DS920+ low H265 / HEVC 4K transcoding rate on Windows Chrome

[YuanminWang 0]

Hi, 

This may have been brought up several times already but somehow I can't find a similar thread, but my apologies if this is repeative. 

I'm running Emby Sever (v. 4.6.4) using docker container on a Synology DS 920+, everything else seems to be great except that when I try to play a H265 / HEVC 4K movie on my Windows 10 laptop using Chrome, the transcoding rate is only 20ish, which leads to periodic freeze of playback. 

However, when I am using iOS Safari to connect to my server (even in 4G mobile network), the playback is no problem even with transcoding rate of over 35 (perhaps that has to do with lower resolution, i.e.: 1080p ?)

I have  attached a few screenshots to help better illustrate the problem.

Please feel free to let me know if anything else needed.

Thanks,

YM

 

This is playback stats on iOS

 

This is the summary of video

 

This is stats playing on Windows Chrome (local network)

 

[YuanminWang 0]

BTW I'm trying out Emby Premiere so currently using HW transcoding I believe, in all the cases mentioned above CPU usage rate is below 20%

[Carlo 4330]

Hi, If you go to logs menu you will see some logs that start with ffmpeg.

Try playing this back again causing a transcode. then upload the ffmpeg log which should be at the top of the list.

[YuanminWang 0]

Hi Cayars: thanks for the instruction, here's the ffmpeg log from the transcode playback, I let it go for 1~2 minutes, same low transcode rate, i.e.: 20ish issue.

ffmpeg-transcode-db27990f-c03d-4cd8-b140-bb3306796c65_1.txt

Thanks,

YM

Edited July 26, 2021 by YuanminWang

[Carlo 4330]

You're problem could be caused by the number of internal subtitles in this file.

As a test could you remux this file using a tool such as xmedia recode to remove all the subs (or leave 1) and then try playing again without the subtitle overhead?

[YuanminWang 0]

21 hours ago, cayars said:

You're problem could be caused by the number of internal subtitles in this file.

As a test could you remux this file using a tool such as xmedia recode to remove all the subs (or leave 1) and then try playing again without the subtitle overhead?

Hi Cayars, do you have guideline as in how to remove all the subs while keep everything else the same, that means keeping the h265/HEVC format (i guess ?) 

Thanks,

YM

[Carlo 4330]

This will take a bit of time to learn and configure correctly but is a great script to have in your pipeline to use before adding media to Emby.  It can do all kinds of things including removing tracks that are in languages you don't want to keep.  It can do things like create 2 channel audio tracks if not present and mark them as defaults to converting video to a specific format.

https://github.com/mdhiggins/sickbeard_mp4_automator

[YuanminWang 0]

Thanks cayars, I just decided to give up on watching HDR10 movie on browser, because the color tune is just not right, see below comparison: using Emby Server to decode vs. playing in an app (decode on the device) 

BTW, do we have plan to correct that in the future ? 

 

Playing in browser:

 

 

Playing in Emby Theater (or any other player applications)

 

YM

[Carlo 4330]

Hi, Can you play this again in the browser, then upload the ffmpeg it generated?

[YuanminWang 0]

16 hours ago, cayars said:

Hi, Can you play this again in the browser, then upload the ffmpeg it generated?

Hi Cayars: it should be the same log file i uploaded earlier, but nvm, here you go again:

ffmpeg-transcode-cf89f8a4-7af5-41a0-bb13-872ecc246701_1.txt

[Carlo 4330]

I'd bet it's because of all the subtitles embedded in this file.

Can you turn off this option Transcoding->Allow subtitle extraction on the fly

and then try playing back this file again with no subtitles selected so we can see how that goes as a test?

Upload new ffmpeg log.

[YuanminWang 0]

Hi Cayars, unfortunately the picture looks the same from playback, after turning off 'allow subtitle extraction on the fly' and subtitle.

Screenshot in below and ffmpeg log in attachment.

ffmpeg-transcode-78e1ea69-cc1f-4047-b745-ca98d30233ac_1.txt

 

[Carlo 4330]

While playing back click on the cog icon then go to quality setting and choose a 1080 resolution such as 30Mb and see what that does for you.

[Luke 37060]

Can you provide a log file from a transcoding session from ios safari to compare? Thanks.

[YuanminWang 0]

18 hours ago, cayars said:

While playing back click on the cog icon then go to quality setting and choose a 1080 resolution such as 30Mb and see what that does for you.

Hi, 

this playback is still with 'subtitle extraction on the fly' TURNED OFF, weirdly, under 1080 x 30mb, the rate is even lower:

ffmpeg-transcode-d67b5c20-b11a-47b2-ab29-7135c857edba_1.txt

[YuanminWang 0]

9 hours ago, Luke said:

Can you provide a log file from a transcoding session from ios safari to compare? Thanks.

Here's an FFMPEG log on iOS Safari playback, i don't know why but usage of RAM on my 920+ quickly went through the roof after a while...

From the task manager you will notice multiple FFMPEG process going on but there're really no session in play at this moment.

While you can also see from the 2nd screenshot there're multple playback starting from aroud that moment... i have attached all the logs as well as embyserver.txt for your reference.

This seems to be only an issue associated with iOS Safari ? 

 

Multiple_FFMPEG_Sessions.zip

[Carlo 4330]

1 hour ago, YuanminWang said:

Hi, 

this playback is still with 'subtitle extraction on the fly' TURNED OFF, weirdly, under 1080 x 30mb, the rate is even lower:

ffmpeg-transcode-d67b5c20-b11a-47b2-ab29-7135c857edba_1.txt 232 kB · 0 downloads

Could you try the next lower Quality setting?  Basically keep lowering it until the Stats for Nerds shows it plating at 1080 vs 4K resolution.  This may not help you but I found one file that would wash out like this at 4K but at 1080 seemed to come back to life color wise.

Is it possible to upload this file somewhere that would could download it to test with?

[YuanminWang 0]

On 30/07/2021 at 21:50, cayars said:

Could you try the next lower Quality setting?  Basically keep lowering it until the Stats for Nerds shows it plating at 1080 vs 4K resolution.  This may not help you but I found one file that would wash out like this at 4K but at 1080 seemed to come back to life color wise.

Is it possible to upload this file somewhere that would could download it to test with?

Thanks Cayars, the file is over 16GB in size, and I don't know how to cut it while retain the coding info, etc.

I think I tried lower resolution earlier but the picture is still washed-out, anyway let me confirm later.

[Carlo 4330]

No I'm talking about during playback in the OSD, click the cog icon then the quality menu and lower it there.

You can do this real-time while it's playing but there will likely be a slight delay with each change you make.

[YuanminWang 0]

8 hours ago, cayars said:

No I'm talking about during playback in the OSD, click the cog icon then the quality menu and lower it there.

You can do this real-time while it's playing but there will likely be a slight delay with each change you make.

I understand lowering resolution through the 'setting' icon during playback, i was referring to your 2nd comment on sharing the file for a more direct diagnositic.

Anyway, here's the screenshot and, as always, logs attached.

Under 1920x1080 x 15mbp/s the rate of transcoding is quite healthy, i.e.: 28 ~ 46

HOWEVER, if I dial up the bit-rate to 20mbp/s the transcoding FPS plumbered to 15~20... which is really strange

ffmpeg-transcode-92e2ef0c-058a-4ea6-a01f-cf58c4ba935d_1.txt

[Carlo 4330]

Got ya.  Do you know how to use ffmpeg from the command line?

if so I could give you a command line you could try that would generate a 2 or 3 minute version of this file.  You would then need to test the sample version to make sure it has the same issue.  But that would make it a lot smaller file to upload.

[YuanminWang 0]

30 minutes ago, cayars said:

Got ya.  Do you know how to use ffmpeg from the command line?

if so I could give you a command line you could try that would generate a 2 or 3 minute version of this file.  You would then need to test the sample version to make sure it has the same issue.  But that would make it a lot smaller file to upload.

Sure please share and I will try it out

[Carlo 4330]

Try this and let's see what you get

ffmpeg -i input.mkv -c copy -t 120 output.mkv

[YuanminWang 0]

On 03/08/2021 at 22:49, cayars said:

Try this and let's see what you get

ffmpeg -i input.mkv -c copy -t 120 output.mkv

120 sec produces over 200mb so i shortend it to 90 sec. 

I have tested it out with emby server and confirmed that the same issue persists, i.e.: washed-out picture, and slow transcode rate.

Thanks Cayars for your support and following this up for so long, i almost give it up.

YM

output.mkv

[Luke 37060]

The washed out colors are probably related to not having tone mapping enabled, right?