920+ : H/W Transcoding not working with 4k HVEC files

[Flasher 0]

Hey guys, 

I'm having an issue getting H/W transcoding working properly on my Synology 920+ NAS (geminilake). 4K HVEC videos cause high CPU load and are played back very choppy - every 3 seconds it stops for roughly 2 seconds, so it's unwatchable (on both the webplayer as well as the Android App). I have H/W transcoding enabled in the settings. Emby is running native on the NAS (not Docker). Here is some part of the ffmpeg log:

Quote

2021-03-21 22:02:28.169
Operating System: Linux version 4.4.59+ (root@build3) (gcc version 4.9.3 20150311 (prerelease) (crosstool-NG 1.20.0) ) #25556 SMP PREEMPT Thu Mar 4 18:03:47 CST 2021
OS/Process: x64/x64
Emby Server version: 4.5.4.0
Operating system: Unix 4.4.59.0
Command Line: /volume2/@appstore/EmbyServer/system/EmbyServer.dll -programdata /volume2/Emby -ffdetect /var/packages/EmbyServer/target/bin/ffdetect -ffmpeg /var/packages/EmbyServer/target/bin/ffmpeg -ffprobe /var/packages/EmbyServer/target/bin/ffprobe -nolocalportconfig -ignore_vaapi_enabled_flag -updatepackage emby-server-synology_{version}_x86_64.spk

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>>>>>>  User policy for Flasher
        EnablePlaybackRemuxing: True
        EnableVideoPlaybackTranscoding: True
        EnableAudioPlaybackTranscoding: True

>>>>>>  Affected codecs
Encoder VAAPI Device 32902:12677 - H.264 (AVC)
        Adapter #0: 'Device 32902:12677' Id:12677 (Driver: Intel i965 driver for Intel(R) Gemini Lake - 2.4.1, Vendor: 32902)
        Frame Sizes: 32x32...4096x4096
        Color Formats: NV12, YUV420P
        Profiles: Constrained Baseline Profile (Level 6), Main Profile (Level 6), High Profile (Level 6)

Decoder VAAPI Device 32902:12677 - H.265 (HEVC)
        Adapter #0: 'Device 32902:12677' Id:12677 (Driver: Intel i965 driver for Intel(R) Gemini Lake - 2.4.1, Vendor: 32902)
        Frame Sizes: max 4096x4096
        Color Formats: NV12, P010
        Profiles: Main Profile (Level 6), Main 10 Profile (Level 6)


>>>>>>  FindVideoEncoder - Media: h264, UseHardwareCodecs: True, Mode: Automatic
Info    Checking: 'VAAPI Device 32902:12677 - H.264 (AVC)'
Info    Check successful - selecting 'VAAPI Device 32902:12677 - H.264 (AVC)'

>>>>>>  FindVideoDecoder - MediaType: hevc, Mode: Automatic
Info    Checking: 'VAAPI Device 32902:12677 - H.265 (HEVC)'
Info    Check successful - selecting 'VAAPI Device 32902:12677 - H.265 (HEVC)'

>>>>>>  Processing Plan
Info    Name                                        CanDoInHardware      WillDoInHardware     Reason                                  
Info    VAAPI Device 32902:12677 - H.265 (HEVC)  >> True                 True                 Hardware Codec                           
Info    VideoInput                               >> True                 True                 Same adapter (/dev/dri/renderD128), s... 
Info    ColorConversion                          >> True                 True                                                          
Info    VideoOutput                              >> True                 True                 Hardware encoder                         
Info    VAAPI Device 32902:12677 - H.264 (AVC)   >> True                 True                 Hardware Codec                           

>>>>>>  Projected Processing Formats
Info    Previous                HW-Context   Format       SW-Format       Next
Info    hevc                 >> VAAPI        vaapi_vld    yuv420p10    >> scale_vaapi
Info    scale_vaapi          >> VAAPI        vaapi_vld    nv12         >> 

Any idea? I've read about an issue in the intel drivers, but not sure if this applies to my situation as well. Here's what the details show in the webplayer. 

 

 

Edited March 21, 2021 by Flasher

[Luke 37064]

Hi there, please attach the complete emby server, ffmpeg and hardware detection log files. thanks.

[Flasher 0]

Hi, after further investigation it looks like the HW transcoding is indeed working. At least with the the emby Windows app or Android app on my smartphone it seems to play without a flaw. But on my Android TV and Chrome Browser it seems to have troubles. I don't really understand as to why.

Below are the requested logs (removed filename in ffmpeg log for privacy reasons)

 

 

embyserver.txt ffmpeg-transcode-62814da5-d6eb-439b-82ff-35c4a4c09506_1.txt hardware_detection-63751962896.txt

Edited March 23, 2021 by Flasher

[Luke 37064]

What do you mean by troubles?

[Flasher 0]

1 hour ago, Luke said:

What do you mean by troubles?

On 3/21/2021 at 10:12 PM, Flasher said:

played back very choppy - every 3 seconds it stops for roughly 2 seconds

 

 

[Luke 37064]

Ok, please try lowering the in-app quality setting to reduce the bitrate and see if that helps. Thanks.

[Flasher 0]

Still the same behavior - even reducing the resolution to 1080p is not helping. It is definitely not a bandwidth problem (2,5 Gbit LAN)

[Happy2Play 8281]

Even with HWA it looks like it is choking on burning in pgssubs.

 

19:56:41.557 Stream mapping:
19:56:41.557   Stream #0:0 (hevc) -> scale_vaapi (graph 0)
19:56:41.557   Stream #0:5 (pgssub) -> scale (graph 0)
19:56:41.557   hwupload (graph 0) -> Stream #0:0 (h264_vaapi)
19:56:41.557   Stream #0:1 -> #0:1 (dts (dca) -> aac (native))

19:56:51.643 frame=   84 fps=8.4 q=-0.0 size=   17461kB time=00:00:03.77 bitrate=42166.2kbits/s throttle=off speed=0.338x

But you do have a 25Mb h265 being converted into a 50Mb h264 stream.

"Bitrate":24339655

-c:v:0 h264_vaapi -b:v:0 48679310 -g:v:0 72 -maxrate:v:0 48679310 -bufsize:v:0 97358620

Edited March 27, 2021 by Happy2Play

[Happy2Play 8281]

I guess one question would be does this happen without subtitles?  Or at least without pgssubs.

But somethings doesn't seem quite right with that GPU though.

Edited March 27, 2021 by Happy2Play

[Flasher 0]

Honestly I don't care about subtitles as all the video content I own has languages I understand. So I don't have any of them enabled. But disabling the real time extraction of subtitles doesn't change anything either. Still stuttering playback.

Edited March 27, 2021 by Flasher

[Luke 37064]

On 3/27/2021 at 7:13 AM, Flasher said:

Honestly I don't care about subtitles as all the video content I own has languages I understand. So I don't have any of them enabled. But disabling the real time extraction of subtitles doesn't change anything either. Still stuttering playback.

@Flasher this is because disabling it causes the server to burn the subtitles in with server transcoding, and it looks like your server machine is also struggling with that.

The reason it plays without a flaw on the windows and android apps is because those apps support the files without the need for any subtitle extraction or any transcoding. Here's what I would suggest to improve your experience:

• Play files in the web app that are natively supported by the browser to avoid server transcoding.
• Or use the windows/android/iOS apps more often because they can direct play more formats without transcoding
• For subtitles, consider acquiring external text-based subtitles, which are the most efficient form of subtitles. Our subtitle download features can help with this.

Please let us know if this helps. Thanks.