Any update from Intel regarding the iHD transcoding driver for Synology NAS?

Plex Media Server
1

Hello! I was wondering why transcoding HEVC on my Synology 1520+ would yield terrible results (usually never-ending buffering), so I did some searching and found that adding VaapiDriver=“i965” to the preferences file fixes that.

Plex teammember @ChuckPa stated in December 2020:

  1. As of 1.21.0, the VaapiDriver="i965" isn’t needed on any J4xxx CPU (DSx20+) but that doesn’t seem the case with my DS1520+ since I still need to add it with the latest PMS for Synology downloaded directly from the Plex site.

I was wondering if there were any updates to this and also why isn’t this line of code in the preferences by default for the Synology PMS package at this point until Plex can confirm with the Intel team that the driver has been updated? I spent hours pulling my hair why some media files just wouldn’t play. Then when I did try to edit the file via Notepad++ in Windows, Synology/Plex apparently didn’t like the formatting that it saved in, so it recreated the preferences.xml from scratch, forcing me to redo my server settings and share it to all my users and explain to them how to reset the home screen customizations so that the media shows up again.

Server: Synology DS1520+ on DSM 6.2
Server Version#: 1.23.2.4656
Player Version#: Any

2

To answer your question about why it’s not in your preferences file by default,

  1. Nobody asked
  2. It doesn’t apply to everyone.
  3. Not really appropriate for me to presume it’s wanted or needed.

What I’ve found is when the source video bitrate is low, the iHD driver can have problems which are solved by the i965.

It’s been largely on a case-by-case basis.

What is the video bitrate of one of these ‘never-ending buffering’ videos ?

(the <media> ..... </media> portion of the XML)

3

thanks for the quick response, I think it mainly has to do that this file has subs as well? Its only 1260 kbps Bitrate:

bitrate=“1260” width=“1280” height=“720” aspectRatio=“1.78” audioChannels=“6” audioCodec=“eac3” videoCodec=“hevc” videoResolution=“720” container=“mkv” videoFrameRate=“PAL” videoProfile=“main 10”>

4

Thanks for sharing that info.

The problem here is simple and unfortunate.

  1. A 1280x720p screen has 921,600 pixels @ 32 bit color/pixel.
  2. The video bitrate is 1,260,000 bits/second.
  3. PAL requires 25 frames/second.
  4. There is barely enough video bitrate for an image refreshed 25 frames per second.

The iHD driver does extremely well when bit rates are above 4 Mbps.
It does “OK” when bit rates are above 2 Mbps.

This video is less than 2 Mbps.

The problem is compounded by being HEVC and UHD color – both of which are inappropriate for such an extremely low quality level. AKA - POOR encoding.

My recommendation.

  1. Replace this video with the same 1.2 - 2.0 Mbps video bit rate
  2. Make certain it is H.264 (not HEVC and definitely not HDR)
  3. Repeat the test
1 Like
5

thanks, will look into replacing it.

So do you recommend me using the iHD driver now instead of the i965 if this seems to be a rare occurrence?

6

What is common in your library?

If the majority of your video library is properly encoded and at higher bit rate, all of which work well with the iHD driver – then use the iHD.

If you have a variety of encoding and quality levels, use the i965.

(Variances like this are why it isn’t appropriate for me to set the default driver to “i965”)

7

This topic was automatically closed 90 days after the last reply. New replies are no longer allowed.