Transcoding Questions

[Spyderturbo007 19]

I have a few questions about transcoding.  I recently installed a Quadro P620 so my server is doing hardware transcoding.

1. Is there a reason the bitrate doesn't seem to get close to a remote user's max setting?  For example, if I have a user set at 5Mbps and they start watching a 4K movie that gets transcoded, it shows about 2 - 2.5Mpbs on their side.  I've never seen it get close to their maximum.

2. Is there a way to set a transcoding buffer?  With the Quadro running at 450+fps for some files, I thought there might be a setting for "Only transcode X minutes of the movie ahead" and then it would wait until there was a Y minutes of buffer left before it went back and transcoded X more minutes.  That way the video card isn't going full throttle transcoding a 2h movie only to have the user stop watching after 30 minutes.

I'm trying to give my family members that access my server the best possibly quality with the lightest load on my server.

Thanks!

[Happy2Play 9783]

5 minutes ago, Spyderturbo007 said:

2. Is there a way to set a transcoding buffer?  With the Quadro running at 450+fps for some files, I thought there might be a setting for "Only transcode X minutes of the movie ahead" and then it would wait until there was a Y minutes of buffer left before it went back and transcoded X more minutes.  That way the video card isn't going full throttle transcoding a 2h movie only to have the user stop watching after 30 minutes.

Have you Enabled throttling on the transcoding page?  I believe by default it stays about 2 minutes ahead.

Enable throttling
Emby will dynamically adjust transcoding speed based in order to reduce CPU utilization.

As for the first issue you will probably need to post the server and ffmpeg log for a specific example.

[Spyderturbo007 19]

13 hours ago, Happy2Play said:

Have you Enabled throttling on the transcoding page?  I believe by default it stays about 2 minutes ahead.

Enable throttling
Emby will dynamically adjust transcoding speed based in order to reduce CPU utilization.

As for the first issue you will probably need to post the server and ffmpeg log for a specific example.

I did not.  It said CPU utilization, so I assumed it didn't apply to GPU use.

I'll get a log and post back the next time I see it happening.

[Luke 42083]

@Spyderturbo007 it's actually not related to throttling. We pass in the max value to the encoder for for some reason some encoders such as libx264 will often encode much lower than that.

You can get closer by lowering the server transcoding crf setting but of course there are drawbacks to that as well.