Stutter frame skipping

Help and Support
1

Had this problem with frame skipping or stutter since day one of owning the vero 4k. But since doing some fixes for HDR it’s worse than before.
Made logs, hopefully I’ve done it correctly.
https://paste.osmc.tv/unajupepox
Thanks.

2

Looks throughput related.
How is your drive formatted?

Sam

4

Drives are ntfs formated. But it does the same when streaming. So I don’t think it’s drives personally.

5

I looked at your logs, and I’m thinking it may be how the files are encoded (at least for the local files).

I don’t know if you’ve checked but you do have the ‘Sync Display to Playback’ option set in Kodi, right?

Can you provide mediainfo on one of the local problem files?

It would be good if we could find out more about the file you are having issues playing. Please see the mediainfo section in How to submit a useful support request - General - OSMC.

You can also create the mediainfo-output of the affected media file on the OSMC device:

  1. login via SSH, user osmc, password osmc
  2. if not already installed: sudo apt-get update && sudo apt-get install mediainfo
  3. cdto the directory containing the video/audio material in question
  4. mediainfo -f "<media file>"|paste-log, where <media file> is your video/audio
  5. publish the returned URL here in this topic

Thx for your help.

6

Same / similar problem here.

Quite bad video skipping / stutter on some video / TV channels (sound is fine).

Didn’t create log / media info yet, but some tests this Saturday showed:

  • source doesn’t matter:
    • NAS (CIFS / Kodi “mounted”)
    • WLAN / cable
    • local USB (FAT32)
  • display doesn’t matter:
    • “old” Toshiba TV (HDMI / 720p)
    • quite new Telefunken TV (HDMI / 1080p)
      (yes, that name is still in use by some Chinese mfg :slight_smile:)
    • computer monitor (ACER KG251Q)
  • it doesn’t help to synchronize display to stream!
  • worst on recordings / live TV from German DVB-T2
    • separate TVHeadend server / HTSP streaming
    • H.256 / 1080/ 50p with AAC (or AAC_latm) sound
      (working fine with EAC sound)
    • regardless of container (raw TS / PS, repacked MKV (AVIDemux))
  • starts / gets worse after skipping (left / right arrows) or
    intermittend throughput problems (WLAN)
    doesn’t re-synchronize after problem starts
  • clean install of OSMC didn’t help

I’ll gladly provide more input (logs / mediainfo) tonight when back home.

7

OK, took some time, but here you are …

Playing a .TS file from USB / FAT32, skipping back after some seconds, BAD video stutter…

Logs: https://paste.osmc.tv/junanayuzi
Mediainfo: http://paste.osmc.io/guqavesixa.vhdl

I can also provide the .TS if required!

@sam_nazarko: thread should be moved to the Vero 4K / Vero 4K+ category.

8

Looks a bit like a messed up file

Duration                                 : 89350884
Duration                                 : 24 h 49 min
Duration                                 : 24 h 49 min 10 s 884 ms
Duration                                 : 24 h 49 min
Duration                                 : 24:49:10.884
Duration                                 : 00:49:10:44
Duration                                 : 24:49:10.884 (00:49:10:44)
9

The transport stream is broken. Needs remuxing.

10

Well, not quite too broken.

Granted, the total run-time of the video stream is “a bit” quirky (should be 17.something seconds), but when taking into account the delays given for each of the streams (video, audio1 & 2), it all falls into place nicely.

Let me make one point once again: the stream starts just fine;
the problem only shows, when skipping forward / back.

As I’m not sure, who performs the skip / ffwd (player, amcodec, …) and resync,
I don’t know whom to “blame” :slight_smile:.
May be it’s just a missed - or miscalculated - I-Frame (wild guess).

Stream plays perfectly on several targets:

  • PC - AMD graphics
  • MacBook pro - dedicated AMD graphics
  • MacBook air - INTeL embedded
  • Vero 4k - software decoding (skipped frames but no judder)
  • RPi 3 - software decoding (as above)

I’ll nevertheless ask the Tvheadend developers about this as well.

11

Hi,

Thanks for your feedback.

Software decoding is trivial and can resolve stream errors pragmatically. Hardware decoders can choke quite easily.

It sounds like your stream is so broken it only plays with software decoders. FFMpeg is not platform specific, which would explain this consistency across other platforms.

Would you be willing to upload a sample at https://collab.osmc.tv/s/3VjTiLcdgZoLqmT

I can’t guarantee any improvement, but I will definitely look in to how we can improve tolerance to this type of stream.

Cheers

Sam

12

Hi Sam,

I uploaded the exact sample we’ve been talking about.
It’s quite short, please state whether you need some longer (how long?) stream!

Oh, btw: PC (AMD graphics) is using HW decoding (as per Kodi Player-Info).

Best regards
Mathias

13

I finally created a Tvheadend issue on this…

14

@sam_nazarko:

Did you find the time to look into this?

15

Have you tried remuxing with something like MKVToolNix news – Matroska tools for Linux/Unix and Windows just to see what happens ?

16

Yeah sure - I did; re-muxing does help.
Works for recordings; but not for live TV and time-shift.