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Amiga computer related discussion => Amiga Hardware Issues and discussion => Topic started by: dirtiemds on February 22, 2009, 08:34:57 PM

Title: Amiga RGB to YUV and capture
Post by: dirtiemds on February 22, 2009, 08:34:57 PM

Hello community,

I have the following problem:

I want to capture all intros and slideshows of my Amiga-group in highest quality to video. Therefore I bought a SCART-RGB to YUV adapter. For recording I have a AVID-MOJO-BOX with YUV inputs. But the signal looks noisy, is jittering and also the colors were slightly wrong. If I connect the adapter to other recording devices, which also can handle YUV, the picture scrolls through (missing H-SYNC???) or is flickering like a stroboscope. The strange thing is if I connect it to a broadcast tv monitor the YUV picture looks very good and stable. Why its not possible to capture Amigas output in this quality too?

Thanks for your hints, thomas aka d!RT!E/ moodsplateau.net

Title: Re: Amiga RGB to YUV and capture
Post by: dirtiemds on February 26, 2009, 07:23:27 PM

It seems no one has an idea how to solve this :( I tried also the capture box of avid liquid (ex pinnacle) but this wont work too. Its a pity...

Title: Re: Amiga RGB to YUV and capture
Post by: Speelgoedmannetje on February 26, 2009, 07:41:00 PM

Quote

dirtiemds wrote:
It seems no one has an idea how to solve this :( I tried also the capture box of avid liquid (ex pinnacle) but this wont work too. Its a pity...

Maybe it can't handle overscan?
Maybe it wants the composite signal as sync signal, instead of composite sync.(or vice versa; I had kinda a similar problem with my 1084s + sega megadrive)

Title: Re: Amiga RGB to YUV and capture
Post by: Zac67 on February 26, 2009, 10:14:19 PM

Are you sure you've got the right converter? Probably you mean a Y/C / s-video / mini-DIN converter - or is that component (YPbPr)?

Y/C differs for PAL and NTSC, only RGB and YPbPr can be used interchangeably.

Title: Re: Amiga RGB to YUV and capture
Post by: dirtiemds on February 26, 2009, 10:43:46 PM

Its a component converter from SCART RGB to YUV.
I fear its not the problem of converting (the video is shown correct on a pal monitor with yuv input) its because Amigas output is not really PAL conform... f.e. in some cases the resolution is 320x256 instead of 720x576. The video is non-interlaced instead of interlaced. Thats why the recording devices go crazy. Probably I need a good time base corrector to record the output... or is there a possibility to use a genlock?

Thanks, d!RT!E

Title: Re: Amiga RGB to YUV and capture
Post by: Skippy on February 27, 2009, 01:37:14 AM

Hiya, the AVID MOJO seems like an awful lot of beefy hardware for an Amiga analogue video signal. Was this a device you had to hand.

"Why its not possible to capture Amigas output in this quality too?"

If you were unable too resolve this issue, here are some workaround thoughts.

Are you trying to retain the best closest match of the original source to recorded file without degrading via say S-Video/Composite.

You could comprise and use the S-Video/Composite on a PC video card and record using http://www.virtualdub.org/ for 95/98/ME/NT4/2000/XP.

Another option you could explore is maybe if you have a DVD recording device/player, plug the Amiga's RGB Scart into it, record the footage in HD to DVD then transfer the DVD material over to your PC workstation and edit and prepare this way with free GNU software.

This way the DVD recording resolution is already higher than the source thus retaining max Amiga video clarity and allowing for degrading/gentle compression from HD to something for comparative to the Amiga's video source.

I think too as you've mentioned and the other posters have followed up with regarding the actual compatibility and reliability of the conversion of the Amiga's RGB analogue signal to YUV too is part of your initial problem.

Also maybe try loading your Amiga demos into UAE and record them to file this way.

Just some ideas, hope it helps.

Title: Re: Amiga RGB to YUV and capture
Post by: bloodline on February 27, 2009, 02:19:36 AM

Just run your. Amiga software in UAE! WinUAE has a simple Video->File output interface, it is the best way!

Title: Re: Amiga RGB to YUV and capture
Post by: Iggy_Drougge on February 27, 2009, 02:21:50 AM

I've been using a Panasonic DVD recorder to capture Amiga RGB pictures with acceptable quality. Here are some samples:

1 (http://homepage.mac.com/idrougge/bilder/AmigaRGB/cosmicspacehead.png)

2 (http://homepage.mac.com/idrougge/bilder/AmigaRGB/f40.png)

3 (http://homepage.mac.com/idrougge/bilder/AmigaRGB/earlystartup.png)

4 (http://homepage.mac.com/idrougge/bilder/AmigaRGB/rtype.png)

Title: Re: Amiga RGB to YUV and capture
Post by: dirtiemds on February 27, 2009, 07:19:41 AM

Heya, thank you Skippy, bloodline and Iggy_Drougge. I tested recording the intros using winuae and it worked in low resolution. It looks better than via cvbs and if the other ways (pc-grafic-card-capture, standalone dvd-recorder) will not work I´ll do it that way. Now I have to find the hardware to test the other two possibilities :D

Thank you, d!RT!E