Hacker News Board Hacker News, browsed like a classic message board
Live data from Hacker News

Twitter's GIF hack

blog.embed.ly

Post reply on HN
Print view View original

131–140 of 160 posts

Re: Twitter's GIF hack

#131

Post by jasonlotito »

fixermark wrote: post #13
stonogo wrote: post #10

This is on a fully-patched RHEL6 workstation: http://i.imgur.com/NleqJTD.png Another example of "use bleeding-edge tech or go fuck yourself" from the modern web.

Support for mp4 isn't bleeding-edge tech on other operating systems / distributions, unfortunately. It's a couple of years old in terms of being supported by Chrome; it's supported in Firefox as of last August. At this point, desktop configurations that can't play mp4s are at risk of being considered "broken."

This is what modern support gets you with this method:

http://imgur.com/Qr3tohD http://imgur.com/Qr3tohD,8okaMlP#1

So... Flash.

This has the added bonus of stealing focus if you click on it, making the "GIF" a UX nightmare.

Re: Twitter's GIF hack

#132

Post by fennecfoxen »

blt wrote: post #97
Rudism wrote: post #88

Correct me if I'm wrong, but wasn't the whole reason gifs started proliferating on the net because people wanted to share short video loops, but didn't want to embed flash or video which may not load or play correctly in a user's browser? And now we are championing the conversion of those gifs back into video? Seems like a strange round-about way of doing things. I forsee a future where all video clips on the net hav…

I don't think gifs' recent surge in popularity has anything to do with technical issues like browser compatibility. They became popular because of artistic/aesthetic value and web culture. These features all differentiate gifs from 2010-mainstream forms of embedded video like Youtube: - starts playing automatically - loops seamlessly - never has sound - no logos or buttons like "share" and "embed" - no scrubber bar o…

> IMO, the 256-color dithering was more of a necessary evil for most gif creators, although some took advantage of it.

I'm under the impression that the format only specified 256 colors per palette, and that you could use different palettes on a per-frame basis, including frames with 0ms delays between them. and I know some software existed to make this possible, though I don't recall if it made it possible with animation at the same time...

Re: Twitter's GIF hack

#134

Post by dunham »

mikeash wrote: post #73
brigade wrote: post #65

Earlier quoted context omitted.

No, there are 4:4:4 and 4:2:2 modes in JPEG. H.264 also defines such modes, but no consumer hardware decoders support them so they aren't commonly used.

My mistake, I must have been going off what's common versus what's allowed. Thanks for pointing it out.

Apple's jpeg animation hack used 4:4:4 so the blocks wouldn't interfere with each other. It's a neat hack, worth reading about if you haven't seen it yet: https://docs.google.com/document/pub?id=1GWTMLjqQsQS45FWwqNG...

Re: Twitter's GIF hack

#135

Post by mikeash »

cratermoon wrote: post #118
mikeash wrote: post #102

Earlier quoted context omitted.

Well, there's a reason for the second half of my comment. GIF isn't bad because it's old, it's bad and old, and it's unreasonable to expect it to continue to be supported because that's a nasty combination. If something sucks but is still the standard technique in recent years then it's reasonable to think it should be supported. Similarly, if something is old but great, it's reasonable to think it should be supporte…

GIF itself is not so bad, for its intended purpose and time, but the animated GIF bit is a serious hack that was a bad idea from the start.

That's a good point, I shouldn't treat them as the same.

Re: Twitter's GIF hack

#136

Post by mikeash »

dunham wrote: post #134
mikeash wrote: post #73

Earlier quoted context omitted.

My mistake, I must have been going off what's common versus what's allowed. Thanks for pointing it out.

Apple's jpeg animation hack used 4:4:4 so the blocks wouldn't interfere with each other. It's a neat hack, worth reading about if you haven't seen it yet: https://docs.google.com/document/pub?id=1GWTMLjqQsQS45FWwqNG...

Holy moly. What a hack.

Re: Twitter's GIF hack

#137

Post by bhashkarsharma »

anon4 wrote: post #48
ars wrote: post #12

This is not true: "A GIF is literally a sequence of independent images squeezed into the same file. An mp4 video can take advantage of all kinds of fancy compression techniques like keyframes and forward-predictive frames." That's not why the mp4 is smaller. A GIF is not [just] independent images, you can have each frame reuse pixels from previous frames. The mp4 is smaller because lossy jpeg compression is used on e…

Not quite true yourself :). GIFs store deltas, true, but they are still raster images. H.264 on the other hand contains specific techniques for compressing sequential frames, including things like recording only pixel motion for some frames. You can see it in those "corrupt movies" gifs (which on twitter would be mp4s... talk about irony) where you take a clip and remove some keyframes from it - then transformations…

I think http://www.reddit.com/r/brokengifs collects such things.

Re: Twitter's GIF hack

#139

Post by TheZenPsycho »

fennecfoxen wrote: post #132
blt wrote: post #97

Earlier quoted context omitted.

I don't think gifs' recent surge in popularity has anything to do with technical issues like browser compatibility. They became popular because of artistic/aesthetic value and web culture. These features all differentiate gifs from 2010-mainstream forms of embedded video like Youtube: - starts playing automatically - loops seamlessly - never has sound - no logos or buttons like "share" and "embed" - no scrubber bar o…

> IMO, the 256-color dithering was more of a necessary evil for most gif creators, although some took advantage of it. I'm under the impression that the format only specified 256 colors per palette , and that you could use different palettes on a per-frame basis, including frames with 0ms delays between them. and I know some software existed to make this possible, though I don't recall if it made it possible with ani…

the format permits frames with 0ms delays. the problem is that there has never ever been a browser that respects the 0ms delay. On the whole, the status quo is that any delay under 10ms gets upgraded to 10ms.

Newer (current) browsers have lowered that to 6ms, and in chrome, 3ms. As yet, there has been no browser that respects the 0ms delay (as in, supposed to display instantaneously, so 2 frames with 0ms delay is supposed to look like 1 frame).

The justification for this is backwards compatibility with incorrectly authored gifs. So .. there you go.

Re: Twitter's GIF hack

#140

Post by michaelmior »

mbesto wrote: post #115
freyr wrote: post #104

Earlier quoted context omitted.

I think your list of features is spot on, but I don't think their mainstream popularity had much to do with artistic expression. I'd include one other big feature: - They are dead simple to save (or link to) and drop into your own page/blog/comment. and claim that GIFs are just really easy to share and view. They've offered a better experience both for post and viewing a short soundless clip than could be provided by…

How about the fact that there is zero advertising. IMO this is the number one piece of friction for videos (mainly YT) and the users don't want them for especially quick moments (a la Vine).

There's nothing really stopping people hosting GIFs from putting in advertising. Although it's true that I haven't seen examples of this happening.
Post reply on HN