Monday, 1 February 2016

Complete DVB-S Transmitter Windows Application

DVB-S Transmitter Application
Now that I have reached a stage were things are starting to work I thought
I would give you all a preview of the program I am currently working on.

It looks simple but a lot of work has gone into this. What is it you ask?

Well it is a Windows based program that can capture video/audio from a source,
compress it using the FFMPEG codec libraries, turn it into a valid MPEG2
Transport Stream and then send it to the DATV-Express board where it is
turned into DVB-S by the FPGA and then transmitted.

Currently it supports H.262 (MPEG 2), H.264 (MPEG4-AVC / MPEG4 part 10 )
and H.265 HEVC. At the moment it only supports MPEG1 Layer II sound although
I will be adding AAC.

I have tested it with 2 different Webcams, an Ezcap capture dongle and of course vMix.
It supports the usual range of symbol rates 200K to 8M and the usual frequency range
65 MHz to 2.48 GHz.

The capturing is done using Windows DirectShow so in theory just about any device
that has DirectShow support will work with it. In practice there is bound to be some
device format I don't have support for.

I am currently doing the boring stuff, adding GUI support via the menus to configure
the large range of parameters.

On my reading list at the moment is the DTG D-Book 7 which describes the standards
that digital TV works to in the UK. Part A covers terrestrial transmission, the majority
of the spec is taken up with standards for connected TV, something that is not really
relevant to Amateur TV.

Everyone on the DATV-Express team is on holiday (except me) at the moment so not
much is happening. Hopefully I will have an  initial version of the software available
in about 2 weeks time. 
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9 comments:

  1. Anonymous1 February 2016 at 13:00

    That's really good news Charles. Possibly more significant than you realise. A number of people have been very interested in my express card but put off by the intricacies required to get it running. Combining the encoder with the programme will make it a product that just works out of the box. I know at least two people who have said they will buy DATV Express when this is available.
    Let us know as soon as you're ready for beta testers!

    Chris (mw0llk)

    ReplyDelete
    Replies
    1. G4GUO1 February 2016 at 13:06

      Hi Chris, yes the feedback I get too is that people want something like this (Windows not Linux and something that just works). I used pre-built FFMPEG Windows libraries that can be easily downloaded as .dlls. The initial release will be pretty basic but it will be something to build on. Theoretically it will support any Windows supported capture device. The limiting factor is how power the CPU is. It should be fine on most machines with MPEG2 but H.264 and H.265 need a high end machine.

      Delete
  2. Anonymous2 February 2016 at 11:05

    Hello Charles and Cris,
    It's wonderful for creating this program. I hear many people say that the DATV Express does not allow easily to send a live image from a webcam, it's done now thanks to you both.

    There is also something very interesting is that the raspberry pi2 with its camera can also do streaming at 30 fps and h264 directly. Here is the program:

    http://www.linux-projects.org/modules/news/article.php?storyid=190

    There are many possibilities with the gpu of the raspberry 2.

    I wish to become beta tester as soon as I received my express DATV which is in order.

    73's from Michael ON7KGK Belgium.

    ReplyDelete
  3. Anonymous2 February 2016 at 11:11

    Hello Charles and Cris,

    It's wonderful for creating this program. I hear many people say that the DATV Express does not allow easily to send a live image from a webcam, it's done now thanks to you both.

    There is also something very interesting is that the raspberry pi2 with its camera can also do streaming at 30 fps and h264 directly. Here is the program:

    http://www.linux-projects.org/modules/news/article.php?storyid=190

    There are many possibilities with the gpu of the raspberry 2.

    I wish to become beta tester as soon as I received my express DATV which is in order.

    73's from Michael ON7KGK Belgium.

    ReplyDelete
  4. G4GUO2 February 2016 at 11:23

    Hello Michael,
    This new software is built on the software I have
    already developed for Linux. The main difference is
    using DirectShow to do the audio and video capture.

    A group of S/W developers are now looking at using
    the PI2 as part of a portable DATV transceiver and
    possibly as part of a repeater.

    It is just a matter of finding the time to do all
    these things.

    - Charles

    ReplyDelete
  5. Anonymous11 February 2016 at 08:06

    Hello Charles,

    When you said : "It should be fine on most machines with MPEG2 but H.264 and H.265 need a high end machine."

    Did you mean a powerful CPU or GPU because I have a lenovo notebook T410s (i5, 8Gb ram, 128Gb SSD) dedicated just for your software but it has a poor embedded graphics card (intel hd4000 or 5000 i don't remember).

    Thank you.

    Michaël ON7KGK.

    ReplyDelete
  6. G4GUO11 February 2016 at 08:55

    Hi Michaël.
    It is the CPU that limits the performance. I am just using
    a dual core machine and it can do H.264 at SD resolution.
    So I expect your laptop will be fine.
    - Charles

    ReplyDelete
  7. Anonymous11 February 2016 at 09:52

    :-) thank you

    ReplyDelete
  8. Accounts Data Entry11 July 2016 at 08:35

    Wow great news..Thanks for keeping us update about this useful software..

    ReplyDelete

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