BATC Forum

Hello,

My first constraint : I only want to use the DATV express under Windows environment.

I only use my DATV Express once every 2 or 3 months and put it away, saying that each time I use it, I loose too much time and get bad results or have to spend time because of bugs ( "French bug", installation bug, "TS data rate" bug...)
(But yes, this hardware could do a fantastic job...)

I use it only sometimes ...
1)Mainly because I need to do some test for friends that ask me to implement new possibilities to Minitioune software.
Now the new version of Minitioune can receive DVB-S2 and also decode H265. (it will be soon available)

2) Because I always think that I cannot make the DATV Express work as I hope ( = correctly in my mind)

a)I have spent many hours to make it recognized on a computer where I had already installed a similar driver for a Technotrend USB tuner ( S-2400 or S2-3600 ) and each time I plug the DATV express it is recognized as a TT USB device!!! I have tried all I can know, deleting all I can find about TT USB in the base registers.... I have not found the solution.
This is the only hardware that gives me this kind of result.
If someone can give me the solution, thanks

b) On another computer, it is recognized and seems to work but
- I cannot make it work in DVB-S2 mode . I know that there is something to do to fix this, but don't remember and don't find where there is the solution, nothing in the DATV express website, nothing on the notes_V1.23.txt.

I really prefer to continue to use the DATV express server as I can create myself the good TS I like.

the Express transmitter software (v1.23) has too much bugs, that doesn't allow to use it more that 1mn
The biggest bug I think is the TS rate computed : If I set SR2000 kS/s fec 3/4, I see on the panel that the Tx bitrate will be 3.000 Mbps.
It is a bad computed value. The good value should be : 2000 x 2 x 3/4 x 188/204 = 2764.7 kbps
So the Datv Express transmitter software send a TS that has a Symbol rate with a big jitter ( I can see it when I use Mintioune in expert mode) with a data rate that doesn't correspond to the SR we should have . If I record the TS with Minitioune and use this TS with any TSplayer/analyzer (StreamXpres..), they say that the TS rate is effectively 3000 kbps but that the SR corresponding, using fec3/4, is SR2170 kS/s, not SR2000!!
So, when I use Minitioune to decode directly the TS transmitted by the DatvExpress transmitter software, I begin to decode, but loose the sound after some tens of second of sometimes some freeze... There is some difficulties to synchronize the sound and the video and the more i wait,the more is the de-synchronization.
So, for me, the biggest bug is firstly this bad data rate.
I am the only user that has this result? Is it only a bad installation on my computer?
I really wonder because I don't understand that other users seem to not have this issue as it has never been reported...
Perhaps I have missed something? As anybody, sometimes I can be stupid.

Whishes:
- As I really like to work Narrow band DATV, I would like also to find
>> the mono 32kbps data rate for the Mpeg Audio codec
>> the possibility to tweak ffmeg parameters.(?) I don't know if the bad result ( video freeze ...) I have using low SR, comes from the ffmepg encoding or from the data rate bug I have talk above.
>> the possibility to use my own graph, or use an UDP input. (I don't like very much ffmpeg).

When I use the DATV express ServerApp, I can create myself a good TS with the good data rate, choose 20 fps for the webcam (not the encoding rate), set the Mpeg2/H264 encoder for the best result I can.
So this for me the only way I can use in good condition my DATV express. ( but no DVB-S2 possibility...)

Last tests show me that I could use the DATV Express with only a Pipo (C615 capture +H264 encoding /decoding and display use only 35% CPU - )
YES, this hardware could do a fantastic job..

Jean-Pierre F6DZP

DATV-Express uses Cypresses default development VID/PID of 0x4B4 / 0x8613
To get our own VID/PID would cost $5000 http://www.usb.org/developers/vendor/

There is now a possible other way of getting a unique VID/PID (I am not totally convinced of its legality)
http://wiki.openmoko.org/wiki/USB_Product_IDs

The VID/PID of the DATV express board cannot be changed due to an error in the hardware design.
The flash chip was placed at the wrong hardware address. To change the VID/PID you need to make
a fairly simple modification to the board. Once that is done there is a utility on my github site
to re-program the VID/PID https://github.com/G4GUO/fx2_programmer.

As far as DVB-S2 not working on your computer. I sent you an email about that months ago.
I believe the problem is due to the wrong driver being installed.

The other issues you mention I am aware of and have been trying to fix them for some time.

I am currently on indefinite leave from the DATV-Express project (for health reasons) so I
won't be making any changes to the software in the foreseeable future.

- Charles

Thank you Charles for the quick answer.

My observation is not a complaint. It was just a report about my tests.

- yes you have already given me the solution to fix the DVB-S2 mode that doesn't work, I must find your email and fix it.
(but I suppose that other people will have also this issue, so it could be a good idea to add the solution in the Notes.)

and OK for the specific VID/PID cost.
"you need to make a fairly simple modification to the board" where can I find this modif?

I know that the development of software takes very much time and you have already done a fantastic job.
I was just astonished to find the data rate value.

Anyway, as I said, the ServerApp can do the job.

Thank you again for this great project.

Jean-Pierre F6DZP

Hello Jean-Pierre,

Here is the link to the picture of the mod
https://www.dropbox.com/s/f0hg15kqacguz ... d.jpg?dl=0

You need to drill out the two plated through holes in the middle on the left side of U11
then short together the 3 pins on the left side of U11. That will change the address of the
FLASH chip to the address that gets looked at when the USB2 chip starts up.

The utility needs to be compiled on a Linux system using QT
https://www.dropbox.com/s/7fu0gyzmcxoep ... l.jpg?dl=0

With that you can change the VI/PID to whatever you want.
Then hit the update (leave the file to flash blank)

(however things are never simple!)

Unfortunately the Express software will need to be changed to look for the new VID/PID
If you let me know the new values you wish to use I will add them to the software and
send you an updated version. Or I can make them configurable from the GUI.

I am sorry I don't have a Windows version of the tool.


- Charles