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Opendigitalradio / dablin

DAB/DAB+ receiver for Linux (including ETI-NI and EDI AF playback)
GNU General Public License v3.0
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Slides from RAI not displayed - Subdir #28

Closed andimik closed 7 years ago

andimik commented 7 years ago

See eti-file in https://github.com/AlbrechtL/welle.io/issues/109

Also dablin_gtk does not display the slides.

basicmaster commented 7 years ago

Thanks for the info and the dump!

Also dablin_gtk does not display the slides.

As welle.io uses DABlin's PAD processing, this makes sense ;-)

That path you mention is not the reason; it is just a string that is used to identify a slide - it may be more or less everything and DABlin just shows it, without any processing.

After analysing the dump and especially Radio 1, two problems result:

Non-conformant PAD encoding

The broadcasted PAD here is not conformant. The reason is that the payload length of the respective element in AAC that contains the PAD data does not match the length of the actual PAD payload. ETSI TS 102 563 requires decoders to discard such PAD (see the very last sentence in chapter 5)!

You are able to see this when you select in XPADxpert e.g. DAB+ AU number 2 of Radio 1 - the raw hex view shows many zeros. These zeros fill up that length difference.

This is unfortunately a known problem of the DAB solution of a specific manufacturer; I will investigate if there has been any progress on fixing that in the meantime.

I will think about a solution here.

PNG as JPEG

Another issue is that all slides are announced as JPEGs. However some slides are PNGs. In this case DABlin won't display them, as the specific image renderer expects a JPEG file (XPADxpert shows them, as a generic image renderer is used).

This is also a bug on the broadcaster's side. I will try to contact RAI to get this fixed. Possibly this results from the DAB solution as well...

andimik commented 7 years ago

I knew you are an expert, and I really underestimated you ;-)

As we are all speaking German I would say: Ein herzliches Dankeschön. Ein Bier steht, falls wir uns je persönlich kennenlernen.

basicmaster commented 7 years ago

Gerne ;-)

Contacting the relevant RAI engineers a question arises: From which transmitter (or at least which region) did you receive that mux on 12D?

andimik commented 7 years ago

He is very funny. As far as I know there are only 2 RAI multiplexes operating in whole Italy, one in Trentino Alto Adige (4 transmitters) and the rest has the same content.

And to find out from where this 12D was received it is not difficult as I am from Austria. It is Monte Venda, received on Dobratsch mountain (not far away from the ORS transmitter). Venice transmitter is too weak and Piancavallo does not send northwards. These are the only 3 transmitters for 12D.

http://www.fmlist.org/sendertabelle/dab-ww_more.php?inputLand=I&inputEn=5001

Whereas the power of Monte Venda is much more in reality. I heard 25 kW.

BTW Even after changing the content in June RAI forgot to change the path to these slides. FD5 is no more existing ;-)

basicmaster commented 7 years ago

@andimik The question arised because I had to ask another person to get the correct contact person at RAI.

Nevertheless I just added a "loose" mode to dablin_gtk that can be enabled by -L to tolerate such non-conformant encoding. As DABlin aims to follow the specs as far as possible, this behaviour is not enabled by default.

@AlbrechtL You might want to enable that loose mode for welle.io by default for the convenience of your users ;-)

AlbrechtL commented 7 years ago

@basicmaster I integrated your X-PAD code with enabled loose mode (https://github.com/AlbrechtL/welle.io/commit/ef3b61f5b3f295237aa56def26b2790e24d49391).

Works great! Thanks!

basicmaster commented 7 years ago

@AlbrechtL I'm glad to hear that! :-)

@andimik As the problem is solved for dablin_gtk (somehow), I close for now. I will inform you via e-mail when I get news regarding RAI; currently I'm still waiting for the answer of my contact person.

andimik commented 6 years ago

Yesterday I found a (very unusual) place 5 km from my home where I could receive the RAI mux error-free even with my Airspy in my car ... (so no more need to drive 1 h to catch it on the mountains and hope the battery will last after a 30 min walk).

They are still using the same config. Even RaiTuttaItaliana has Light Classical as PTY ...

rai.txt

rai_12d_2018-02-19_1926_short.eti.zip which is 1 min 38 sec long

Try Radio1:

(dablin_gtk:5932): glibmm-CRITICAL **: unhandled exception (type Glib::Error) in signal handler: domain: gdk-pixbuf-error-quark code : 0 what : Error interpreting JPEG image file (Not a JPEG file: starts with 0x89 0x50)

basicmaster commented 6 years ago

OK, thanks for the new dump. I will ask the contact person about the progress.