Short guide for getting 60fps captures

Tech Talk
1

I wrote a short guide on my upstart blog (god I hate that word) on how to get 60fps video from your capture card. This can be useful for finding/confirming frame data. You can look at how exactly the game works by stepping through each frame one by one. Also, you get super smooth video which is allways nice to impress people with in a combo vid or whatever.

It took me a while to figure out the deinterlacing part cus of all the filters that produced sub-par results, so maybe I’ll spare someone that trouble.

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If you’re simply looking to create 60fps content, for whatever reason, very nice work. Your title, however, is a bit mis-leading, as you are not actually capturing 60fps. De-interlacing does not automatically double the frames (maybe bob deinterlacing does, but that’s not the purpose of deinterlacing), but rather draws the frame “progressively”, based on the interlaced fields. Coming from a console, unless we’re talking component capture from a newer console that supports 720p, your video signal is still 30fps. If you were to break down the 30 frames per second of interlaced video, you would have half of the image (odd lines, for instance) in one field, and the other half of the image (even lines, for instance) in the other field. If you join them together, they make a single complete frame. So, if creating full frames from fields, and having a full frame where previously there was only “half a frame”, then you are essentially creating/inserting frames that didn’t originally exist.

If a game is intended to be played at 60fps (such as the Street Fighters, or any arcade game, as arcade is 60fps…well, actually around 59.xx hz, but that’s another discussion), you also have to take into account that any console game has been adapted to NTSC output…and unfortunately, that is not indicative of arcade frame data. Deinterlacing to create 60fps, also, would not be indicative of full 60fps gameplay. If, however, you want to analyze console frame data for what it is (console data, that is), then 30fps is what you would need to do so.

Another suggestion: rather than using compression, even “lossless”, just capture to uncompressed RGB. Then you are assured of getting every frame (with your other options disabled, which you outlined)…of course, this requires a hard drive with enough space and capable of reading/writing at the necessary bitrate.

Those things said, you have certainly created a very nice guide for creation of high quality content.

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Thanks for the comments. Bob deinterlacing does double the number of frames, in fact some deinterlacers do this by default and then cull every other frame to produce the resulting 30fps video. As you said, only half of each of the original game-frames are transmitted, so obviously you’re not gonna get info back that was never broadcast. However, it’s not entirely true that bob-deinterlacing inserts or creates frames (that makes it sound like telecine), the deinterlacer is just interpolating (and more) between things you know to be true.

For frame data alone it would have sufficed to use an AviSynth command SeperateFields which does exactly what the name says, but I decided to use a motion detecting deinterlacer because that way there is no ugly shudder, and so people can use the video for combovideo production and stuff.

EDIT: and you’re right about the title. It should have been something like “getting 60fps VIDEO from your captures”