Vero V audio sync issue since last update

This is my case too, altough I live in EU and PAL 50 Hz world. If I watch videos with multi channel audio, such as DTS-HD , DD+ etc. everything is fine. But when I switch to tvheadend feed of two channel MPEG-2 tv-streams, either live or recorded, there is almost immediately significant audio sync glitch. Reboot usually helps. It is difficult to explain but it looks like if I’ve watched blu ray rips or other multichannel content (without delay glitches), the audio delay is more likely to occur with tvheadend content immediately after watching those other videos.

I received my Vero V in December and I’m (almost) sure these problems were introduced in February update.

@sam_nazarko I’m willing to provide you with logs, samples or whatever you need at this point. I’m also willing to test the staging update repository if that is what you would suggest. Please advise.

Good to know that it is MPEG2 content that’s affected. Are you software decoding this?

HW passthrough for all audio (that are selectable) in my case for all formats. I have Denon AVC-X3800H as an audio sink.

Now, my apologies for incorrect information: content in my case seems to be MPEG-1 audio with AVC video after all. Please see enclosed mediainfo.

For what it’s worth; I’ve tried both TS and MKV wrapping with tvheadend - no difference.

General
Unique ID                                : 267087275964369492967649903284761908860 (0xC8EF2364A4EEB3DDAFD9B514B1D3D67C)
Complete name                            : \\DiskStation\Tallenteet\Australian rajalla\Australian rajalla2024-02-28-2.mkv
Format                                   : Matroska
Format version                           : Version 2
File size                                : 2.14 GiB
Duration                                 : 41 min 0 s
Overall bit rate                         : 7 460 kb/s
Frame rate                               : 25.000 FPS
Movie name                               : Australian rajalla
ContentType                              : Movie / Drama
Writing application                      : Tvheadend 4.2.8
Writing library                          : Tvheadend Matroska muxer
Original source form                     : TV
DATE_BROADCASTED                         : 2024-02-28 22:35:00
SUMMARY                                  : Säsong 16. Avsnitt 14/20. Korv i bagaget. En koreansk kvinna reser med ett par kilo otullad korv. En container från Malaysia innehåller mer än bara solpaneler. En australisk realityserie.
TVCHANNEL                                : Jim HD

Video
ID                                       : 1
Format                                   : AVC
Format/Info                              : Advanced Video Codec
Format profile                           : Main@L4
Format settings                          : CABAC / 4 Ref Frames
Format settings, CABAC                   : Yes
Format settings, Reference frames        : 4 frames
Format settings, GOP                     : M=4, N=24
Codec ID                                 : V_MPEG4/ISO/AVC
Duration                                 : 41 min 0 s
Bit rate                                 : 7 119 kb/s
Width                                    : 1 920 pixels
Height                                   : 1 080 pixels
Display aspect ratio                     : 16:9
Frame rate mode                          : Constant
Frame rate                               : 25.000 FPS
Color space                              : YUV
Chroma subsampling                       : 4:2:0
Bit depth                                : 8 bits
Scan type                                : Interlaced
Scan type, store method                  : Separated fields
Scan order                               : Top Field First
Bits/(Pixel*Frame)                       : 0.137
Stream size                              : 2.04 GiB (95%)
Language                                 : English
Default                                  : Yes
Forced                                   : No
Color range                              : Limited
Color primaries                          : BT.709
Transfer characteristics                 : BT.709
Matrix coefficients                      : BT.709

Audio
ID                                       : 2
Format                                   : MPEG Audio
Format version                           : Version 1
Format profile                           : Layer 2
Codec ID                                 : A_MPEG/L2
Codec ID/Hint                            : MP2
Duration                                 : 41 min 0 s
Bit rate mode                            : Constant
Bit rate                                 : 192 kb/s
Channel(s)                               : 2 channels
Sampling rate                            : 48.0 kHz
Compression mode                         : Lossy
Delay relative to video                  : -19 ms
Stream size                              : 56.3 MiB (3%)
Language                                 : Finnish
Default                                  : Yes
Forced                                   : No

This is more likely than not just inherent in the film itself.
Sub 30fps video (ie: 24 fps and 25 fps) is notorious for these issues with camera pans.
There are many articles online discussing judder.
If only the industry would move toward 60 fps episodes and movies…

No, unfortunately this is not the typical slow frame rate panning issue which should be constant, but sudden dropped frames, where the whole panning stops for a while.

Did you mean to quote some other message?

Any new news?

We have some improvements but they are still being fine tuned.

ok, thxs! For your information… I can often trigger the problem, when I use fast forward while watching my PVR recordings.

I found a workaround for me… removing 720p resolutions from whitelist to force upscaling to 1080p does the trick.

Hmm – I don’t think that will be related to the changes we’ve made then.

I don’t know exactly… should be a combination of 720p 25fps source data and double framerate (to play at 720p 50Hz that triggered the audio async.

Thanks for your patience to everyone here who has had some playback issues. We’ve now got something we’d like you to try after a lot of fine tuning from @tanio99.

To test this update:

  1. Login via the command line
  2. Run the following command to add the staging repository:
    echo 'deb http://apt.osmc.tv bullseye-devel main' | sudo tee /etc/apt/sources.list.d/osmc-devel.list
  3. Run the following commands to update: sudo apt-get update && sudo apt-get dist-upgrade && reboot
  4. Your system should have have received the update.

Please see if the issue is resolved.

I also recommend you remove /etc/apt/sources.list.d/osmc-devel.list after updating.

This will deactivate the staging repository. You can do so with the following command:
sudo rm /etc/apt/sources.list.d/osmc-devel.list.

Please note that we will automatically disable this update channel after 14 days on your device in case you forget to do so to ensure that your system reverts to the stable update channel.

Cheers

Sam

2 Likes

I’ve been watching this thread with interest as I’ve been having lip-sync issues with my PVR playback, which I typically watch via a direct connection to a very old plasma. First impressions of this new build are favourable but need to test further.

Has anything been included in a recent build that would improve HDR to SDR conversion? It’s a while since I looked at that, I don’t remember the V’s SDR conversion looking as good as what I’m seeing now.

No changes to HDR-SDR. We are using the stock AMLogic code which includes some dynamic adjustments based on measurements the chip takes of the incoming video.

So far so good - few hours and no audio sync issues that were pretty constant while playing PVR via IPTV Simple Client (on Vero 4K). I hope it will stay this way. Thanks guys! :slight_smile:

3 Likes

Test build seems very good indeed. Tvheadend syncs perfectly and remains synced after pause and skips back and forth on both live and recordings. Thank you! :+1:

2 Likes

It will.

Thanks for your testing.

workaround doesnt work in all situations… :laughing: I did a roleback and use the test build without any audio sync problems so far.