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:[email protected]:box=1:[email protected] -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] <[email protected]> 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" <[email protected]> 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] <[email protected]> >> wrote: >> >>> The ts mux bitrate has to match the modulator's >>> Avconv parameter -muxrate >>> El 5/7/2015 14:11, "Craig Barber" <[email protected]> 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 <[email protected]> >>>> 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 < >>>>> [email protected]> 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:[email protected] >>>>>> :box=1:[email protected] -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 <[email protected]> >>>>>> 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 <[email protected]> >>>>>>> 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 >>>>>> [email protected] >>>>>> https://pairlist9.pair.net/mailman/listinfo/hackrf-dev >>>>>> >>>>>> >>>>> >>>> >>>> _______________________________________________ >>>> HackRF-dev mailing list >>>> [email protected] >>>> https://pairlist9.pair.net/mailman/listinfo/hackrf-dev >>>> >>>> >>
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