Selur's Little Message Board

Greetings !

I did an x265 conversion with OPUS 7.1 and OPUS 5.1 audio.
The resulting .mkv heavily stutters with the 7.1 OPUS audio. If i switch to 5.1 ,everythings fine.
With 7.1 audio ,CPU usage is ~30 %...
No matter what player i use. Never experienced like this before....
Any idea guys ?

Some infos :

Hybrid : V2024.06.09.1
CPU : i5-6600
RAM : Much more than enough
Audio 1 source : TrueHD/Atmos Audio English 4944 kbps 7.1+11 objects / 48 kHz / 4304 kbps
Audio 2 source : Dolby Digital Audio 640 kbps 5.1 / 48 kHz / 640 kbps
Any errors : Nope

Sample : Cant upload ,due to copyright laws.

Other infos from player :

      Format : Matroska
      Format version : Version 4
      File size : 2.15 GiB
      Duration : 2 h 10 min
      Overall bit rate : 2 361 kb/s
      Encoded date : UTC 2024-06-17 05:35:38
      Writing application : mkvmerge v83.0 ('Circle Of Friends') 64-bit
      Writing library : libebml v1.4.5 + libmatroska v1.7.1
      Encoding Gui : Hybrid 2024.05.11.1
  Video #1
      ID : 1
      Format : HEVC
      Format/Info : High Efficiency Video Coding
      Format profile : Main 10@L4.1@High
      Codec ID : V_MPEGH/ISO/HEVC
      Duration : 2 h 10 min
      Bit rate : 1 873 kb/s
      Width : 1 920 pixels
      Height : 1 080 pixels
      Display aspect ratio : 16:9
      Frame rate mode : Constant
      Frame rate : 23.976 (24000/1001) FPS
      Color space : YUV
      Chroma subsampling : 4:2:0
      Bit depth : 10 bits
      Bits/(Pixel*Frame) : 0.038
      Stream size : 1.70 GiB (79%)
      Writing library : x265 3.6+13-9a75b5947:[Windows][GCC 13.2.0][64 bit] 10bit
      Default : Yes
      Forced : Yes
      Color range : Limited
      Color primaries : BT.2020
      Transfer characteristics : PQ
      Matrix coefficients : BT.2020 non-constant
  Audio #2
      ID : 2
      Format : Opus
      Codec ID : A_OPUS
      Duration : 2 h 10 min
      Bit rate : 245 kb/s
      Channel(s) : 8 channels
      Channel layout : L
      Sampling rate : 48.0 kHz
      Frame rate : 50.000 FPS (960 SPF)
      Compression mode : Lossy
      Stream size : 229 MiB (10%)
      Writing library : opusenc from opus-tools 0.2-34-g98f3ddc
      Language : English
      Default : Yes
      Forced : No
      Comment : Processed by SoX
      ENCODER_OPTIONS : --bitrate 352 --comp 10 --framesize 20 --expect-loss 0 --max-delay 1000
  Audio #3
      ID : 3
      Format : Opus
      Codec ID : A_OPUS
      Duration : 2 h 10 min
      Bit rate : 239 kb/s
      Channel(s) : 6 channels
      Channel layout : L R C Ls Rs Cb LFE
      Sampling rate : 48.0 kHz
      Frame rate : 50.000 FPS (960 SPF)
      Compression mode : Lossy
      Delay relative to video : 11 ms
      Stream size : 223 MiB (10%)
      Writing library : opusenc from opus-tools 0.2-34-g98f3ddc
      Language : Hungarian
      Default : No
      Forced : No
      Comment : Processed by SoX
      ENCODER_OPTIONS : --bitrate 256 --comp 10 --framesize 20 --expect-loss 0 --max-delay 1000


And thats all.... ( At the moment, I'm away from my PC.)

No clue, can't reproduce the problem here.
Did two test encodes with 7.1 audio and the output plays fine, no stuttering.


Maybe try whether it makes a difference if you use 512 as bitrate.

Cu Selur

Thanks for the quick reply/test.

An "interesting/funny" fact : the mentioned .mkv plays fine even on a Samsung A25...
Investigating more....

Btw encoding @512 kbps : didnt tried,im on it.

What is the player&co setup that stutters? Does it support opus 7.1?

SOLVED !

I cant imagine how,but the players audio playback settings were changed. 
Everythings fine now! Banal. Damn.

Selur,many thanks for your efforts!

I'm happy you figured out what was causing the problem.


Cu Selur