DATV-Express Project - January update report
Posted: Sun Feb 07, 2016 3:51 pm
Art WA8RMC was very busy in January manufacturing a new production batch of DATV-Express boards. Twenty-four assembled PCBA’s were picked up from the nearby assembly vendor on 2016-01-26. The first 4 boards that Art tested all came up OK on that day….and so Art tested the rest of the boards. USA inventory of DATV-Express boards are now full.
The EU distribution center for DATV-Express shipped five boards….all to a new group of hams working on a new DATV repeater in The Netherlands. Art immediately sent another batch of completed boards to the EU distribution center to replenish that inventory location and relieve a back-order from Belgium.
Charles G4GUO has been doing some testing of H.262 and H.265 compression CODECs for video/audio. (BTW – H.262 is just the formal name for MPEG2 CODECs.) H.265 supports HD video very efficiently…essentially twice the compression (averaging one-half the bits per frame) oh H.264. BUT…the H.265 latency is much longer than H.264. Part of the latency problem is (a) the H.265 algorithm looks forward at more video frames before it begins to create a “short hand” compression of each frame and (b) the H.265 compression algorithm is very processing intensive (Charles reported that his four-core 64-bit computer had each core running at nearly 100% of capacity). The new Windows-based programming effort by Charles 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.
This new software is all still being worked on, but does currently 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 Charles will be adding AAC audio.
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 project team does not have support for. G4GUO has 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.
On the Yahoo DigitalATV forum, there is a lot of discussion that Hauppauge has now released the drivers for the HD PVR2 model 157210 capture unit for ubuntu. Grant ZL1WTT/VE3 reported that the ubuntu drivers can be obtained at the Hauppauge support download area. But no one has yet said that they have actually used these new linux drivers with DATV-Express and HD PVR 2 unit?? G4GUO suspects that the PVR 2 drivers are source code and may have to be compiled by the installer to be compatible by DATV-Express?? But, perhaps a new distribution by Ubuntu now contains the drivers? (Is they any feedback from readers on this topic?)
Art WA8RMC is off in Florida escaping the snow storms of Ohio and Ken W6HHC is now happily-married and getting ready for ski vacation in the Sierra-Nevada mountains of California at Mammoth.
"project is set to slow speed"....de Ken W6HHC
The EU distribution center for DATV-Express shipped five boards….all to a new group of hams working on a new DATV repeater in The Netherlands. Art immediately sent another batch of completed boards to the EU distribution center to replenish that inventory location and relieve a back-order from Belgium.
Charles G4GUO has been doing some testing of H.262 and H.265 compression CODECs for video/audio. (BTW – H.262 is just the formal name for MPEG2 CODECs.) H.265 supports HD video very efficiently…essentially twice the compression (averaging one-half the bits per frame) oh H.264. BUT…the H.265 latency is much longer than H.264. Part of the latency problem is (a) the H.265 algorithm looks forward at more video frames before it begins to create a “short hand” compression of each frame and (b) the H.265 compression algorithm is very processing intensive (Charles reported that his four-core 64-bit computer had each core running at nearly 100% of capacity). The new Windows-based programming effort by Charles 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.
This new software is all still being worked on, but does currently 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 Charles will be adding AAC audio.
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 project team does not have support for. G4GUO has 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.
On the Yahoo DigitalATV forum, there is a lot of discussion that Hauppauge has now released the drivers for the HD PVR2 model 157210 capture unit for ubuntu. Grant ZL1WTT/VE3 reported that the ubuntu drivers can be obtained at the Hauppauge support download area. But no one has yet said that they have actually used these new linux drivers with DATV-Express and HD PVR 2 unit?? G4GUO suspects that the PVR 2 drivers are source code and may have to be compiled by the installer to be compatible by DATV-Express?? But, perhaps a new distribution by Ubuntu now contains the drivers? (Is they any feedback from readers on this topic?)
Art WA8RMC is off in Florida escaping the snow storms of Ohio and Ken W6HHC is now happily-married and getting ready for ski vacation in the Sierra-Nevada mountains of California at Mammoth.
"project is set to slow speed"....de Ken W6HHC
