4k stuttering playback (with and without hardware transcoding)

Plex Players Desktop Players
,
1

Server Version#: 1.32.4.7195 (Synology)
Player Version#: 1.45.1.3942-6fc4ceab (Plex HTPC for Mac)
Player logs:

Aug 13, 2023 01:25:50.157 [0x700001921000] INFO - Debug info:
File:
  URL: http://192.168.1.191:32400/library/parts/142/1691755445/file.mkv?X-Plex-Token=xxxxxxxxxxxxxxxxxxxx&X-Plex-Product=Plex%20HTPC%20for%20Mac&X-Plex-Platform=macos&X-Plex-Platform-Version=13.5&X-Plex-Model=Gecko&X-Plex-Device=&X-Plex-Device-Name=MacScan.local&X-Plex-Device-Vendor=Plex&X-Plex-Device-Screen-Resolution=1792x1120&X-Plex-Drm=widevine%3Avideo&X-Plex-Version=1.45.1.3942-6fc4ceab&X-Plex-Client-Identifier=zrvtm1qjrkqhrnb5rbpu956c&X-Plex-Language=en&X-Plex-Features=external-media%2Cindirect-media&X-Plex-Session-Id=bd9602b7-65f7-4280-83bd-92bfece8fb6a&Accept=application%2Fjson&Accept-Language=en&X-Plex-Playback-Session-Id=5c7acda4-867f-44cd-9037-f9bcd93407a3&X-Plex-Playback-Id=5fc47356-12ed-41c8-bd5a-659ba3303ca3
  Container: mkv
  Native seeking: yes

Video:
  Codec: hevc (HEVC (High Efficiency Video Coding))
  Size: 3840x2160
  Duration: 2855.81
  FPS (container): 23.98
  FPS (filters): 23.98
  Aspect: 1.78
  Bitrate: 26,248,102
  Display FPS: 60.00
  Hardware Decoding: no (?)

Audio: 
  Codec: eac3_at (eac3 (AudioToolbox))
  Bitrate: 768,031
  Channels: 5.1(side) -> stereo
  Output driver: coreaudio

Cache:
  Total Used (B): 207,032,576
  Forward Used (B): 157,521,360
  Forward Available (B): 157,286,400
  Backward Available (B): 52,428,800
  Speed (bytes per second): 3,229,420

Misc: 
  Seekable: true
  Partially seekable: false
  Paused for cache: false
  Buffering state: 100
  Frame drop count: 65
  Time: 2235.61 / 2855.81 (78.28%)
  State: playing 
Aug 13, 2023 01:26:05.174 [0x700001921000] INFO - Debug info:
File:
  URL: http://192.168.1.191:32400/library/parts/142/1691755445/file.mkv?X-Plex-Token=xxxxxxxxxxxxxxxxxxxx&X-Plex-Product=Plex%20HTPC%20for%20Mac&X-Plex-Platform=macos&X-Plex-Platform-Version=13.5&X-Plex-Model=Gecko&X-Plex-Device=&X-Plex-Device-Name=MacScan.local&X-Plex-Device-Vendor=Plex&X-Plex-Device-Screen-Resolution=1792x1120&X-Plex-Drm=widevine%3Avideo&X-Plex-Version=1.45.1.3942-6fc4ceab&X-Plex-Client-Identifier=zrvtm1qjrkqhrnb5rbpu956c&X-Plex-Language=en&X-Plex-Features=external-media%2Cindirect-media&X-Plex-Session-Id=bd9602b7-65f7-4280-83bd-92bfece8fb6a&Accept=application%2Fjson&Accept-Language=en&X-Plex-Playback-Session-Id=5c7acda4-867f-44cd-9037-f9bcd93407a3&X-Plex-Playback-Id=5fc47356-12ed-41c8-bd5a-659ba3303ca3
  Container: mkv
  Native seeking: yes

Video:
  Codec: hevc (HEVC (High Efficiency Video Coding))
  Size: 3840x2160
  Duration: 2855.81
  FPS (container): 23.98
  FPS (filters): 23.98
  Aspect: 1.78
  Bitrate: 24,169,131
  Display FPS: 60.00
  Hardware Decoding: no (?)

Audio: 
  Codec: eac3_at (eac3 (AudioToolbox))
  Bitrate: 767,969
  Channels: 5.1(side) -> stereo
  Output driver: coreaudio

Cache:
  Total Used (B): 202,749,088
  Forward Used (B): 157,551,120
  Forward Available (B): 157,286,400
  Backward Available (B): 52,428,800
  Speed (bytes per second): 3,093,490

Misc: 
  Seekable: true
  Partially seekable: false
  Paused for cache: false
  Buffering state: 100
  Frame drop count: 109
  Time: 2250.62 / 2855.81 (78.81%)
  State: playing 
Aug 13, 2023 01:26:20.189 [0x700001921000] INFO - Debug info:
File:
  URL: http://192.168.1.191:32400/library/parts/142/1691755445/file.mkv?X-Plex-Token=xxxxxxxxxxxxxxxxxxxx&X-Plex-Product=Plex%20HTPC%20for%20Mac&X-Plex-Platform=macos&X-Plex-Platform-Version=13.5&X-Plex-Model=Gecko&X-Plex-Device=&X-Plex-Device-Name=MacScan.local&X-Plex-Device-Vendor=Plex&X-Plex-Device-Screen-Resolution=1792x1120&X-Plex-Drm=widevine%3Avideo&X-Plex-Version=1.45.1.3942-6fc4ceab&X-Plex-Client-Identifier=zrvtm1qjrkqhrnb5rbpu956c&X-Plex-Language=en&X-Plex-Features=external-media%2Cindirect-media&X-Plex-Session-Id=bd9602b7-65f7-4280-83bd-92bfece8fb6a&Accept=application%2Fjson&Accept-Language=en&X-Plex-Playback-Session-Id=5c7acda4-867f-44cd-9037-f9bcd93407a3&X-Plex-Playback-Id=5fc47356-12ed-41c8-bd5a-659ba3303ca3
  Container: mkv
  Native seeking: yes

Video:
  Codec: hevc (HEVC (High Efficiency Video Coding))
  Size: 3840x2160
  Duration: 2855.81
  FPS (container): 23.98
  FPS (filters): 23.98
  Aspect: 1.78
  Bitrate: 31,490,727
  Display FPS: 60.00
  Hardware Decoding: no (?)

Audio: 
  Codec: eac3_at (eac3 (AudioToolbox))
  Bitrate: 767,969
  Channels: 5.1(side) -> stereo
  Output driver: coreaudio

Cache:
  Total Used (B): 206,559,600
  Forward Used (B): 157,431,824
  Forward Available (B): 157,286,400
  Backward Available (B): 52,428,800
  Speed (bytes per second): 2,933,755

Misc: 
  Seekable: true
  Partially seekable: false
  Paused for cache: false
  Buffering state: 100
  Frame drop count: 153
  Time: 2265.64 / 2855.81 (79.33%)
  State: playing 
Aug 13, 2023 01:26:35.222 [0x700001921000] INFO - Debug info:
File:
  URL: http://192.168.1.191:32400/library/parts/142/1691755445/file.mkv?X-Plex-Token=xxxxxxxxxxxxxxxxxxxx&X-Plex-Product=Plex%20HTPC%20for%20Mac&X-Plex-Platform=macos&X-Plex-Platform-Version=13.5&X-Plex-Model=Gecko&X-Plex-Device=&X-Plex-Device-Name=MacScan.local&X-Plex-Device-Vendor=Plex&X-Plex-Device-Screen-Resolution=1792x1120&X-Plex-Drm=widevine%3Avideo&X-Plex-Version=1.45.1.3942-6fc4ceab&X-Plex-Client-Identifier=zrvtm1qjrkqhrnb5rbpu956c&X-Plex-Language=en&X-Plex-Features=external-media%2Cindirect-media&X-Plex-Session-Id=bd9602b7-65f7-4280-83bd-92bfece8fb6a&Accept=application%2Fjson&Accept-Language=en&X-Plex-Playback-Session-Id=5c7acda4-867f-44cd-9037-f9bcd93407a3&X-Plex-Playback-Id=5fc47356-12ed-41c8-bd5a-659ba3303ca3
  Container: mkv
  Native seeking: yes

Video:
  Codec: hevc (HEVC (High Efficiency Video Coding))
  Size: 3840x2160
  Duration: 2855.81
  FPS (container): 23.98
  FPS (filters): 23.98
  Aspect: 1.78
  Bitrate: 12,085,286
  Display FPS: 60.00
  Hardware Decoding: no (?)

Audio: 
  Codec: eac3_at (eac3 (AudioToolbox))
  Bitrate: 768,000
  Channels: 5.1(side) -> stereo
  Output driver: coreaudio

Cache:
  Total Used (B): 198,719,968
  Forward Used (B): 157,308,032
  Forward Available (B): 157,286,400
  Backward Available (B): 52,428,800
  Speed (bytes per second): 1,453,096

Misc: 
  Seekable: true
  Partially seekable: false
  Paused for cache: false
  Buffering state: 100
  Frame drop count: 201
  Time: 2280.65 / 2855.81 (79.86%)
  State: playing 
Aug 13, 2023 01:26:50.273 [0x700001921000] INFO - Debug info:
File:
  URL: http://192.168.1.191:32400/library/parts/142/1691755445/file.mkv?X-Plex-Token=xxxxxxxxxxxxxxxxxxxx&X-Plex-Product=Plex%20HTPC%20for%20Mac&X-Plex-Platform=macos&X-Plex-Platform-Version=13.5&X-Plex-Model=Gecko&X-Plex-Device=&X-Plex-Device-Name=MacScan.local&X-Plex-Device-Vendor=Plex&X-Plex-Device-Screen-Resolution=1792x1120&X-Plex-Drm=widevine%3Avideo&X-Plex-Version=1.45.1.3942-6fc4ceab&X-Plex-Client-Identifier=zrvtm1qjrkqhrnb5rbpu956c&X-Plex-Language=en&X-Plex-Features=external-media%2Cindirect-media&X-Plex-Session-Id=bd9602b7-65f7-4280-83bd-92bfece8fb6a&Accept=application%2Fjson&Accept-Language=en&X-Plex-Playback-Session-Id=5c7acda4-867f-44cd-9037-f9bcd93407a3&X-Plex-Playback-Id=5fc47356-12ed-41c8-bd5a-659ba3303ca3
  Container: mkv
  Native seeking: yes

Video:
  Codec: hevc (HEVC (High Efficiency Video Coding))
  Size: 3840x2160
  Duration: 2855.81
  FPS (container): 23.98
  FPS (filters): 23.98
  Aspect: 1.78
  Bitrate: 22,347,110
  Display FPS: 60.00
  Hardware Decoding: no (?)

Audio: 
  Codec: eac3_at (eac3 (AudioToolbox))
  Bitrate: 767,969
  Channels: 5.1(side) -> stereo
  Output driver: coreaudio

Cache:
  Total Used (B): 209,465,184
  Forward Used (B): 157,327,152
  Forward Available (B): 157,286,400
  Backward Available (B): 52,428,800
  Speed (bytes per second): 3,025,163

Misc: 
  Seekable: true
  Partially seekable: false
  Paused for cache: false
  Buffering state: 100
  Frame drop count: 263
  Time: 2295.67 / 2855.81 (80.39%)
  State: playing 
Aug 13, 2023 01:26:58.935 [0x700001486000] WARN - [MPVEngine/mpv] cplayer: Audio device underrun detected.
Aug 13, 2023 01:26:58.935 [0x700001486000] DEBUG - [MPVEngine/mpv] cplayer: restarting audio after underrun
Aug 13, 2023 01:27:05.265 [0x700001921000] INFO - Debug info:
File:
  URL: http://192.168.1.191:32400/library/parts/142/1691755445/file.mkv?X-Plex-Token=xxxxxxxxxxxxxxxxxxxx&X-Plex-Product=Plex%20HTPC%20for%20Mac&X-Plex-Platform=macos&X-Plex-Platform-Version=13.5&X-Plex-Model=Gecko&X-Plex-Device=&X-Plex-Device-Name=MacScan.local&X-Plex-Device-Vendor=Plex&X-Plex-Device-Screen-Resolution=1792x1120&X-Plex-Drm=widevine%3Avideo&X-Plex-Version=1.45.1.3942-6fc4ceab&X-Plex-Client-Identifier=zrvtm1qjrkqhrnb5rbpu956c&X-Plex-Language=en&X-Plex-Features=external-media%2Cindirect-media&X-Plex-Session-Id=bd9602b7-65f7-4280-83bd-92bfece8fb6a&Accept=application%2Fjson&Accept-Language=en&X-Plex-Playback-Session-Id=5c7acda4-867f-44cd-9037-f9bcd93407a3&X-Plex-Playback-Id=5fc47356-12ed-41c8-bd5a-659ba3303ca3
  Container: mkv
  Native seeking: yes

Video:
  Codec: hevc (HEVC (High Efficiency Video Coding))
  Size: 3840x2160
  Duration: 2855.81
  FPS (container): 23.98
  FPS (filters): 23.98
  Aspect: 1.78
  Bitrate: 14,608,123
  Display FPS: 60.00
  Hardware Decoding: no (?)

Audio: 
  Codec: eac3_at (eac3 (AudioToolbox))
  Bitrate: 767,969
  Channels: 5.1(side) -> stereo
  Output driver: coreaudio

Cache:
  Total Used (B): 204,720,448
  Forward Used (B): 157,443,504
  Forward Available (B): 157,286,400
  Backward Available (B): 52,428,800
  Speed (bytes per second): 1,881,448

Misc: 
  Seekable: true
  Partially seekable: false
  Paused for cache: false
  Buffering state: 100
  Frame drop count: 427
  Time: 2310.68 / 2855.81 (80.91%)
  State: playing 
Aug 13, 2023 01:27:06.510 [0x700001486000] WARN - [MPVEngine/mpv] cplayer: Audio device underrun detected.
Aug 13, 2023 01:27:06.510 [0x700001486000] DEBUG - [MPVEngine/mpv] cplayer: restarting audio after underrun
Aug 13, 2023 01:27:08.928 [0x700001486000] WARN - [MPVEngine/mpv] cplayer: 
Aug 13, 2023 01:27:08.928 [0x700001486000] WARN - [MPVEngine/mpv] cplayer: Audio/Video desynchronisation detected! Possible reasons include too slow
Aug 13, 2023 01:27:08.928 [0x700001486000] WARN - [MPVEngine/mpv] cplayer: hardware, temporary CPU spikes, broken drivers, and broken files. Audio
Aug 13, 2023 01:27:08.928 [0x700001486000] WARN - [MPVEngine/mpv] cplayer: position will not match to the video (see A-V status field).
Aug 13, 2023 01:27:08.928 [0x700001486000] WARN - [MPVEngine/mpv] cplayer: 
Aug 13, 2023 01:27:20.858 [0x700001921000] INFO - Debug info:
File:
  URL: http://192.168.1.191:32400/library/parts/142/1691755445/file.mkv?X-Plex-Token=xxxxxxxxxxxxxxxxxxxx&X-Plex-Product=Plex%20HTPC%20for%20Mac&X-Plex-Platform=macos&X-Plex-Platform-Version=13.5&X-Plex-Model=Gecko&X-Plex-Device=&X-Plex-Device-Name=MacScan.local&X-Plex-Device-Vendor=Plex&X-Plex-Device-Screen-Resolution=1792x1120&X-Plex-Drm=widevine%3Avideo&X-Plex-Version=1.45.1.3942-6fc4ceab&X-Plex-Client-Identifier=zrvtm1qjrkqhrnb5rbpu956c&X-Plex-Language=en&X-Plex-Features=external-media%2Cindirect-media&X-Plex-Session-Id=bd9602b7-65f7-4280-83bd-92bfece8fb6a&Accept=application%2Fjson&Accept-Language=en&X-Plex-Playback-Session-Id=5c7acda4-867f-44cd-9037-f9bcd93407a3&X-Plex-Playback-Id=5fc47356-12ed-41c8-bd5a-659ba3303ca3
  Container: mkv
  Native seeking: yes

Video:
  Codec: hevc (HEVC (High Efficiency Video Coding))
  Size: 3840x2160
  Duration: 2855.81
  FPS (container): 23.98
  FPS (filters): 23.98
  Aspect: 1.78
  Bitrate: 15,873,672
  Display FPS: 60.00
  Hardware Decoding: no (?)

Audio: 
  Codec: eac3_at (eac3 (AudioToolbox))
  Bitrate: 768,000
  Channels: 5.1(side) -> stereo
  Output driver: coreaudio

Cache:
  Total Used (B): 205,875,824
  Forward Used (B): 157,394,832
  Forward Available (B): 157,286,400
  Backward Available (B): 52,428,800
  Speed (bytes per second): 3,562,484

Misc: 
  Seekable: true
  Partially seekable: false
  Paused for cache: false
  Buffering state: 100
  Frame drop count: 552
  Time: 2325.74 / 2855.81 (81.44%)
  State: playing 
Aug 13, 2023 01:27:35.831 [0x700001921000] INFO - Debug info:
File:
  URL: http://192.168.1.191:32400/library/parts/142/1691755445/file.mkv?X-Plex-Token=xxxxxxxxxxxxxxxxxxxx&X-Plex-Product=Plex%20HTPC%20for%20Mac&X-Plex-Platform=macos&X-Plex-Platform-Version=13.5&X-Plex-Model=Gecko&X-Plex-Device=&X-Plex-Device-Name=MacScan.local&X-Plex-Device-Vendor=Plex&X-Plex-Device-Screen-Resolution=1792x1120&X-Plex-Drm=widevine%3Avideo&X-Plex-Version=1.45.1.3942-6fc4ceab&X-Plex-Client-Identifier=zrvtm1qjrkqhrnb5rbpu956c&X-Plex-Language=en&X-Plex-Features=external-media%2Cindirect-media&X-Plex-Session-Id=bd9602b7-65f7-4280-83bd-92bfece8fb6a&Accept=application%2Fjson&Accept-Language=en&X-Plex-Playback-Session-Id=5c7acda4-867f-44cd-9037-f9bcd93407a3&X-Plex-Playback-Id=5fc47356-12ed-41c8-bd5a-659ba3303ca3
  Container: mkv
  Native seeking: yes

Video:
  Codec: hevc (HEVC (High Efficiency Video Coding))
  Size: 3840x2160
  Duration: 2855.81
  FPS (container): 23.98
  FPS (filters): 23.98
  Aspect: 1.78
  Bitrate: 22,942,491
  Display FPS: 60.00
  Hardware Decoding: no (?)

Audio: 
  Codec: eac3_at (eac3 (AudioToolbox))
  Bitrate: 768,000
  Channels: 5.1(side) -> stereo
  Output driver: coreaudio

Cache:
  Total Used (B): 201,978,688
  Forward Used (B): 157,319,136
  Forward Available (B): 157,286,400
  Backward Available (B): 52,428,800
  Speed (bytes per second): 2,600,851

Misc: 
  Seekable: true
  Partially seekable: false
  Paused for cache: false
  Buffering state: 100
  Frame drop count: 601
  Time: 2340.71 / 2855.81 (81.96%)
  State: playing

Client specifications:

MacBook Pro 16 inch, 2019
2,3 GHz 8-Core Intel Core i9
AMD Radeon Pro 5500M 4 GB
16 GB 2667 MHz DDR4
Ventura 13.5

Mediafile:

MPEG-H Part2/HEVC (H.265) (hevc)
3840x2160
SDR (10-bit 4:2:0, 1-1-1)
23.97

A/52 B Audio (aka E-AC3) (eac3)
3F2M/LFE
48000 Hz
32 bits per sample

VLC is playing these files just fine, however Plex HTPC for Mac is stuttering after a few minutes and continues to do so. Why?

2

After some digging it appears that I’m experiencing this problem here:

Which dates back to 2019 and was completely ignored by Plex staff. Wonderful.

3

I suspect the entirety of your problem is due to Hardware Decoding: no (?) but since you elected to only provide a small subset of the logs, I can’t tell you any more than that.

1 Like
4

Full logs:
Plex HTPC.log (353.3 KB)

This attempt was with hardware acceleration disabled. However enabling this doesn’t solve the issue.

5

Enabling it would log why it is not being used but disabling it means there is no log entries indicating such. Please enable it and capture logs again.

6

Same video file, hardware acceleration is enabled.

With HA enabled the video lags immediately.

Plex HTPC 2.log (359.2 KB)

7

There is an error associated with decoding EAC3 mentioned in your logs. To eliminate this as a variable, does the same occur when you play HEVC video that has audio which is not using any Dolby codec (AC3, EAC3, TrueHD)?

8

Still choppy/laggy playback, it’s definitely dropping frames;
HA is still enabled, this time the mediafile has AAC instead of EAC3 as requested.

Plex HTPC 3.log (295.8 KB)

9

The hardware acceleration appears to be working properly.

Perhaps you should try changing the quality setting to a lower level. You currently have it set to Maximum Quality which may be too much for your GPU with this content. In your OP, you compared the playback to VLC but to match the output of VLC you would need to set the quality setting to Low Quality. VLC doesn’t have the same processing capabilities as MPV.

1 Like
10

Thank you so much, this did the trick!
Even the original file (with eac3) plays normally now.

11

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