Apologies for the delay in responding. My Internet service has been out for several days due to weather issues. I’m in via a hotspot, but mobile service has occasionally dropped out as well. Hopefully fully back online by the end of the week…
Thanks for sending the additional info.
I’ve been over the info several times and searched other forum threads and on the Internet.
The short answer is I cannot tell why Plex is having trouble with News of the World. The log files show what is happening, but I cannot tell why it is happening. Maybe someone else can take a look and see what is happening.
The best I can tell, Plex is handling Synchronic correctly, using hardware acceleration. Plex tries to use hardware acceleration for News of the World, then falls back to software. I cannot tell why this is happening - Plex error, driver error, bad movie file, or something else.
If the problem happens with just one or two files, then there is probably a problem with the file that prevents Plex from handling it correctly (even though other programs may handle it OK).
You should also run Windows Update to make sure you have the latest video driver version.
Attaching a short snippet of the movie could help as well. I most likely won’t be able to look at it for a couple of days (aforementioned Internet issues), but someone else might be able to help.
Additional details below.
i5-6200U and 10-bit HEVC video
Intel i5-6200U (Skylake), HD Graphics 520 (ark.intel.com)
Per the Intel datasheet, the 6200U can decode 8-bit HEVC, but not 10-bit HEVC (Section 2.2.2.1 Hardware Accelerated Video Decode, pg 27-28).
However, the log files show Plex is using hardware acceleration for both Synchronic and News of the World (both 10-bit HEVC):
Synchronic:
Feb 13, 2021 07:31:30.476 [0904] DEBUG - [Transcode] Synchronic - video.bitDepth limitation applies: 10 > 8
Feb 13, 2021 07:31:30.729 [0904] DEBUG - [Transcode] Streaming Resource: Reached Decision id=35996 codes=(General=1001,Direct play not available; Conversion OK. Direct Play=3000,App cannot direct play this item. Direct play is disabled. Transcode=1001,Direct play not available; Conversion OK.) media=(id=72626 part=(id=73281 decision=transcode container=mpegts protocol=hls streams=(Video=(id=154370 decision=transcode bitrate=9004 encoder=h264_qsv width=1920 height=804) Audio=(id=154371 decision=copy channels=6 rate=48000))))
Feb 13, 2021 07:31:30.885 [0904] DEBUG - [Transcode] TPU: hardware transcoding: final decoder: dxva2, final encoder: qsv
News of the World:
Feb 13, 2021 07:32:23.340 [12112] DEBUG - [Transcode] News of the World - video.bitDepth limitation applies: 10 > 8
Feb 13, 2021 07:32:23.590 [12112] DEBUG - [Transcode] Streaming Resource: Reached Decision id=35982 codes=(General=1001,Direct play not available; Conversion OK. Direct Play=3000,App cannot direct play this item. Direct play is disabled. Transcode=1001,Direct play not available; Conversion OK.) media=(id=73170 part=(id=73872 decision=transcode container=mpegts protocol=hls streams=(Video=(id=159262 decision=transcode bitrate=9441 encoder=h264_qsv width=1920 height=800) Audio=(id=159263 decision=copy channels=6 rate=48000))))
Feb 13, 2021 07:32:23.697 [12112] DEBUG - [Transcode] TPU: hardware transcoding: final decoder: dxva2, final encoder: qsv
It may be correct for Plex to use hardware decoding for 10-bit HEVC video:
- Intel released a driver update for Broadwell U processors enabling 10-bit HEVC decode (reference). I could not find a similar announcement for Skylake, but it seems odd Intel would enable the capability for Broadwell, a previous generation, and not Skylake, which can already decode 8-bit HEVC.
- CPU Monkey also shows Intel HD Graphics 520 with the ability to decode 10-bit HEVC.
Plex fallback to software transcoding for News of the World
Here’s the log entries showing Plex falling back to software transcoding for News of the World.
Feb 13, 2021 07:34:24.436 [8520] ERROR - [Transcoder] [Parsed_scale_qsv_1 @ 02833fc0] Error synchronizing the operation: -21
Feb 13, 2021 07:34:24.437 [8520] ERROR - [Transcoder] Error while filtering: Unknown error occurred
Feb 13, 2021 07:34:24.437 [8520] ERROR - [Transcoder] Failed to inject frame into filter network: Unknown error occurred
Feb 13, 2021 07:34:24.437 [8520] ERROR - [Transcoder] Error while processing the decoded data for stream #0:0
Feb 13, 2021 07:34:24.522 [11316] DEBUG - Jobs: 'C:\Program Files (x86)\Plex\Plex Media Server\Plex Transcoder.exe' exit code for process 6904 is 1 (failure)
Feb 13, 2021 07:34:24.522 [3632] DEBUG - Streaming Resource: Changing client to use software decoding
I searched the forum using “Error while filtering.” I found one relevant thread, but there was no solution mentioned.
