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

n0p [Luis Bernal] lbernal at gmail.com
Sun Jul 5 09:16:49 EDT 2015


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
>>> HackRF-dev at greatscottgadgets.com
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>>>
>>>
>
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