S905x Video - MPEG2 720P/50 AC3 2 ch Stutters

redger · December 7, 2016 at 5:36 AM

I have MPEG2 720P video recordings via a Mythtv backend which "stutter" when played on Libreelec build 7.0.2.009 from 7.0.2.009

About once per second there will be a brief pause in the video.
This occurs whether the video is played via the mythtv addon or directly from the server via an NFS share

Device details - AMLogic S905X, Mini M8S II, 2GB/8GB boot from SD Card (16GB Sandisk)

Hardware acceleration is turned on for MPEG >= 720P

Logfile posted at Ubuntu Pastebin
Video stream commences at about log time 16:02:07

Same problem occurs for all videos 720p from this channel

filename1024_20161203090100.ts (current affairs)- H264 MPEG-4 AVC (part 10) (h264), 1280x736, framerate 50hz
- A52 Audio (aka AC3) (a52) Stereo Rate 48000 Hz Bitrate 256kb/s

I have a video sample but was unable to successfully attach it ....

**lrusak** · December 7, 2016 at 6:12 AM Official Post

MOD NOTICE: moved to amlogic community forum because the user is using a community build not an official build

redger · December 7, 2016 at 9:14 PM

The problem can be reproduced on the alpha version LibreELEC-S905.arm-8.0-devel-20161204210449-r24821-g9f57b18.img.gz

Log Ubuntu Pastebin starting from log time 08:03:08.740

In this case the same content as above is played (a) on the alpha release (b) from a file on an NFS share rather than via the pvr-mythtv addon - note that it's still the same file being played
Filename = 1024_20161203090100.ts

Codec info
- MPEG-2 (mpgv), 1280x736, display 1280x720, framerate 50hz
- A52 Audio (aka AC3) (a52) Stereo Rate 48000 Hz Bitrate 256kb/s

Display capabilities (confirm 50Hz is available)

Code

cat /sys/class/amhdmitx/amhdmitx0/disp_cap
480i60hz
480p60hz
576i50hz
576p50hz
720p60hz
1080i60hz
1080p60hz
720p50hz
1080i50hz
1080p50hz*
1080p24hz

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This looks like -

A highly repeatable problem. It always occurs on these 720P/50 files
It looks as though it could be related to a timing issue eg. 50Hz content played at 60Hz, which would create a "judder" every 5/6 of a sec (say), tho it appears the output has been set to 1080p/50 (see above) .. perhaps related to upscaling ?
The issue occurs in both the "stable" and "alpha" releases ie. Kodi v16 and v17

This does not look like a de-interlacing issue based on the available information (of course I could be wrong ) particularly since this is Progressive content ie. does not need deinterlacing

redger · December 8, 2016 at 9:43 AM

link to test file Dropbox - 1024_20161203090100_short.7z

password is the same as my 6 character user name