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| From: | Ralph A. Schmid, dk5ras |
| Subject: | Re: [Discuss-gnuradio] DVB-T/T2 |
| Date: | Wed, 8 Apr 2015 16:34:26 +0200 |
Hi, The Us are when I do something else with the machine. They do not show when I keep my fingers off the mouse, so no reason to worry, it runs for ages without a single U when the machine is kept alone. I already found out about the rate. The coding also needs to be reflected by the transport stream, or just regarding the bitrate? I did not find a setting for that, but I will look deeper into it during the next days, when I find some time. My first test trying to set identical settings like from the working test stream brought just a black picture. Another question...when looking into the constellation, what are the two dot clouds on the X/I-axis, outside the expected 4*4 cloud matrix? Some embedded BPSK? I could not find this in the DVB-T specs at first glance... Ralph. From: Bogdan Diaconescu [mailto:address@hidden Hi Ralph, DVB-T.png shows some u's on the command line which means the whole flowgraph do not provide data to USRP at the right speed. It basically mean the computer cannot cope with the required processing requirement. As for the video parameters, in the DVB-T specs (http://www.etsi.org/deliver/etsi_en/300700_300799/300744/01.06.01_60/en_300744v010601p.pdf) you will find Table 17 where the rates are presented. FYI, the settings you have used are 8Mhz bandwidth, QAM-16 constellation, coding 1/2, guard interval 1/32. The video should be constant bit rate but it is not a hard requirement (see below). If you just broadcast video from a file and not plan to use a live streaming from camera, the rate should not matter too much. The video is sent at the rate of the DVB-T according to it's parameters and with RTL2832 receiver it is buffered and played at the correct speed (at least for short files like test.ts). Bogdan On Wednesday, April 8, 2015 11:55 AM, "Ralph A. Schmid, dk5ras" <address@hidden> wrote: Yep, this would be quite useful! I modified your flow graph according to Rons hints, and now I have a stable and reliable DVB-T transmission path with your package. See http://dk5ras.dyndns.org/tmp/DVB/ with a screenshot. I am using the Ettus B210, and for reception a second PC with DVB-T stick, or a DVB-x tester that does them all, DVB-C/S/S2/T/T2. You and Ron really did a great job with coding those DVB-x packages! Ralph. From: address@hidden [mailto:address@hidden] On Behalf Of Bogdan Diaconescu Ok, it would be useful to have receivers too like for the DVB-T. Bogdan On Tuesday, April 7, 2015 11:23 PM, Ron Economos <address@hidden> wrote: Only transmitter implementations for now. They are here: On 04/07/2015 06:38 AM, Bogdan Diaconescu wrote:
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