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HDMI Video Capture Devices - following up on Baggers presentation — Parallax Forums

HDMI Video Capture Devices - following up on Baggers presentation

Ken GraceyKen Gracey Posts: 7,392
in Propeller 2

Hey there,

On Tuesday Baggers showed some real gems with Chip - Space Invaders, Space Invaders 2 and Lunar Rescue.

Of course, I want to post all of the source as Quick Bytes, excluding the ROMs, which people will need to scour from the web.

I'd like to include a video capture of the games, too. I asked @Baggers how to go about this and he flashed a little black HDMI to USB video capture device. I'd like to get a couple of these to be sure I buy one that actually works (or supports whatever signals the P2 is sending it).

I'm entirely confused about the connection of these devices. If they capture the signal from HDMI, how can I see what the video capture looks like? Is there some sort of splitter device that I can use to send the same video signal to a display?

Not asking for a friend, just for my dumb honest self.

Thanks,


Ken Gracey

Comments

  • iseriesiseries Posts: 1,492

    My understanding is that the device capture the video and then a USB driver takes in the video. With some USB software it displays it on your computer which then allows you to see the video output from the HDMI device.

    From there you can capture or screen print pictures.

    Mike

  • Ken GraceyKen Gracey Posts: 7,392

    That part I understand.

    If I want to capture a video of a game, I'd like to be playing the game to capture it with my own eyeballs AND the HDMI memory capture device. Like having two video outputs.

    Ken Gracey

  • Wuerfel_21Wuerfel_21 Posts: 5,053
    edited 2021-01-29 22:12

    Every capture program has a preview window. However, due to inherent delays (desktop compositing) and how the video capture system (especially on Windows) works it will be horribly delayed (haven't ran a test, but feels like at least 4 or 5 frames delay). You can get HDMI splitter boxes though, they will allow you to run two displays off one source, no delay. Usually these have certain issues relating to handshaking, but that doesn't matter with a dumb source like the P2. If you get the right kind, a splitter box will also strip the HDCP copy protection off your bluray, netflix, pay-tv or whatever signals :) (that has to do with how an HDMI splitter works - you can't just splice the wires because that'd mess up the impedance or smth. So what they do is put a TMDS receiver IC and two transmitter ICs back-to-back. And sometimes they forget to disable the decryption support in the receiver...)

  • Ken GraceyKen Gracey Posts: 7,392
    https://forums.parallax.com/discussion/comment/1515714#Comment_1515714

    HDMI splitter. Thanks @Wuerfel_21! The frame delay won't be a problem.

    Since I have you here, I think somebody in the P2 Live Forum mentioned that you've also been porting games. I haven't kept track of all the forum activity, but if you've got some links for me to look at that would be neat.

    Ken Gracey

  • Ken GraceyKen Gracey Posts: 7,392

    I found this: https://www.amazon.com/IPXOZO-Directly-Streaming-Conference-Broadcasting/dp/B08V86C2VT/

    I think I get the idea now. The capture is happening on the device, but the display output for the human is the computer.

    It wasn't this clear when I was searching earlier.

    Thanks all! Case closed.

    Ken Gracey

  • Wuerfel_21Wuerfel_21 Posts: 5,053
    edited 2021-01-29 22:58

    The frame delay won't be a problem.

    Well, it is a problem if you're trying to play any game through the capture preview. So yeah, getting a splitter is a good idea.


     I think somebody in the P2 Live Forum mentioned that you've also been porting games

    Not on P2, at least, for I actually don't have one. I do have what is probably the largest collection of P1 games though, most with a description, metadata and video capture, all ready to run on my board that I eventually want to make available... I also made Spin Hexagon and am working on a real nice one (that'll likely also run on P2). Probably still years out at the current pace of development. Ask if you want to know more about that one, I can talk about it for days.


    Some more game capture wisdom, mostly gathered from my adventures in P1 game cataloging:

    • If you want capture 640x480p video from a P2 and have it not look like brap when you upload it to youtube, you must do a 300% nearest neighbor(!!!!) scale to 1920x1440p. Youtube always rounds your video down to the next fixed step from your upload resolution and you NEED to upload at least 720p to get full framerate and at least 1080p to get decent bitrate. But 1080p isn't an integer multiple of SD/ED resolutions (240p/480p), so 1440p is the minimum you should upload.
    • Assuming you need to capture audio off analog (I don't think HDMI audio is a thing on P2?), do not plug it into your microphone socket, it belongs in the blue line-in socket on (likely the back of) your PC. If it doesn't have one, do not get the cheapest audio interface off amazon, it will sound like brap. Most capture programs, you need to dig a little to find the option to use an audio input seperate from the video device.
    • Make sure your capture resolution matches the native resolution of what's being captured. To make sure, write a program that displays a checkerboard screen. Especially over HDMI, this should be 100% clean edges.
    • Similarly, make sure the frame rate matches or you'll get skipped/duplicated frames. Similarly, write a program that displays flicker or smooth motion to make sure this is right. With raw capture programs like VirtualDub, this is less necessary.
    • If you want to use OBS Studio to capture or stream (it has a virtual camera plugin that'd allow you to pipe it into ZOOM, maybe that's interesting...),
      • Increase the bitrates for audio and video a bit from the defaults. Maybe less necessary for pure digital capture.
      • install the CoreAudio AAC thing or your audio will be brap


  • dgatelydgately Posts: 1,630
    edited 2021-01-30 01:01

    Ken,

    I use an HDMI Capture device I bought via Amazon (https://www.amazon.com/gp/product/B08C9WJKXB/ref=ppx_yo_dt_b_asin_title_o00_s00?ie=UTF8&psc=1) to capture the HDMI from the Parallax Digital Video Out accessory board. I input from that device via a USB-C adapter to my MacBookPro. On the Mac, I run the OBS application to display the P2 output to a recordable window. In this image (below), I'm playing Space Invaders, live. The OBS window is fairly configurable (I have not discovered if I can twist the screen 90 degrees, yet:-) ... I don't see a delay with this setup and I'm able to record whatever is displayed.


    SpaceInvader_on_OBS.jpg

    You could actually use this HDMI adapter and app during live Zoom meetings to share P2 video output! With a little effort, you can also record any sound from the P2, via a mic input on your computer.

    Here's the entire OBS window, where you can see its options. This app can take multiple inputs & allows switching between video inputs, PC screens, cameras, etc.. And it can do this, live! It is basically a video switcher app that can be used in live/recorded video studio operations, similar to expensive Black Magic hardware & software solutions.

    OBS_App.jpg

    Recorded from the OBS app: https://youtu.be/-e3RiFUHfC8


    dgately

  • Wuerfel_21Wuerfel_21 Posts: 5,053

    I have not discovered if I can twist the screen 90 degrees, yet

    Right click the source, rotation is somewhere under "Transform".

    Also, your aspect ratio is wrong. Either change capture res or resize the source (you can precisely resize a source using the "Edit Transform" option)

  • dgatelydgately Posts: 1,630
    edited 2021-01-30 01:05
    https://forums.parallax.com/discussion/comment/1515733#Comment_1515733

    Excellent! That worked. If I rerecord, I'll update the YouTube link!

    Thank you!

  • Wuerfel_21Wuerfel_21 Posts: 5,053
    edited 2021-01-30 02:12

    Oh, I didn't even see that YT link. There seems to be something weird going on, look at the fringe on those magenta invaders. I think you might want to dive into some of those capture settings. (If you have a choice of capture format, choose RGB!) As said above, HDMI capture should give you perfectly sharp edges. Relatedly, to get nearest-neighbor scaling in OBS, you rightclick the source and go "Scaling Filter -> Point". Use "Scaling Filter -> Area" if you can't set the resolution to an integer multiple (for example, when capturing anamorphic sources).

  • Ken GraceyKen Gracey Posts: 7,392

    @Wuerfel_21 this is especially helpful, as there will be a lot of video capture in my future for the Quick Bytes, so I need to get my game down on process, configuration, matching frame rates, and everything else you described. It would be a shame to show a P2 video show up with missing frames and we want it to display with the original, highest quality. If you're interested in doing some P2 work and sharing it, I'd be happy to share hardware with you. E-mail me kgracey@parallax.com.


    @dgately since you've already got the setup working, could you make a video capture for me of Space Invaders? I'd probably be able to post it by Monday or Tuesday, but it'll be next weekend before I have a functional video capture set up. During the week I can't really do any P2 stuff. . .instead it's purchasing, communication, marketing, and now this very lovely thing I'm looking forward to called CE compliance.


    Thanks, Ken

  • Cluso99Cluso99 Posts: 18,069

    @Ken Gracey

    Baggers program outputs both VGA and HDMI so problem solved - use both. Also means you could use capture VGA instead. I would think that you can rotate 90deg when editing the file.

  • Cluso99Cluso99 Posts: 18,069
    edited 2021-01-30 04:01

    BTW Ken, You will need to do something with the audio as it's not output to HDMI.


    If you record both the HDMI and the Audio at the same time and send me the two separate files I can combine them using AVS before you do any editing.

  • Ken GraceyKen Gracey Posts: 7,392


    https://forums.parallax.com/discussion/comment/1515766#Comment_1515766

    Yep, excellent point. I could capture it via a microphone worst-case, I suppose, and overlay the audio track against the video. Whatever I do, it shall be much better than pointing a cell phone at a display while trying to play a game :)


    Ken

  • Cluso99Cluso99 Posts: 18,069
    edited 2021-01-30 04:17

    Hey Ken,

    Just found this while searching. It's not available but there's probably something similar.

    https://www.amazon.com/dp/B08LPCS1XW?pd_rd_i=B08LPCS1XW&pd_rd_w=vtrsa&pf_rd_p=2e62cf0a-1323-46ac-bbb9-19dc851997c6&pd_rd_wg=43uKI&pf_rd_r=HCKTG7BRCDEQT9BJ97YA&pd_rd_r=299f7679-7dc4-4749-a361-5202b6058608

    Still looking :)

    https://www.amazon.com/Give-Definition-Streaming-Broadcasting-Teaching/dp/B08L3TX725/ref=sr_1_14?dchild=1&keywords=HDMI+Audio+Video+Capture+Card+USB+3.0&qid=1611979914&sr=8-14


    https://www.amazon.com/DADAWE-Loop-Out-Streaming-Recorder-Nintendo/dp/B08P4ZQN1V/ref=sr_1_10?dchild=1&keywords=HDMI+Audio+Video+Capture+Card+USB+3.0&qid=1611979914&sr=8-10


  • dgatelydgately Posts: 1,630

    Ken,

    I'll try a video capture and post it, on Saturday night.

  • BaggersBaggers Posts: 3,019

    I was going to suggest an HDMI splitter, but if it is just for the Space Invaders demo then as you said it plays both VGA and HDMI at the same time.

    I'll look forward to seeing the video :D

  • dgatelydgately Posts: 1,630
    edited 2021-01-31 04:14

    Ken,

    Here are 2 captures of Space Invaders being payed on the P2 Edge, recorded via HDMI adapter into and recorded in the OBS App. One video displays just the game screen, while the other includes a still from the Live Forum with Jim Bagley, to fill some of the window. These are currently on YouTube, but are unlisted... I can place the videos in DropBox or send them, if needed...

    https://youtu.be/-RYpLI4T39w
    https://youtu.be/-RYpLI4T39w 


    https://youtu.be/sdRgNcx08fE
    https://youtu.be/sdRgNcx08fE

    My game playing skill is not really up to the task of giving the best demo...

    dgately

  • Wuerfel_21Wuerfel_21 Posts: 5,053

    Also, @Ken Gracey, I did send that email some time ago. Did you receive it?

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