H.264, also known as MPEG-4 Part 10, also known as Advanced Video Coding, is the New Hotness when it comes to video codecs. What's it offer? Lower bit rate (and file size) than anything else out there, while looking better. Or higher resolution, also looking better, at the same bit rate and file size. Scalability from third-generation cell phones to high-definition audio.
Friday, May 13, 2005
H.264 - The Thin End of a Big Wedge
For
example, a typical 320x240 multiplexed MPEG plays back at roughly 1.1
to 1.8 megabits of data per second; a QuickTime movie using H.264 video
and AAC audio can do just as well in one half to one third the space
(meaning faster downloads) - or at 1.1 to 1.8 megabits per second, can
deliver two to three times the resolution. Suddenly, a "high-definition"
version of something takes only as long to download as one the size of a
postage stamp used to. And that "something" could be a music video, a
television show, a Hollywood movie, or other content - the kind that
drove sales of VCRs.
The first large-scale roll-out of H.264 capability that I know of is, of course, Apple's QuickTime 7,
which is included in Mac OS X 10.4 "Tiger," available free for Mac OS X
10.3 "Panther," and will be released for Windows soon. Really. Honest.
Any day now. :) Upon installing QuickTime 7, suddenly all sorts of
things went all high-definition on me.
With
a QuickTime 7 Pro license (which costs about $30), one can even create
H.264 content, or convert other video formats to H.264. Actually doing
this, though, made me aware of something:
Apple is going to make a lot of money because of H.264.
Why,
you ask? Simple. My 1.5-gigahertz G4 can export video in MPEG-4 format
(previously the New Hotness, now Old and Busted) with AAC audio at a
speed that, while not quite real time, is pretty acceptable. A dual G5
can do an even better job of it, of course. Exporting a QuickTime movie
with H.264 video is a lot more processor-intensive, and takes, oh,
probably six to twelve times longer. The results are stunning, of
course, but given the amount of thinking that goes into creating them,
this isn't a surprise.
So
while all of us who consume content are grinning our little heads off
over how awesome H.264 is compared to all the old formats, the people
who actually create (or even just encode) content for our consumption
are now probably waiting impatiently for Apple to introduce 3-gigahertz
Power Macs with 4 to 8 processor cores, so they can churn it out in a
reasonable amount of time.
Elite
black no-limit American Express Centurion cards at the ready, they're
counting the days to Apple's Worldwide Developers Conference in June,
hoping to order new über-shiny-toys... and you know who's going to be
laughing all the way to the bank when that happens.
World
domination through awesome video? Yeah, I suppose that's what this is.
But considering the current (if slightly faded) style of world
domination was built on a feature-bloated word processor and spreadsheet
and a buggy GUI with its roots in DOS and VMS... I, for one, welcome
our new high-definition video overlords.
The Earth Moved!
After 3 years of living in a volcanic, seismically active area, I've finally managed to feel an earthquake!
Around
midnight, I was sitting in the remote control room with three Japanese
observers. The telescope was cheerily doing telescope things, including
some rather precise guiding indicated by a crosshair in a window on my
screen.
Several
minutes past midnight, the remote control room shook, and the crosshair
on my screen jumped all over, indicating that the telescope (27 miles
away, and 2.5 miles higher than us) was doing the same. A call to
another observatory on the summit confirmed that folks up there had felt
it too. A friend I was chatting with reported that another friend of
hers who lives near me had actually been woken up by it, and within an
hour or so, a colleague had emailed me from London (he's on the road, as
usual) to ask whether I'd felt it.
According to the nice folks at the USGS, 'twas a 5.1 magnitude
quake off the southeast side of the island, 55 miles or so from here.
I've failed to notice quakes before, so it was pretty interesting to be
in a room where things are ordinarily very still - it made this one much
more obvious.
This
fleshes out my selection of natural hazards a little bit. Along with
the dangers of volcanic eruptions, tsunamis, altitude sickness and
venomous sea urchins, I can now enjoy earthquakes. :)
Tuesday, May 10, 2005
I'll see you on the poorly-lit side of the moon.
It's been an interesting night so far at the observatory.
My
observers are three postdocs from the University of Tokyo. They have no
professor with them, and when I ask who is in charge, who is
responsible, who wrote the proposal... they all point at one another. :)
They
are using a 4-megapixel visible light CCD camera which actually takes
rather nice pictures, and they're running it through our wide-field
grism spectrograph. Their first question was "how do we rotate the slit
on the spectrograph?" The answer unfortunately involved rotating the
entire instrument rack on the cassegrain focus... which means every time
they change objects, we have to do that.
Did
I mention the instrument rack is rotated manually? With various ropes
being unfastened before each change in rotation angle and refastened
afterward? And we have to use a hydraulic lift platform to get up to it? Yeah. Fun. Fortunately they have a short list of objects to
observe!
Anyway,
at twilight, I noticed a very thin crescent moon, so I went out on the
catwalk and took an 8-second exposure of it. This resulted in the
"visible" part of the moon being overexposed and very bright, and the "hidden" part of
the moon becoming visible. It was kinda fun.
Sunday, May 8, 2005
Welcome to the future, folks.
We just had a nice chat with a couple friends.
One of the friends is in London. The other is in Stafford, about 40 miles north of London. We, of course, are in Hawaii.
We all had live audio and video of each other, courtesy of iChat AV 3,
the latest version of Apple's audio and video chat program (which also
does AOL-compatible text chat perfectly well, of course), part of the
new Mac OS X 10.4 "Tiger." And we could have actually had a fourth party in on the chat, too.
Hosting
a multi-way video chat like this requires a reasonably good broadband
connection (DSL or cable modem), a fast Mac (at least an iMac G5, prices start around $1299 new), and a FireWire video camera like Apple's slick, tiny $150 iSight. But any computer Apple currently sells - even the $500 Mac Mini
- is powerful enough to participate in a group video chat, with as
little as an ISDN connection. And of course they can all do one-to-one
video chats, one-to-one audio chats, and group audio chats with up to 10
participants.
This
is one of those "the future has arrived" moments, really. I half expect
to go outside tomorrow morning and discover that my Honda is now a
flying car. If you've got a proprietary video conferencing system from
Polycom or whoever, it just became a dinosaur - and there's an big nasty
asteroid heading toward its planet. It can all be replaced by a thin,
light iMac or laptop, a tiny camera and a piece of software.
Monday, May 2, 2005
Uncovered: The Terrorism-Chowder Connection
Ask yourself this question: "Are old men standing in knee-deep mud and digging for clams A) a possible terrorist threat, or B) a defense against terrorism?" I'm not sure which one is least plausible, but in the last four years, the Boston area has seen both.
Some of the most productive clam-digging mudflats in the area lie on the sides of Logan International Airport bounded by Boston Harbor, providing a livelihood for dozens of people. After two flights out of Logan were hijacked and flown into the World Trade Center on September 11, 2001 (not, mind you, by clam-diggers), various measures were taken to improve security at the airport, including banning clam-diggers from the flats. Eventually, a 500-foot-wide perimeter was set up around the airport, then altered to contain a 250-foot "warning zone" and a 250-foot "arrest zone."Meanwhile, the clam-diggers were out of work. They petitioned their legislators, and after 14 months of their livelihood being disrupted (much to the delight of their bivalve prey, who were presumably happy as clams about all this protection), a transportation bond bill passed containing a measure that granted them an exemption allowing them to enter the security zone, provided they were first fingerprinted and background-checked (at a cost to the clam-diggers of over $100 each), and given anti-terrorism training.
Now, the clam-diggers look for clams, but are also expected to report anything suspicious that might indicate terrorist activity. They wear special brightly colored vests and ID badges issued by the airport, are checked on regularly by airport security, and to make matters even more interesting, are being loaned GPS-equipped cell phones by the Transportation Security Administration to help them contact authorities in the event that any of the clams turn out to be terrorists.
So it's a happy ending for everyone, except the terrorists and their fearsome allies... the clams.
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