4k 24.000 fps file on Apple TV 4K extremely choppy

Just curious if anyone might have a clue about this. I have a 4k file that plays extreeeeeemly choppy (imagine a variable 2-5 fps) on my Apple TV 4k, but is perfectly smooth with Plex on my iPhone 13 and iPad Pro.

Off hand the only thing that seems different to me, from my other high bandwidth 4k files that play fine on the ATV, is that this one is 24.000 fps rather than the more common 23.976 fps.

I’ve tried turning on/off matching frame rate on the ATV but it had no effect. I’m not using the “old” player, as that requires transcode (although that does end up playing smoothly).

So I’m curious if the newer embedded ATV player just has trouble with true 24fps decoding?

And if not what else might it bet?

FWIW, here is mediainfo output of the video stream:

Video
ID                                       : 1
Format                                   : HEVC
Format/Info                              : High Efficiency Video Coding
Format profile                           : Main 10@L5.1@High
HDR format                               : SMPTE ST 2086, HDR10 compatible
Codec ID                                 : V_MPEGH/ISO/HEVC
Duration                                 : 1 h 36 min
Bit rate                                 : 33.9 Mb/s
Width                                    : 3 840 pixels
Height                                   : 1 606 pixels
Display aspect ratio                     : 2.40:1
Frame rate mode                          : Constant
Frame rate                               : 24.000 FPS
Color space                              : YUV
Chroma subsampling                       : 4:2:0 (Type 2)
Bit depth                                : 10 bits
Bits/(Pixel*Frame)                       : 0.229
Stream size                              : 22.9 GiB (94%)
Writing library                          : x265 3.5+19-8003e4382:[Windows][MSVC 1900][64 bit] 10bit
Encoding settings                        : cpuid=1111039 / frame-threads=5 / numa-pools=32 / wpp / no-pmode / no-pme / no-psnr / no-ssim / log-level=2 / input-csp=1 / input-res=3840x1606 / interlace=0 / total-frames=139639 / level-idc=51 / high-tier=1 / uhd-bd=0 / ref=4 / no-allow-non-conformance / repeat-headers / annexb / aud / no-eob / no-eos / hrd / info / hash=0 / no-temporal-layers / no-open-gop / min-keyint=24 / keyint=250 / gop-lookahead=0 / bframes=4 / b-adapt=2 / b-pyramid / bframe-bias=0 / rc-lookahead=25 / lookahead-slices=4 / scenecut=40 / no-hist-scenecut / 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 / no-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=-3:-3 / 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=crf / crf=15.5 / qcomp=0.60 / qpstep=4 / stats-write=0 / stats-read=0 / vbv-maxrate=160000 / vbv-bufsize=160000 / vbv-init=0.9 / min-vbv-fullness=50.0 / max-vbv-fullness=80.0 / crf-max=0.0 / crf-min=0.0 / ipratio=1.40 / pbratio=1.30 / aq-mode=2 / aq-strength=0.80 / 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=9 / transfer=16 / colormatrix=9 / chromaloc=1 / chromaloc-top=2 / chromaloc-bottom=2 / display-window=0 / master-display=G(8500,39850)B(6550,2300)R(35400,14600)WP(15635,16450)L(10000000,1) / 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=0.03 / no-opt-cu-delta-qp / no-aq-motion / hdr10 / 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 / scenecut-aware-qp=0conformance-window-offsets / right=0 / bottom=0 / decoder-max-rate=0 / no-vbv-live-multi-pass
Default                                  : Yes
Forced                                   : No
Color range                              : Limited
Color primaries                          : BT.2020
Transfer characteristics                 : PQ
Matrix coefficients                      : BT.2020 non-constant
Mastering display color primaries        : BT.2020
Mastering display luminance              : min: 0.0001 cd/m2, max: 1000 cd/m2

You may have nailed down a problem I couldn’t,
choppy playback on a specific 4K on ATV4K direct play.
It turns out it’s 24 fps. I’m off to do some more testing.

@nibbles @GlowingBits Have you guys figured out this issue?

I have several videos in 4k hevc that are both 24fps and 23.976 fps that play fine. but this one set of videos (that are 4k hevc 24fps) stutter no mater what.

Some progress. In the last few days I swapped to an Ultra HDMI certified cable.
I switched to a TV port with HDMI 2.1 /eArc in case the TV favored it.
I tried with Match Frame Rate on or off.
I continue to get the same issue with this one film.

I did run across another 24 fps 4K HDR in my collection that played well.
So I’m leaning toward the problem I can demonstrate is an issue with one video.
I’m going to collect some logs today, though.

If you guys do have 24.000 files that play fine, I’d be curious to see mediainfo output on their video track to see if there are some differences in encoding parameters. My (total) guess is that Plex’s embedded Apple TV player has an issue with some encoding parameter, as the same file plays fine on iOS players or when re-encoded for me.

1 Like

Ok here are some samples from my end. Can confirm the issue is only present ATV4k using Plex. iOS, iPadOS, macOS, Web browser work fine.

ATV settings:
4K HDR 50Hz
Match Dynamic Range & Frame rate: OFF

Plex settings:
Old player: OFF
Direct Play: ON

Video 1 - 4K, HEVC, 24fps - [Plays fine]:

Video
ID                                       : 1
Format                                   : HEVC
Format/Info                              : High Efficiency Video Coding
Format profile                           : Main 10@L5@Main
Codec ID                                 : V_MPEGH/ISO/HEVC
Duration                                 : 37 min 43 s
Bit rate                                 : 22.0 Mb/s
Width                                    : 3 840 pixels
Height                                   : 2 160 pixels
Display aspect ratio                     : 16:9
Frame rate mode                          : Constant
Frame rate                               : 24.000 FPS
Color space                              : YUV
Chroma subsampling                       : 4:2:0
Bit depth                                : 10 bits
Bits/(Pixel*Frame)                       : 0.111
Stream size                              : 5.80 GiB (97%)
Writing library                          : x265 3.5:[Linux][GCC 9.3.0][64 bit] 10bit
Encoding settings                        : cpuid=1111039 / frame-threads=1 / numa-pools=16 / wpp / no-pmode / no-pme / no-psnr / no-ssim / log-level=2 / input-csp=1 / input-res=3840x2160 / interlace=0 / total-frames=0 / level-idc=50 / high-tier=0 / uhd-bd=0 / ref=3 / no-allow-non-conformance / repeat-headers / annexb / no-aud / no-hrd / info / hash=0 / no-temporal-layers / no-open-gop / min-keyint=48 / keyint=48 / gop-lookahead=0 / bframes=2 / b-adapt=0 / b-pyramid / bframe-bias=0 / rc-lookahead=48 / lookahead-slices=8 / scenecut=0 / hist-scenecut=0 / radl=0 / no-splice / no-intra-refresh / ctu=32 / min-cu-size=8 / no-rect / no-amp / max-tu-size=16 / tu-inter-depth=2 / tu-intra-depth=2 / limit-tu=0 / rdoq-level=1 / dynamic-rd=0.00 / no-ssim-rd / signhide / no-tskip / nr-intra=0 / nr-inter=0 / no-constrained-intra / no-strong-intra-smoothing / max-merge=3 / limit-refs=1 / no-limit-modes / me=1 / subme=2 / merange=44 / 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 / early-skip / rskip / no-fast-intra / no-tskip-fast / no-cu-lossless / b-intra / no-splitrd-skip / rdpenalty=1 / psy-rd=1.60 / psy-rdoq=5.00 / no-rd-refine / no-lossless / cbqpoffs=0 / crqpoffs=0 / rc=abr / bitrate=23000 / qcomp=0.75 / qpstep=4 / stats-write=0 / stats-read=0 / vbv-maxrate=25000 / vbv-bufsize=25000 / vbv-init=0.9 / ipratio=1.40 / pbratio=1.30 / aq-mode=3 / aq-strength=1.00 / no-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=9 / transfer=16 / colormatrix=9 / 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=0.00 / hist-threshold=0.01 / no-opt-cu-delta-qp / no-aq-motion / no-hdr10 / 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
Default                                  : Yes
Forced                                   : No
Color range                              : Limited
Color primaries                          : BT.2020
Transfer characteristics                 : PQ
Matrix coefficients                      : BT.2020 non-constant

Video 2 - 4K, HEVC, 24fps - [Plays fine]:

Video
ID                                       : 1
Format                                   : HEVC
Format/Info                              : High Efficiency Video Coding
Format profile                           : Main@L5@High
Codec ID                                 : V_MPEGH/ISO/HEVC
Duration                                 : 50 min 1 s
Bit rate                                 : 19.5 Mb/s
Width                                    : 3 840 pixels
Height                                   : 2 160 pixels
Display aspect ratio                     : 16:9
Frame rate mode                          : Constant
Frame rate                               : 24.000 FPS
Color space                              : YUV
Chroma subsampling                       : 4:2:0
Bit depth                                : 8 bits
Bits/(Pixel*Frame)                       : 0.098
Stream size                              : 6.83 GiB (96%)
Writing library                          : x265 3.5:[Linux][GCC 9.3.0][64 bit] 8bit+10bit+12bit
Encoding settings                        : cpuid=1111039 / frame-threads=1 / numa-pools=16 / wpp / no-pmode / no-pme / no-psnr / no-ssim / log-level=2 / input-csp=1 / input-res=3840x2160 / interlace=0 / total-frames=0 / level-idc=50 / high-tier=1 / uhd-bd=0 / ref=2 / no-allow-non-conformance / repeat-headers / annexb / no-aud / no-hrd / info / hash=0 / no-temporal-layers / no-open-gop / min-keyint=48 / keyint=48 / gop-lookahead=0 / bframes=4 / b-adapt=0 / b-pyramid / bframe-bias=0 / rc-lookahead=48 / lookahead-slices=8 / scenecut=0 / hist-scenecut=0 / radl=0 / no-splice / no-intra-refresh / ctu=32 / min-cu-size=8 / no-rect / no-amp / max-tu-size=16 / tu-inter-depth=2 / tu-intra-depth=2 / limit-tu=0 / rdoq-level=1 / dynamic-rd=0.00 / no-ssim-rd / signhide / no-tskip / nr-intra=0 / nr-inter=0 / no-constrained-intra / no-strong-intra-smoothing / max-merge=3 / limit-refs=1 / no-limit-modes / me=1 / subme=2 / merange=44 / 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 / early-skip / rskip / no-fast-intra / no-tskip-fast / no-cu-lossless / b-intra / no-splitrd-skip / rdpenalty=1 / psy-rd=1.60 / psy-rdoq=5.00 / no-rd-refine / no-lossless / cbqpoffs=0 / crqpoffs=0 / rc=abr / bitrate=20000 / qcomp=0.75 / qpstep=4 / stats-write=0 / stats-read=0 / vbv-maxrate=24000 / vbv-bufsize=40000 / vbv-init=0.9 / ipratio=1.40 / pbratio=1.30 / aq-mode=3 / aq-strength=1.00 / no-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=1 / transfer=1 / colormatrix=1 / chromaloc=0 / display-window=0 / cll=0,0 / min-luma=0 / max-luma=255 / 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=0.00 / 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
Default                                  : No
Forced                                   : No
Color range                              : Limited
Color primaries                          : BT.709
Transfer characteristics                 : BT.709
Matrix coefficients                      : BT.709

Video 3 - 4K, HEVC, 24fps - [STUTTER]:

Video
ID                                       : 1
Format                                   : HEVC
Format/Info                              : High Efficiency Video Coding
Format profile                           : Main 10@L5@High
HDR format                               : SMPTE ST 2086, HDR10 compatible
Codec ID                                 : V_MPEGH/ISO/HEVC
Duration                                 : 52 min 28 s
Bit rate                                 : 15.4 Mb/s
Width                                    : 3 840 pixels
Height                                   : 2 160 pixels
Display aspect ratio                     : 16:9
Frame rate mode                          : Constant
Frame rate                               : 24.000 FPS
Color space                              : YUV
Chroma subsampling                       : 4:2:0
Bit depth                                : 10 bits
Bits/(Pixel*Frame)                       : 0.077
Stream size                              : 5.65 GiB (95%)
Language                                 : English
Default                                  : Yes
Forced                                   : No
Color range                              : Limited
Color primaries                          : BT.2020
Transfer characteristics                 : PQ
Matrix coefficients                      : BT.2020 non-constant
Mastering display color primaries        : BT.2020
Mastering display luminance              : min: 0.0000 cd/m2, max: 1000 cd/m2

Video 4 - 4K, HEVC, 24fps - [STUTTER]:

Video
ID                                       : 1
Format                                   : HEVC
Format/Info                              : High Efficiency Video Coding
Format profile                           : Main 10@L5@High
HDR format                               : SMPTE ST 2086, HDR10 compatible
Codec ID                                 : V_MPEGH/ISO/HEVC
Duration                                 : 44 min 34 s
Bit rate                                 : 15.4 Mb/s
Width                                    : 3 840 pixels
Height                                   : 2 160 pixels
Display aspect ratio                     : 16:9
Frame rate mode                          : Constant
Frame rate                               : 24.000 FPS
Color space                              : YUV
Chroma subsampling                       : 4:2:0
Bit depth                                : 10 bits
Bits/(Pixel*Frame)                       : 0.077
Stream size                              : 4.78 GiB (95%)
Language                                 : English
Default                                  : Yes
Forced                                   : No
Color range                              : Limited
Color primaries                          : BT.2020
Transfer characteristics                 : PQ
Matrix coefficients                      : BT.2020 non-constant
Mastering display color primaries        : BT.2020
Mastering display luminance              : min: 0.0000 cd/m2, max: 1000 cd/m2

Thanks… Quite a few differences between your two playable files (with encoder info) and my non-playable file with encoder info. It will take some time to digest that some night :slight_smile:

Just to confirm though, your ATV 4K is on 50hz, like you’re in Europe?

@erkned is seeing:

  • 4K 24 fps constant bitrate HDR - stutter on > 1 film
  • 4K 24 fps constant bitrate SDR - okay

I saw

  • 4K 24 fps variable bitrate HDR - stutter on 1 film

I’m still gathering test samples. I have tried remuxing the file without any SRT sub tracks, but I got no changes.

I am in Europe yes. Just the default setting currently. I did test with 4K 60Hz and 4K Dolby Vision, same result. When turning on Match Frame-rate, it does help a bit, but stutter still noticeable.

My TV is 55" LG OLED C7.

No luck playing three different 4K 24fps films smoothly, SDR or HDR.
They all had a commonality, though. So my testing isn’t done.
I’ll gather or generate more source material today.

1 Like

Apple introduced a new feature recently

Plex playback of a specially crafted 4K @ 24 fps on the ATV4K with >= 14.5 and Match Frame Rate shows a lot of micro stutter.

What I tried -

  • I set ATV4K to match frame rate
  • Turned on Plex advanced debug overlay when playing
  • Played a 4K SDR 24 fps film
  • I can see 24 fps source in the overlay
  • I can 24 fps thru the filter
  • I can see the tv matching that as best it can 23.999 and 23.998 fps.
  • I see micro stutter and dozens of frames delayed

Content like this is extremely rare. 23.976 is the normal frame rate of UHD BluRay we see, so that it can multiply and get near 60 like a TV, doing 23.976 * 5 / 2 = 59.96 fps.

Anyway the point is that Netflix started to release this integral fps content, and so will others. Will the whole industry shift to 60 fps to get rid of motion judder? It’s another thing to code for I guess :slight_smile:

Tomorrow I’m going to recode a Jellyfish to 24 fps and verify that it easily reproduced.

1 Like

I tested all day today generating 24 fps 4K content. I can’t reproduce any stutter, and all my samples play smooth as silk, at exactly 24.000 fps. It’s really nice.

The details:

I took a 140 Mbps Jellyfish 4K HDR w/TrueHD and converted the audio to AC3.
I then converted the mkv to 24 fps three different ways using ffmpeg, and a fourth way using Avidemux.

I also used ffmpeg to generate 4K colorbars at 24 fps in 4:2:0 10bit HEVC

ffmpeg -f lavfi -i testsrc=duration=30:size=uhd2160:rate=24 -pix_fmt yuv420p10le -f hevc pattern.420p10le.h265.mkv

Plex + AppleTV4K + my LG played everything perfectly, at exactly 24.000 fps according to the advanced debug overlay on the ATV.

24.000 fps from the container.
24.000 fps after the filter
24.000 fps tv refresh rate

smooth as silk

My conclusion: it’s the encodes.

I agree, it’s definitely some encoding parameter(s). I’d just love to know which it is that trips up the AppleTV 4k’s encoder. :slight_smile: I think there are potentially more than one though, as what I’m seeing with my file definitely isn’t micro stutter, it’s completely horrible playback that results in a variable 2-8 fps (my guess). But only on AppleTV 4k – on phone and iPad it’s totally smooth.

You’ve inspired me to try a re-encoding though. As even if I can find the encoding issue, it seems doubtful Plex would jump to a fix for the encoder. :wink:

I decided to test the 24fps HDR videos via Kodi on ATV. It played smoothly there, but looked awful. Probably since Kodi doesn’t support HDR.

Then I went to the ATV settings, and changed the profile to “4k SDR 60Hz”. Went back into Plex, and played the same video, still micro judder, but much much less compared to 4K HDR or DV mode.

I started to notice similar problems recently, and I couldn’t nail down what was going on. Then I noticed on DirectPlay for one of the file sets I was having trouble with, the Bitrate that the Apple Plex player claimed was double (39.5Mbps) the rate it actually should be (18.6 as shown in the LG Plex app). The same could be seen on the iOS app when I told it to do Original Playback, which says the file is 18.6 Mbps, but then the playback details says 39.5Mbps…

So check the playback info and see if you’re seeing a similar incorrect value…

Ok I’ll check.

Any chunk of a video that claims to be 15 Mbps could peak to 25Mbps without deviating from the Main10@L5@Main standard and no summary of a file will tell you it did that. If it goes beyond that to the 39.5 Mbps you mentioned as an example, that would not be in spec. and could be the issue. The table linked below is very good for knowing specs.

I got into watching the live bandwidth usage on my Dashboard. The graph lets me see what’s up better than anything I know so far.

My video is 24.000 fps constant frame rate, 4:2:0 YUV bt.709, Main 10@L5@Main

  • Mediainfo says the video track Bit rate : 15.4 Mb/s
  • ffprobe says the video tracks has BPS : 15440905
  • Plex for Mac Get Info says video track Bitrate 15683 kbps
  • Plex for Mac View XML says video track bitrate="15683"
  • Dashboard bandwith on this video is a gentle roller coaster that stays below 25 Mbps and hovers more around 16.

So the first video is all in spec for Main10@L5@Main unless I missed short bursts.
For a second video that’s also 24 fps Main10@L5@Main

  • Dashboard immediately peaks to 240 Mbps and drops to 16.

This second video is clearly out of spec.

Share the media info XML for those files, especially RequiredBandwidths.

All of those bit rate numbers you listed are whole-stream averages. While that gives a sense of things, peaks can be much higher. Plex’s bandwidth analysis is much more informative.

It is normal for streaming video to use the maximum amount of bandwidth, then 0, then the maximum amount, while playing. But if a player consistently uses a huge amount of bandwidth for a video, averaging more than the file bitrate, that typically indicates a muxing problem.

Quite often disabling Direct Play will be enough to address this.

Some files are very badly encoded, however, with nonsense timestamps in the video frames.

(And there are obviously problems with some HDR formats the Apple TV doesn’t support.)

PM me a link if you can.

Yeah that’s what I started thinking last night, where is the output of the Plex “Analysis” I asked it to do. I forgot it might be in the XML output, which is a bummer considering I read it a few times and never noticed that. Thanks for the tip, and I’ll work on getting it.

I turned on the debug overlay on the iOS app, and the Bitrate during Directplay HEVC did fluctuate up and down from 18709288 and Performance->A/V ran up the numbers quickly while dropped frames were racking up also. Switch to 4K @ 40Mbps transcoded h264 and A/V was 0.0000xx levels and no dropped frames.

The Old Video Player works as well as the Enhanced Player using transcoded (since it too uses transcode).

I compared against another file that DirectPlay’s perfectly, and the only notable difference was the audio codec was eac3_at (bad file) vs aac (good file).

Both files are Matroska V4
bad file is Main 10@L5.1@Main, good file is Main 10@L5@Main and also has HDR

Frame rate of bad is 25.0, Frame rate of good is 23.976

So I’ll try to find another file that more closely matches the bad file and see if it produces the same issue.

Share some files/links please. PM is fine.