4K HEVC stutter on 4500U, Vega 6 (A515-44)

mike999
mike999 Member Posts: 3 New User
edited November 2023 in 2020 Archives
Did anybody encounter stuttering while playing 4K HEVC video files (in VLC or W10 "Movies & TV" app)? I expected it to run smoothly on the 4500U. Any ideas on what could be  causing this?

Best Answer

  • aphanic
    aphanic Member Posts: 959 Seasoned Specialist WiFi Icon
    edited August 2020 Answer ✓
    Thanks for all of the stats! It's a simple file apparently, and while my system is nothing like yours (it's Intel based to begin with), I do see stuttering as well. I can't describe it well, but it's clearly not running smoothly even if my system is not being taxed either.

    From the stats I could see from MPC it is being decoded with hardware acceleration (that DXVA2 native listed the decoder line) and it is resized to 1080p using Catmull which is not particularly system intensive. In fact you can see that the usage of the CPU and GPU is barely anything. No bit depth conversion needs to be done either, it's an 8-bit file played in an 8-bit panel... but! I noticed the file has a rather higher bitrate compared to what I'm used to seeing.

    And yet why don't we see higher numbers in CPU/GPU usage if that's the problem? Or Memory for that matter, even buffering I had 1 free just like yours, it wasn't needed.

    To assess if that's the problem, I'm downloading two more files, one that uses an average bitrate of 3.8 Mb/s (Sintel, from 2010, I just like the story) and another that goes up to 140 Mb/s (well, I'm getting the crazy bitrates too just for fun), yours would be the middle ground and these would represent a low to normal-ish bitrate and a somewhat higher one. We can certainly go higher, but if the bitrate is what's causing the stutter we should see it too in that 140 Mb/s file, especially because there's more processing to be done because it uses 10-bit per color; but I suspect it has something to do with your file, the way it was encoded I mean.

    They seem to be taking their time downloading so I'm going to report tomorrow (got kind of late here), but for the reference here you can get the same files as me:
     - Sintel: https://www.libde265.org/downloads-videos/
     - Jellyfish: http://jell.yfish.us



    EDIT: Okay, it is related to your encode for sure, I have no stuttering even on the crazy ~400 Mb/s encode of those jellyfishes.

    At least over here, HEVC playing works just fine (MPC-BE, didn't test on any other program though).

Answers

  • aphanic
    aphanic Member Posts: 959 Seasoned Specialist WiFi Icon
    edited August 2020
    That is... interesting, because there are something things at play here:
    • I wonder if the "Movies & TV" app is actually making use of the hardware decoding capabilities for HEVC without the HEVC extension installed, and it seems to be a paid one...



    • That Vega 6 GPU is capable of HEVC accelerated processing, meaning it's not all done by the CPU, but unless you're outputting to a 4K screen there's also resizing work to be done, and that can be done hardware assisted or not.

    • Also to take into consideration is the details of that HEVC file, just like with AVC it's not the same to play a base or main profile at 8 bit with 3 refrerence frames vs. some high profile, 10 bit color with more reference frames. Requirements increase, still your system ought to be able to handle it.
    Assuming proper drivers are installed, could you give a different player a try and see how it behaves? It's portable if you don't want to install it there's no need for it, but I'm interested. Get the latest portable nightly version just to test, and see how it behaves: https://www.videohelp.com/software/MPC-BE

    Also, when you're playing the file press Ctrl+J to show some stats and post a screenshot here for me to see (pressing Ctrl+J a couple more times should take the stats out of the screen).



    There is also another interesting bit pressing Shift+F10 that can show us more info on the file you're trying to play:

    Video
    ID                             : 1
    Format                         : HEVC
    Format/Info                    : High Efficiency Video Coding
    Format profile                 : Main 10@L4@Main
    Codec ID                       : hev1
    Codec ID/Info                  : High Efficiency Video Coding
    Duration                       : 3 h 48 min
    Bit rate                       : 2 001 kb/s
    Width                          : 1 920 pixels
    Height                         : 800 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                      : 10 bits
    Bits/(Pixel*Frame)             : 0.054
    Stream size                    : 3.19 GiB (90%)
    Writing library                : x265 3.3+4-30eb4de83092:[Linux][GCC 8.3.1][64 bit] 10bit
    Encoding settings              : cpuid=1111039 / frame-threads=4 / wpp / no-pmode / no-pme / no-psnr / no-ssim / log-level=2 / input-csp=1 / input-res=1920x800 / interlace=0 / total-frames=0 / level-idc=0 / high-tier=1 / uhd-bd=0 / ref=4 / no-allow-non-conformance / no-repeat-headers / annexb / no-aud / no-hrd / info / hash=0 / no-temporal-layers / open-gop / min-keyint=23 / keyint=250 / gop-lookahead=0 / bframes=4 / b-adapt=2 / b-pyramid / bframe-bias=0 / rc-lookahead=25 / lookahead-slices=4 / scenecut=40 / hist-scenecut=0 / radl=0 / no-splice / no-intra-refresh / ctu=64 / min-cu-size=8 / rect / no-amp / max-tu-size=32 / tu-inter-depth=1 / tu-intra-depth=1 / limit-tu=0 / rdoq-level=2 / dynamic-rd=0.00 / no-ssim-rd / signhide / no-tskip / nr-intra=0 / nr-inter=0 / no-constrained-intra / strong-intra-smoothing / max-merge=3 / limit-refs=3 / limit-modes / me=3 / subme=3 / merange=57 / temporal-mvp / no-frame-dup / no-hme / weightp / no-weightb / no-analyze-src-pics / deblock=0:0 / no-sao / no-sao-non-deblock / rd=4 / selective-sao=0 / no-early-skip / rskip / no-fast-intra / no-tskip-fast / no-cu-lossless / no-b-intra / no-splitrd-skip / rdpenalty=0 / psy-rd=2.00 / psy-rdoq=1.00 / no-rd-refine / no-lossless / cbqpoffs=0 / crqpoffs=0 / rc=abr / bitrate=2000 / qcomp=0.60 / qpstep=4 / stats-write=0 / stats-read=2 / cplxblur=20.0 / qblur=0.5 / ipratio=1.40 / pbratio=1.30 / aq-mode=3 / aq-strength=1.00 / cutree / zone-count=0 / no-strict-cbr / qg-size=32 / no-rc-grain / qpmax=69 / qpmin=0 / no-const-vbv / sar=1 / overscan=0 / videoformat=5 / range=0 / colorprim=2 / transfer=2 / colormatrix=2 / chromaloc=0 / display-window=0 / cll=0,0 / min-luma=0 / max-luma=1023 / log2-max-poc-lsb=8 / vui-timing-info / vui-hrd-info / slices=1 / no-opt-qp-pps / no-opt-ref-list-length-pps / no-multi-pass-opt-rps / scenecut-bias=0.05 / hist-threshold=0.01 / no-opt-cu-delta-qp / no-aq-motion / no-hdr10 / no-hdr10-opt / no-dhdr10-opt / no-idr-recovery-sei / analysis-reuse-level=0 / analysis-save-reuse-level=0 / analysis-load-reuse-level=0 / scale-factor=0 / refine-intra=0 / refine-inter=0 / refine-mv=1 / refine-ctu-distortion=0 / no-limit-sao / ctu-info=0 / no-lowpass-dct / refine-analysis-type=0 / copy-pic=1 / max-ausize-factor=1.0 / no-dynamic-refine / no-single-sei / no-hevc-aq / no-svt / no-field / qp-adaptation-range=1.00 / no-scenecut-aware-qpconformance-window-offsets / right=0 / bottom=0
    Encoded date                   : UTC 2020-04-04 13:36:10
    Tagged date                    : UTC 2020-04-04 13:36:10
    Codec configuration box        : hvcC

  • mike999
    mike999 Member Posts: 3 New User
    edited August 2020
    Hi, thanks for the interest!

    It stutters in every player I have tried: VLC, Movies & TV app, MPC.
    I actually did install the HEVC extension for the Movies & TV app - it still stutters.
    I do have the latest drivers.
    The screen resolution is 1920x1080.
    You can even try to play the file for yourself: https://filebin.net/t5mabq2evjx9ot6y

    These are the stats you asked for:





  • aphanic
    aphanic Member Posts: 959 Seasoned Specialist WiFi Icon
    edited August 2020 Answer ✓
    Thanks for all of the stats! It's a simple file apparently, and while my system is nothing like yours (it's Intel based to begin with), I do see stuttering as well. I can't describe it well, but it's clearly not running smoothly even if my system is not being taxed either.

    From the stats I could see from MPC it is being decoded with hardware acceleration (that DXVA2 native listed the decoder line) and it is resized to 1080p using Catmull which is not particularly system intensive. In fact you can see that the usage of the CPU and GPU is barely anything. No bit depth conversion needs to be done either, it's an 8-bit file played in an 8-bit panel... but! I noticed the file has a rather higher bitrate compared to what I'm used to seeing.

    And yet why don't we see higher numbers in CPU/GPU usage if that's the problem? Or Memory for that matter, even buffering I had 1 free just like yours, it wasn't needed.

    To assess if that's the problem, I'm downloading two more files, one that uses an average bitrate of 3.8 Mb/s (Sintel, from 2010, I just like the story) and another that goes up to 140 Mb/s (well, I'm getting the crazy bitrates too just for fun), yours would be the middle ground and these would represent a low to normal-ish bitrate and a somewhat higher one. We can certainly go higher, but if the bitrate is what's causing the stutter we should see it too in that 140 Mb/s file, especially because there's more processing to be done because it uses 10-bit per color; but I suspect it has something to do with your file, the way it was encoded I mean.

    They seem to be taking their time downloading so I'm going to report tomorrow (got kind of late here), but for the reference here you can get the same files as me:
     - Sintel: https://www.libde265.org/downloads-videos/
     - Jellyfish: http://jell.yfish.us



    EDIT: Okay, it is related to your encode for sure, I have no stuttering even on the crazy ~400 Mb/s encode of those jellyfishes.

    At least over here, HEVC playing works just fine (MPC-BE, didn't test on any other program though).
  • mike999
    mike999 Member Posts: 3 New User
    Hi, BIG thank you for solving my issue! You were right, my files are corrupt. Anyway, thanks for the time & effort!