How I can build dvb-t/dvb-t 2 transceiver?

I need dvbt2 transreceiver. I tried gnuradio with https://github.com/BogdanDIA/gr-dvbt. The "apps/dvbt_tx.grc" is working. But, video cannot transfer flexibly.

On gnuradio flow, I adjust multiple const value, and tx gain of limeSDR-mini sink.

Anyway, video transfer is not good.

• How I can convert video.mp4 to adv8dvbt34.ts?
• Why "multiple const" used before LimeSdr sink?
• How do I transfer videos flexibly?
• gr-dtv is part of GNU Radio's mainline tree by now, and while a bit of work on DVB stuff is done outside GNU Radio, you really shouldn't be using Bogdan's stuff as end-user. – Marcus Müller Feb 21 '19 at 17:56

Yes and no: T2 reception is too computationally hard so far. It's work in progress, but it's almost certain that your average PC can't decode full standard T2 rates in real time on its CPU. The channel coding is just too involved.

Transmission is always computationally easier.

See gnuradio/gr-dtv/ example flowgraphs.

Why "multiple const" used before LimeSdr sink?

To adjust the amplitude – that's what the multiplication with a constant does.

How I can convert video.mp4 to adv8dvbt34.ts?

FFMPEG can be used to convert video file containers to MPEG transport streams. You need to exactly use the same bit rate as your DTV transmission chain uses for the transport stream.

How do I transfer videos flexibly?

Stretch multiple times daily and make sure to train hard so that you'll be the most flexible user of GNU Radio in existence.

No seriously, "flexibly" doesn't tell me anything about what you need.

• Thanks for your kindly answer. - I tested only dvbt, but it is not good. - I tested ffmpeg.exe, but there is no parameter relative DVBT for example, guard interval, Transmmit mode, Code rate, Constellation type I can found adv7dvbt78qam64.ts, adv8dvbt34qam64.ts. So, what means this videos? – John Feb 22 '19 at 5:13
• ffmpeg doesn't know anything about RF things like Constellation type; it is just a tool to transcode between different video formats. .ts is for "transport stream", and it's the video container format that DVB uses. The GNU Radio transmit flowgraphs on the other hand know nothing about video things – all they do is take the bits from a file. So that file needs to be in a format that the receiver would understand, and that's why I instructed you to use FFMPEG with the parameters you need. Since I don't know which bitrate you're planning on transmitting, I can't help you with how to use ffmpeg – Marcus Müller Feb 22 '19 at 6:20
• @MarcusMüller It is simply amazing to me that you know so much about this and related subjects! You are a real asset here. :-) – Mike Waters Feb 22 '19 at 19:05
• @MikeWaters thank you :) I don't really feel like I know much :) I look up to your practical experience! – Marcus Müller Feb 22 '19 at 20:32
• Thanks. Well, there are hams here that forgot more than I know. And you know who they are. :-) – Mike Waters Feb 22 '19 at 20:35