Jump to content


Photo

DS916+ transcode buffer material acceleration ON/OFF questions

synology hardware acceleration material acceleration

Best Answer Luke , 14 May 2019 - 12:09 PM

Ok, if you want to avoid burning in PGS, then you'll need to play with an app that supports that subtitle format natively without transcoding.

 

That would include our Android apps, iOS app, and Emby Theater.

Go to the full post


  • Please log in to reply
6 replies to this topic

#1 yarez0 OFFLINE  

yarez0

    Member

  • Members
  • 26 posts
  • Local time: 04:32 AM

Posted 10 May 2019 - 11:03 AM

hi guys, 

 

I'm a user of plex and video station on synology, I'm testing emby and it works great ! I don't understand how video can stream without need of transcoding VS plex and emby but that not the point. 

 

during my tests, I purchased monthly premiere license to test material acceleration : a transcode consume 98% of my CPU, now with HA it consume 28%

 

but, I have now transcode buffer problem : 

  • without material acceleration, transcode buffered 10/15 seconds, the video can be streamed but CPU goes to 98%
  • with material acceleration, transcode buffered 3 seconds every 3 seconds so the video freezes every 2 seconds but CPU goes to 28/30%

 

I use a mkv file with pgs subs to do a stress test, I want to test emby in every case before buying a full premiere license for many users but if one user cause 90% of CPU, others cannot use it and my license is useless.

 

 

why material acceleration causes that ? emby plays transcoded temp files faster than ffmpeg created it. can someone explain me why and how to solve it please ? thank you

 

 

  • synology DS916+
  • DSM 6.2-23824 Update 6
  • Intel® Pentium® CPU  N3710  @ 1.60GHz
  • emby 4.1.1.0 synology package behind synology ngynx
  • chrome 74.0.3729.131 64 bits
  • volume : 4x SEAGATE ST2000DM006-2DM164 7,2k SHR RAID

 

here are my full logs hardware acceleration ON vs OFF

 

 

Attached Files



#2 d21mike OFFLINE  

d21mike

    Advanced Member

  • Members
  • 57 posts
  • Local time: 07:32 PM

Posted 10 May 2019 - 11:20 AM

I use both PLEX and EMBY.  I am not sure why you are having a problem with Hardware Transcoding but Transcoding is very CPU intensive.  Especially Software.  For me, I figured if I had to do transcoding than what I wanted to do would not work.  I have about 8 users that could be active at the same time.  I made sure that all of my users had set the clients to MAXIMUM Resolution and all of my streams use DIRECT PLAY (or whatever it is called).  My files are all MKV files as well.  The server will not transcode if the client is setup to handle it.  Most of my TV Clients use Apple TV 4 or 4K.  One was using XBOX  but now use ROKU 4K Stick (have not check to make sure he is setup correctly).



#3 d21mike OFFLINE  

d21mike

    Advanced Member

  • Members
  • 57 posts
  • Local time: 07:32 PM

Posted 10 May 2019 - 11:58 AM

I use both PLEX and EMBY.  I am not sure why you are having a problem with Hardware Transcoding but Transcoding is very CPU intensive.  Especially Software.  For me, I figured if I had to do transcoding than what I wanted to do would not work.  I have about 8 users that could be active at the same time.  I made sure that all of my users had set the clients to MAXIMUM Resolution and all of my streams use DIRECT PLAY (or whatever it is called).  My files are all MKV files as well.  The server will not transcode if the client is setup to handle it.  Most of my TV Clients use Apple TV 4 or 4K.  One was using XBOX  but now use ROKU 4K Stick (have not check to make sure he is setup correctly).

 

I just checked my Internet User that is using the New ROKU 4K Stick with "default" Plex Client Setting.  When he played a 1080p Movie it was transcoding from 1080p to 720p.  He then changed to Original on everything and then it was using Direct Streaming (almost no overhead on my Plex Server).  It was streaming at 5Mbps.  My uplink is 200Mbps so this is not very much on my end.



#4 yarez0 OFFLINE  

yarez0

    Member

  • Members
  • 26 posts
  • Local time: 04:32 AM

Posted 10 May 2019 - 05:24 PM

Let me clarify

My users don’t have huge internet connections, my syster for example bas 2 Mb internet. This is for her, my orher sister has 5 mb connection. If both of her connect at the same time my syno is out.

Most of my friends has fibre, up to 300 mb minimum, for those there is no problem, most of them has direct stream.

I want to know why, in case of hardware accelerarion, when transcode happens the read of temp file is faster than creation. Is this cpu (i don’t think so), ram (no), disk bandwith ? (Maybe). I’m an IT guy i try to understand, « pgs is a high process that need ressources » is not an answer to me, I need to understand what is this happening.

For pgs normally i extract pgs and convert to srt with ocr scan. In this particular case there is no transcode

#5 Luke OFFLINE  

Luke

    System Architect

  • Administrators
  • 128649 posts
  • Local time: 10:32 PM

Posted 11 May 2019 - 12:51 AM

@yarez0, the above example is doing a full video transcode because PGS subtitles are selected. Given that this is true, this is entirely normal:

 

 

 

emby plays transcoded temp files faster than ffmpeg created it.

 

Try selecting the SRT subtitles in the video player and then you should see much better performance from ffmpeg. Please let us know if this helps. Thanks.



#6 yarez0 OFFLINE  

yarez0

    Member

  • Members
  • 26 posts
  • Local time: 04:32 AM

Posted 14 May 2019 - 04:01 AM

Hi Luke, 

 

thanks, no problem with SRT, I know that PGS burn CPU in hell but I hoped there was a way to enjoy PGSSUB



#7 Luke OFFLINE  

Luke

    System Architect

  • Administrators
  • 128649 posts
  • Local time: 10:32 PM

Posted 14 May 2019 - 12:09 PM   Best Answer

Ok, if you want to avoid burning in PGS, then you'll need to play with an app that supports that subtitle format natively without transcoding.

 

That would include our Android apps, iOS app, and Emby Theater.


  • yarez0 likes this





Also tagged with one or more of these keywords: synology, hardware acceleration, material acceleration

0 user(s) are reading this topic

0 members, 0 guests, 0 anonymous users