Video sources

g4bbh
Posts: 74
Joined: Thu Mar 13, 2008 7:19 pm

Re: Video sources

Post by g4bbh » Mon Feb 20, 2012 12:20 am

I'm getting a Pad% of around 5.2, very similar to what I get with a GBPVR produced file.
Note that Digilite Transmit 1.40 tends to crash on the AVS produced file, 1.40b is just fine. It would take some more investigation to see how good the MPEG-2 encoder in AVS compared to the MainConcept one which is pretty good or the Hauppauge hardware encoder. I have not yet had the opportunity to really concentrate on watching for artefacts etc. I did wonder how it would work out for lip-sync but that looks near perfect.
I have also managed to get the WinTV USB and DigiLite software working an an NC10 atom based netbook although I had to change the FEC to 3/4. Ideal for portable use as the netbook only takes 15W of power and gives several hours on it's battery.
Now how about HDATV :-)
Dick G4BBH

G4EWJ
Posts: 1377
Joined: Wed Feb 17, 2010 10:11 am

Re: Video sources

Post by G4EWJ » Mon Feb 20, 2012 11:38 am

Their 2920 must be the same as GBPVR's then.

I'm looking for a netbook myself for portable work. Why did you have to change the FEC?

HDTV may take some time. :) DVB-T2 has a 1.7MHz bandwidth mode apparently, which would be good for 70cm, but it's probably the most complicated system of the lot.

Brian

g4bbh
Posts: 74
Joined: Thu Mar 13, 2008 7:19 pm

Re: Video sources

Post by g4bbh » Mon Feb 20, 2012 12:56 pm

Brian

With an FEC (on serialiser) of 1/2 the PCR lag creeps negative until I guess the -999 point is exceeded at which point Digilite Transmit seems to restart (version 1.40 or 1.40b). Pad% around 0.2

With FEC at 2/3 to 7/8 it works. PCR lag remains positive and Pad% is about 15 at FEC 2/3 and higher as the FEC is increased.

These are probably due to a limitation of the netbook coping with the WinTV GBPVR source and DigiLite Transmit simultaneously. No such problem when playing a pre-recorded file.

I had a few headaches getting the WinTV running on the netbook with it's basic XP system. The faster Toshiba laptop with Windows 7 was no problem. The Samsung NC10 only runs an atom with it's two logical cores and has various internal USB devices which load the controller down. More recent versions of the netbook may be better.
The things I found are:-
1. Do NOT use any external USB hub - even if the WinTV and DigiLite are connected directly to USB ports and the external hub not in use.
2. Do not attach any external USB devices other than WinTV USB, DigiLite and a mouse.
3. Make sure no other applications are running in the background - AVG doing a scan really screws things!
4. If the red light on the WinTV USB does not come on power it off and on again. Do not unplug and replug the USB cable or it usually triggers off a driver reinstall.
5. Sometimes Digilite Transmit reports a missing port (the FTDI). Just unplug and replug the USB cable to the DigiLite and restart Transmit. This seems to happen if I have had to take action (4) above.

Regarding Batch file operation I tried a batch file that has a GOTO START and a :START label instead of PAUSE . I wanted a short testcard sequence to continuously repeat. Unfortunately DigiLite Transmit 1.40 has a PAUSE built in so human intervention is needed to make it repeat.

Dick G4BBH

G8HCB
Posts: 11
Joined: Fri Feb 10, 2012 11:41 am

Re: Video sources

Post by G8HCB » Sat Feb 25, 2012 7:10 pm

Hi,

Just tried the AVS Video recorder now I have my digilite working. It seems that via my HP laptop and webcam I can get things to work.

Here is a short video:- http://www.youtube.com/watch?v=kuaWsvlduro

Only thing that may be an issue is that the pad% hits around 74%. I would not understand if that is an issue or not?

The video shows my settings for AVS Video recorder and the digilite transmit command line status.

Sorry for the poor quality! I used my camera on the mobile phone and it whited out on me when pointing to the TV screen.

de
G8HCB
Chris

G4EWJ
Posts: 1377
Joined: Wed Feb 17, 2010 10:11 am

Re: Video sources

Post by G4EWJ » Sat Feb 25, 2012 7:52 pm

The high PAD% means that the bit rate of the MPEG file is a lot lower than it could be. It isn't a problem as such, it just means you could increase the MPEG recording bit rate and increase quality. The recording bit rate is shown as 1.5Mbps. The video bit rate in the bottom left corner of DigiLite Config shows the sort of figure you could increase it to, if the recording program gives you the option. Try 4000-4500 in the recording program. The PAD% needs to be 5% or above.

720 x 576 at 25fps, audio 192kbps at 48kHz is the usual output from GBPVR.

Brian

G8HCB
Posts: 11
Joined: Fri Feb 10, 2012 11:41 am

Re: Video sources

Post by G8HCB » Sat Feb 25, 2012 9:43 pm

Brian,

Thanks for the explanation of the pad%. I got better results with AVS Recorder with higher resolution and bitrate. Strange resolutions in the software though. 640x480 was the closest to the 720x576 specification that I could choose. But still padded.

I also did experiments with Xilisoft HD Video Convertor 6 for pre-recorded HD (1920x1080p) content to MPEG2 and set 4000K 720x576, 196K 48Khz audio. This worked a treat for my prerecorded content. Not free but I own it anyway.

Again shown working on my camera phone. So I am quite happy I have some other solutions....

http://www.youtube.com/watch?v=aslrngjGe5s

Where's my WINTV card gone? Still can't find it....

Chris

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