When I first learn’t about the json format, I thought: “what a great idea!”.
All the great things about it- simplicity, leanness, exactly what xml wasn’t but ought to be.
Soon I reasoned that the json format can be persisted in storage in its own form. One can build a simple, portable database using json records with minimal code.
Its kinda sad. We drove over 4 states (5 if we count montana) for over a day (another half to get to old faithful), setup my equipment, and when the recording of the eruption was almost over, I tripped over my own cables which caused this laptop to crash to the floor while recording the video to crash , with the battery pack disengaged.
Maybe its one of those times my heart dropped together with my items, but since the rugged laptop still manage to boot, and some hope lied within me that I would be able to recover the video one day. While I thought streaming broken video files were no big deal, it wasn’t so easy. My usual tools- media player classic, virtualdub, videolan etc were unable to play this file at all. It wasn’t until yesterday I attempted to rescue this file again.
1st I tried this open source “DivFix++ is #1 AVI Video Repair & Preview Utility” called DivFix++. While it managed to detect FourCC frames, the resulting video file was still unplayable. Okay let’s take a step back. Then because the Canon 40D I was using have officially has no video features, I used the open source EOS Video Record which allowed some form of video recording if the camera was tethered to a pc.
EOS Movie Record saves the resulting video in a MJPG format, so I tried figuring if JPGs could be extracted from the motion video file. I tried looking for MJPG2JPEG converters but none existing other than 2 examples of source codes here and here. I also started to examine and studying the file structures of AVIs, RIFF, JPEG etc, and with the help of a hex editor (the freeware HxD works great ), started digging around the file.
So when I’m peeking around the file at HEX Offset 04F0000 or human friendly number 75431936, the viewer showed full of zeros. Not a good news, because it meant there was not data beyond that point (buffer were not flush). From my estimation, based on file sizes, what was an approximately 2minute video is probably a sub 20s video. Which makes me feel like rewriting the subject as: “repairing a broken heart”, but read on…
I noticed DivFix++ almost generated a 75MB file which i meant it must have found the same errors I suspected and strip them off. So using the software did not entirely gone to waste. On examining the headers of the file, I found it empty which is a pretty good reason that nothing could play this file. I then remembered that EOS Movie Record writes the video headers only after recording. So following the avi riff structure, I copied in header values like frame rate, resolution etc, and eureka, the video became playable.
So, its not too sad and not all’s lost. The badly abused laptop (actually my mom’s and the 1st laptop I used much) still survived, I managed to recover 16s, and learn a couple of things about video file formats. And my photography apprentice of that day Ben Chua did took some photos with my spare camera.
p.s. You might be able to see the short segment of the recovered video below.
Here’s something that has kept me a little occupied over the past weeks.
To find out, head over to http://howmean.com. This site belongs to the couple to be, Caleb and How Mean. And no, rather than its perceived adjective “how mean!”, I hope one experience some sweetness visiting the site.
There are several talented people behind the making of this site. Graphics and concept were designed by Grace Wong, and the web design was done by Meng Lung of Gold Coast Web Design. My little contributions would be some subjective augmentations to the site and one might make intelligent guesses to what I did by spotting non-traditional elements on the site. For those who aren’t guessing, here’s a list
+ Mouse over the dandelions near the footer, and one may see little particles floating away. On most modern browsers except IE, these particles are drawn with html 5 canvas elements. In unsupported browsers, 1 pixel rendering with css are used instead.
+ Meant to be an easter egg, rolling the mouse wheel renders lighter dandelions particles around the screen.
+ Ajax calls are used for navigation when possible to prevent disruption of the background music
+ To support browsers not running flash (the iPhones and Androids mainly!), flash objects degrade gracefully
+ To degrade the photo gallery for non flash clients, the xml used by the flash slideshow player is parsed and rendered with jquery.
+ A small widget (which dates back to my legendary ORD count down wallpaper) is used to display the time till or from the wedding date in the credit page.
Of course all these would not be present if not for the weds-to-be.
So this’s my 1st post of the new year, and its a great reminder to reflect whether each passing day gets sweeter. A blessed new year for you readers!
Seems that I happen to like coding several stuff when it comes to the end of the year. As such, I’ll decide to delicate this piece of script/code/site to my all my fellow photo enthusiasts and geeky friends as a late Christmas but an early new year’s gift.
I decided to implement a Panning Navigator in Canvas while experimenting with various UI navigation working on my notation project (like the navigator in Sibelius). This panning navigator is what one might usually see in Adobe Photoshop, Illustrator, etc, and it seems few have implemented this, perhaps a handful implementations with flash, but none I came across with javascript. As for its name, I was not even sure what’s the name but seem this site seem to suggest this ui pattern as a panning navigator for dealing with large canvases with a draggable viewport.
Here are some of the features
+ Drag the viewport in the navigator to view around
+ Mouse wheel can control the zoooming
+ Fill, Fit to screen for quickly zooming out, 1:1 for actual size and 3:1 for zooming in.
+ Fullscreen photos and navigator response to browser resizes
+ Features some photos from my early photography
+ Canvas used for drawing the navigator and creating the “thumbnailed” image.
+ Css for aligning navigator, resizing and repositioning image
+ Seems useful with large photos and panoramas
+ Should run iphone and android browsers although experience may be improved
+ Oh also released as do what every you like to do with the source license, but remember to let me know your comments.
(Warning: Some images are huge, please be patient while waiting)
Comments are welcomed. Maybe, when its polished up, bug free and extensible, I might release this as a jquery plugin.
Goodbye 2009 and an early happy new year to all!
p.s. One might check out the jQuery supersized plugin for where the fullscreen photos were partly inspired by.
p.p.s. For source code: use your browser “View Source”.
I couldn’t remember when was the last time I even logged into my blog. Certainly I can’t even remember my password each time. Thankful I manage to retrieve my password each time.
At times when I’m doing something experimental I think, maybe someone would find such information useful if I place it on my blog- since I learn a great deal from many other’s developers’ blogs.
Just to touch quickly, I’m working on a personal project to build an online music notation software which works in a modern browser (think Noteworthy Composer in the cloud with Html 5). I soon find the canvas element really powerful (supported in all major browser - firefox, safari, chrome, opera except ie), but a really raw api. Yet possibilities are already very attractive, and closes the gap between flash and web design (as mentioned in my last geeknote on facebook).
Anyway, more the project next time, but what I would like to cover here is dealing using scrollbars to deal with an oversized canvas. If you ever did any Java AWT/Swing programming, you might know this can be done simply with placing your components into a JScrollPane. So here’s my current quick implementation of a scrollpane with CSS.
First the html elements.
<div id="omw_scrollpane">
<canvas id="omw_canvas" width="800" height="320"></canvas>
</div>
Basically, this wraps the canvas element into a div container we call scrollpane, responsible for providing the scrollbars.
This simply constrains the enclosing div to a view port, and the overflow properties automatically adds scrollbars when the canvas element is larger than the specified width. The canvas would continue to work without recalculating coordinates.
Real simple hack? Yes and no. This may works for simple application, but perhaps more complex situations may require custom scrollbars (which brings me back to the flash pre-mx days where scrollbars need custom coding). Its seems to me that having a canvas of over 80,000 pixels width seems to hang chrome and opera 9 browsers.
The only other example I could find on the net which require scrollbars with their canvas application is actually the amazing Mozilla Bespin project (collaborative “code in the cloud” with your browser). Right now their implementation uses a custom scrollbar which docks/hides itself when not being used. One might wish to investigate the ui framework mozilla built ontop of canvas call Mozilla Thunderhead used in the bespin project. Seen by some to be a competitor to flex or other RIAs, you may wish to learn more following one of their developer’s blog.
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Here lies a photo of the world’s sleepiest animal, and your sleepiest friend.
In his bloggy dreamworld, he writes clearly as his nights dreamy.
More seriously, his life revolves around God, music, sports, computers, and you.
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