Colored vertical lines when hw transcoding HEVC on 918+

[toyanucci]

I’m getting some vertical lines that almost look like deinterlacing lines whenever I transcode any HEVC file. I found a thread here that talks about it and has a script to fix it but when I try the script it makes all HEVC transcodes sw only on my system which isn’t ideal even though sw transcoding doesn’t seem to have the problem.

I read it’s an issue with the cpu in the 918+ but if that script could fix it in the past I’m just checking if there’s an up to date fix that allows hw transcoding.

Thanks

[ChuckPa]

Can you give us a pic of it please?

Deinterlacing lines are horizontal lines across the image.

[toyanucci]

These are screenshots without and with transcoding enabled.

It’s exactly as described here

[ChuckPa]

Thanks. I see it. That’s actually macro-blocking caused by the iHD driver.

There is a way around this (permanently).

1. Install the Synology Text Exitor (package center)
2. Stop Plex
3. Open File Station
4. Navigate into the Plex share / Library / Application Support / Plex Media Server
5. Right-click “Preferences.xml” -> Open in Text Editor.
6. Cursor down and to the right until you get to the /> on the last line. You’ll see other information there which you identify as your email address, etc. This is to help confirm you’re on the right line.
7. Before the /> type VaapiDriver=“i965” (one space before and after)
   a. It will look like VaapiDriver="i965" />
8. Save the file
9. Exit the Text Editor
10. Start PMS.

[toyanucci]

I actually have that setting already set. I had seen it in another thread to make the i965 driver the default driver. I had the vertical lines problem before I had made that change and after so this doesn’t fix it.

While I don’t know the technical term I don’t think it’s macro-blocking as it only happens with hardware transcoding HEVC files.

Here it is blown up like it looks on my TV. When viewed here in this thread without it being blown up it doesn’t look as bad as it does on a bigger screen. Also see why I say it looks like deinterlacing lines but arranged vertically?

[ChuckPa]

Thank you. I can see that much more clearly and yes, it’s not macro-blocking.

That looks very much like a stride (stepping) problem.

Can you get me a piece of that file to test with here?
I have several HEVC-capable machines. I want to determine if it’s PMS version or hardware specific.

[toyanucci]

Based on this it seems to be a hardware issue. But in this same thread they had found a work around but that doesn’t seem to work anymore. It defaults to software transcoding when I try the fix suggested there.

[ChuckPa]

That’s why I requested a piece (sample) of the file.

There is a known issue with the ApolloLake CPUs
I would like to test the video on other CPUs to confirm whether indeed ApolloLake or something else.

[toyanucci]

I found a solution by following the instructions from here but using the updated code from here. It now does hw transcoding of HEVC without any of the visual issues that I’ve been complaining about.