The Transcode Blog

Don't Clean My Room!

2012-02-29T05:20:00.001-08:00

Recently I stayed at a Sheraton hotel on business travel. In many
hotels, I notice a note that says something to the effect of "Help us
save the environment: if you want your towels washed, leave them on
the floor; if you hang them up, we won't wash them." I don't know
that the hotels always follow their own guideline, but I like the
sentiment.

Well, the Sheraton Raleigh City Center hotel goes one step further, in
what I think is a clever idea. They have a little sign you can hang
outside your room by 2AM that says "Hey, don't have housecleaning come
and clean my room." In return, the Sheraton will slip a voucher for
$5 every day except the day you check out. That's plenty of money for
a latte and a banana at the coffee kiosk near the lobby, or I could
use it for a happy hour drink at the hotel's bar.

Maybe you'll think me filthy, but I don't always feel like I need the
room cleaned every single day of my stay. This seems like a great way
to save the staff a little time, and some cleaning costs. The five
bucks is not even really the point, although I like getting a little
cash out of the deal. Mostly, though, what I like is that I feel that
I have a little control over the hotel's using a little bit less water
and power when it doesn't need to use them on me.

Oh, and every time I've hung their sign, they've taken the hint and
not come in to clean the room. Nice job, Sheraton.

A Request For Snapcasts on G-Snap!

2009-08-15T13:48:00.001-07:00

I love the social event-casting service "G-Snap!" (twitter feed here, Facebook page here) It seems like every other week, I get another idea about a kind of event I'd like to follow with their service. Today's bright idea was PGA Tour events like the one this weekend, where it looks like Tiger Woods has a strong chance to win. But I don't really know enough about golf to create my own snapcast, plus I'm going to a wedding today and couldn't snapcast the event myself if I wanted to.

So I'd like to have a way to ask somebody else if they would snapcast this weekend's event. Plus, I think golf is perfectly suited to snapcasting.

I sent a message to the folks at G-Snap! Here's what I wrote, which I am copying here because it applies to the whole community of G-Snap! fans, not just the creators of the service.

Hey whipper-snappers,

I gotta question and am not sure where to direct it. Here's my deal:

I want to follow Tiger Woods at this weekend's PGA Tour event, and the live blog on golf.com just isn't gonna cut it: http://blogs.golf.com/presstent/2009/08/live-pga-championship-coverage-third-round.html?eref=sihpT1

So I thought "Hey, golf could actually be a great g-snap! event...it goes at a pace that is slow enough that somebody could probably update the game stats fairly easily, more easily than the fast pace of a football game." And I bet there are a ton of business-type people who would follow golf on gsnap.

But here's my problem: I'm not going to snapcast golf, because I don't know much about it and don't feel comfortable. Instead, I'd rather ask if somebody would please snapcast the event.

How do I ask the G-Snap! community if somebody would please snapcast a golf event?

Is there a G-Snap! community site where I could ask something like this? You know, place a request for a snapcast?

Thanks for anything you can say. There's no rush to reply.

G.

Some drumline audio clips for DCI 2009

2009-08-07T13:35:00.000-07:00

Tonight is the semifinals show for the Drum Corps International 2009 World Championships. I love this time of year, the height of summer and the height of musical competition. I can't get enough of the music, especially the drumlines (I marched in the Santa Clara Vanguard in 1985, part of the drumline, so I'm biased).

So for your listening and watching pleasure, here are a few clips of drumline coolness for this year.

By the way, do you have any favorite drum line audio or video clips? If so, comment on this blog post and share the links. I'm always looking for new, cool stuff to listen to.

http://www.youtube.com/watch?v=dlEICx5e96M

(Vanguard 2009; the show this year is Appalachian Spring, by Aaron Copland)

http://www.youtube.com/watch?v=7IUrOqVuaRY

(more Vanguard 2009)

http://www.youtube.com/watch?v=CYKgFVVqU4E

(Blue Devils tenor flams; wow, those guys can move around the drums)

http://www.youtube.com/watch?v=OD0U-Flufzw

(more Blue Devils 2009 drumline)

http://www.youtube.com/watch?v=M2w8EuHKnJ0

(Some Cavaliers 2009 drumline stuff)

http://www.youtube.com/watch?v=Gv4WQwkLb4c

(More 2009 Cavaliers drumline)

http://www.youtube.com/watch?v=YrzSEza7eUw

(Some Carolina Crown 2009 snare line)

http://www.youtube.com/watch?v=dz08UFgIqk0

(Holy Name Cadets 2009 on the move)

Podcasts I'm currently listening to

2009-07-26T15:12:00.001-07:00

I've been meaning to write some notes about the podcasts I listen to these days, but I just haven't made it a priority. But a friend of mine just asked me if I have any I'd recommend, so I'll list what I listen to and note my current favorites.

Favorites:

TED Talks (audio): The TED Conference has made available all of the talks for several years. I love high-quality presentations, and I find the majority of these talks are excellent. Not all, but many. There's also a video version of the same podcast. Talks are usually 18 minutes.

The Onion Radio News: If you don't already know The Onion (satirical newspaper, hilarious), check it out first to get a feel of how they write. They have a daily podcast that does one news headline. Each podcast lasts less than 60 seconds; always good for at least a chuckle. I haven't been to the main website in a while, but it looks like their current schtick is having been bought by a major Chinese conglomerate. Excellent.

The Official LOST Podcast: it helps if you follow the show, because the podcast is all about what's going on with the ABC TV series. What I like about it is that the two hosts, co-producers Damon Lindelof and Carlton Cuse, are both smart-alecks and informative. They give you clues about what the show is going to do and what the current episodes mean, but they're also just funny guys. They make gentle fun at the viewer email they get. They generally only podcast during the season. Each episode is about 20 minutes, and I always want it to last longer. That's the mark of a great podcast.

NPR's Fresh Air: I'm gritting my teeth with this recommendation, because I generally can't stand Terry Gross but I enjoy the show despite her interview technique. Lately, though, I feel she's gotten to be a better interviewer in the sense that she's managed to make her questions less about her agenda and more about the guest, and more open-ended so that we learn more about the guests. I don't listen to every show; I scan for guests and topics that interest me. Often, there are great guests. 45 minutes long, usually several subjects being covered per podcast.

NPR's Wait Wait... Don't Tell Me!: The weekly current events quiz show is always good for a laugh. It's never bad, and sometimes it's brilliant. Their sense of humor (especially the host's, ) is really sharp. Personally, my favorite panelist is Paula Poundstone, but there's a nice variety of panelists from week to week.

Podcasts I Listen To But Not Sure They're For Everybody:

This next set of podcasts, I listen to but you gotta be either into the subject matter or pretty patient, or both.

Engadget: the website that talks about what's new in electronic gadgetry also has a podcast. It rambles -- it's about 90 minutes each week and could easily be cut to half that length if they were a little more focused -- but the subject matter is good. I use this to keep up with what's happening in the consumer tech world. I used to get that info from TWiT (see below), but they ramble even more, the signal-to-noise ratio got too low, and they mostly talk about Twitter now. Oh yeah, the Engadget podcasts begin with these brilliant 8-bit versions of pop and rock tunes; it always cracks me up. Nice touch, guys.

~~This Week In Tech (TWiT)~~: I stopped listening, probably too late. Leo Laporte does a great job, although he interrupts his guests far too much: he'll ask them a question, and when they just start to answer, he'll jump in with his summary of what he thinks they were about to say. The audience ends up missing out on some great info, and if you aren't as familiar with the news as Leo is, you miss out. Plus, John C. Dvorak doesn't like anything, and he's simply an annoying presence on the show. They ramble too much, more than they used to 2-3 years ago. And the in-show ads are becoming more annoying all the time. Signal to noise ratio has just fallen below my threshold of patience; I cut bait a couple of months back.

IT Conversations: the first podcast I listened to on a regular basis, and still do (thanks, Stergios!). I pick and choose which topics to listen to from this podcast, which is an aggregation of talks and interviews from several conferences and online radio shows. It's the podcast I use to keep up with enterprise computing, green technology, and some biotech stuff. Podcasts last from about 15 minutes to 90 minutes, depending on where they come from.

Manager Tools: I'm torn about this one. If you're interested in learning more about all aspects of management from how to create goals to preparing for a layoff (both laying somebody off and being laid off yourself) to running a meeting to introducing people to calendar management (plus other, more interesting topics), this is a fantastic podcast. So what's the problem? They take 30 minutes to say what they could get across in 10-15 minutes. Really, I swear they should have somebody in their network go through each podcast and edit them down to create a "Manager Tools - Executive Summary" version that lasts 5-10 minutes. These guys have nuggets of gold in each podcast but they just talk too much. (mostly it's Horstman, and I'm guessing that would not surprise him to hear it)

They have more recently created a related podcast called Career Tools. There's some overlap, but some stuff unique to this podcast. Same comments as above.

The CNET News Daily Podcast: the title pretty much says it all. It's generally a 10-minute podcast each weekday. They do a good job. Why don't I recommend it more highly? Because the news just isn't all that exciting to me day to day; maybe once a week I find a story that's really interesting, but this podcast is short enough that I listen to it maybe half the time.

FLOSS Weekly: I'm just starting to get into this one, but am liking it a lot. Hosted by Leo Laporte (the creator of This Week In Tech), it's an interview with somebody in the open source world. The podcasts look to be about an hour per episode, but they're good interviews, if you want to learn more about open source.

American Public Media's Marketplace: daily business news radio show broadcast from the University of Southern California. You may already listen to it via public radio; I catch an episode here and there to keep up on business goings on when I don't read the Wall Street Journal that day. Great show, 30 minutes each weekday.

Guilty Pleasures:

Here are some other podcasts that I listen to but may not be for everybody. I dunno; you be the judge.

Drum Corps International Field Pass: almost daily podcast during the summer marching season, keeps me up to date with the competition across the country. Good production values, and surprisingly informative and entertaining...if you like drum and bugle corps. Go Vanguard!

Mugglecast: I stopped listening once the 7th and final Harry Potter book came out, but until then this was a fantastic podcast, created and run by a group of precocious high school kids. It's all aspects of Harry Potter, from talk about upcoming films and gossip to analysis of each and every book. They had some imaginative ways of discussing the books, which I enjoyed (one example: The Dueling Club, a segment where they'd talk about who might win a duel between any two characters, like Professor Trelawney vs. Luna Lovegood). Usually about an hour. I'm going to listen again for a bit, since the 6th movie just came out and I'd like to hear what they have to say about it.

NPR Planet Money: hit or miss. Sometimes they explain economics and money issues really well, other times it's just kinda boring. The staff is cool, though.

The Vic Firth Marching Percussion VIDEO Podcast: again, the title pretty much says it all. If you enjoy the sound of modern drum corps drumlines, this is a great way to get snippets on at least a weekly basis. Each cast is 5 minutes or less. Sweet.

G-Snap! gaining in popularity, reach

2009-07-25T16:10:00.001-07:00

G-Snap! is a cool, interesting web application that lets you set up flash crowds to follow an event together. One great example is happening right now: the Drum Corps International Southeast competition in Atlanta, Georgia. Thousands of fans will be in the stands watching young adults from across the United States compete, but hundreds of thousands of fans won't have the chance to see the event.

I've been watching G-Snap! for a while now (the company was launched over a year and a half ago) and I notice that it's starting to gain popularity. I've watched NFL games and college football bowl games, and I hear that NASCAR events are getting a pretty good fan base.

Drum corps is a natural: lots of people want to follow the progress of their favorite corps, and parents want to hear how their kids are doing on the summer-long nationwide tour that their corps is on. This way, you can join a group of fans just like you, and unlike Twitter, you can easily communicate directly with the others on the snapcast. Plus, you can see live video and photos of somebody uploads them to the snapcast.

The Blue Devils drum corps is promoting G-Snap! on its front page today; looks like they're interested in using the technology to enhance their fan network's experience following the corps.

It's also designed for mobile devices: if you're out and about but have a web browser on your mobile phone, snapcasts do great.

Click here to join the snapcast live (as of Saturday, July 25, from 4PM ET to 11PM ET). It's free and you don't need to log in to follow it.

It's hard for me to describe how different the G-Snap! experience is from, say, Twitter. I use both and like both, but snapcasting is a much richer, more inclusive group experience. If you want true feedback and interaction, there's no comparison: snapcasting is much better than tweeting.

Drum Corps International is on twitter!

2009-07-18T19:27:00.001-07:00

Yes folks, it is drum corps competition high season again. I've already seen a couple of shows in California and loved them both; the corps left the state a couple of weeks ago to head to the center of the country for the national tour. It all ends up in Indianapolis for finals week but in the mean time, there are a ton of great shows all across the nation.

You can get up-to-the-moment tweets from the DCI Tour twitter id: http://twitter.com/DCI_Tour.

And just for fun, I'll leave you with this link: Drumline's Greatest Moments, going back 28,000 years. Excellent, fun timeline.

Go Vanguard!

Interesting opinion about VLC media player

2009-07-16T11:02:00.001-07:00

Hmm, I wonder how significant the VLC 1.0 software release is? Here's an interesting, brief take on how the media player software could change the media world.

Looks like it's time to check out the latest version of the software.

Drum Corps Season Is In Full Swing

2009-07-13T13:57:00.001-07:00

This is the happiest time of year for me. Not just because it's summer, but because of what summer brings. What summer brings is drum and bugle corps competitions, courtesy of Drum Corps International.

Here are just a couple of notes. First, the Santa Clara Vanguard, my alma mater corps (1985, pit), has a gorgeous show based on Aaron Copland's "Appalachian Spring". It's doing well, but the Vanguard is still a couple of points behind the Blue Devils. Let's hope SCV catches up!

Second, DCI has a nice podcast called "DCI Field Pass", hosted by a gentleman named Dan Potter. It's kind of market-y, but in a great way. It's a good way to keep up with what's going on in drum corps competition all around the country, week by week. I listen to the podcast during my runs because they're bite-sized (I can listen to a few of them during a normal run). They don't last so long as to get boring. Nice job, DCI.

Amazing Season Finale - Terminator: The Sarah Connor Chronicles

2009-04-16T15:14:00.000-07:00

I've been watching "Terminator: The Sarah Connor Chronicles" since it began last year. Season One was fine; I felt it was something of a guilty pleasure with great promise. Season Two started out well, and I just feel like the show got progressively stronger and more complex as it went on.
But the last two episodes of Season Two were on an entirely different plane: wow. I'm not going to spoil it here, but if you were watching Terminator: TSSC and gave up before the end of Season 2, you really need to get back on it and watch all the way to the end. The last two episodes were amongst the best TV I've seen in years. Incredibly cool, incredibly powerful stuff, and the season finale did something rare: it both left you hanging and it provided huge resolution to a lot of storylines.

There are so many things to like about the show. If you like gender balance, this is a great show because three of the primary characters, perhaps the most interesting characters, are women. And for an action show, there is a surprising amount of emotional depth, character development, and attention to relationships. Don't get me wrong: there's plenty of action. But there's a lot more than just the action.

Here are some interview clips with a few of the stars of the show, for those of you who are becoming even more engrossed with the show as I am. I plan to re-watch both seasons, so I can go through the whole storyline again and pick up pieces that I missed.

I hope that FOX renews the show for a third season, because the stories set up by the season finale are amazing.

Interview with Lena Headey (Sarah Connor)

Interview with Shirley Manson (Miss Weaver)

Interview with Summer Glau (Cameron, a Terminator)

Interview with Thomas Dekker (John Connor)

Interview with Garret Dillahunt (John Henry)

How to update the feeds on my Drupal-based web site

2009-03-21T11:50:00.000-07:00

My web site, transcode.com, displays blog entries from two blogs right now:

I'm using a Feed Aggregator module in Drupal to tell it to pick up blog entries and display them on the front page of the transcode.com web site.

But Drupal doesn't automatically pick up new entries; you have to tell Drupal to go out and check for new entries every once in a while. In the Unix world, that kind of periodic activity is usually known as a cron task, something you would tell the "cron" program to run from time to time.

I currently host my Drupal site on GoDaddy.com; there is a nice, easy way to have GoDaddy run the cron task as often as you'd like, and it'll wake up Drupal and get Drupal to update all the feeds it receives.

For simple instructions on how to configure the GoDaddy cron service, look at this web page. It's simple and complete; it tells it all.

How to push a simple Drupal web site from test to production

2009-03-15T23:45:00.000-07:00

I decided to give up on the twitter issue for now (I've been trying to get tweets onto my Drupal web site but couldn't make it work right). So I decided to go with what I have, which is my basic web pages + my Transcode blog showing up on the Drupal-created web site's main page.

My next task was to try to push the web site live, onto my hosted web server. I had to learn how to create a MySQL database on the hosting company, which was easy to do but took a couple of hours to show up. I also wanted ssh access to my site, which apparently caused my hosting company to move my hosted environment to a different server; that also took a few hours to get going, but was relatively painless. I tried to connect to it after a few hours, and couldn't; I found out that I needed to create a new password for the ssh service to work (makes sense, no problem).

Once I did all that, a few hours later I was able to get to the site. Here were the basic steps I took:

- I took my whole web site's "htdocs" directory tree and made a tarball of it:

tar cvf website.tar ./htdocs

This is where my images, PHP code for Drupal + modules, and all my other content sits, at least the content that doesn't get stored directly into the database. (e.g., PostScript documentation that I store on the site for public download)

- I FTPd the tarball over to my hosting provider, just put it somewhere for the time being.

- I took a snapshot of my Drupal database using "mysqldump":

mysqldump -u myusername -pmypassword mydatabasename > databasename.sql

(note: no space between the "-p" and the beginning of the password string. Not sure why that was the case, when there is a space between the "-u" and the beginning of the username string.)

- I FTPd the databasename.sql file to my hosting provider as well.

- I logged into my hosting provider's site, went into the administration interface for it, and asked it to create a new MySQL 5.0 database. I gave the database the same name as I gave when I set up Drupal on my local site. I picked a username and password, then it was ready to go. I noted the hostname where that DB sits, because I need to use that later.

- I used ssh to get into my site. Once there, I unpacked the htdocs tarball:

tar xvf htdocs.tar

- I moved the htdocs directory to be a peer of my existing html directory (the top of the html tree for my existing web site; I'm going to replace that html tree with my new Drupal-based html tree). Now, typing "ls" I see the following

htdocs html

- I went into htdocs/sites/default/files/ and edited the "settings.php" file to make sure the setting for connecting to the database is correct. I needed to update the username, password, and hostname to make sure they all correctly use the production site's values. The line looks something like this:

$db_url = 'mysqli://user:password@nameofdbhostname.com/nameofdb';

- I moved the original html directory out of the way

mv html html.orig

- I moved the Drupal-based htdocs document tree into place

mv htdocs html

- I was then ready to test by going here: http://www.transcode.com/

The Drupal-based content showed up like a charm. Voila!

My first live site push with Drupal worked, no problem.

Next, I'll need to learn how to do site updates: I intend to do more web site development via Drupal on my local machine, using my test/development environment (using VirtualBox to run OpenSolaris as a guest OS, so that my whole environment sits in a single .vdi file that I can put on a USB stick and take and use anywhere I want to go, or copy it onto a DVD or anywhere, really). Anyway, once I make more improvements to my web site, I'll want to push them live, too, so I need to learn how to update an existing live site. I'm hoping that will be pretty easy.

Drupal Question: Putting Content Into A Block

2009-03-12T23:29:00.000-07:00

I'm struggling again today. Yesterday, I managed to put some static content into my Drupal-based web site, and I even have the front page showing this blog. That's great; I was ready to push my test site live, which I don't yet know how to do but was going to read up on it.

But then I got greedy and decided "Hey, wouldn't it be great to show my Twitter 'tweets' on one of the sidebars of the web site? I mean, as long as I'm showing my blog here, why not my micro-blog?" So I did some searching and found a Twitter module that does the opposite: every time I make a change to my Drupal site, Drupal will tweet with my account. I want my account's tweets to show up on my Drupal site!

So, I found different instructions that look better; the section of the page that says to use FeedAPI looked reasonable. I had to install a couple more modules. I did that, configured as the author said (I think), but still no content. I can't see my tweets!

Here's my question: how do I put content into a block? I can see my overall page design has a bunch of blocks. I can create new blocks. But how do I tell a block what kind of content should go into it, or what kind of stuff a block should show? I've put other content into other blocks, but I don't really know how I did it. I'm thinking that's a pretty key concept, connecting content to blocks.

And I don't want to have to write PHP to do it. There must be a simpler way.

I'll keep reading, but right now, it's all pretty confusing to me.

Today's Novice Drupal Question

2009-03-11T12:41:00.000-07:00

I'm now at the point where I have a really simple web site: maybe 10 pages total, in a hierarchy. All but one page is static content; the one page that isn't static is used for displaying this blog.

Most of the web content is text, with a few links and some images. I need to fix my web pages so that they correctly refer to the images (if I view one of my pages, I just see "broken image" icons showing that the link is no good). That's where my question comes in. I want to know: how does Drupal store my content?

This web page seems to indicate that the content is all stored in the database (MySQL in my case).

Okay, fine. So now I need to transfer my image files onto my web server so that my Drupal pages (nodes) can see them. Does that mean I need to somehow put each image into Drupal so Drupal can assign a node ID to them, keep them in the database? That seems a little goofy; the images are already sitting on my web server in my htdocs directory. Can't I just have my web pages refer to those images?

I'm trying to do this the Drupal way, but I don't know what the Drupal way is for dealing with images.

I'll keep looking for answers.

Oh, and by the way: in the Drupal 6 "Getting Started" documentation, I can't find anything about how to take my test web site and push it to my actual web server. Somebody told me about using "mysqldump", but I don't know if that will cover everything in my web site, or what. And I've never used it before; I need to find documentation on drupal.org on how to use it to push my site live.

Using Drupal to display this blog

2009-03-10T19:35:00.001-07:00

I went to DrupalCon last week and had a blast. I decided to try out Drupal by running my web site, transcode.com, with Drupal. So far, mixed news.

It was incredibly easy to install Drupal. But I've just spent about two hours trying to do what I thought was a simple thing: display my blog on the front page of transcode.com. Turns out it is simple; I just got confused by the Drupal terminology and menu system.

I thought the right thing to do was to create a "Page" node, then somehow find a way to include the contents of the "Feed aggregator" module into the page. Makes sense to me: I've got a module ("Page") for displaying content, and I've installed another module that knows how to grab an RSS feed and extract its contents. I thought that telling Feed Aggregator to put its contents inside my Page node would be the way to do it.

I still don't know how to make that happen, but it turns out there is an easier way to accomplish what I need. I got the info from this tutorial page, entitled "Using Drupal as your RSS Feed Aggregator". That's exactly what I want, and the directions were simple and clear.

The trick: go ahead and activate the Feed aggregator module, which gives it a name that Drupal can refer to as a URL. Then for my site information (Drupal->Administer->Site configuration->Site information menu), tell Drupal that this feed aggregator should be my default front page.

It worked! Now, time to move the rest of the original transcode.com site into Drupal, then test it out before I publish it.

More Coming in 2009

2009-03-09T00:31:00.000-07:00

I've been away from this blog for about a year now, but watch this space: there's more to come. I plan to write a little about media, but also about other technical and non-technical topics.

For example: spreadsheets. I like to use spreadsheets to help me make decisions, mostly purchasing decisions. I created a spreadsheet for house shopping, one for car shopping, and I intend to post both of them to this blog, to share what I learned in case it helps others in their own shopping.

Watch for a spreadsheet I used to track sales prices of homes in Alameda and San Mateo counties in California over the last 3 years. Maybe you'll find it useful.

A cool audio-video library for Linux (ffmpeg)

2008-01-03T22:47:00.001-08:00

Happy New Year, folks. It's nice to be back at the keyboard after a hectic week with family. Fun, but hectic.

Recently I was looking to upgrade the movie playback capabilities of my home machine, which currently runs Ubuntu Linux, OpenSolaris, and Windows XP as a guest OS under VMware. Specifically, I was looking to make movies play well on the Ubuntu Linux OS and there are several software packages to help out. The movie player I was using is called "Totem", but there are others.

While I was looking at what software packages to get, I ran across "ffmpeg", which is a nice collection of software for doing the common things you would want to do with continuous media (like movies, as opposed to static media like photos): encode, decode, and transcode (or "convert", as the Wikipedia entry on FFmpeg says).

This is a nicely fleshed-out version of what the Transcode company used to do: take movies in one format, convert them to a different file format, and if you wish, also transcode the content into a different encoding.

There are tons of codecs in the FFmpeg package; if you look at the Wikipedia page, you'll see the mention of something called "FourCC", which is a Microsoft term for specifying the kind of encoding scheme used in a movie. It's a four-alphanumeric word (e.g., "MPEG", "DIVX"), and movie players look at the FourCC near the beginning of a movie file to determine what decoder to use to playback the movie content.

Anyway, check out the package if you're looking for good software for dealing with movie-type media on Linux machines. It's pretty good stuff.

Motion-JPEG vs. MPEG

2007-10-29T23:50:00.001-07:00

There has been a lot of work in image compression and motion compression formats over the years. At the time Parallax Graphics was still around, high-quality movies were often recorded in what was commonly referred to as "Motion-JPEG". If you've done any study about digital movie formats, you may be asking yourself "Why such a goofy name? Why not just call it MPEG? After all, that's pretty much what you mean, isn't it?" Well sure: pretty much, but not exactly. And it has to do a lot with the hardware that was available at the time to do real-time encoding of video signals.

First, a bit of terminology. In movie and video terms, you'll often see the unit of measurement "frames per second"; films are shot at 24 frames per second (abbreviated as "fps"), video in North America is shot at 30 fps, and video shot in Europe is generally shot at 25 fps. Film is just a series of still photographs shot really quickly -- 24 still images per second -- and each still photograph in a film is called a "frame". Same with video.

Motion-JPEG movies are movies that consist of a series of individual JPEG images. If you're recording video at 30 fps, each individual frame can be extracted and decompressed separately. In essence, Motion-JPEG is a way of saying "This movie consists of a bunch of individual JPEG still images." It's nothing more than that; it's not as if JPEG and Motion-JPEG images are decoded differently. They're all just JPEG images.

MPEG, however, is more sophisticated. It uses some of the same principles as JPEG encoding, but MPEG adds another layer of compression: MPEG compression looks at an image and its neighbors to see if there are similarities across time that can be compressed away. Think about this: if you're watching a courtroom drama on TV, there are plenty of shots of the judge talking, or somebody on the witness stand. Their heads may be moving, maybe even their arms, but not much else. The background remains motionless, so doesn't really change from one frame to the next. MPEG recognizes this and stores only the changes from one frame to another.

MPEG and Motion-JPEG turn out to be pretty different things. If you ever look at movie compression software or video capture products and see that they create Motion-JPEG files, you know you can do better nowadays. But you should also know that the Motion-JPEG movies can be pretty easily transcoded into MPEG movies.

Transcoding vs. file format conversion

2007-10-12T16:24:00.000-07:00

When I wrote the software to transcode digital movies, I made a distinction between the term "transcode" and file format conversion. To me, they are two different things; let me see if I can explain.

When you look at popular movie file formats like Quicktime or Windows Media Video, you see two things:

A file format that describes how the movie is laid out; how many audio tracks, the size of the images in the movie, encoding information, all kinds of stuff;
The data itself: frames of compressed or uncompressed images and digitized audio.

When I first created the Movie Conversion Tools product, it was to take movies created by Parallax Graphics video capture cards. Parallax had its own movie file format (this was in the days before Quicktime and Windows had well-established movie file formats, if you can believe that). The Parallax products had hardware to quickly compress images into JPEG format, so the movies were a series of individual JPEG images, not MPEG files. (I'll write later on the difference between motion-JPEG and MPEG). So to convert Parallax movies into something that could be played by a Mac or PC that could only deal with Quicktime or Windows Media, I had to deal with potentially two problems. The harder one was the transcoding.

To convert from a Parallax movie to an AVI movie file, I had to:

Change the file format: Parallax has one way of describing the contents of the audio and video data (think of the file format as a table of contents; different file formats have different ways of describing what's inside the file, but they all have the same basic information);
Sometimes, change each individual image from one image format (e.g., JPEG) to another (e.g., YVU9). This last part is the transcoding part: it takes the actual image content and re-codes it into something else. Sometimes during this process, the image quality will be changed because if you're re-coding into a lossy compression format, you'll lose some image quality. (but that's another topic)

I don't consider file format conversion "transcoding" because you're not really changing the nature of what's in the movie file itself; it's just knowing how to say "There is one minute of video content in this movie at 30 frames per second, and 2 channels of audio at 44.1KHz" in two different ways. The transcoding is when you have to pull out the audio/video data itself and possibly re-encode it into something different.

File format conversion alone doesn't always get you all the way there. For example, you can take a valid Parallax movie file, convert it into a valid AVI file that any AVI player should be able to parse, and yet the AVI file would not be playable. Why? Because the PC playing the AVI file may not have a JPEG decoder, so doesn't know how to display each image ("frame") in the movie file. It can tell you exactly how long the movie file is, and how many bytes are in each frame of the movie; it just doesn't have the capability of playing back the movie. The movie was not transcoded into a format that the player could play.

That's how I distinguish between transcoding and file format conversion. One converts the movie's wrapper (file format conversion), the other converts the movie's content (transcoding).

Welcome to the Transcode Blog

2007-10-09T23:57:00.001-07:00

I was talking to a friend of mine recently about a business I started some years ago, called Transcode. He suggested that it might be a good idea to create a blog about the company and the work I've done over the years with multimedia computing; I thought that was a good idea, so I've created this blog.

My intent is to spend my time here writing about various aspects of multimedia computing and things related to transcoding media. Who knows where it will go, but where I want it to start is as an informal history of transcode.com, the company Transcode.

I'd love to hear from you; comment on the blog if you've got something to say about media, transcoding, anything like that.

Welcome. Let's see where this blog takes us.