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Reply 20 of 68, by elianda

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Some may find this useful. I have updated my tool for alignment, you can grab it here: ftp://retronn.de/align_tool/
It has now some small GUI interface which is easier to use as the configure dialog in the epiphan tool.
You need the test images as well to get the correct graphs in the lower panel and the "auto" functionality to work.

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Reply 21 of 68, by mr_bigmouth_502

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elianda wrote:
The given VGA modes of the card are a bit misleading, it defaults to 720x400 for DOS text modes/low res graphics. […]
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The given VGA modes of the card are a bit misleading, it defaults to 720x400 for DOS text modes/low res graphics.

The truth is that the vertical number of scanlines is given but the number of horizontal pixels can freely be chosen. So it will also sync to 1280x400 or 640x400 and so on with the same source mode.
Considering that text mode is 640x400 pixels and low res graphic modes are scandoubled versions of it like 320x200 then capturing this at 720x400 gives a non-integer oversampling horizontally.
So better disable 720x400 and add 640x400 as own mode for all low res DOS stuff.

Well there is a lot more to consider...

The card usually comes with two brackets (for use with and without A/V-Kit). So I most likely have one left for use without A/V-Kit. Anyone?

VGA text mode is 720x400. https://en.wikipedia.org/wiki/VGA-compatible_ … mmon_text_modes

Reply 22 of 68, by elianda

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mr_bigmouth_502 wrote:
elianda wrote:
The given VGA modes of the card are a bit misleading, it defaults to 720x400 for DOS text modes/low res graphics. […]
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The given VGA modes of the card are a bit misleading, it defaults to 720x400 for DOS text modes/low res graphics.

The truth is that the vertical number of scanlines is given but the number of horizontal pixels can freely be chosen. So it will also sync to 1280x400 or 640x400 and so on with the same source mode.
Considering that text mode is 640x400 pixels and low res graphic modes are scandoubled versions of it like 320x200 then capturing this at 720x400 gives a non-integer oversampling horizontally.
So better disable 720x400 and add 640x400 as own mode for all low res DOS stuff.

Well there is a lot more to consider...

The card usually comes with two brackets (for use with and without A/V-Kit). So I most likely have one left for use without A/V-Kit. Anyone?

VGA text mode is 720x400. https://en.wikipedia.org/wiki/VGA-compatible_ … mmon_text_modes

Please read what I wrote, I did not state otherwise. I wrote that the pixel resolution is 640x400 and you can suppress oversampling artifacts by choosing the horizontal pixel number for the capture freely.
The actual graphics mode does not change of course (How could it anyway?)

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Reply 23 of 68, by elianda

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Another small update for the alignment tool:
You have now also an indicator for the analog noise at the black level and and the 50% grey level. This helps to identify cable problems and also helps to compare graphics cards.
As well as the slight detuning of the PLL allows to measure the sharpness of the signal.

Both are great indicators to compare 2D signal quality of cards.

Screenshot with slightly detuned PLL and intersection points where the sampling position shifts from black to white and vice versa:
screenshot.png

The curve shape represents the analog signal over a single pixel.
With correct PLL the Phase is typically set to the maximum point / minimum point for white / black.
You can of course play around live and see how changing the phase with a slightly detuned PLL shifts the curves.

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Reply 24 of 68, by DNSDies

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Oh, if anyone is still looking for a compatible bracket for this card, I used a DELL X8760 DVI card.
It's a perfect fit.

Also, would still like pics front and back of the AV expansion board. It would be nice to see if it's possible to tap into the expansion pins directly.

Reply 25 of 68, by PhilsComputerLab

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That new version is looking very nice!

Will check it out when I start testing my next card, likely an ATI card 😀

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Reply 26 of 68, by elianda

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My current next plans are:
- move the analysis graph panel to the GUI window, as it gets covered below the lower screen edge when e.g. having 1280x1024 output on a 1920x1080 display.
- automatically reconstruct the pixel shape curve by finding the two intersection points between the black and white curve. As the distance between the intersection points is exactly a single pixel I can scale it always the same. Currently detuning the PLL by +1 (-1) is roughly 1024 samples on 1025 (1023) pixels. This gives you one intersection point but you will notice that of you would extend the curves periodically they would not fit perfectly. So detuning by 2 is better as one gets two intersection points that define the range of a single pixel within the graph itself. (downside is that you only have about ~256 samples over a single pixel instead of ~512 for a detuning of 1 at 1024 horizontally, but I guess thats ok to work with).
You may wonder how that works:
If you sample periodically 1024 times on 1024 pixels with the identical frequency then the point where the sample is taken is always the same on a pixel. Now if you sample 1024 times on 1023 pixels then on the second pixel the sample point is shifted relative by +(1024/1023). So the second pixel is sampled at a relative position of 1.001, the third at 1.002 and so on. Now if you have a periodic signal like black/white alternating vertical lines then for the transitions from black to white (even pixels) the first sample would be at 1.000, the third at 1.002, fifth at 1.004 and so on. Of course the third sample at a relative shift of 1.002 samples a different black to white transition than the first sample, but the pattern is periodic. This way the sample position is shifted in small steps over the periodic signal, thus over the pixels.

I most likely should split this also up by R,G,B component as the output amplifiers of the cards could have different rising/falling edges.

- I didn't mention it but if you click on the test image you can move horizontal and vertical alignment by using the cursor keys.

Well, if you got any more ideas what would be nice to implement...

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Reply 27 of 68, by elianda

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I updated the program:

http://retronn.de/ftp/align_tool/Screenshot.png

It is all now component resolved. When detuned it detects the intersection points automatically and plots in the lower graph the signal shape over two pixels (black/white).
This graph should scale independent of the resolution and shows always two pixels range.

I guess that is a pretty good resolution to check 2D signal quality.

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Reply 28 of 68, by DNSDies

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So, I got tired of waiting for someone to take some photos of their AV kit and just probed the board myself.

The AV kit is a SCAM. You're paying $250 for a breakout board.

The pinout of the JP1 header is:

Top row (Pins 1-5)- Ground
Pin 6 - Composite Video/ Svideo Luminance (Y)
Pin 7 - Svideo Chrominance (UV)
Pin 8 - Microphone In
Pin 9 - Audio Left In
Pin 10 - Audio Right In

I didn't probe the JP4 header for "balanced" very carefully, but:
Pin 2, 5, 6, and 9 are ground, and it just uses 2 pins for each audio channel.
Left is likely pins 1&7, right is likely pins 4&8

For $20, you can get a DB9 to Motherboard 2x5 pin header bracket, female Svideo/Composite/L/R cables, and a DB9 connector and hood and make a custom breakout cable.

Reply 29 of 68, by soviet conscript

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DNSDies wrote:
So, I got tired of waiting for someone to take some photos of their AV kit and just probed the board myself. […]
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So, I got tired of waiting for someone to take some photos of their AV kit and just probed the board myself.

The AV kit is a SCAM. You're paying $250 for a breakout board.

The pinout of the JP1 header is:

Top row (Pins 1-5)- Ground
Pin 6 - Composite Video/ Svideo Luminance (Y)
Pin 7 - Svideo Chrominance (UV)
Pin 8 - Microphone In
Pin 9 - Audio Left In
Pin 10 - Audio Right In

I didn't probe the JP4 header for "balanced" very carefully, but:
Pin 2, 5, 6, and 9 are ground, and it just uses 2 pins for each audio channel.
Left is likely pins 1&7, right is likely pins 4&8

For $20, you can get a DB9 to Motherboard 2x5 pin header bracket, female Svideo/Composite/L/R cables, and a DB9 connector and hood and make a custom breakout cable.

Intresting, and thank you for the tip on a compatible bracket.

Reply 30 of 68, by Beegle

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DNSDies wrote:

So, I got tired of waiting for someone to take some photos of their AV kit and just probed the board myself.

From my understanding most people here bought their card from ebay, and thus, without the bracket AND without the A/V kit. Maybe that explains why no pictures showed up. 😒

Thanks for the investigation on this, from the specs you wrote I might try to build myself one eventually.

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Reply 31 of 68, by PhilsComputerLab

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Good to know, thanks for investigating this.

The way I see it, I already have plenty of composite and S-Video capture options, and I assume most have one, and they don't cost much. From USB adapters to vintage graphics cards like the All in Wonder cards. Like Elinda mentioned, vintage capture cards might actually be better suited for machines like the Commodore 64, something I didn't know 😊

The DVI2PCIe real strength is definitely the VGA capture capabilities. I don't think it has any competition in that regard.

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Reply 32 of 68, by soviet conscript

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well, finally got around to testing my card and I have a few quick questions. keep in mind I'm not very tech savoy when it comes to capture cards and resolution stuff as it applies to them. I didn't do anything with the software or tweak anything I just connected my DOS PC and recorded. it detected the signal without any issues.

1) how do I get it to not stretch the image and keep the regular aspect ratio

2) is there any way to not record in AVI? just minute or two of footage is a massive size? or am I forced to record in avi and have to use a separate program to compress?

Reply 33 of 68, by elianda

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Which programs do you use for viewing/capturing ?

1) Pixels are always treated as quadratic as no additional information is present. You have to set you viewer to show it as 4:3.

2) The AVI video container does not say anything about compression. For the epiphan tool by default no compression is configured. I would recommend to use another program, like VirtualDub.

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Reply 35 of 68, by DNSDies

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You might want to try using Open Broadcaster Studio to view/record from the capture device.
It's a fairly robust program, and it's very popular, so there are many easy to read guides on doing anything you would need.

OBS also allows you to record directly to a YouTube-friendly format.

I used it to capture output from my Neo Geo MVS hooked up to an Arcade Supergun through RGB+Sync, and it looks fantastic.

Reply 36 of 68, by elianda

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OBS works for simple captures, however it has a the problem by design that it can not capture frame exact.
Since one could add multiple video sources to a scene the input frame rate of a source is not connected in any way to the output frame rate of the video. OBS takes the last frame of each source.
This can lead to stuttering. I noticed this specifically with a C64 as source signal where the 50 fps progressive PAL is captured as 25 Hz interlaced (2 frames combined). So if OBS skips/doubles one source frame it stutters with two frames skipped/reused.
It might be disturbing when trying to capture fluent animations/scrollers.

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Reply 37 of 68, by soviet conscript

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I haven't had much luck. I haven't tried OBS because of the aforementioned skipping issues but nothing else I've tried for capturing has been very convenient. I have to also say the quality of the captures isn't as good as I thought or have seen from other peoples videos but I'm guessing that has to do with me just using default settings. I am clueless when it comes to the technical side of this.

using Epiphans software works but is very inconvenient as it only captures in AVI and in smaller 2gb or so chunks which is only a few minutes if that. so I have to splice the separate videos together and then convert it to MP4 using windows movie maker which is kind of inconvenient.

Vitrual Dub at least seems to capture the AVI as one giant file but I've had a few times where it had trouble centering the image where I didn't have that issue with Epiphans software.

I tried Windows media encoder because the DVI2PCIe website said it was compatible to capture as windows movie files but I get a "no specific device driver found" error.

Lastly VLB player sort of works. I was able to get it to capture in mp4 format but it only seems to work if there is no sound. If there is any sound the image stutters and sound is out of sync.

Reply 38 of 68, by stynx

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elianda wrote:

My current next plans are:
...
Well, if you got any more ideas what would be nice to implement...

Hi, Im using the DVI2PCIe for capturing RGBs Video from Apple IIgs, Atari ST and Amiga computers. It's a bit tedious to configure the settings every time i start the capture tool. It would be nice to have the following resolutions added to your align tool:

31khz mode
640x400 72hz b/w

15khz modes:
640x200 4c
640x256 4c
320x200 16c
320x256 16c

The colors should be from a 512 color palette. Amiga, Atari STe and Apple IIgs support 12bit color (4x4x4) but for compatibility it should be the Atari ST palette with 9bit color (3bit R, 3bit G, 3bit B). RGBs can be connected to the DVI2PCIe by connecting the Csync to the Hsync line on the VGA-adapter. I can test the Apple pigs and Atari modes, but since my A500 is bust at the time, the x256 modes cannot be tested by me.

Reply 39 of 68, by elianda

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With 'resolution added' you want to have test images that run on the specific platform?
If you mean physical resolution that the card detects you have to add those to the Epiphan Tool/Configuration/Modes tab to the Modes List.

The physical resolution is probably somewhat different for the 320x200 16c modes? (like 640x400?)
Also for the test images on low color modes the problem arises that the color dynamic can only be optimized if the pure Red/Green/Blue colors are part of the available palette. (e.g. for VGA this is true).

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