Real-time video streaming

[Ahmet DEMIR]

Hi,
Thanks for the help.
I am trying to stream a real time video taken from a camera. I know that I
will use gstreamer to take and encode the video. And then pass it to the
gnuradio and do some digital processing operations on it. And lastly by
using a usrp, I will transmit it in radio frequency range. Can I use
uhd_packet_tx.grc example which is used to message passing for this aim? Or
how can I find the flowgraph of video transmitter? I am using Gnuradio3.8
version and linux OS. I will be very happy if you help me.
Regards.

Re: Real-time video streaming

[sumit kumar]

Hello Ahmet,
If can make tunnel script working , then video transmission using vlc will
be very straightforward.
We did this long back
https://youtu.be/bKF67pFQy1k
Regards
Sumit

On Sat, Mar 7, 2020, 9:54 AM Ahmet DEMIR  wrote:

> Hi,
> Thanks for the help.
> I am trying to stream a real time video taken from a camera. I know that I
> will use gstreamer to take and encode the video. And then pass it to the
> gnuradio and do some digital processing operations on it. And lastly by
> using a usrp, I will transmit it in radio frequency range. Can I use
> uhd_packet_tx.grc example which is used to message passing for this aim? Or
> how can I find the flowgraph of video transmitter? I am using Gnuradio3.8
> version and linux OS. I will be very happy if you help me.
> Regards.
>

Re: Real-time video streaming

[Ahmet DEMIR]

Hello Sumit,
Thanks a lot for the help firstly. I want to ask you a number of questions.
Which video encoding method are you using in your project? I am asking this
because this is a part of my thesis study and my teacher wants me to encode
the video by using H.264. I am beginner in this area. Can you explain
shortly your project? What are the steps to follow? Lastly, if I request
can you share your gnuradio flowgraph?
Regards.

7 Mart 2020 Cumartesi tarihinde sumit kumar  yazdı:

> Hello Ahmet,
> If can make tunnel script working , then video transmission using vlc will
> be very straightforward.
> We did this long back
> https://youtu.be/bKF67pFQy1k
> Regards
> Sumit
>
> On Sat, Mar 7, 2020, 9:54 AM Ahmet DEMIR  wrote:
>
>> Hi,
>> Thanks for the help.
>> I am trying to stream a real time video taken from a camera. I know that
>> I will use gstreamer to take and encode the video. And then pass it to the
>> gnuradio and do some digital processing operations on it. And lastly by
>> using a usrp, I will transmit it in radio frequency range. Can I use
>> uhd_packet_tx.grc example which is used to message passing for this aim? Or
>> how can I find the flowgraph of video transmitter? I am using Gnuradio3.8
>> version and linux OS. I will be very happy if you help me.
>> Regards.
>>
>

How GNURadio3.8.1 on RasperryPi4 ?

[Robert Heerekop]

Dear radio friends,

Can anyone guide me (a rookie on HelloWorld level) how to install GNU Radio
Campanion 3.8.1 on Rasperry Pi4?

If I follow the (currently) most recent RPi NOOBS 3.3.1 the installation
guides fail (e.g.
https://wiki.gnuradio.org/index.php/InstallingGRFromSource_on_Raspberry_Pi)

I’m searching for a few days now, but get stuck because the information I
can find is only related to previous versions.

Thanks a lot for getting me and others rookies on track!

rrrRbert

Re: How GNURadio3.8.1 on RasperryPi4 ?

[Marcus Müller]

Dear rrrBbert,

the instructions are in fact for GNU Radio 3.8, so not for a previous
version.

Anyway, I'd not recommend building GNU Radio from source, at all, when
there's binary packages available. That's just way harder, and has no
advantages.

Especially, at high cost, avoid building on an embedded system like the
RPi: these are not machines meant for building software. Developers who
target embedded devices compile the software on their PCs and transfer
the binaries to the embedded devices; in fact, building GNU Radio
typically exceeds the RAM you have in an RPi by far, and the poor
device, aside from compiling Megabytes of C++ code, also needs to start
swapping RAM to the incredibly slow medium of SD cards.

So, simply use Raspbian Testing on your Rpi, which simply comes with GNU
Radio 3.8.1-rc1:

sudo apt install gnuradio

and done.

There should be a guide how to update your Raspbian to that, somewhere
(I'm not a Raspbian user myself, so I can't help you). That should be
pretty straightforward, and at the very least, much, much easier than
building GNU Radio from source.

Also, a note on NOOBS/the raspbian, that it installs: Raspbian, for some
reason, has decided that "all RPis are alike", which they really are
not. The older RPi are least-performance 32 bit machines without
acceleration for a lot of things, whereas the RPi 3 and RPi4 are 64 bit
machines with support for accelerated vector math, which GNU Radio
really uses *a lot*. So, Raspbian throws a lot of performance, as far as
I know, by forcing software to run in legacy armhf mode.

Sadly, "real" Debian (which Raspbian is based on) hasn't fully been
ported to the RPi 4 yet, so I don't have a great alternative to updating
your Raspbian from buster to testing yet.

Best regards,
Marcus

On 07.03.20 16:46, Robert Heerekop wrote:
> Dear radio friends,
> 
> Can anyone guide me (a rookie on HelloWorld level) how to install GNU
> Radio Campanion 3.8.1 on Rasperry Pi4?
> 
> If I follow the (currently) most recent RPi NOOBS 3.3.1 the installation
> guides fail (e.g.
> https://wiki.gnuradio.org/index.php/InstallingGRFromSource_on_Raspberry_Pi)
> 
> I’m searching for a few days now, but get stuck because the information
> I can find is only related to previous versions.
> 
> Thanks a lot for getting me and others rookies on track!
> 
> rrrRbert
> 

Re: Real-time video streaming

[Marcus Müller]

I'd really recommend using uhd_packet_tx_tun or any other of the current
examples over tunnel.py, which we mourningly¹ retired² a while³ ago.

Tunnel.py was meant as a demo of how to make GNU Radio work with network
interfaces, and as a proof of concept that you can make GNU Radio your
real-world packet transport. It was never meant to be a great
transceiver, just one that works and exercised our –now mostly replaced–
packet infrastructure.
Yet, we saw literally dozens of questions on people who thought it was
their optimum solution and were wondering why it wasn't as great as a
properly optimized transceiver.

Best regards,
Marcus

¹ ...with a vengeance
² ...six feet deep
³ to be exact, Fri Nov 4 09:43:04 2016 -0700 was the time the OFDM
tunnel.py was removed from the source tree.
On 07.03.20 10:12, sumit kumar wrote:
> Hello Ahmet, 
> If can make tunnel script working , then video transmission using vlc
> will be very straightforward. 
> We did this long back
> https://youtu.be/bKF67pFQy1k
> Regards
> Sumit 
> 
> On Sat, Mar 7, 2020, 9:54 AM Ahmet DEMIR  > wrote:
> 
> Hi,
> Thanks for the help.
> I am trying to stream a real time video taken from a camera. I know
> that I will use gstreamer to take and encode the video. And then
> pass it to the gnuradio and do some digital processing operations on
> it. And lastly by using a usrp, I will transmit it in radio
> frequency range. Can I use uhd_packet_tx.grc example which is used
> to message passing for this aim? Or how can I find the flowgraph of
> video transmitter? I am using Gnuradio3.8 version and linux OS. I
> will be very happy if you help me. 
> Regards. 
> 

Sv: Accessing top_block from an embedded python block?

[Steffen Kiel]

Hi Derek, thanks a lot for your reply.
That kinda makes sense to me, but im not sure about the tutorial, it doesn't 
seem to be very explanatory.

You say that i can pass the buttons ID to the python block, but i cant seem to 
figure out how i would do that, as variables don't have outputs that i can 
connect to the block?


//Steffen



Fra: Derek Kozel 
Sendt: 5. marts 2020 16:34
Til: Steffen Kiel ; discuss-gnuradio@gnu.org 

Emne: Re: Accessing top_block from an embedded python block?

Hi Steffen,

You're missing that the embedded Python Block should work just like any other 
block. If you want to read a button state or accept a message then you'll need 
to add a parameter to the Python block and pass in the button's ID (variable) 
to it or add a message port to the block.

The Embedded Python Block tutorial does a good job covering the message side 
and adding a parameter is part of the default Python Block template.
https://wiki.gnuradio.org/index.php/Embedded_Python_Block

As a related note, in the very latest maint-3.8 and master codebases there are 
now Python Snippets for injecting Python code directly into the generated 
program. It's useful for a variety of situations, but the ones you're 
describing here are already usually handled well by the existing features.

Cheers,
Derek

On 05/03/2020 13:13, Steffen Kiel wrote:
Hello!

I am new to using GNU radio, and i would like to implement some custom features.
I would like to access functions like the get_push_button to read its state, or 
read a message box etc.
Is this even possible from the epy block?

I could also implement this directly in the top_block.py file, but my problem 
is that if i want to change something in the GUI, this file is overwritten, and 
the custom code will be erased. Or am i missing something?

is there a set_output_multiple() in pyhton blocks?

[Achilleas Anastasopoulos]

Hi all,

I was writing an embedded python (general) block in 3.8 and wanted to
use set_output_multiple as I have done in C++ in the past.
It seems that this method does not exist.
I just wanted to verify this.
Is there a way to set the output multiple in a general block in python?

thanks
Achilleas

Re: How GNURadio3.8.1 on RasperryPi4 ?

[Manolis Surligas]

Hey,

you can use also our repo if you use the Raspbian that has everything 
pre-built. Tested and working well on RPi4 with Buster on many SatNOGS 
stations.


https://software.opensuse.org/download/package?package=gnuradio&project=home%3Alibrespace%3Asatnogs-unstable

On 3/7/20 6:45 PM, Marcus Müller wrote:

Dear rrrBbert,

the instructions are in fact for GNU Radio 3.8, so not for a previous
version.

Anyway, I'd not recommend building GNU Radio from source, at all, when
there's binary packages available. That's just way harder, and has no
advantages.

Especially, at high cost, avoid building on an embedded system like the
RPi: these are not machines meant for building software. Developers who
target embedded devices compile the software on their PCs and transfer
the binaries to the embedded devices; in fact, building GNU Radio
typically exceeds the RAM you have in an RPi by far, and the poor
device, aside from compiling Megabytes of C++ code, also needs to start
swapping RAM to the incredibly slow medium of SD cards.

So, simply use Raspbian Testing on your Rpi, which simply comes with GNU
Radio 3.8.1-rc1:

sudo apt install gnuradio

and done.

There should be a guide how to update your Raspbian to that, somewhere
(I'm not a Raspbian user myself, so I can't help you). That should be
pretty straightforward, and at the very least, much, much easier than
building GNU Radio from source.

Also, a note on NOOBS/the raspbian, that it installs: Raspbian, for some
reason, has decided that "all RPis are alike", which they really are
not. The older RPi are least-performance 32 bit machines without
acceleration for a lot of things, whereas the RPi 3 and RPi4 are 64 bit
machines with support for accelerated vector math, which GNU Radio
really uses *a lot*. So, Raspbian throws a lot of performance, as far as
I know, by forcing software to run in legacy armhf mode.

Sadly, "real" Debian (which Raspbian is based on) hasn't fully been
ported to the RPi 4 yet, so I don't have a great alternative to updating
your Raspbian from buster to testing yet.

Best regards,
Marcus

On 07.03.20 16:46, Robert Heerekop wrote:

Dear radio friends,

Can anyone guide me (a rookie on HelloWorld level) how to install GNU
Radio Campanion 3.8.1 on Rasperry Pi4?

If I follow the (currently) most recent RPi NOOBS 3.3.1 the installation
guides fail (e.g.
https://wiki.gnuradio.org/index.php/InstallingGRFromSource_on_Raspberry_Pi)

I’m searching for a few days now, but get stuck because the information
I can find is only related to previous versions.

Thanks a lot for getting me and others rookies on track!

rrrRbert


--
/* Code is the Law */

qt window closed but flowgraph not killed

[jsdenis]

I'm new with GNU Radio. Usualy when I close a Qt window, the flowgraph
stops, but when I use a USRP source or sink, the window closes but the
flowgraph still run and I need to close it with the kill button.
I have googled a lot but I can't find an explanation.
Can someone give me some ideas
Thanks a lot
Juanjo