Channels DVR iOS App and VPN fails

masterakk · May 6, 2020, 1:53pm

Hi, here in Finland we have DVB subtitles in DVB streams and they are working nicely when iPhone (or AppleTV) is used in home network. But remote connection with iPhone does not display subtitles because transcoding does not add them to remote stream (why?).

I'm trying to solve this by VPN connection (L2TP) to my DVR Server computer (macOS) and using iOS App through that. VPN connection is created correctly and I'm able to do everything else but watch recordings with subtitles. I noticed, that this happens when I use cellular network (4G) in iPhone and create VPN tunnel through it. It always uses remote connection (which transcodes) and does not find DVR even if trying to connect to it by "At home" connection option. iPhone gets IP -address of my home network when VPN is active and I have specified that all traffic should go through VPN.

But, if I have connected iPhone to some other network with Wifi and create VPN tunnel from it to home network, everything works perfectly. IOS App is able to display subtitles just fine and DVR is found automatically (with Bonjour or previously given IP-address or from the same computer, I don't know).

Why is VPN from 4G cellular network not working the same way as from other Wifi network in iOS App? In both cases iPhone gets the same local IP-address, DNS server is the same and everything else seems to be the same way. By comparison, Plex App is able to find Plex Server with both of the cases and display subtitles in recordings (those few ones that succeeded in period of two years

Other thing: Why not allow streaming with Original quality in cellular network and not transcode every time? Shouldn't that solve this subtitle problem?

eric · May 7, 2020, 6:55pm

That sounds really complicated. Would you be able to put a recording of something with the DVB subtitles somewhere and email a link to [email protected] so we can play with fixing the transcoder to make it work properly?

racameron · May 7, 2020, 7:09pm

What about something like:

… -map 0:s -c:s copy …

That way all subtitle tracks in the source stream will be copied straight over, without any need to re-encode.

eric · May 7, 2020, 7:41pm

That was definitely what I was looking at. It would just be easier to have an example to work with to ensure that everything works as expected.

masterakk · May 8, 2020, 7:10am

Email with links to examples sent.

eric · May 19, 2020, 11:50pm

Having these example files has been very helpful. I was able to make some changes that have allowed us to pass the DVB subtitles along to our client apps over HLS. This is not compliant with the HLS spec, so it won't be sent to browsers, but this is a big step forward for the client apps.

I did notice there was a different strange issue with the Muumilaakso episode that caused the transcoder to hang forever and not make any progress. We haven't been able to identify what the issue is there, but the Hercule Poirot did play over HLS properly.

Please press-and-hold on the Check For Updates button in the Settings page of your DVR to update to the latest pre-release to check it out and let us know how it works for you.