Thanks for your help guys. Yeah same here Simon, I have been playing with frame rates and noticed my TV supports up to 50ish then display nothing!
I'd like to play with DVB-T2 next once I've got the hang of this. On 5 Jul 2015 15:08, "Simon Kennedy" <si...@thekennedys.info> wrote: > Cool, I'll delete the email I was about to send! I had forgotten that you > were trying to tx DVB-T. However, I remember that when I was playing with > DVB-T I was able to use framerates from 25 to 60, but maybe it depends on > the TV your are using. > > I used an RTL-SDR dongle for receiving and found that avconv worked > perfectly but using ffmpeg I could only get a pixellated image, go figure! > > Simon. > > On 5 July 2015 at 15:04, Craig Barber <radiocrai...@gmail.com> wrote: > >> Bingo... I had to change the video frame rate from 60 down to 25 which I >> found is apparently what is broadcasted in the UK for Digital TV... and now >> I have video! >> >> On Sun, Jul 5, 2015 at 2:54 PM, Craig Barber <radiocrai...@gmail.com> >> wrote: >> >>> Hi Simon, >>> >>> The mpeg2 TS plays fine in mplayer and VLC and I get video and sound, >>> but on my test bench TV I only hear the audio. I've tried a couple of >>> different bitrates for the video too but no luck. >>> >>> I've edited dvbt-hackrf_tx_sk.py to use channel_mhz = 8 as I understand >>> that is what is normally used in the UK for UHF DVB-T. Any other option >>> other than that and I don't seem to see any signal at all on the test TV. >>> >>> Craig >>> >>> On Sun, Jul 5, 2015 at 2:51 PM, Simon Kennedy <si...@thekennedys.info> >>> wrote: >>> >>>> HI Craig, >>>> >>>> just seen your emails. Try using mplayer to play the ts from the fifo >>>> file. This will enable you to double check that the first part of the >>>> process is ok, ie. the creation of the mpeg2 ts. >>>> >>>> Where have you put channel_mhz = 8? >>>> >>>> Earlier today I had someone else email me to tell me that they have had >>>> success with the commands and program I put on my blog post so I know it >>>> does work for someone else! >>>> >>>> Regards >>>> Simon. >>>> >>>> On 5 July 2015 at 14:41, Craig Barber <radiocrai...@gmail.com> wrote: >>>> >>>>> 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@0.6:box=1:boxcolor=black@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] <lber...@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" <radiocrai...@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] <lber...@gmail.com >>>>>>> > wrote: >>>>>>> >>>>>>>> The ts mux bitrate has to match the modulator's >>>>>>>> Avconv parameter -muxrate >>>>>>>> El 5/7/2015 14:11, "Craig Barber" <radiocrai...@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 < >>>>>>>>> radiocrai...@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 < >>>>>>>>>> si...@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@0.6 >>>>>>>>>>> :box=1:boxcolor=black@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 <si...@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 <radiocrai...@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@greatscottgadgets.com >>>>>>>>>>> https://pairlist9.pair.net/mailman/listinfo/hackrf-dev >>>>>>>>>>> >>>>>>>>>>> >>>>>>>>>> >>>>>>>>> >>>>>>>>> _______________________________________________ >>>>>>>>> HackRF-dev mailing list >>>>>>>>> HackRF-dev@greatscottgadgets.com >>>>>>>>> https://pairlist9.pair.net/mailman/listinfo/hackrf-dev >>>>>>>>> >>>>>>>>> >>>>>>> >>>>> >>>>> _______________________________________________ >>>>> HackRF-dev mailing list >>>>> HackRF-dev@greatscottgadgets.com >>>>> https://pairlist9.pair.net/mailman/listinfo/hackrf-dev >>>>> >>>>> >>>> >>> >> >
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