29 replies to this topic

[groovyclam]

Hi I have DVB-T transport steam recordings from UK DVB-T with DVB subtitles in the stream.

I can play the files back in VLC and turn on the DVB subtitles and they show up ok.

If I try to play them in ZoomPlayer Pro then the video/audio is fine but I can't get the DVB subtites to show.

If I right click the playing video and choose "Stream Selection" under subtitles there is both "Disabled" and "English [eng] (dvbsub)" but if I tick the "English [eng] (dvbsub)" option to on the subtitles still don't show up.

What am I doing wrong ?

My splitter is LAVFilter - have I got that set up wrong ?

[ehathgepiurhe]

Hi groovyclam,

LAV does support DVB - nev (LAV's developer) has a basic DVB setup himself and I know of a few others over on Doom9 who also use DVB with LAV and provide feedback to nev on how it works. Silly question probably - are DVB files able to be saved to a hard drive, or are they streaming only? If possible, I'd like to get a sample of a DVB clip and test it on my system (I don't have a DVB setup myself).

The thing you could immediately try is to change the subtitle renderer - by default, Zoom uses DirectVobSub, but it also supports ffdshow. Select whichever one you aren't using in Advanced Options-->Playback-->Video-->Subtitles and see if that helps (restart of Zoom required after you change the subtitle renderer).

ehat

Edit: I answered my own question - yes, DVB files can be saved. I found a test clip with subtitles here:
https://bugs.launchp...-tv/ bug/624781 (the first post has the link)

On my system, I see no subtitles either with that clip, despite my best attempts to get Zoom to do so (tried both DirectVobSub and ffdshow). MPC-HC shows the subtitles fine. Logged #310 into the bug tracker for the dev's to look at.

Edited by ehathgepiurhe, 23 July 2012 - 10:49 AM.

[SimonP]

This is a long-standing problem that has never been fixed - Zoom hasn't been able to display DVB-Sub subtitles in UK .ts recordings for as long as I've been using it.

Here is a 10MB sample UK DVB recording with subtitles that show in most players except ZP - https://rapidshare.c...sync_example.ts (originally used for a problem with another player but it was online and handy...)

That file is odd, Ehat, it's .mpeg which doesn't officially support subtitles and they don't show in VLC so don't go by that one, they must only work in the player they're talking about (Nebula used to do something similar with their DigiTV software).

[groovyclam]

Thanks for the replies - even though it is bad news.

I have been investigating further about DirectShow filters using GraphEdit - the LAV Splitter *will* accept a UK DVB-T .ts file and split it correctly into a video, an audio and a subtitle stream.

The FFDShow subtitle DirectShow filter *wont* connect to the LAV Splitter subtitle output though.

The DirectVobSub filter *will* connect to the LAV Splitter subtitle output ( hence it shows up in ZoomPlayer's right click "Stream Selection" ) but must not be able to work out what to do with the DVB-T subtitle info.

I have noticed that Microsoft's Windows Media Center and MediaPortal both have their own DirectShow filters for decoding subtitles which may be of use but I think ZoomPlayer would need altering to include activating either of these filters in it's Options/Playback/Video/Subtitles setting page. ( Also I have no idea if these two filters would work or fail - but both the MediaPortal and Media Center apps can show DVB-T subtitles ).

Another way forward would be to persuade the DirectVobSub developer to make that filter be able to handle DVB subtitles. Is DirectVobSub still developed ?

[ehathgepiurhe]

That file is odd, Ehat, it's .mpeg which doesn't officially support subtitles and they don't show in VLC so don't go by that one, they must only work in the player they're talking about (Nebula used to do something similar with their DigiTV software).

Yes, thanks for the new sample. I've added a link into the tracker report for it, and have suggested the dev's use it instead of the MPEG sample that I found.

Another way forward would be to persuade the DirectVobSub developer to make that filter be able to handle DVB subtitles. Is DirectVobSub still developed ?

Yes it is - sort of. The original DirectVobSub is no longer developed, but there is a fork called 'xy-vsfilter' (which is under active development) which replaces the vsfilter.dll of DirectVobSub. Install Center actually uses xy-vsfilter instead of the original DirectVobSub:
http://code.google.com/p/xy-vsfilter/

There is a request in with the Zoom dev's to update Zoom to the current release of xy-vsfilter, 3.0.0.53 (Install Center is on 3.0.0.8). I've just tried that version - and it doesn't fix this issue sadly (I was hoping that it would). It would probably be worth posting this to the xy-vsfilter issues tracker as well, just in case. The link for that given in the xy-vsfilter release notes is:
http://code.google.c...er/issues/entry

ehat

[groovyclam]

I've done a bit more graph investigation - the only two filesource/splitters that split a UK DVB-T file into an audio, video AND subtitle stream are LAV and Gabest. Both of these *will* connect the subtitle stream to VSFilter.

However in Zoom's reported graph both of these filters give a subtitle output pin of:

Major Type: UnKnown {E487EB08-6B26-4BE9-9DD3-993434D313FD} - Sub Type: UnKnown {34FFCBC3-D5B3-4171-9002-D4C60301697F} Format: Unknown

I am getting out of my knowledge depth now, but I wonder if those reported "unknowns" above need fixing and then VSFilter might be able to do it's job with the data ?

Or... are the "unknowns" irrelevant and VSFilter just needs updating to recognise and handle the UK DVB-T subtitle data it is being passed ?

Can anyone clued up on DirectShow filters comment whether the "Unknowns" are important/need fixing or is it just a case of VSFilter needs fixing ?

( All the above was using the xy-VSFilter v3.0.0.53 you mentioned. )

------

Other observations:

1) Zoom can use MediaPortal's file splitter and it DOES produce the 3 output pins of audio, video and subtitle when given a UK DVB-T file BUT then the subtitle pin won't attach to either VSFilter nor FFDShow ( but MediaPortal installs a directshow filter called "MediaPortal DVBSub2" - maybe if Zoom adds this filter to the subtitle configuration screen it might also be a way forward. )

2) MS Media Center on Win7 has directshow filters of "Microsoft TV Captions Decoder" and "Microsoft TV Subtitles Decoder" - again, maybe if Zoom had these as options on the subtitle config screen it might solve the problem.

[ehathgepiurhe]

Major Type: UnKnown {E487EB08-6B26-4BE9-9DD3-993434D313FD} - Sub Type: UnKnown {34FFCBC3-D5B3-4171-9002-D4C60301697F} Format: Unknown

Yes - I saw those GUID's in the graph as well. Googling them produces nothing really concrete sadly. I've pretty much reached the extent of my knowledge in this particular area as well. I did play around with the test file in GraphStudio - and I was not able to get those subtitles to display. That is outside of Zoom - so I'm not sure if Zoom is the problem or not. I'm thinking at the moment that the issue is with DirectVobSub, and that is where it has to be fixed though. And why ffdshow does not accept the subtitle stream at all - I have no idea. Hopefully the dev's will be able to give us some guidance when they look at the bug report.

ehat

[ehathgepiurhe]

Ok, the Zoom dev's have looked at the issue and can't tell if the issue is with the splitter, or xy-vsfilter. Accordingly, I've opened a ticket on the xy-vsfilter tracker:
http://code.google.c...s/detail?id=108

ehat

[groovyclam]

Many thanks for that ehat - would you be so kind as to post any news from the xy-vsfilter team about the issue to this thread ?

If it helps the xy-vsfilter team, I have found that VLC and MPC-HC will show UK DVB-T subtitles properly from a UK DVB-T .ts recording ( but I think that those apps render the subtitles internally rather than use DirectShow filters ).

[ehathgepiurhe]

Yes, I will post back with any news for the xy-vsfilter people. My understanding is that yes, both VLC and MPC-HC have internal subtitles filters. At least in MPC-HC, you can disable the internal filter and use an external filter, but the internal filter is enabled by default, so you have to actively do this after you have installed it - otherwise it will use the internal filter. I haven't had a great deal to do with VLC, so I am unaware if you can disable its subtitle filter or not - last time I went through the VLC options, I didn't see any place that you could enable external filters, but I may just have missed it. VLC isn't something I've used a great deal of - I used to have it installed to play clips that Zoom could not play, but now I have MPC-HC installed for that same purpose.

ehat

[groovyclam]

I should also say that I can supply many examples of UK DVB-T MPEG2 transport stream recordings for any testing any development team requires, if requested.

[ehathgepiurhe]

Heh - got a response already

Please report this to the MPC-HC project as well, since they are the maintainer of the DVB & PGS rendering code we're using.

It appears they made some changes in the last few months which allow DVB subtitles to display with VSFilter 2.41 on that sample, but the rendering is messed up with YV12 (see attached image of VSFilter 2.41 r5672 + LAV Splitter). Only the MPC-HC ISR seems to display them correctly.

Once the MPC-HC project fixes this issue, we'll merge in the changes. I'll pass it along to our dev as well, but unless it's something trivial, all we can do is wait.

I will pass this onto the Zoom dev's and see where we go from here. Essentially it is saying that the MPC-HC internal sub renderer shows them correctly, but the MPC-HC maintained xy-vsfilter doesn't show them correctly in YV12. They also say that as their code is based on the MPC-HC code, it needs to be fixed upstream before they can merge the changes into their version.

As a note, I believe MPC-HC's xy-vsfilter is based on DirectVobSub 2.41, whereas xy-vsfilter is based on DirectVobSUb v2.39. See the following link for a brief discussion that someone had recently with the Zoom dev's regarding this very thing:
http://www.facebook....153702108100093

I tested Zoom with the test clip SimonP uploaded, using XhmikosR's 26 July build of DirectVobSub - which is the v2.41 variant. Subtitles now display in Zoom for the file - but they are a bit wonky.
http://img194.images...84/snap046p.png

Interestingly, that matches the screenshot of MPC-HC shown in the xy-vsfilter bug report.

The MPEG test clips I found still don't work - though I'm not particularly worried about these as I'm not convinced these are valid clips. The first one does not show the subs at all. The second only shows the audio in the stream selection menu - no subs entries.

ehat

[groovyclam]

Wow - that is excellent news. I am optimistic for a solution soon then ( as long as the MPC-HC developers care enough to squash the bug quickly ).

Thanks ehat - you have been very helpful and also explained the issues well.

I'll try the XhmikosR's 26 July build of DirectVobSub you mention - even wonky subs are better than none for me at the moment.

Cheers.

Please post again here if we get a fixed version of MPC-HC/xy-vsfilter.

[ehathgepiurhe]

I've logged a ticket into the MPC-HC tracker:
https://sourceforge....-hc/ticket/2516

We will see what the response is!

ehat

[groovyclam]

I've tried XhmikosR's 26 July build of DirectVobSub from http://xhmikosr.1f0...._apps/vsfilter/ (x86 version ) - I'm on 32bit WinXP

But am not seeing wonky subs - what splitter, video decoder and renderer are you using on the file ?

Or do I need to register the xy-vsfilter over the top of that installation ?

[ehathgepiurhe]

I sort of did things in a bit of an odd way - I manually unregistered (regsvr32 /u vsfilter.dll) the vsfilter.dll installed by Install Center, made a backup copy of it, then copied across the new vsfilter.dll from XhmikosR's build (I obtained this from the installer by running it with the /dir and /noicons parameters). I then registered that new vsfilter.dll manually (regsvr32 vsfilter.dll). All this with Zoom closed of course. I then ran Zoom with that test clip. The subs weren't automatically selected - I had to select them from the streams sub-menu. I think also that I found that if I paused Zoom and then selected the subs, it was more likely to work than if I did that with Zoom not paused.

There is another way to install the new build, and that is what I'd recommend - don't do it the way I did it:
1. Open Install Center, tick DirectVobSub and click Uninstall.
2. Once Install Center uninstalls it, check that the DirectVobSub folder in Program Files has been removed (Program Files x86 on Windows 64bit). Delete it manually if it still exists - if you get a 'file in use' (or similar error), see the next step.
3. Reboot your PC. If that DirectVobSub folder was not deleted in step #2, delete it after your PC reboots.
4. Upon rebooting, run XhmikosR's installer. Once that installer completes, the new vsfilter.dll should be registered.
5. At this point try the files again. If that doesn't work, post one of your sample files and I will take a look at it and see if I can get it to work with the new vsfilter.dll on my system.

ehat

[ehathgepiurhe]

There's been some discussion in the MPC-HC bug report - the discussion seems to be focusing on whether the anamorphic test clip is part of the problem. Would anyone have any non-anamorphic sample clips they could provide?

Your intuition might be correct, not sure if we can get a non-anamorphic sample to test that.

From the following, it seems the subs may render correctly - position wise anyway - with some resizing:

If I resize the video from 544x576 to 1024x576 in FFDShow, VSFilter 2.41 renders correctly to the 1024x576 frame.

ehat

[groovyclam]

I'll record some samples from various UK TV channels today and get back when I have uploaded them.

However - some UK channels ( not all ) do broadcast at stupid resolutions such as 544x576 and ultimately the solution should be able to cope with that.

[groovyclam]

Ok I've recorded five different UK TV channels' transport streams and put them up for download here:

https://skydrive.liv...AP8sQHM91yd0SpA

Only one ( the BBC2 stream ) broadcasts at standard DVD 720x576 resolution - only the various BBC channels in the UK broadcast at 720x576. Most other UK channels broadcast at either 704x576 or 544x576 in order to save bandwidth transmission costs. I therefore think that a final solution needs to fix the subtitling placement for any broadcast resolution.

Note also that the UK now has four HiDef DVB-T2 channels that broadcast 1080i with h.264 compression and carry the same DVB subtitles ( but I don't have the equipment to capture DVB-T2 streams on my PC )

In terms of which stream is a good example I would say that an advert for "EDF Energy" at 14 seconds into the samples called "UK DVB-T sample as broadcast (ITV2 - 704x576)" is a good example because it illustrates the ability of UK DVB subtitles to:
1) appear at different specified points on screen
2) have different font colour changes within a subtitle
3) have different font background colours ( not just black )

For comparison MPC-HC media player can play these samples and render the UK DVB subtitles correctly.

[ehathgepiurhe]

Thanks groovyclam - I've pasted your SkyDrive link into the MPC-HC bug report, and have also linked to your post giving some more information on the recordings.

ehat