HEVC video from DVB-T2 stuttering

[eugeno]

Hi

Recently Poland has moved from DVB-T to DVB-T2 standard using HEVC codec. Now any video from new channels is stuttering. Audio is OK. The same applies to recordings. But the recordings on another device (laptop) play well. So it seems to be a decoding issue (no hardware acceleration).

My device is Vero 4K+. Tvheadend is installed on a separate server with a PCIe TV tuner (TBS 6281SE). The same problem is observed when using the OSMC TV dongle, no matter if plugged into Vero 4K+ or the server.

Here are the logs (I’ve played a TV recording):
https://paste.osmc.tv/duvojimufu

Mediainfo logs:
https://paste.osmc.tv/okojiyiboh.pl

[sam_nazarko]

Can you provide us with a sample recording so we can reproduce the issue here?

Many thanks

Sam

[eugeno]

Sure, here you go:

https://drive.google.com/file/d/1ahVqe_EfbvpMfWz-NEECU9zzgNYS2--E/view?usp=sharing

[eugeno]

I’ve made some investigation:

1. Hardware acceleration shows ON during playback
2. When transcoded using ffmpeg libx265 codec, the video plays OK, with no stuttering.

For the original file, ffmpeg shows the following:
Stream #0:0[0xa8e]: Video: hevc (Main) ([36][0][0][0] / 0x0024), yuv420p(tv), 1920x1080 [SAR 1:1 DAR 16:9], 50 fps, 50 tbr, 90k tbn, 50 tbc

For the transcoded one:
Stream #0:0: Video: hevc (Main), yuv420p(tv, progressive), 1920x1080 [SAR 1:1 DAR 16:9], 50 fps, 50 tbr, 1k tbn, 50 tbc (default)

Does anybody know what is the difference and why Vero 4K+ cannot play smoothly the original file?

I now recall that previously I had some BD rips (HEVC) which also had the same problem, but those were rare.

[eugeno]

Another observation:

This video recorded from another mux plays OK:

https://drive.google.com/file/d/1-VKsGOHluhuJ_S3RPcVRU6wI9j3lMLKK/view?usp=sharing

The strange thing is that ffmpeg and mediainfo show exactly the same codec info as for the “bad” video.

ffmpeg:
Stream #0:0[0x2be]: Video: hevc (Main) ([36][0][0][0] / 0x0024), yuv420p(tv), 1920x1080 [SAR 1:1 DAR 16:9], 50 fps, 50 tbr, 90k tbn, 50 tbc

mediainfo:

ID                                       : 1 (0x1)
Complete name                            : TV_sample_good.ts
Format                                   : MPEG-TS
File size                                : 4.70 MiB
Duration                                 : 9 s 165 ms
Overall bit rate mode                    : Variable
Overall bit rate                         : 4 277 kb/s
Original network name                    : Astra Satellite Network 19,2'E

Video
ID                                       : 702 (0x2BE)
Menu ID                                  : 1 (0x1)
Format                                   : HEVC
Format/Info                              : High Efficiency Video Coding
Format profile                           : Main@L4.1@Main
Codec ID                                 : 36
Duration                                 : 9 s 400 ms
Bit rate                                 : 3 839 kb/s
Maximum bit rate                         : 9 000 kb/s
Width                                    : 1 920 pixels
Height                                   : 1 080 pixels
Display aspect ratio                     : 16:9
Frame rate                               : 50.000 FPS
Color space                              : YUV
Chroma subsampling                       : 4:2:0
Bit depth                                : 8 bits
Bits/(Pixel*Frame)                       : 0.037
Stream size                              : 4.30 MiB (91%)
Language                                 : Polish
Color range                              : Limited```

[eugeno]

@sam_nazarko Have you had a look at the sample(s)?

[sam_nazarko]

Not yet. I’ll let you know when I’ve had a chance.

[sam_nazarko]

@eugeno

I now recall that previously I had some BD rips (HEVC) which also had the same problem, but those were rare.

Can you still reproduce this?

[eugeno]

@sam_nazarko

Can you still reproduce this?

Yes, but this is a huge BD Remux. Here is the mediainfo output:

http://paste.osmc.tv/weciveneme.mel

[eugeno]

I’ve found a recent thread with a very similar issue:

HEVC issues with Vero4K+

Hello, Since an update which occured between friday night and saturday night last week, all HEVC files are choppy. One frame every 10 or so seconds. Whatever the resolution (FullHD/4K), HDR or not, the audio codec… In comparison, all other video codecs files are fine whatever the resolution. The files are played from a NAS with a 1000Mbits/s link. The UI is ok during playback. CPU usage is not through the roof and network is 1000Mbits/s. Here are my logs : http://paste.osmc.tv/ruqeyetozi

Has it been fixed finally?

[sam_nazarko]

You could try with the 4.9.269 video stack, which is where our next major focus is.

[eugeno]

@sam_nazarko

You could try with the 4.9.269 video stack, which is where our next major focus is.

Where can I get it? I can only see vero364-image-4.9.113-64-osmc in the repository.

[sam_nazarko]

Sent you the details

Sam

[ctyrka]

When reading this thread, it seems I am experiencing same issue that I described here (it’s actually 1 of 3 issues I’ve got with TV dongle):

https://discourse.osmc.tv/t/tvheadend-osmc-tv-tuner-issues/93135/10

Anyway the stuttering/lagging is dominant on DVB-T2 HEVC streams. This is what I can see in the TVH server.

[ctyrka]

I might have found fix for this. At least it is currently working for me. Go to Adapter settings in the TVH server and check “force old status” on demodulator you are using. Once checked, I can no more see “continuity counter error” and TV stream is smooth with no lagging.
The SNR and signal strength are no longer displayed, but the main function of DVB-T2/C tuner is currently working fine.

It was already reported here:
https://tvheadend.org/issues/5625

[eugeno]

@sam_nazarko

You could try with the 4.9.269 video stack, which is where our next major focus is.

I’ve tried on 4.9.269, all the “bad” videos now play well, both TV recordings and the BD Remux.

[sam_nazarko]

Thanks for confirming. As the current kernel is EOL, we won’t investigate further

Sam