Video sources

[g4bbh]

I am just embarking on 'going digital' or more correctly 'going DigiLite' and have started ordering all the bits needed, cleaning up the binocular microscope and pacifying the XYL. I am now at the stage of simple questions such as:-

Can the software accept video files from other sources than the WinTV card. For example can I prepare video in something like Premiere and use some other way to produce the .ps file and store it for later transmission. If so can I then switch sources between 'live' from the WinTV and the pre-prepared recording? This is primarily because I am loath to convert good quality digital video to PAL Y/C and back to digital with all the losses involved.

Dick G4BBH

[G4EWJ]

Yes, that is possible.

There's a facility in DigiLite Transmit at the moment that can play back pre-recorded MPEG-2 program stream files, as produced by GBPVR. I haven't publicised it much as it's not finished yet and there are still some bugs.

If you drag and drop or copy and paste one of the files that GBPVR has recorded, onto the DigiLite Transmit program icon, DigiLite Transmit will process and send it. Make sure that DigiLite Transmit isn't already processing a file. It can be left "Waiting for an active recording file" as it won't have opened the USB ports at that point. Note that you can't use links.

You can also use a batch file. This has the added advantage that it can start at an offset into the MPEG-2 file. E.g.

Create a file called sendit.bat, enter something like the lines below, including the quotes and save it in your DigiLite program folder. For convenience, change the MPEG-2 file name to something shorter than GBPVR uses.

"DigiLite Transmit v1-40" "C:\myfiles\Manual Recordings\testcard.mpg" 123.4
PAUSE

Change the filename and path to wherever GBPVR stores its recordings.

This replays the file starting at an offset of 123.4MB. PAUSE will stop the batch file from exiting immediately so you can see any error messages. The main bug is that it will survive one resync, but a second will send it back to the start of the file.

If you create your own .mpg files, they need to be in program stream format in 2kB blocks with 000001BA PS pack headers. If you can send me one you've produced, I can give it a try and see if it works.

Brian

[w0fms]

Thanks for letting us know about this Brian! I have some tricks that I've done to make test cards/test patterns using ffmpeg and having the ability to send them like this would be super for testing and maybe even over the air use in the future.

Once I clean up the tricks I'll post them. FFMPEG is really powerful but it's a bear to learn how to do the command line options. I hope to "catch back up" after Christmas Day and get back on this project!

Fred W0FMS

[g4bbh]

Using Brian's batch file method I have had excellent success in transmitiing files previously created by GBPVR. I have a testcard sequence which I can call up at any time without having to set up the WinTV etc. However to get best results in transmitting testcards I really need to avoid having to go through the analogue PAL stage required by the WinTV device. So far I have had no success in creating GBPVR compatible files that don't crash Digilite Transmit V1-40. The only software I have found that can transcode to program stream or transport stream is MainConcept Reference v2 which can transcode most formats. However I have failed miserably to get settings that produce the right structure. MainConcept Reference can analyse files from GBPVR and I can compare this with analysis of files it has produced which has helped get close but something just doesn't match. My not being very conversant with mpeg doesn't help. I think the GOP structure was created by Turing's team at Bletchley Park!
Has anyone found any other software than create the correct format?
Dick G4BBH

[G4EWJ]

I've had similar problems.

I wrote DL Transmit to handle the format of the output from GBPVR and WinTV and there are lots of other little sections that it's possible to put in a program stream that DL won't cope with. The blocks can be of varying length, but DL only handles 2kB fixed. Another item to go on the development list.

I've tried creating some moving test cards with MS Photostory and using free MPG converters, but although the format is correct, there's something wrong in the timing and they tend to jump on a receiver.

Brian

[G8HCB]

I've nearly finished my Digilite and can't find my Hauppage wintv card, so..... I was playing with software to record video to mpeg2 streams and the Digilite transmit software seemed to make something happen when I fed it with the output from this software. I.e. I could see packets being pushed. I am hoping this maybe an easy none hauppage solution, but I've not been able to see my own video yet as I still need to screen my LO and finish off tweaking things. But I will post the link to the software here to see if anyone can make it work.

http://www.avs4you.com/AVS-Video-Recorder.aspx

Interesting to see if it is an option other than using a Hauppage card. I know the resolutions wern't ideal when testing with my HD webcam. But if it actually produces output and doesn't stutter, then maybe an option. Maybe someone who has a board up and running could try it and either verify it is ok, or bin the idea? And if it doesn't work, maybe a future build would allow this type of software based solution to work?

Cheers

Chris
G8HCB

[g4bbh]

Chris

I could not see any suitable options in AVS Video Recorder so I downloaded AVS Video Converter version 8.1.2.510 and fed in a short video of a testcard sequence (created in Adobe Premiere as a DV format AVI). I selected MPEG-2 output and in the advanced tab set the bitrate to 2920, to match what I had in Digilite Config, size 720 x 576 and 25fps. I also set audio to a bitrate of 192 and 48k 16 bit sampling. The resultant file crashed the stock Digilite Transmit program but seemed to work OK with Brian's 'b' version. Unfortunately there is a rather too clear watermark on the result as I only have the demo version of AVS Video Converter

I am now transcoding a 1 hour video to MPEG-2 to see how that looks. Perhaps AVS is useable route and simple to set up but lacks the facility to fine tune the settings.

Dick G4BBH

[g4bbh]

Just to confirm that using the above method I converted a one hour DV AVI to mpeg-2 and it ran flawlessly with good sound timing. Looks promising.
Dick G4BBH

[G8HCB]

Excellent news. Pity it isn't free, but it opens options up for prerecorded video content over digilite.

It's a real shame that AVS Recorder will not give the right resolution or bitrate options.

Chris
G8HCB

[G4EWJ]

Good news. Did it give a reasonable value for Pad%? I'm not sure which layer of the MPEG onion the GBPVR bit rate refers to, so the converter might have other ideas.

Have you tried it with a WMV file? I did and it said 'Cannot convert using these output settings' or something similar.

Brian