Cypheros Transportstream Forum

English-speaking Support => Specific problems with recordings of satellite/cable receivers => Thema gestartet von: zeros am Dezember 10, 2019, 09:59:43

Titel: HD DVB Subtitles and enigma2 software
Beitrag von: zeros am Dezember 10, 2019, 09:59:43
Hi dear Cypheros!
I need your opinion as You're an expert on this.

The problem is, that on ETV DVB subtitles (one specific channel here in DVB-T2) are skipping with DVB-T2 external DVB - C/T2 tuner. I tried with different OpenPLi software, right now on the last version of the day. I think it's a Box mistake but not sure. Lunix3 - 4K and it's external DVB - C/T2 tuner.
The mistake is from me from the beginning, and I took it into research.
The leakage is that English is significantly spoken more when the subtitles are translating. Maybe the first sentence OK, the second stays, the third without subtitles, the fourth will be skipped, then on the same order etc.
I tried just in case also with the openatv to have a chance, how the situation on them, but the same thing happens with their software. The mistake is otherwise from a long time, and it could be box specific error.
Same mistake we also have with a few other TV models and Ariva box for example.
It's Đ•xternal DVB - C/T2 tuner.

If I record it and play it later with player from my hdd, then all OK! Do you have ideas to explain this and where is the mistake?

When you play this sample with Lunix, it's fine! But on the same time, when I recorded it, it show's on TV screen like I describe.
The exact the same concern with openatv. I tried with build openatv-6.3-lunix34k-20191204_usb

I'm not sure how many boxes get hit on that.

From TS Doctor about these subtitles, I will add the log as well:

3.
   stream_type              : 6 = ITU-T Rec. H.222.0 | ISO/IEC 13818-1 PES packets containing private data (Subtitle)
   elementary_pid           : 165 (00A5)
   ES_info_length           : 18

4.
   stream_type              : 6 = ITU-T Rec. H.222.0 | ISO/IEC 13818-1 PES packets containing private data (Subtitle)
   elementary_pid           : 166 (00A6)
   ES_info_length           : 18

5.
   stream_type              : 6 = ITU-T Rec. H.222.0 | ISO/IEC 13818-1 PES packets containing private data (Subtitle)
   elementary_pid           : 167 (00A7)
   ES_info_length           : 18

About from six sentences are with subtitles only one. Is there a buffer somewhere wrong, but then where, we try find the place. And why some of the boxes are OK (if they are, I'm not sure).
It looks in TV screen like

1 - sentence/phrase with subtitles, 2 - no subtitles, 3 - no subtitles, 4 - no subtitles, 5 - no subtitles, 6 - no subtitles, 7 - with subtitles, 8 - no subtitles, etc.

It means a lot of text without translation/subtitles. But when play the recorded file with player, all OK. So it just so, when directly from DVB-T2 tuner.
If I use a timeshift (have to set path for timeshift files, then just press pause button on the remote, wait 30 seconds and then press again pause or play.) then all fine!

One PLi team user find an important reverted commit on their Github:
https://github.com/OpenPLi/enigma2/commit/2a799739f44671caf6dfcfd01fa98a3ff9c85f80#diff-78e2fa7291d464f214cea43e65e918d5

Now I want your expert opinion. Maybe it's broadcaster fault? Can you guess something, after overreview my samples, which I send to your PM. Or do we need some extra code to solve this issue on enigma2? I'm just asking what you see.

Thanks in advanced!
Titel: Re: HD DVB Subtitles and enigma2 software
Beitrag von: Cypheros am Dezember 10, 2019, 16:53:37
The recording looks fine and subtitles are displayed correctly on most players (VLC,DVBViewer) I tested, even on a receiver with OpenPLi 7.1.

The problem is a new one, not identical with the problem discussed on Github. That problem is about incremental subtitles, where the subtitles growing in size, step by step.

The subtitles on ETV are complete lines. No idea yet, what is causing the problems.
Titel: Re: HD DVB Subtitles and enigma2 software
Beitrag von: zeros am Dezember 11, 2019, 16:20:18
Thank you very much for your valuable feedback. Weird is that it is one of the few channels, where the subtitles like this way. But it is our main (FTA) channel.

ZgemmaH7S and T2 Tuner - OK as users claim. At least with OpenATV 6.1, what he uses.
Also is OK with Vu+ Duo4K and DVB-T2.

I Googled about stream_type ITU-T Rec. H.222.0 and find this documentation:
https://www.itu.int/rec/dologin_pub.asp?lang=f&id=T-REC-H.222.0-201206-S!!PDF-E&type=items

Is this anything special, do you know? What part to start looking the mistake, I have no ideas. Anyway, thanks for your comments!
Titel: Re: HD DVB Subtitles and enigma2 software
Beitrag von: Cypheros am Dezember 12, 2019, 01:15:48
Oh yes, spent a lot of time, reading specs and standards the last years. I love it how simple things are described in the most complicated ways. But nevertheless, there is room for interpretations and often problems are caused by different interpretations of that documents.

Sadly, finding the source of such problems is taking a lot of time and at the moment I have not the time to look deeper into it. Maybe in January.
Titel: Re: HD DVB Subtitles and enigma2 software
Beitrag von: zeros am Dezember 12, 2019, 05:55:18
Buffering on page 28 (on the document, on which I referred)
2.4.2.6 Buffer management etc. I think the mistake it's over there somewhere. What can I try, is I'm adding the patch, which PLi turned back and will test how it affects. I'm also sure that it doesn t solve my issue, but it should change something there. If the error was on external DVB-T2 Tuner drivers, the recording would not be OK, is this correct, what do you think? On the other hand, since some of the boxes are okay, it can't be on enigma2 side. Anyway, I think the mistake is not complicated, but there must know a lot to find and correct it. Thank you for the testing you did.  :)
Titel: Re: HD DVB Subtitles and enigma2 software
Beitrag von: zeros am Dezember 12, 2019, 16:33:26
I found on the enigma2 code somthing like 8bit DVB subtitles, about what they say completely untested.
Can you confirm, what in my sample this subtitles are? I know they said they were called HD subtitles.

And I googled about 8bit subtitles:
https://www.etsi.org/deliver/etsi_en/300700_300799/300743/01.06.01_20/en_300743v010601a.pdf
And sorry, that I write it all here. Don't get very deep into it, I'll try to think more myself!
Titel: Re: HD DVB Subtitles and enigma2 software
Beitrag von: Cypheros am Dezember 12, 2019, 17:38:10
That are 4 bit bitmaps for a resolution of 1920x1080 pixels.

Check out DVBInspector from SourceForge. That tools can give you many details about the subtitle data structure of your recordings. But use it only on short recordings, it's slow, needs a huge amount of memory, it's Java  ;)

https://sourceforge.net/projects/dvbinspector/ (https://sourceforge.net/projects/dvbinspector/)

To get the subtitle details, select subtitle PID, use the right mouse botton and choose "Parse data".
Titel: Re: HD DVB Subtitles and enigma2 software
Beitrag von: zeros am Dezember 13, 2019, 12:46:48
Thanks for pointing it out!

https://www.etsi.org/deliver/etsi_en/300700_300799/300743/01.02.01_40/en_300743v010201o.pdf

I searched from this focument a phrase 'Pixel buffer memory'. Maybe something there is wrongly presented on enigma2. I will dig more. Anyway, I understand, that this 4 bit bitmaps for a resolution of 1920x1080 pixels is not very usual format.
I try to find the differences on these DVB subs, which are OK and on these, which are NOK. I think, the main difference is the resolution. But I need to make tests and it takes time.
Titel: Re: HD DVB Subtitles and enigma2 software
Beitrag von: zeros am Dezember 13, 2019, 16:12:04
I find this in enigma2 code (added screenshot). And as I can see from your screenshot, that my subtitles are exactly 'DVB subtitling EN 300 743'
So maybe this is the faulty place for me. OK, I will let it know to Pli team, let's see, what they think.
Titel: Re: HD DVB Subtitles and enigma2 software
Beitrag von: zeros am Dezember 14, 2019, 17:48:04
I got info, that the BBC (on 28.2E) uses 1920x1080 based DVB subtitles and the BBC subtitles on 28.2 don't work properly with enigma2 boxes. I can't control it myself, but we deal with the problem. I had a great help from this topic and thank you for answers!
Titel: Re: HD DVB Subtitles and enigma2 software
Beitrag von: Cypheros am Dezember 14, 2019, 23:24:30
VTI 14.0.5 (Enigma 2) on a VU+ Solo4K produced this subtitles for BBC One HD some seconds ago.

But your are right, there are some problems if it comes to live tv like a sport event, they have this special subtitles, where the subtitles are growing word by word and OpenATV 6.3 shows this staccato behaviour discussed on Github.
Titel: Re: HD DVB Subtitles and enigma2 software
Beitrag von: zeros am Dezember 15, 2019, 07:06:26
Thanks for Interesting information. If You can try, if you can just get recording it and then you'll play it again, then there's no mistake? You must wait for this show again. Anyway, we're on it.
Titel: Re: HD DVB Subtitles and enigma2 software
Beitrag von: Mam am Dezember 15, 2019, 09:05:05
may I kindly remember that Tool I've once made and offered here?
It collects all these single letter/words subs into ONE line and shows it for the whole period (from letter one to the end of the last letter/word) without any flicker.

I think it was called "BBC Killer"  8) but its so long ago already, I dont remember it completely.
Titel: Re: HD DVB Subtitles and enigma2 software
Beitrag von: zeros am Dezember 15, 2019, 14:01:43
Yes, I remember that, then, uh, that's what I remember, was a strange Not for me problem. Now it's directly touches me. If it's been corrected, it would be good if anyone else can test this English thing with enigma2, because I can't test it myself. I may let you know if the solution hopefully there. And on dreambox this error don't exist, as they probably fixed that enigma2 mistake on their closed sources.
Titel: Re: HD DVB Subtitles and enigma2 software
Beitrag von: zeros am Dezember 15, 2019, 19:15:30
Idea to Cypheros- if it would be possible to add to TS-Doctor to the log file for DVB-Subtitles to read the data_identifier and present it on the log file? It would simplify analysis a lot. In my case I would see then data_identifier: EN 300 743
But I think if it's not easy to do, then let it be.
Titel: Re: HD DVB Subtitles and enigma2 software
Beitrag von: zeros am Februar 21, 2020, 18:25:25
The Lunix3-4K problem is solved 100% with this:
Zitatqviart: update bsp
commit aaac331
Author: elminster <kamase79@daum.net>
Date: Mon Feb 3 15:46:20 2020 +0900

update driver for lunix3-4k subtitle issue
Thanks all involved!  :)
I tested with Estonian HD subtitles and develop image. ETV HD subtitles all OK now.