[Hackrf-dev] DVB-T and DVB-T2

[Craig Barber]

Thankyou, I just found it (https://en.wikipedia.org/wiki/DVB-T), I now have
stable sound (getting there!) but no video oddly! The command I'm using to
create the TS before broadcast is as follows:

avconv -f alsa -i hw:0,0 -f video4linux2 -s 640x480 -i /dev/video0 -vf
drawtext=fontfile=/usr/share/fonts/truetype/freefont/FreeMonoBold.ttf:text="TEST
":x=440:y=420:fontsize=48:fontcolor=white at 0.6:box=1:boxcolor=black at 0.4
-vcodec mpeg2video -r 60 -b 2500000 -acodec mp2 -ar 48000 -ab 48000 -ac 2
-muxrate 4976000 -mpegts_transport_stream_id 1025 -mpegts_service_id 1
-mpegts_pmt_start_pid 4096 -mpegts_start_pid 400 -f mpegts -y test3

I'm then using QPK, with 1/2 code rate and 1/4 guard interval which expects
a bitrate of 4.976mbps so should be correct?

On Sun, Jul 5, 2015 at 2:16 PM, n0p [Luis Bernal] <lbernal at gmail.com> wrote:

> The modulator bitrate depends of it's parameters, there's a nice table
> with the formula but i can't find it now since I'm on mobile
> El 5/7/2015 14:48, "Craig Barber" <radiocraig28 at gmail.com> escribió:
>
>> Thanks for the fast response n0p but I cannot find that parameter?
>>
>> On Sun, Jul 5, 2015 at 1:34 PM, n0p [Luis Bernal] <lbernal at gmail.com>
>> wrote:
>>
>>> The ts mux bitrate has to match the modulator's
>>> Avconv parameter -muxrate
>>> El 5/7/2015 14:11, "Craig Barber" <radiocraig28 at gmail.com> escribió:
>>>
>>>> The good news is I got it working, sort of, using channel_mhz = 8 -
>>>> however the picture and audio judders really badly, and basically plays
>>>> back really slow! I don't have a stream of UUUUUUUUUUU appearing in my
>>>> console window, so can't be buffer underruns, any ideas Simon?
>>>>
>>>> On Sun, Jul 5, 2015 at 12:30 PM, Craig Barber <radiocraig28 at gmail.com>
>>>> wrote:
>>>>
>>>>> Hi Simon,
>>>>>
>>>>> I've tried your script today with my test TV but see no signal
>>>>> whatsoever on the TV although the hackrf is definitely transmitting. I've
>>>>> also tried with a pre-recoded mpeg2 file from avconv but no luck.
>>>>>
>>>>> Any suggestions?
>>>>>
>>>>> Craig
>>>>>
>>>>> On Tue, Jun 30, 2015 at 10:57 PM, Simon Kennedy <
>>>>> simon at thekennedys.info> wrote:
>>>>>
>>>>>> I feel slightly embarrassed as I subscribed to this list using an
>>>>>> email address that is redirected to my main email, so consequently replies
>>>>>> sent from my main email address were not coming from the correct address.
>>>>>> Hence, none of the replies I posted have been seen on the list. Oops!
>>>>>>
>>>>>> Here is my reply about this thread:
>>>>>>
>>>>>> Hi Craig,
>>>>>>
>>>>>> Check out Clayton's web page (who created the sdr-examples you refer
>>>>>> to) here <http://www.irrational.net/2014/03/02/digital-atv/>
>>>>>>
>>>>>> I amended his BladeRF script and I have put my HackRF version here
>>>>>> <https://www.dropbox.com/s/bdnzoa0kn01dfav/dvbt-hackrf_tx_sk.py?dl=0> for
>>>>>> download
>>>>>> My version transmits DVB-T on the lowest Freeview channel in the UK
>>>>>> at 474MHz (obviously only while using a dummy load). I successfully
>>>>>> received the transmission of my webcam image this way using an RTL-SDR
>>>>>> dongle.
>>>>>>
>>>>>> The command I used was very heavily influenced (ok, basically copied)
>>>>>> from Clayton's examples:
>>>>>> avconv -f alsa -i hw:0,0 -f video4linux2 -s 640x480 -i /dev/video0
>>>>>> -vf
>>>>>> drawtext=fontfile=/usr/share/fonts/truetype/freefont/FreeMonoBold.ttf:text="TEST
>>>>>> ":x=440:y=420:fontsize=48:fontcolor=white at 0.6
>>>>>> :box=1:boxcolor=black at 0.4 -vcodec mpeg2video -r 60 -b 2000000
>>>>>> -acodec mp2 -ar 48000 -ab 48000 -ac 2 -mpegts_transport_stream_id 1025
>>>>>> -mpegts_service_id 1 -mpegts_pmt_start_pid 4096 -mpegts_start_pid 400 -f
>>>>>> mpegts -y in.fifo
>>>>>>
>>>>>> I used a standard web cam to capture the image, sent the output to a
>>>>>> fifo file (in.fifo) and consumed the output through the python program with
>>>>>> the command:
>>>>>> ./dvbt_hackrf_tx_sk.py in.fifo
>>>>>>
>>>>>> The fifo file can be created using the command mkfifo in.fifo
>>>>>>
>>>>>> Run the avconv command and the python program in the same directory
>>>>>> as you created the fifo file in.
>>>>>>
>>>>>> I have also transmitted DVB-S which I have documented on my blog here
>>>>>> <http://photohamrad.blogspot.co.uk/2015/06/transmitting-video-with-hackrf-blue.html>
>>>>>>
>>>>>> Simon.
>>>>>>
>>>>>>
>>>>>> On 30 June 2015 at 17:35, Simon Kennedy <simon at thekennedys.info>
>>>>>> wrote:
>>>>>>
>>>>>>> Can you tell us the command you used to get this error please.
>>>>>>> I remember that I got a smilar error but cannot look up how I solved
>>>>>>> it until I get home in a couple of hours.
>>>>>>> The key point is that the program is trying to open a UDP port to
>>>>>>> receive the data and error relates to the asignment of the argument you
>>>>>>> supply to the program to the variable 'port' in the program.
>>>>>>>
>>>>>>> Simon.
>>>>>>>
>>>>>>> On 30 June 2015 at 16:49, Craig Barber <radiocraig28 at gmail.com>
>>>>>>> wrote:
>>>>>>>
>>>>>>>> Here's the error I get:
>>>>>>>>
>>>>>>>> Traceback (most recent call last):
>>>>>>>>   File "./dvbt-hackrf.py", line 123, in <module>
>>>>>>>>     main(sys.argv[1:])
>>>>>>>>   File "./dvbt-hackrf.py", line 31, in main
>>>>>>>>     port    = int(args[0])
>>>>>>>> ValueError: invalid literal for int() with base 10: 'testdvbt'
>>>>>>>>
>>>>>>>>
>>>>>>>>
>>>>>>>
>>>>>>
>>>>>> _______________________________________________
>>>>>> HackRF-dev mailing list
>>>>>> HackRF-dev at greatscottgadgets.com
>>>>>> https://pairlist9.pair.net/mailman/listinfo/hackrf-dev
>>>>>>
>>>>>>
>>>>>
>>>>
>>>> _______________________________________________
>>>> HackRF-dev mailing list
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>>>>
>>>>
>>
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