I can't do anything there from Javascript, because I have no file i/o. Also, the CPU on which JS runs does not itself know what will appear on the screen, since rendering is done by the GPU; it can only ask, which means a PrintScreen call in Windows. But we need to be able to program that.
I messed around with Java and C++ for a while, but then I found some very neat freeware that does what I need. It's called NirCmd, and comes from Nirsoft. It's the sort of software I like - a 43 Kb executable with no installation but lots of very good documentation. You can download from CNet, but there's no need. It does all sorts of windows things, but the particular example I wanted was a one line command to periodically capture the screen to a PNG file.
So then my task was to setup a movie and run it, downloading each frame with NirCMD. I didn't find any way to send signals, so I had to find ways to match the timing. I ran the movie with 4 secs delay, and NirCMD with 3. This risks getting extra shots, but that isn't a problem. Then I used ImageMagick to crop the files and convert to .jpg. Then JPGVideo to convert to .avi, then FFmpeg to convert to .swf. Along the way, I put a timestamp on the WebGL. It starts top left, but you can Shift_click (click with Shift pressed) to move it where you like.
So I have some samples here. I made five movies, all at the medium 1/2° resolution:
- 2012 ENSO Weekly - a weekly picture of the tropical E Pacific through 2012. It shows an alternation of weak El Nino and La Nina conditions, with a strong La Nina at the end,
Update - I've added 4-day time step version - 2011 ENSO Weekly - mainly La Nina
- 2010 ENSO Weekly - again weekly E Pacific. A strong early El Nino plume moves to a La Nina jet as the year progresses. One thing I find fascinating is the classic vortex street pattern.
- 2012 Arctic weekly - a weekly picture of the Arctic region. The region with uniform zero anomaly is guaranteed to be ice, but the converse isn't sure - you'll see an anomaly assigned to regions which would have been classified as ice extent. However, it gives a detailed picture, enriched by the neighboring SST patterns.
- Recent 100/2 days - the most recent 100 days at 2 day intervals. It's a more detailed picture of the development of a La Nina plume.
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Safari works too. The formatting is a bit strange, but if I click on the pull down menu, select then click on the screen it switches movies.
ReplyDeleteThanks, Carrick.
DeleteI take it the WebGL stuff works too. It doesn't with Safari on a PC, but they say it should on a Mac.
You have to enable WebGL from the Developer menu on a Mac (and you have to enable the Developer Menu from Preferences). The part that doesn't work is anything that uses the CONTROL key modifier, since on a Mac that is a hold over from the days where macs only had one button (control left click = right click).
ReplyDeleteThanks, Carrick - I'll add that to the advice.
DeleteWorking fine in Firefox, no problems.
ReplyDeleteAlthough would be nice to have a pause feature; or a slower frame by frame choice.
And thanks for making these video, always appreciate the visuals to help explain these expansive seasonal climate systems of our earth.
- reader from WUWT
Thanks, reader,
DeleteThe controls are a function of the viewer your system brings up. It's a swf file, so that would usually be Adobe. I can't get them to show either.
In my system right click on the movie throws up a useful menu. There is a forward option that lets you go one frame at a time. It isn't convenient, because you have to open the menu every step. But it's possible.
Delete