how to change the quality of captured video?

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Re: how to change the quality of captured video?

Postby Falcosoft » 2017-12-29 @ 16:58

Yes, Dune 2 is a special beast. But it does not change the facts about the correct aspect ratio of MCGA 320x200 mode. In the Dune 2 HD port topic I referred above you can read many opinions:
gerwin wrote:
Leolo wrote:Your workaround works for me as well (with a Dell 2209WA panel), but then you have to switch back to 16:9 (or 16:10 in my case) to play the game properly (otherwise you'll get extremely thin and tall soldiers).
You change it back when entering the battle screen, but that part should also be authentic with the rectangular pixel settings which I stated. Although I agree it looks a bit stretched, I will have to compare it to my retro system with CRT screen. Maybe Westwood somehow did not feel like drawing the units and map graphics with rectangular pixels in mind.


And here is how the 'squares' looked like on a period correct CRT:
download/file.php?id=11325

Also the creator of the HD mod decided to set the deafult pixel aspect ratio to 1:1.1 as a compromise because of this:
VileRancour wrote:yep, aspect correction is there -- the default value is 1.1, but can be changed to the correct 1.2. It does "blocky" scaling, but the options are flexible enough to avoid it where you don't want it.

But e.g. in case of Doom and many other games there is no such ambiguity and the correct pixel aspect ratio is 1:1.2, period.

it turns out all this time since Millenium, I played in Dosbox with wrong proportions?

It's not likely since not all games used MCGA 320x200 display modes. E.g. all later SVGA games (Duke 3D, Warcraft II etc.) used square pixel modes (such as 640x480, 800x600) without this kind of problems. But to be on the safe side you should set aspect=true in your dosbox.conf file and choose an output mode that supports scaling.
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Re: how to change the quality of captured video?

Postby BOBAH1 » 2017-12-31 @ 09:21

oh, i found now where this dosbox.conf ...
https://wiki.archlinux.org/index.php/DOSBox
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Re: how to change the quality of captured video?

Postby BOBAH1 » 2018-1-01 @ 08:57

For the new year with fresh thoughts I found another version of compression. Instead UncompressedRgb/YCbCr of Dub, painfully huge size leaves under a Gig. I tried my old russian video editor - VSDC . version 3.3.5 was still buggy, but completely free. In General, it does have one built-in codec Lagarith Lossless Codec. https://en.wikipedia.org/wiki/Lagarith Which somehow, he connected to my VirtualDub. In short using this codec - quality like original, and the size is only 30 meters instead of Gigabyte.
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Re: how to change the quality of captured video?

Postby ripa » 2018-1-03 @ 21:52

FYI, the bad video quality (blurriness and color bleeding) is caused by your video playback software / video card, not by the ZMBV codec. It's doing a color space conversion (from RGB to some YUV-like format which includes color subsampling).

If you can find a way to force video playback in RGB color space, you shouldn't have quality problems. No need to re-encode to Lagarith or some other format.

Relevant, although not very well written Wikipedia articles:
https://en.wikipedia.org/wiki/Chroma_subsampling
https://en.wikipedia.org/wiki/YUV
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Re: how to change the quality of captured video?

Postby BOBAH1 » 2018-1-09 @ 02:03

thank you) In Lagarith I translate only because of the size of the output video. But another little question. How can I capture gameplay with game Retal ? https://en.wikipedia.org/wiki/F29_Retaliator Except the Videocam from the screen. The game requires install it on the C: drive. Start normal with Win, and with DOSBox is not start.

(from its help text inside: "Jake's Notes: First off, you MUST run this game from a directory off the root called Retal. Sorry but this is the subdirectory the game automatically installs
in and apparently the only place the log can be stored. I did not have the time
to get around this slight annoyance.")
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Re: how to change the quality of captured video?

Postby Asterisk » 2018-1-17 @ 10:48

If you are trying to upscale your video and get proper aspect correction, the best way to do that is to upscale to 1600x1200 using a nearest-neighbor/point filter. 320x200 graphics meant for 4:3 display require upscaling to 1600x1200 or an exact multiple thereof to view without artifacts or distortion on a modern square-pixel display. You can then subsequently downscale to a lower resolution, e.g. 1440x1080 or 960x720, using an interpolative algorithm, like bilinear, so you get nice-looking 4:3 graphics at a resolution suitable for current video formats. If you're using VirtualDub, it's as simple as adding two scaling filters sequentially from the filters interface. You can also use FFMpeg on the command line (e.g. ffmpeg -i dosbox_000.avi -vf scale=1600:1200:sws_flags=neighbor ...).

Color space can be a bit tricky, since video distribution today most commonly uses YUV 4:2:0 rather than RGB, and some devices won't properly play RGB encoded video. I normally convert to yuv420p with FFMpeg after scaling captured videos, but this does result in certain colors being slightly off when the source is 16-color EGA/CGA videos. Fortunately, the x264 codec *does* support RGB, and also has a lossless mode which encodes much faster and compresses much better than ZMBV when you're dealing with high-resolution upscaled video. If you're using VirtualDub on Windows, ffdshow-tryouts is a great way to get FFMpeg installed as a DirectShow filter, and make its integrated codecs available to VirtualDub, which should allow you to encode with h264 losslessly and in RGB.
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Re: how to change the quality of captured video?

Postby BOBAH1 » 2018-3-21 @ 14:11

thank you all! The deed is done. the result can be seen here:
Image
https://www.youtube.com/watch?v=YvqgwWJyTkA
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