDfJsKbBQEo0XGzEY

    My observations so far are that it doesn't matter if it's 23.976p or 24p. They both suffer from the same judder (about every 1 to 2 seconds) in Skybox and Oculus Gallery.


    Now you've got me totally confused!

    I've been using Sidequest for a little while and as far as I can tell it's just for installing non-Oculus Store apps not for accessing app that otherwise don't show up. In either case I don't see any Gallery app other than Oculus Gallery.

    Anyway, back to the subject of judder. I double checked and (Oculus) Gallery definitely plays my vids with no judder at all, perfectly smooth. Yes, judder is there in Skybox but not in Gallery. I've tested with both 3D side-by-side and regular 2D bluray rips. So I think something other than frame rate is causing judder for some.

    For those that have judder in Gallery, what are you using to encode your files? what video and audio codec and what container? what bitrate? is it constant or variable? etc If you're not sure how to get all the info, there's a small program called MediaInfo from MediaArea which is very useful.

    I use DVDFab and all my movies are similar to the below:

    General
    Format   : Matroska
    Format version  : Version 2
    File size  : 9.09 GiB
    Duration  : 2 h 9 min
    Overall bit rate mode : Variable
    Overall bit rate : 10.1 Mb/s
    Writing application : DVDFab 11.0.2.8
    Writing library  : libebml v1.3.4 + libmatroska v1.4.5

    Video
    ID   : 1
    Format   : AVC
    Format/Info  : Advanced Video Codec
    Format profile  : High@L4
    Format settings  : CABAC / 1 Ref Frames
    Format settings, CABAC : Yes
    Format settings, RefFrames : 1 frame
    Format settings, GOP : M=1, N=24
    Codec ID  : V_MPEG4/ISO/AVC
    Duration  : 2 h 9 min
    Bit rate mode  : Variable
    Bit rate  : 9 447 kb/s
    Maximum bit rate : 11.7 Mb/s
    Width   : 1 920 pixels
    Height   : 804 pixels
    Display aspect ratio : 2.40:1
    Frame rate mode  : Constant
    Frame rate  : 23.976 (24000/1001) FPS
    Color space  : YUV
    Chroma subsampling : 4:2:0
    Bit depth  : 8 bits
    Scan type  : Progressive
    Bits/(Pixel*Frame) : 0.255
    Stream size  : 8.51 GiB (94%)
    Default   : Yes
    Forced   : No
    Color range  : Limited
    Color primaries  : BT.709
    Transfer characteristics : BT.709
    Matrix coefficients : BT.709

    Audio
    ID   : 2
    Format   : AC-3
    Format/Info  : Audio Coding 3
    Codec ID  : A_AC3
    Duration  : 2 h 9 min
    Bit rate mode  : Constant
    Bit rate  : 640 kb/s
    Channel(s)  : 6 channels
    Channel positions : Front: L C R, Side: L R, LFE
    Sampling rate  : 48.0 kHz
    Frame rate  : 31.250 FPS (1536 SPF)
    Bit depth  : 16 bits
    Compression mode : Lossy
    Stream size  : 591 MiB (6%)
    Language  : English
    Service kind  : Complete Main
    Default   : Yes
    Forced   : No

    Intel 5820K OC@4Ghz, Titan X (Maxwell), 16GB Corsair Vengeance DDR4, ASRock X99 Taichi, Samsung 500Gb 960 Evo M.2, Corsair H100i v2 Cooler, Inateck KTU3FR-4P USB 3 card, Windows 10 Pro v1903 (18362.239)
  • SpuzzumSpuzzum Posts: 311
    Trinity
    SideQuest should show all apps installed, Oculus or otherwise. Similar TotalCommander. Or at least that's the way it looked to me when I clicked on SideQuest's Home link while wearing the Quest.
  • DaftnDirectDaftnDirect Posts: 4,804 Volunteer Moderator
    Yep it does Spuzzum, there's no gallery app listed in the installed list so I assume Oculus Gallery isn't an app as such, it's part of the OS, but also there's no other gallery app available to install if you do a search using SideQuest's search function so like I say, I'm a bit confused there.
    Intel 5820K OC@4Ghz, Titan X (Maxwell), 16GB Corsair Vengeance DDR4, ASRock X99 Taichi, Samsung 500Gb 960 Evo M.2, Corsair H100i v2 Cooler, Inateck KTU3FR-4P USB 3 card, Windows 10 Pro v1903 (18362.239)
  • SpuzzumSpuzzum Posts: 311
    Trinity
    You should see if you can extract the Oculus Gallery off a Go, then sideload to the Quest. :P
  • DaftnDirectDaftnDirect Posts: 4,804 Volunteer Moderator
    Ah, if I had a Go I might have dug a bit deeper... I'll have to leave that to someone else to investigate!
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  • SpuzzumSpuzzum Posts: 311
    Trinity
    Maybe I can extract then upload...somewhere. :P
  • shamo42shamo42 Posts: 6
    NerveGear
    edited June 22
    Yep it does Spuzzum, there's no gallery app listed in the installed list so I assume Oculus Gallery isn't an app as such, it's part of the OS, but also there's no other gallery app available to install if you do a search using SideQuest's search function so like I say, I'm a bit confused there.

    SideQuest doesn't show system apps unless you go to SideQuest's settings and enable "show system apps". The native Android Gallery is one of these apps. At least on my Quest (bought on Amazon Japan).

    Did you have judder in the Oculus Gallery with the sample I provided?

    If yes, could you share a sample that does not judder in the Oculus Gallery app?
  • DaftnDirectDaftnDirect Posts: 4,804 Volunteer Moderator
    edited June 22
    I'm away from home @shamo42 so will take another look at Sidequest when I get back. I meant to say in my last post that the sample you posted showed up as a 4 or 5 second clip that was totally black so can you try posting again? I'll see about posting a short clip of my bluray rip tonight also.
    Intel 5820K OC@4Ghz, Titan X (Maxwell), 16GB Corsair Vengeance DDR4, ASRock X99 Taichi, Samsung 500Gb 960 Evo M.2, Corsair H100i v2 Cooler, Inateck KTU3FR-4P USB 3 card, Windows 10 Pro v1903 (18362.239)
  • DaftnDirectDaftnDirect Posts: 4,804 Volunteer Moderator
    edited June 22

    OK I managed to find the android gallery app. You're right @shamo42 it's there and I was looking in the wrong place... sorry, it's my age! Anyway that gallery doesn't play my videos at all so seems to have a problem with either the H.264 or the AC3 audio codec.

    So, back to Oculus Gallery, I've uploaded the intro of Bohemian Rhapsody as it has a lot of slow pans so should be easy to see if there's judder, if anyone's interested in testing in Gallery and Skybox you should be able to download the clip form my OneDrive public folder below. It's just over 2 minutes long and about 164MB and plays smoothly in Gallery for me.

    https://1drv.ms/u/s!Aiqx6ObJzVZxmQKw5lVfk15kE-bW?e=H6FOap

    Intel 5820K OC@4Ghz, Titan X (Maxwell), 16GB Corsair Vengeance DDR4, ASRock X99 Taichi, Samsung 500Gb 960 Evo M.2, Corsair H100i v2 Cooler, Inateck KTU3FR-4P USB 3 card, Windows 10 Pro v1903 (18362.239)
  • shamo42shamo42 Posts: 6
    NerveGear

    OK I managed to find the android gallery app. You're right @shamo42 it's there and I was looking in the wrong place... sorry, it's my age! Anyway that gallery doesn't play my videos at all so seems to have a problem with either the H.264 or the AC3 audio codec.

    So, back to Oculus Gallery, I've uploaded the intro of Bohemian Rhapsody as it has a lot of slow pans so should be easy to see if there's judder, if anyone's interested in testing in Gallery and Skybox you should be able to download the clip form my OneDrive public folder below. It's just over 2 minutes long and about 164MB and plays smoothly in Gallery for me.

    https://1drv.ms/u/s!Aiqx6ObJzVZxmQKw5lVfk15kE-bW?e=H6FOap


    Thanks for the sample!

    Skybox: Obvious stutter. Especially on that huge screen.
    Oculus Gallery: Less visible stutter but far from smooth. The easiest scene to see it is when the camera is making a fast pan at 1:18.
    Native Android Gallery: Says it can't play the video but actually it starts playing in the background without audio if you don't press anything. By far the smoothest motion for me.

    Could you try my sample with the Oculus Gallery? I sent a link via PM.
  • DaftnDirectDaftnDirect Posts: 4,804 Volunteer Moderator

    Hey @shamo42 just examined my test video and yours so thanks for that... very interesting!

    Yes, there's very slight judder noticeable when the microphone case pans close to the camera, it feels a little random and small enough for me not to notice in most scenes but yeah it's there.

    Skybox seems to me not to be random but has that regular and much more noticeable pulldown type stutter.

    The system galley app has that error message that obscures the frame and the picture is dimmed but you could be right in that it's smoother.

    Your clip though is night and day... very pronounced stuttering in Oculus Gallery and completely smooth in system gallery.

    So as well as the apps performing differently, there must by an optimum encoding method that minimises that difference. I can live with the movies I've encoded as the judder is so small but I'd certainly have a problem with the amount of judder on your clip. I'll have to investigate with different encodings, bitrates etc. to see if there's something that proves to be perfectly smooth in both apps.

    Intel 5820K OC@4Ghz, Titan X (Maxwell), 16GB Corsair Vengeance DDR4, ASRock X99 Taichi, Samsung 500Gb 960 Evo M.2, Corsair H100i v2 Cooler, Inateck KTU3FR-4P USB 3 card, Windows 10 Pro v1903 (18362.239)
  • shamo42shamo42 Posts: 6
    NerveGear
    Thanks for your observations @DaftnDirect
    They are pretty much the same as mine.

    I was in contact with someone from Skybox and provided them samples too. I'll let them know about this thread. I hope @OculusSupport and sees this too and if we're lucky we'll get smooth motion with one of the next firmware updates.
  • DaftnDirectDaftnDirect Posts: 4,804 Volunteer Moderator

    OK that's good @shamo42 and thanks for being patient with me, I'm learning more about the Quest and these hidden apps & I'm often reminded this forum is a good source of info.

    I mentioned in the Skybox thread about the stuttering so hopefully they can get to the route cause, it's a great app and the devs seem to be very active in improving it.

    Intel 5820K OC@4Ghz, Titan X (Maxwell), 16GB Corsair Vengeance DDR4, ASRock X99 Taichi, Samsung 500Gb 960 Evo M.2, Corsair H100i v2 Cooler, Inateck KTU3FR-4P USB 3 card, Windows 10 Pro v1903 (18362.239)
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