412 replies to this topic

[dolphs]

Hi - After quicky browsing thru this wiki I was just wondering if it is possible to use your enigma2 receiver for DAB(+) reception.

Maybe even with a DVB-T2 tuner on which you hook up a DVB-T2 antenna that is also capable of receiving DAB signals?

 

[WanWizard]

Afaik you can't do it with a regular DVB-T tuner. But there seem to be USB tuners that are capable, and people have been looking at it. Search for rtl_sdr.

[littlesat]

You have dab+ sticks that offer mp3 files as stream. I don’t have one, but this might work right a way.

[amigo]

yep with a simple DVB-t tuner/antenne on your usb. Scan on DVB-t tuner to make list. 

[dolphs]

was ​more thinking if a combo antenna, like sv 9323, can be hooked up to a DVB-T2/C tuner so in theory you should be able to scan fpr both DAB(+) and DVB-T(2).

not sure though how that can be combined though 

[Erik Slagter]

This has been discussed before. It may work on a PC, but really not on a STB.

[WanWizard]

DAB and DVB-T are in completely different bands (220Mhz vs 570Mhz+), so first you need a tuner that is able to tune this range. Once tuned, you get a digital stream you need to demultiplex. The SoC can't do it afaik, so you need to be able to pull the complete raw data stream into userspace, and demux it in software (this is doable, and what the https://www.rtl-sdr.com software does. Once you have the required channel from the demuxed stream, you can feed it back in (like you do with a recording), which is also technically possible.

 

So, the first challenge is to make the tuner tune. If I look at the specs of the VU+ DVB-T2 tuner, that should be possible:

VHF channels: 2-12 (49 ... 230 MHz)
UHF channels: 21-69 (470 ... 861 MHz)

as DAB is within the VHF range.

 

I think (the first) main challenge is to get access to the data. I think no current driver supports this, and without that, I don't give you a lot of chance for success. The rtl_sdr project works around that by directly accessing the I/O of the USB chip in their own drrver. So in short, I think you need driver support from the manufacturer for this, and chances are that is not going to happen without hardware demux support.

 

ETSI DAB spec: http://www.etsi.org/...401v010401o.pdf

ETSI DAB+ spec: http://www.etsi.org/...563v010201p.pdf

[athoik]

The rtlsdr is capable to do that.

We already created a plugin that uses fm/am band.

https://github.com/satdreamgr/SDGRadio

We can create a servicedab that will use available dab libraries and the sound can feed directly the audio0.

https://github.com/J...ijk/dab-cmdline
https://github.com/A...tl_dab_streamer
https://sdr.kt.agh.e...sdrdab-decoder/

[Erik Slagter]

But first you need to have the code that tricks the DVB-T device into receiving DAB. When you have that, you'll need to have some compatible audio stream, like mp2, mp3, ac3 or aac. If all of these are met, you might start feeding the audio device, but you'll need to have some code to activate the audio device as input.

[dolphs]

So ​it appears my thoughts were not that bad, theoretically it is possible but it requires lots of development/ driver "tuning" to get this going and most likely even support of manufacturer - thanks all for clarification!

[WanWizard]

But first you need to have the code that tricks the DVB-T device into receiving DAB. When you have that, you'll need to have some compatible audio stream, like mp2, mp3, ac3 or aac. If all of these are met, you might start feeding the audio device, but you'll need to have some code to activate the audio device as input.

 

Correct. The rtlsdr library solves this issue by doing this all itself, in userspace, and talk dicectly with the Realtek DVB-T chip. To do this on the box, it needs support from the manufacturer in the driver.

[Rob van der Does]

If the manufacturer would understand the value of receiving DAB(+) for their clients, I'm sure he would at least have a look at the amount of work/cost involved.

Seems to me that "DAB+ compatible" on the box would be a good sales argument !

[athoik]

I guess we need to "ping" some manufactures and see what we can do officially.

The DAB/DAB+ can be just another service (like servicedvb), if the demodulation is happening on the tuner, the scanning should offer channels to the users (available on the channel list).

Tuning to a channel and then the stream will simply feed the audio decoder with the appropriate bypass (mp2 or aac or dd+).

Some kind of filtering is required also, since each TP can carry several radios.

That's the theory...

The practice is much harder, but the first step is to get manufacturers working on this.

Personally talking, I prefer having DAB/DAB+ more than having the crappy Kodi.. Whoever want's Kodi can buy a cheap Android box, it always beats our E2 implementations,

[zeros]

Look at here:
http://support.sundt...p3&topic=2115.0

[WanWizard]

For Sundek, the same applies as for rtl_sdr, their driver runs in userspace and accesses the hardware directly.

[athoik]

BTW, I was able to compile example-3 from dab-cmdline.

Unfortunatelly in Greece there is not active DAB/DAB+ broadcast (tried all band III frequencies)

# dab-rtlsdr-3 -C 5A
dab_cmdline V 1.0alfa,
                          Copyright 2017 J van Katwijk, Lazy Chair Computing
opt = C
going for rtlsdr 174928000 35
OK, functions seem to be loaded
Found Rafael Micro R820T tuner
[R82XX] PLL not locked!
samplerate set to 2048000
Supported gain values (29): 0.0 0.9 1.4 2.7 3.7 7.7 8.7 12.5 14.4 15.7 16.6 19.7 20.7 22.9 25.4 28.0 29.7 32.8 33.8 36.4 37.2 38.6 40.2 42.1 43.4 43.9 44.5 48.0 49.6
effective gain: index 10, gain 166
ofdm word gestart
There does not seem to be a DAB signal here
ofdmProcessor is shutting down

Unfortunately also raw files do not work, so I contact dab-cmdline author (https://github.com/J...dline/issues/19) and hopefully he will add support for raw files.

I can continue experiment once implemented



Band III frequencies:

5A 174.928 MHz
5B 176.640 MHz
5C 178.352 MHz
5D 180.064 MHz
6A 181.936 MHz
6B 183.648 MHz
6C 185.360 MHz
6D 187.072 MHz
7A 188.928 MHz
7B 190.640 MHz
7C 192.352 MHz
7D 194.064 MHz
8A 195.936 MHz
8B 197.648 MHz
8C 199.360 MHz
8D 201.072 MHz
9A 202.928 MHz
9B 204.640 MHz
9C 206.352 MHz
9D 208.064 MHz
10A 209.936 MHz
10B 211.648 MHz
10C 213.360 MHz
10D 215.072 MHz
10N 210.096 MHz
11A 216.928 MHz
11B 218.640 MHz
11C 220.352 MHz
11D 222.064 MHz
11N 217.088 MHz
12A 223.936 MHz
12B 225.648 MHz
12C 227.360 MHz
12D 229.072 MHz
12N 224.096 MHz
13A 230.784 MHz
13B 232.496 MHz
13C 234.208 MHz
13D 235.776 MHz
13E 237.488 MHz
13F 239.200 MHz

[Abu Baniaz]

If you want to test, I have a Sundtek ad we have DAB in the UK

[athoik]

Sundek, are doing great job, I am sure.

Although I prefer playing with opensource projects.

If you have an rtl-sdr USB stick, then we can test it.

[athoik]

I was able to play|back my first DAB+ radio on receiver

# dab-raw-3 -F ./antena-1_dab_229072kHz_fs2048kHz_gain42_1_long.raw -P "Radio Rytm"  | gst-launch-1.0 fdsrc ! audio/x-raw, format=S16LE, channels=2, layout=interleaved, rate=48000 ! dvbau
diosink
dab_cmdline V 1.0alfa,
                          Copyright 2017 J van Katwijk, Lazy Chair Computing
opt = F
opt = P
Setting pipeline to PAUSED ...
Pipeline is PREROLLED ...
Setting pipeline to PLAYING ...
New clock: GstSystemClock
ofdm word gestart
Period = 8000
ensemble Polskie Radio    is (3203) recognized
PR Jedynka       (3211) is part of the ensemble
PR Dw�jka        (3222) is part of the ensemble
PR Tr�jka        (3233) is part of the ensemble
PR Czw�rka       (3223) is part of the ensemble
Radio Poland     (332A) is part of the ensemble
Radio Krak�w     (37FC) is part of the ensemble
Radio Rytm       (32A7) is part of the ensemble
Polskie Radio 24 (32A6) is part of the ensemble
there might be a DAB signal here

going to start program Radio Rytm
selected Radio Rytm
        startaddress    = 444
        length          = 72
        subChId         = 7
        protection      = 2
        bitrate         = 96
we have now DAB+
YAH
Teraz gramy:
KAYAH
Teraz gramy:
KAYAH
Teraz gramy:
KAYAH
Teraz gramy:
KAYAH
Teraz gramy:
KAYAH
Fleciki
...


# dab-raw-3 -F ./antena-1_dab_229072kHz_fs2048kHz_gain42_1_long.raw -S 3211  | gst-launch-1.0 fdsrc ! audio/x-raw, format=S16LE, channels=2, layout=interleaved, rate=48000 ! dvbaudiosink
dab_cmdline V 1.0alfa,
                          Copyright 2017 J van Katwijk, Lazy Chair Computing
opt = F
opt = S
Setting pipeline to PAUSED ...
Pipeline is PREROLLED ...
Setting pipeline to PLAYING ...
New clock: GstSystemClock
ofdm word gestart
Period = 8000
ensemble Polskie Radio    is (3203) recognized
PR Jedynka       (3211) is part of the ensemble
PR Dw�jka        (3222) is part of the ensemble
PR Tr�jka        (3233) is part of the ensemble
PR Czw�rka       (3223) is part of the ensemble
Radio Poland     (332A) is part of the ensemble
Radio Rytm       (32A7) is part of the ensemble
Radio Krak�w     (37FC) is part of the ensemble
Polskie Radio 24 (32A6) is part of the ensemble
there might be a DAB signal here

going to start program PR Jedynka
selected PR Jedynka
        startaddress    = 0
        length          = 84
        subChId         = 1
        protection      = 2
        bitrate         = 112
we have now DAB+
Sygnaly Dnia
Sygnaly Dnia  S.A.
Sygnaly Dnia  S.A.
Sygnaly Dnia  S.A.
Sygnaly Dnia  S.A.
Sygnaly Dnia  S.A.
Sygnaly Dnia  S.A.
Sygnaly Dnia  S.A.
^Chandling interrupt.
Interrupt: Stopping pipeline ...
Execution ended after 0:00:22.886502875
Setting pipeline to PAUSED ...
Setting pipeline to READY ...
Setting pipeline to NULL ...
Freeing pipeline ...

[athoik]

Here is the recipe if somebody wants to experiment...

SUMMARY = "DAB decoding library with example of its use"
SECTION = "libs/multimedia"
LICENSE = "GPLv2"
LIC_FILES_CHKSUM = "file://../license;md5=427d5433a7bd7fc1e38dc15e93cbc645"

SRCREV = "${AUTOREV}"

DEPENDS = "fftw libusb1 faad2 zlib rtl-sdr"
RDEPENDS_${PN} = "rtl-sdr"

PV = "1.0"
PR = "r0"

SRC_URI = "git://github.com/JvanKatwijk/dab-cmdline.git"

EXTRA_OECMAKE = "-DRTLSDR=ON -DCMAKE_INSTALL_PREFIX=/usr/bin"

S = "${WORKDIR}/git/example-3"

inherit cmake pkgconfig

do_configure_prepend() {
	sed -i -e 's:librtlsdr.so:librtlsdr.so.0:g' ${WORKDIR}/git/devices/rtlsdr-handler/rtlsdr-handler.cpp
}

Then use one of the frequences posted above to scan for channels.

dab-rtlsdr-3 -C XXX

Once you find the channel, either use the name (-P parameter) or the hex number (-S parameter) followed by Gstreamer pipeline.

dab-rtlsdr-3 -C XXX -S YYY | gst-launch-1.0 fdsrc ! audio/x-raw, format=S16LE, channels=2, layout=interleaved, rate=48000 ! dvbaudiosink

Enjoy.