Game screen capture

This discussion was created from comments split from: New P1 game: Spin Hexagon.

Comments


  • JT Cook wrote: »
    When I did all my Propeller stuff I would have a TV right by my computer so I could see how things look and tweak as needed (at least for NTSC stuff).

    With how I'm set up right now, the nice big NTSC/S-Video capable CRT is actually behind me. A bit annoying when I want to type something on the P1 keyboard and my gamepad also frequently gets tangled on my chair when I turn (well, I just got a bluetooth dongle, so maybe that won't happen anymore). I also often just use the preview window of my video capture device. That doesn't need me to turn my head as far (and I don't have to feel bad about leaving it on a static picture), but has terrible latency. It's also very tolerant to signal corruption (such as color $00 showing up in the active area), which is useful when debugging video code. (I've ordered some cables to get P1 S-Video hooked to the capture device... That'll be cool if it works.)

    And of course for the big game that I haven't decided on a tile for yet, I mostly test on the PC version, which also catches a lot more runtime mistakes than the native P1 version (such as reading nonexistant SD ROM pages, writing to hub locations that shouldn't be written by user code, etc). My high-level emulator is seemingly perfect now, I can't remember the last time I had a bug on real HW that I couldn't reproduce on the PC.
  • P1 S-video should work fine. I used it regularly with my capture device.

    Also, a good CRT can be tuned and align to perform very well, if anyone is into that kind of thing.

  • potatohead wrote: »
    P1 S-video should work fine. I used it regularly with my capture device.

    Well, it works fine on my TV, but the capture device may be a bit more picky. Using a digital (=> non return to zero) chroma signal is kinda weird, isn't it?

    @potatohead What capture device do you have? I have a USB stick kinda one using the UTV007 chipset (nice because it doesn't attempt to do any deinterlacing of its own) that says "EasierCAP". It really doesn't like some video drivers though. Through oscilloscope observation I found out that it doesn't like it when the burst phase doesn't alternate relative to Hsync (i.e. if I set the scope to TV-H triggering and look at the burst, it should be an eye pattern. If it's just a normal wave, the UTV007 won't like it).
  • I have two: ADS HDTV, which is an odd duck. Briefly made, and only useful on WinXP, maybe 7. It is exemplary, does full frame and will display a small pixel as color and small and in the right position. Very accurate.

    My other one is an EZ CAP, and it is less accurate, bit fast and tolerant.

    Both will struggle with PAL signals that deviate from broadcast.

  • Wuerfel_21Wuerfel_21 Posts: 986
    edited 2020-10-01 - 07:41:43
    @potatohead Well, so much for the S-Video capture... it seems to just (very poorly) recombine it into composite and then capture that
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  • Major bummer!

    I never did s-video with my EZ CAP device. I bet it does the same thing. That ADS HDTV one, which is basically impossible to find now, does actually improve with s-video, but frankly will do crazy good on ordinary composite too. It uses an odd chipset that does not have current Windows drivers last I looked. I boot an old XP machine to use it, and I sort of got it to work in Win 7.

    My current HDTV sets vary widely. The two newer LCD ones, ROKU style, are OK. My older Samsung plasma is great on composite, very similar to the ADS device actually.

    If capture really matters, it might be worth looking at different chipsets. Some are going to do much better than others do.
  • potatohead wrote: »
    I never did s-video with my EZ CAP device. I bet it does the same thing.

    Actually, maybe not - there are at least 4 different variations that look almost the same on the outside but are completely different on the inside - that's why I specified that mine has the UTV007 chipset (the STK1160 is apparently also good - I'd order one of those for science if all the listings hadn't disappeared...). I actually had another one before this one that was just UTTERLY TERRIBLE. Basically, it captured the video, then applied the world's ugliest deinterlacing filter, then rescaled the output of that to 720x480 (it actually captures slightly less than 240 lines per field, so now the captured lines are smeared across the output lines) and sent that to the PC. On the outside they looked almost the same (you could tell it wasn't the exact same plastic mold though...)

    Here's what mine looks like for reference: S7300502.jpg

    Also, could @VonSzarvas or any of the other moderators split out the non-hexagonal video quality discussion?
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  • We should make another thread.


    https://www.beachaudio.com/Ads/Ptv-384-p-114321.html

    That's the great one. Perhaps its chipset is available in another device.

  • potatohead wrote: »
    We should make another thread.

    The powers that be seem to have done it for us.

  • Thanks!
  • Wuerfel_21Wuerfel_21 Posts: 986
    edited 2020-10-01 - 20:02:40
    Anyways, what I see a lot of people doing is using some sort of whatever->HDMI converter and then capturing the output of that. Of course, all the generic NTSC->HDMI boxes are utterly terrible (100% a firmware issue, I'd say - just disable the terrible deinterlacing filter when receiving progressive video. If only these things were open source) and the good ones are ludicrously expensive (and so is the actual HDMI capture device...)

    Basically, such a setup for 150+€ vs. a dodgy Easier CAP (lol) for under 15€.
    To be fair, the expensive setup would properly capture SVideo (I think the screenshot above doesn't quite show how utterly unusable the S-video on the utv007 ezcap is - there's, like, a terrible highpass on the luminance) and obviously HDMI, too.

    I also see some people swear by certain Datapath capture cards - except those are ludicrously expensive on the used market as well, lol. 150+€ again

    I'm not exactly in need of super high quality capture, as it were - if I want to capture my work on that game for which I still haven't decided a title because I suck at writing I can just capture the PC version. And for everything else, I guess the Excruciating CAP will have to suffice for the time being.
  • That is about where I got to. That ADS device was $80

    And it did not see ongoing support. But, I was cool in many ways. Stick the little antenna on a car roof and it delivered nice HDTV while in motion. Let the kids play a time or two with that.

    My EZ CAP was like $25 and the few times I use it, it does the job, poorly.

    I could just point a phone at my plasma and get better, which is hilarious!
  • Wuerfel_21Wuerfel_21 Posts: 986
    edited 2020-10-01 - 20:57:10
    Hm, mine does reasonably well with most sources I've tried. Might also be a software thing - I use OBS classic to record it - not necessarily the best software for just recording, but everything else I tried had sync issues - AmarecTV can't keep audio/video in sync and the "bottom field first" radio box in the deinterlace settings is borken and OBS studio produces obnoxious audio popping. And I'm not aware of any other software that can do 240p friendly deinterlacing (OBS calls this setting "retro/scandoubling").

    The default picture settings the driver does are also terrible - I put everything at 128 except sharpness, which I put at 32. Oh and if you use OBS you have to crank the resolution (I use 1440p) to preserve all the resolution, especially when uploading to YouTube and enable point filtering on the source to make it not blurry AF. Oh, and one has to install the CoreAudio AAC thing to make the audio be not poopoo for some dumb reason - who even likes AAC? Opus gang, Opus gang...

    Anyways, it can do... OK... when it's handled correctly and it doesn't hate the signal, certainly better than pointing a camera at a screen, I'd say... At least for P1 capture, haven't really used it for anything else.

    (be sure to actually crank the video resolution to 1440p, it magically looks so much better, especially on the dither heavy Turbulence capture)





    (The Turbulence NTSC signal is actually vaguely troublesome - the color burst phase isn't always perfectly synchronized between cogs and my big TV really does not like that and either only decodes U (really strange) or goes into monochrome mode. Some game graphic drivers (read: COP_gfx) have the same problem. Anyways, the ezcap doesn't mind that, which is actually kinda cool)

  • Those are actually good. Better than I got with my EZ CAP
  • Wuerfel_21Wuerfel_21 Posts: 986
    edited 2020-10-14 - 22:14:06
    So I just did another batch of archive videos and for the occasion, I figured out what the optimal settings for the UTV-007 EZCap/EasierCAP are, to get it too look as close as possible to my actual TV:

    (excuse the German..)
    ezcap_settings.png

    Previously, i'd set sharpness (really just an artificial sharpening filter, 128 is waaay too much) to 32 and everything else to 128, but that doesn't result in perfect blacks and whites. Annoyingly, it sometimes forgets the settings and set itself to random values... Oh the wonders of cheap electronics.

    Also interesting: It does auto gain control on the incoming signal, unlike basically any TV. So if I have both my TV and the capture hooked up, the TV becomes dark due to double termination, but the capture doesn't.
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  • Wuerfel_21Wuerfel_21 Posts: 986
    edited 2020-10-30 - 17:25:34
    Aaand here's to another one.

    So I found some STK1160 easycaps (which allegedly have good S-Video) listed on ebay. What got shipped to me is not an STK1160 easycap. ..but an MS2106 one (VID 534D PID 0021).

    This chipset has quite good picture quality, but doesn't capture full frame rate (25 FPS only! URGH! As opposed to the UTV007 which captures 60 FPS just fine (interlaced into a 30FPS stream that is, but OBS can undo that)) and using it in OBS makes it glitch out a lot (other capture software is fine...). It also isn't very resilient to offspec signals - all the stuff that causes jailbars on the UTV007 is completely messed up on the SM2016.

    So, yeah, this is one to stay away from.

    bad_ezcap_glitch.png
    Pictured: glitchy capture in OBS

    bad_ezcap_miner.png
    Pictured: P1 Manic Miner (has jailbars on UTV007)
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  • Wuerfel_21Wuerfel_21 Posts: 986
    edited 2020-10-30 - 17:26:08
    Wuerfel_21 wrote: »
    This chipset has quite good picture quality,

    Here's a side-by-side: As you can see, the MS2106 would give much better stills if only you could turn down that obnoxious sharpening filter (the config window is all greyed out!) and if it could output full-resolution YUV - you have to choose between lowres YUV and MJPEG (the latter has artifacts and can't be saved to image by amarec, thus the PrintScreen comparsion).

    Also note the weird gradient on the UTV007

    (also note that I misspelled MS2106 as SM2106)

    utv007_vs_sm2106.png
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  • Wuerfel_21 wrote: »
    JT Cook wrote: »
    When I did all my Propeller stuff I would have a TV right by my computer so I could see how things look and tweak as needed (at least for NTSC stuff).

    With how I'm set up right now, the nice big NTSC/S-Video capable CRT is actually behind me. A bit annoying when I want to type something on the P1 keyboard and my gamepad also frequently gets tangled on my chair when I turn (well, I just got a bluetooth dongle, so maybe that won't happen anymore). I also often just use the preview window of my video capture device. That doesn't need me to turn my head as far (and I don't have to feel bad about leaving it on a static picture), but has terrible latency. It's also very tolerant to signal corruption (such as color $00 showing up in the active area), which is useful when debugging video code. (I've ordered some cables to get P1 S-Video hooked to the capture device... That'll be cool if it works.)

    And of course for the big game that I haven't decided on a tile for yet, I mostly test on the PC version, which also catches a lot more runtime mistakes than the native P1 version (such as reading nonexistant SD ROM pages, writing to hub locations that shouldn't be written by user code, etc). My high-level emulator is seemingly perfect now, I can't remember the last time I had a bug on real HW that I couldn't reproduce on the PC.
    Have you tried two mirrors - one on the ceiling and the other on the wall in front of you?
  • Cluso99 wrote: »
    Wuerfel_21 wrote: »
    JT Cook wrote: »
    When I did all my Propeller stuff I would have a TV right by my computer so I could see how things look and tweak as needed (at least for NTSC stuff).

    With how I'm set up right now, the nice big NTSC/S-Video capable CRT is actually behind me. A bit annoying when I want to type something on the P1 keyboard and my gamepad also frequently gets tangled on my chair when I turn (well, I just got a bluetooth dongle, so maybe that won't happen anymore). I also often just use the preview window of my video capture device. That doesn't need me to turn my head as far (and I don't have to feel bad about leaving it on a static picture), but has terrible latency. It's also very tolerant to signal corruption (such as color $00 showing up in the active area), which is useful when debugging video code. (I've ordered some cables to get P1 S-Video hooked to the capture device... That'll be cool if it works.)

    And of course for the big game that I haven't decided on a tile for yet, I mostly test on the PC version, which also catches a lot more runtime mistakes than the native P1 version (such as reading nonexistant SD ROM pages, writing to hub locations that shouldn't be written by user code, etc). My high-level emulator is seemingly perfect now, I can't remember the last time I had a bug on real HW that I couldn't reproduce on the PC.
    Have you tried two mirrors - one on the ceiling and the other on the wall in front of you?

    That would probably work, but it'd be way too high-effort. Especiall if I don't want to live in constant fear of the mirrors crashing down onto my head :)
  • The video capture saga continues!

    New contender: Phillips SAA7134-based PCI TV Tuner card, bought for 7€ on eBay
    20201111_152503.jpg

    Being a PCI card, one may need to dig up an older PC to put it in, but luckily my main PC has a PCI slot, so I just put it in there.
    These are of course no longer made, but it's not super difficult to procure one with this chipset online. The other (slightly more?) common one is from Conexant, IDK how well that works.

    Okay, sooo....
    The Quality on both composite and S-Video is leagues ahead of any EasyCap I've seen. On S-Video it looks more like a low-quality JPEG of an emulated screenshot than an analog capture.
    BUT the (Win7 64bit) driver is once again a bit of a trashfire:
    - Doesn't work at all with AmarecTV (just gives an "unknown error" box when trying to open the device)
    - OBS Classic works but is unusable, the crossbar always resets back to the S-video input when stopping the preview and the feed has weird corruption in it.
    - OBS Studio has the same issues, but due to how it never closes the device, the crossbar resetting is less of an issue and for some unfathomable reason the corruption goes away when you start actually recording (doesn't on classic...). You can see it a little bit in the first second of the test recording.
    - Only reports 768x576 as available (and stretches the combed video to that when selected, ugh), but manually forcing 768x480 makes it nice and 1:1, allowing for custom deinterlacing.
    - It hasn't BSOD-ed my system yet or inexplicably stopped working, so that's cool I guess.

    Here's a test recording over S-Video:


    Here's a still with the corruption. Note that not every frame has corruption and most frames only have one or two corrupted lines, it's only really bad in motion.
    saa7134_corruption.png
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  • Wuerfel_21Wuerfel_21 Posts: 986
    edited 2020-11-11 - 18:59:26
    Wuerfel_21 wrote: »
    and for some unfathomable reason the corruption goes away when you start actually recording (doesn't on classic...).
    Well, I figured it out: The corruption only occurs when CPU usage is low (I assume the CPU going into a low power state when all cores are idle messes it up). The reason it went away in Studio is because I didn't have NVENC hardware acceleration enabled, so when recording the CPU was busy compressing video.
    Luckily, the problem can simply be worked around by getting some other program stuck in an infinite loop.
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