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I like to write with others just about as much as I like to write by myself. SubEthaEdit has long been one of our primary tools at TidBITS for collaborating simultaneously among editors and writers. The program lets us write in the same virtual document while seeing each other type. We can quickly produce a lot of text and edit each other's work, all the while checking in (sometimes through an iChat backchannel) on changes as we make them.

Simultaneous writing might seem like the authorial equivalent of the four-way intersection car crash in Steve Martin's L.A. Story. Instead, we find it makes it possible for us to write faster (especially under deadline), and speed up editing, too.

EtherPad treads on SubEthaEdit's turf. The new software, released just yesterday, is a free, hosted Web application with many of SubEthaEdit's key features, although it's both missing a pile of them (not surprising for a first release), while also being freed from many of SubEthaEdit's desktop application constraints.

Let's take a look at the two.

Compare and Contrast, in Real Time -- SubEthaEdit (from Coding Monkeys, 30-day trial, 29 euros or US$38) requires one writer to host a document and others to connect over the Internet or using Bonjour. Once connected, other writers (with read/write permission) are assigned a unique color, and can begin editing at once. Edits appears color-coded by author as soon as a character is typed or text deleted on all participants' open copy of the document. (Deletions aren't shown or retained. You can use Undo to revert back through edits.)

EtherPad (from AppJet, free) does away with many of these constraints, although it's nowhere near as mature in this first release as SubEthaEdit. But let's be fair: SubEthaEdit has been under development for years. And EtherPad is just as impressive in its first appearance as SubEthaEdit (then called Hydra, for obvious reasons) was when it first showed up as something close to a student programming project in 2003.

EtherPad opens up editing to any platform with support for one of several major browsers: Internet Explorer (version 6 or later), Safari (3 or later), and Firefox (2 or later). Other browsers may also work. This means that iPhone users can (tediously) participate as well as our friends suffering through Windows or enjoying their own unique blend of GNU/Linux.

Because the service is hosted as a Web application, EtherPad does away with the requirement for one user to have a publicly reachable IP address. This has bedeviled us many times, sometimes requiring us to open a SubEthaEdit document on a Mac OS X server system to all participate. Many features, like color coding of each participant's changes, will be familiar to SubEthaEdit users.

EtherPad also allows revision saving coupled with restoration from stored versions, something not found in SubEthaEdit. The Web app also centralizes storage of the current document and revisions on AppJet's servers. Both editors lack auto-save, a feature we've wanted for years, but EtherPad's ability to save a version trumps SubEthaEdit's simple save command, which overwrites the previously stored version. (You can use third-party programs to add an automatic saving option, but this should be a piece of core functionality.)

Centralized storage means that any participant always has access to the current state of the document or previous revisions. With SubEthaEdit, users other than the host can save a copy at any point, but aren't assured of having the last version of the document unless they save and the host immediately closes before other edits take place.

SubEthaEdit was designed, in part, for extreme programming, which includes the principle of pairing programmers to work on the same code at the same time. Some studies have shown that multi-person programming actually improves efficiency by reducing errors and producing more readable code in fewer lines.

As such, SubEthaEdit includes a long list of syntax coding options for popular programming languages, where code elements are colored for better recognition and to avoid making errors in spelling a name. Help in ensuring paired, nested parentheses and braces is also found in SubEthaEdit. (Nearly all non-collaborative SubEthaEdit features appear in BBEdit.)

Only JavaScript syntax coding appears in this first EtherPad release, which isn't odd given the developers. The folks who wrote EtherPad developed AppJet, a JavaScript-driven Web application engine that they had to revise substantially to make EtherPad work. They'll release an updated version of AppJet at some point rolling those features out, too.

EtherPad even throws in chat among participants in a document, allowing chronological archived discussion alongside the live space in which everyone is edited.

Collaborate over Time, Space -- When I look at collaboration tools for writing and editing, I break them down into points on two axes of time and space. Depending on the project, you might use instant messaging (IM), a blog, a wiki, a simultaneous editor, a text or Microsoft Word file that's passed around (using a difference detector or Word's Track Changes feature), and other tools.

A blog is a reverse chronological accounting that uses space (scrolling in one dimension) to indicate the passage of time. A wiki is a fixed space that changes over time, but includes history (in most cases) to go backwards to see edits. Wikis are edited successively or iteratively.

An IM session is live, with no editing, allowing synchronous communication with viewable history. Even something like using Leopard's Screen Sharing over iChat feature fits into this continuum.

(Google Docs, by the way, allows simultaneous editing that's not in real time. Rather, each save pushes a copy to other active editors, but you can't see each other type or delete.)

EtherPad and SubEthaEdit's collaborative writing allows synchronous editing over virtual space (the medium of the document) and real space (many people simultaneously writing in different places). I've long argued this modality was the one missing piece in the modern business workflow, and in some creative processes engaged in by teams - like writing TidBITS articles.

Competition Improves Collaboration -- I look forward both to more developments in EtherPad, and the response from Coding Monkeys. For many years, I've wanted to have a tool that's a bit easier to use - especially freed from the storage and public IP requirement - for less-technical friends and colleagues. And Windows users have previously been left out in the cold.

Competition should help spark innovation, but EtherPad will certainly allow more unfettered communication. We know from history, more communication either leads to better understanding or a complete breakdown. I hope for the former.

Copyright © 2008 Glenn Fleishman. TidBITS is copyright © 2008 TidBITS Publishing Inc. If you're reading this article on a Web site other than TidBITS.com, please let us know, because if it was republished without attribution, by a commercial site, or in modified form, it violates our Creative Commons License.

Bare Bones Software's BBEdit 9.0 -- A burly upgrade introducing newcapabilities like Projects, non-modal Find and Multi-File Search,editing in browsers, text completion, Scratchpad, new Ruby module,better JavaScript, ObjC, Obj-C++, YAML <http://www.barebones.com/>

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digg_skin = 'compact'; digg_bgcolor = '#f1f8fa'; digg_url = 'http://digg.com/tech_news/Giz_Explains_Every_Video_Format_You_Need_to_Know';

Once upon time, video codecs and formats were really only the concern of AV nerds, anime freaks and hardcore not-so-legal movie downloaders. Now, even the most part-time of geeks has to deal with them, whether they're trying to stream a flick across their house with an Apple TV, dump some video onto their phone or just trying to grab last night's episode of Dexter because they, uh, forgot to renew their Showtime subscription. It's messy and annoying, but we're here to clean it up. Take a deep breath.

You might recall our discussion about video bitrates earlier, or how much data is packed into a file. As a general rule, more bits per second translates into more betterer quality audio and video. The variable in that—the other part of the equation—is how the content is compressed and de-compressed. Better compression techniques—the zen of knowing what bits of data to pull out to make big data chunks smaller—make for better quality video while taking up less space on your hard drive. Basically, the part you need to know is that codecs are the software that make that magic happen.

Standard Standards • H.261 is not a term you have to worry about, but it's the technology that most video standards and codecs were originally based on. Originating in 1990, it's the first major digital video compression standard, and like other "H" standards, it was developed by the International Telecommunication Union. This one was primarily for teleconferencing over ISDN lines, and as such, it looks like ass.

• MPEG-1 Part 2 is another oldie, developed by the Movie Picture Experts Group and approved in 1991. (BTW, the whole "part" thing is because video is just one "part" of each MPEG standard.) Based quite a bit on H.261, MPEG-1 was designed to take VHS quality video and squeeze it down to a bit rate of about 1.5Mbps, optimized for CD transfers. No surprise, it's the standard used for all VCDs (which can play in most DVD players), but not a standard you would see hanging around today.

• With MPEG-2 Part 2, approved in 1994, we're finally talking decent vid. Also known as H.262, since it was developed jointly by the ITU-T and ISO, MPEG-2 is an extension of MPEG-1 that delivers better resolution and higher bit rates (3-15Mbps for standard def and 15-30Mbps for HD). It's the video codec used by DVD and digital television, though now it's slowly being replaced by the more efficient MPEG-4, except on DVDs, where it'll ride out that disc format's lifetime.

• H.263 is designed for sending video over crappy connections. So it's used to encode most Flash video and to send video over mobile networks.

• MPEG-4 is where we really stand right now. It has a much broader scope than past MPEG standards, aiming to tackle both the low end (crappy cellphones on a crappy network) and the high end (Blu-ray). It's still developing, so it's not-so-coincidentally where this whole story gets messier. There are two relevant parts of the MPEG-4 standard for our myopic video purposes: Part 2 and Part 10—which is also known as H.264 or Advanced Video Coding (AVC). To be clear though, even though they're both part of the MPEG-4 standard, they're totally different formats. Nevertheless, both are more efficient at compression than past MPEG codecs, delivering better quality using less space.

• Okay, so if you've ever frequented a Torrent site, you've actually watched tons of videos that use MPEG-4 Part 2, though it's not like they would've had a flashing sign telling you so. MPEG-4 Part 2 actually has different "profiles"—the two that matter being Simple Profile, for low bitrate, low-res stuff, and Advanced Simple Profile. The latter profile is what's used by movies you would download in formats like DivX or XviD or 3ivx—which are all codecs that are essentially just differing implementations of the MPEG-4 Part 2 standard.

• MPEG-4 Part 10, the other part, was actually co-devopled by MPEG and the ITU-T, so it's also known—in fact, more commonly known—as H.264. It's more efficient than MPEG-2 and MPEG-4 Part 2, delivering the same quality video in as little as half the space, making it suitable for the low and high-end. Because of this, it's quickly becoming the standardest standard. It's part of the HD DVD and Blu-ray spec, replacing MPEG-2 in digital TV (like with satellite services and AT&T's U-Verse IPTV) and supported by pretty much every portable video player on the planet from the iPod to the PSP. Apple has a decent, if Kool-Aid flavored, FAQ about H.264.

• VC-1 is essentially a Microsoft developed alternative video codec to H.264 released as a standard by the Society of Motion Picture and Television Engineers, though it descends from the same H.26X/MPEG family. (It essentially started life as WMV9, but then Microsoft shopped it to the SMPTE to make it an industry standard, and now it is.) It too, is part of the mandatory Blu-ray and HD DVD spec, and is the official video codec of the Xbox 360. It's pitch is the same as H.264's—trying to deliver better quality using less space, like HD video in 6-8Mbps.

Free-Floating Codecs Okay, so all that stuff up there are industry-wide standard video codecs. On top of all of those, various entities love putting out their own spin on those standards. As we mentioned before, DivX (proprietary) and XviD (open source), for instance, use MPEG-4 Part 2 (more specifically, MPEG-4 ASP) compression, meaning stuff that'll natively play back MPEG-4 ASP will also play back DivX. Like the Xbox 360, for instance. There are a ton of MPEG-4 ASP-based codecs, actually, like FFmpeg, 3ivx and others, but DivX and XviD are the most common. Same deal with H.264: Some well known codecs that use it are Apple's Quicktime H.264, x264 and Nero Digital. You've also got Windows Media Video (WMV) codecs, which are Microsoft's proprietary twists on industry standards.

Containers aka Wrappers Alright, well you've probably noticed that none of your video files have the extension .h264 or .vc1 or the like. That's because videos are packaged in containers or wrappers that stuff things like the audio, navigational info, etc. along with the video in a single pretty file. Naturally, there are about as many of them as there are codecs. To be clear, you would take a video encoded with, say, H.264, and wrap it up as a .mp4 or .avi file.

The majors ones are: • AVI (Audio Video Interleave) is Windows' standard multimedia container • MPEG-4 Part 14 (known to you as .mp4) is the standardized container for MPEG-4 • FLV (Flash Video) is the format used to deliver MPEG video through Flash Player • MOV is Apple's QuickTime container format • OGG, OGM and OGV are open-standard containers • MKV (Mastroska) is another open-specification container that you've seen if you've ever downloaded anime • VOB means DVD Video Object. Guess what? It's DVD's standard container, and what you get when you rip a DVD. • ASF is a Microsoft format designed for WMV and WMA—files can end in .wmv or .asf

So, in order to play a video file, your setup has to be able to handle both the actual video codec and the container. It's why you can try to play an AVI file and Windows Media Player laughs at you, even though it totally played one a minute ago— the container was no problem, but it didn't have the right codec. Or conversely, even though an iPod could play back an H.264 encoded video, if it was wrapped up in MKV, it won't be able to read it.

Okay, my brain hurts. Hopefully this will make yours hurt less when it comes to dealing with pesky videos. If you'd like to do even more homework, Wikipedia, as always, has a more in-depth discussion. And Doom9 is always an amazing resource for all things digital video.

Something you still wanna know? Send any questions about codecs, kitties or pad thai (but not RealMedia) to tips@gizmodo.com, with "Giz Explains" in the subject line.

[Image: ME@Flickr]

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