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UMS/PS4 issues

Posted: Fri Sep 08, 2017 6:54 am
by radamanthyspl
Hi guys, having trouble figuring out if it's PS4 media player changes or UMS bugs. It's been terrible for several weeks now.

One major issue is that videos played through PS4 tend to get choppy at times, not always the same moments, but surely the same files will play with errors. It feels like buffer is getting full, so pausing the video stops the problem for a few seconds but then it's stuttering again. Both picture and sound are affected (attaching trace log with the problem reproduced). Playing through a different player (Xbox one) is problem-free.

Also not sure why PS4 always picks up where I stopped watching, with no visible option to start from the begining (not possible through menu on PS4). Rewinding seems to bring me back to the moment where I stopped last time so it's as if UMS deliveres the resume-type file, but I have disabled resuming... Have I missed a setting? I vaguely remeber PS4 player gave the option to play/play from begining. Not anymore though. I would rather PS4 always started from the begining.

Last issue I had was with language subtitles preference. Despite having "force external" checked, UMS would give priority to Audio/subtitles language priority setting. In reality, even though I had the desired srt in place, UMS would read subtitles embedded in MKV first while ignoring srt. Is that by design? If so, seems counter-intuitive, I always have the srt I want, while subtitles emedded in MKV tend to get on my nerves as I struggle to switch them off :)

Any help appreciated.

Re: UMS/PS4 issues

Posted: Thu Sep 14, 2017 1:45 am
by Nadahar
I can't answer about resume or subtitle preferences, I haven't looked into that part of the code.

When it comes to the playback problems, there's been all kind of problems with the PS4 and it's very hard to actually know anything for sure without having one. But, from the behaviour you describe, it really sounds like you have bandwidth issues. Wifi networks are problematic because of their erratic behaviour and often high latency. It might be that the network connection between UMS and the PS4 is particularly bad (because of the PS4's location, the quality of its Wifi NIC or local radio noise from other devices).

If possible, I would try to connect UMS and the PS4 with a cable to see if that makes a difference. Other possible remedies is to turn on "automatic maximum bandwidth" (although I usually don't recommend it because it has its issues, it might be worth testing at least) or to manually limiting your maximum bandwidth. That will impact all renderers, not only your PS4 though. The result of bandwidth limiting is that UMS turns down the quality when transcoding so that the bitrate is lower. It will also transcode content that could otherwise be streamed if the bitrate is to high, so this isn't without its downsides - but you can't force more information through a network than it can carry :roll:

If you find a limitation that makes your PS4 work well, you could edit the "Sony-PlayStation4.conf" file and add a line with "MaxVideoBitrateMbps = " and the value in megabits per second. That way, the limitation would only apply to the PS4 and your other renderers wouldn't have to be affected.

Re: UMS/PS4 issues

Posted: Fri Sep 15, 2017 11:57 pm
by mik_s
i have found the the PS4 keeps an internal history of the last 20 or so files and if you play one of those that was stopped before the end it will automatically resume from the last point (i'm guessing its like like the go to option on ps3 but is automatic). however resuming a file from UMS that is not in the PS4 history for me makes UMS transcode the file starting from the last played point(and for some reason takes ages to get started).

the PS4 will read the subtitles in a MKV automatically and you can turn them off in the Closed Captions option in media player. to use other subtitles you will have to transcode the file as most MKV's are compatible with the PS4 so UMS will just stream them.

Re: UMS/PS4 issues

Posted: Sat Sep 30, 2017 1:56 am
by mik_s
i have found that if a file has forced embedded subtitles (like English for foreign speaking parts) it would cause ums to transcode the file instead of streaming it. after playing around with the config file i added -

SupportedExternalSubtitlesFormats = SUBRIP,ASS,TEXT,MICRODVD,WEBVTT,SAMI
SupportedInternalSubtitlesFormats = SUBRIP,ASS,TEXT,MICRODVD,WEBVTT,SAMI

which stopped unnecessary transcoding and let the PS4 handle the subs.(not sure which formats are supported as don't have enough to test with so added all).
unfortunately PS4 Media player does not support more than one subtitle per file so if you need any other you will have to transcode.

i also found that the PS4 supports streaming external subtitles too, not sure what gets priority if it has external and internal subs though.

maybe it is possible to have an option for UMS to create a virtual files for renderers that only support one subtitle to allow access to others without transcoding. ripping the subtitle stream and then streaming it as an external sub file like -
film - Original file
film (S) - External Subtitle
film (S.i Eng) - Internal Subtitle Eng etc

Re: UMS/PS4 issues

Posted: Mon Oct 02, 2017 7:54 am
by Nadahar
All this is already there if you use the "TRANSCODE" folder. In there, you can find all combinations of transcoding engines (or no transcoding) and audio and subtitle tracks.

Re: UMS/PS4 issues

Posted: Mon Oct 02, 2017 1:58 pm
by Madoka
The PS4 can do internal and external .srt subs. I can read internal .ass subs but strips all formatting away, so they become basic text subs. It cannot handle external .ass subs.