8 ms·

IN JS? This is so cool. Also: fun to compare the raw video to the original: http://www.youtube.com/watch?v=12zJw9varYE http://www.youtube.com/watch?v=12zJw9varY

by beggi 13y ago

IN JS? This is so cool. Also: fun to compare the raw video to the original: http://www.youtube.com/watch?v=12zJw9varYE http://www.youtube.com/watch?v=12zJw9varYE :)

aantix 13y ago
How are they changing out the backgrounds in the tech demo? I was expecting the original to be a green screen background...
- zlapper 13y ago
  Click in the Raw button, you will see the green background :)
- deleted 13y ago
  [deleted]
- BHSPitMonkey 13y ago
  "Original" meaning the original finished released music video from 2009. The band released the raw green-screen footage later for remixing.
  - lessnonymous 13y ago
    Respect for OK Go videos just went up a level. What an awesome idea!
moskie 13y ago
Would also be interesting to see if they could recreate the effect of the original video in JS also.
- JimJames 13y ago
  Isn't the algorithm just, filter out the greenscreen, for each remaining pixel draw it to the buffer, draw the buffer to the screen? That doesn't seem more complicated than the examples they showed.
  - johncoogan 13y ago
    No one said it would be MORE complicated than the examples. "Would also be interesting" and "fun to compare" give no implication of relative difficulty. I would like to see the algorithm though so please post the code if you get it working in JS! That would be awesome!
  - daeken 13y ago
    It is actually slightly more complicated. The existing effects work in GLSL and are just transforming single frames of video. For that effect to work, you need the previous buffer states; this means that seeking will cause the image to be different, and you need to feed the previous render state back as a texture.
    - deleted 13y ago
      [deleted]
      - daeken 13y ago
        Well no, because each frame builds on all the frames before it. Either way, seeking is still broken unless you run through all the frames up to that point.
        deleted 13y ago
        [deleted]
        daeken 13y ago
        Each frame has the greenscreen turned into a fully transparent pixel, then gets blitted onto a buffer containing all of the existing buffer's data. That means that for each frame, you're building on the data from every frame that came before. This is fine if you're playing from beginning to end, but when you seek, you're going to break that continuity.
        deleted 13y ago
- BHSPitMonkey 13y ago
  I (very hackishly, but nonetheless) got it to sort of work: http://imgur.com/a/PQX63#1 http://imgur.com/a/PQX63#1 It's full of lots of (mostly green) noise because the demo's chroma key algorithm/parameters aren't that good, but it was fun to do!
Mindless2112 13y ago
Ah, their movements and actions in the video make a lot more sense after seeing the original.

by beggi 13y ago

IN JS? This is so cool. Also: fun to compare the raw video to the original: http://www.youtube.com/watch?v=12zJw9varYE http://www.youtube.com/watch?v=12zJw9varYE :)

aantix 13y ago

How are they changing out the backgrounds in the tech demo? I was expecting the original to be a green screen background...

zlapper 13y ago
Click in the Raw button, you will see the green background :)
deleted 13y ago
[deleted]
BHSPitMonkey 13y ago
"Original" meaning the original finished released music video from 2009. The band released the raw green-screen footage later for remixing.
- lessnonymous 13y ago
  Respect for OK Go videos just went up a level. What an awesome idea!

moskie 13y ago

Would also be interesting to see if they could recreate the effect of the original video in JS also.

JimJames 13y ago
Isn't the algorithm just, filter out the greenscreen, for each remaining pixel draw it to the buffer, draw the buffer to the screen? That doesn't seem more complicated than the examples they showed.
- johncoogan 13y ago
  No one said it would be MORE complicated than the examples. "Would also be interesting" and "fun to compare" give no implication of relative difficulty. I would like to see the algorithm though so please post the code if you get it working in JS! That would be awesome!
- daeken 13y ago
  It is actually slightly more complicated. The existing effects work in GLSL and are just transforming single frames of video. For that effect to work, you need the previous buffer states; this means that seeking will cause the image to be different, and you need to feed the previous render state back as a texture.
  - deleted 13y ago
    [deleted]
    - daeken 13y ago
      Well no, because each frame builds on all the frames before it. Either way, seeking is still broken unless you run through all the frames up to that point.
      - deleted 13y ago
        [deleted]
        daeken 13y ago
        Each frame has the greenscreen turned into a fully transparent pixel, then gets blitted onto a buffer containing all of the existing buffer's data. That means that for each frame, you're building on the data from every frame that came before. This is fine if you're playing from beginning to end, but when you seek, you're going to break that continuity.
        deleted 13y ago
BHSPitMonkey 13y ago
I (very hackishly, but nonetheless) got it to sort of work: http://imgur.com/a/PQX63#1 http://imgur.com/a/PQX63#1 It's full of lots of (mostly green) noise because the demo's chroma key algorithm/parameters aren't that good, but it was fun to do!

Mindless2112 13y ago

Ah, their movements and actions in the video make a lot more sense after seeing the original.