DATV-Express Project - March update report

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KenW6HHC
Posts: 309
Joined: Mon Jun 01, 2009 4:20 pm

DATV-Express Project - March update report

Post by KenW6HHC » Thu Apr 02, 2015 2:34 pm

DATV-Express efforts remained quiet in March.

Art WA8RMC has several HiDes UT-100B users on the ATCO DVB-T repeater WR8ATV that have difficulty changing the factory-default PID values on UT-100B transmitters. Three of the UT-100B PIDs are different that the PID values usually being used by hams for DATV and are values greater than 4095.
UT-100B default
PCR = 4097
Video = 4113
Audio = 4352
DATV-Express default
PCR =256
Video = 256
Audio = 257

In order to accommodate these UT-100B users, Art has allowed the DVB-T at WR8ATV to use those default HiDes PID values instead of the normal DATV PID values (almost "standard" values that are defaulted by DATV-Express). But it turns out that The DATV-Express has a simple bug (the MSB of PID values is masked) and will not currently allow users to configure values that are using the MSB. So Art can NOT transmit DVB-T to WR8ATV using his DATV-Express station. HiDes technical support explains that the software program they supply called PC2TV will allow reconfiguring PID values on the UT-100B. But so far, nobody has tried to reconfigure their UT-100B transmitter using PC2TV...so Art is locked out of his club's DVB-T repeater using DATV-Express.

Charles G4GUO has prepared a draft of v2.04 software (currently 64-bit) for the fixing the PID MSB bug on the DATV-Express board. The current plan is that Art will test the 64-bit v2.04 draft deb file build. The v2.04 is intended to include four fixes/features:
  • (1) extend the range of PID values (correct PID MSB masking bug)
    (2) add sin(x)/x compensation to improve the OFDM waveform (suggested by Ron Economos W6RZ)
    (3) a few minor fixes involving UDP support
    (4) support for Hauppauge HD-PVR encoder
Currently, Charles does not have a 32-bit development PC available to build a draft deb file of v2.04 32-bit. So Ken W6HHC will start the 32-bit build of v2.04 and test when USA tax reports are finished towards the end of April.

Ken W6HHC has not made much progress on the Logitech C920 HD web camera project for DATV-Express. Ken has learned how to compile code from source on Ubuntu and Lubuntu in an attempt to duplicate the efforts accomplished by Alex OZ9AEC. Alex has provided lots of support and guidance, but Ken seems to end up with two competing installations of gstreamer software on the PC. One installation is from Ken's build and one installation seems to occur from installing VLC. No progress for two months now with C920. Charles G4GUO found some worthwhile DATV articles by Chris MWØLLK and announced them on the BATC Forum. The good news is that Chris MWØLLK has been experimenting with using FFMPEG software on Windows to create valid transport stream (TS) for DATV-Express without one of the listed Hauppauge PVR type of encoder cards The MPEG2 TS is generated on a Windows machine using ffmeg/avcom and sent by UDP protocol via Ethernet to the DATV-Express board controlled by a Ubuntu PC or ODROID, etc.

Chris has a companion article about using vMix software and FFMPEG on a Window machine to generate the Transport Stream for the FATV-Express board. You can find Chris’ articles at:

http://www.tannet.org.uk/using-ffmpeg-t ... -overlays/

Ken hopes to start back up on DATV...working soon on Chris MWØLLK 's efforts and also Alex OZ9AEC's efforts.

As a final note - the DATV-Express project team has dropped further support for the older Ubuntu Version 12.04.4 LTS operating system and is now focused on only the newer Ubuntu Version 14.04.1 LTS OS. All new DATV-Express users are requested to install only Ubuntu 14.04.1 LTS.

"project is set to slow speed"....de Ken W6HHC

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