Re: [videoblogging] question

On 27/08/2004, at 4:08 AM, Jay Dedman wrote:

> Let's say I want to make a bigger screen for my videos.
> how do i do it without making the file size too big?

chicken and egg sort of question Jay 🙂

1. you can make the video present at twice its current size. this is
pretty common when using something like Cleaner. you capture/compress
at, say, 320×240 but then indicate that the video is to be displayed at
640×480. If you do the compressing right then it can look fine when
blown up, but you need to pay attention to black and white levels and
stuff. (Because rather than trying to preserve details in shadows just
make it black, otherwise it tends to make compression artefacts very
visible. Also frees up space for detail in the more important parts of
your images.)

2. qt player pro does all this too. not sure why the free player
doesn't (though keep in mind thre are lots of applications that can
play qt. you don't need to use qt player if you don't want to. just get
a free player that supports full screen and multiscale playback.)

3. trivial to script if you script quicktime. as is full screen

now most of this can present the videos larger with no change in file
size. but of course you can go bigger with change in file size. keep in
mind that doubling dimensions does not double amount of info. needed:
320×240=76800 pixels per frame, 640×480=307200 pixels per frame. It
quadruples the amount of info needed. Here you seriously wnat to tweak
frame rate, compression rates, and so on. once upon a time, might still
be the case, apple engineers would spend up to a week compressing those
clips from starwars and stuff that they provided. And they're the
people who write quicktime from the inside out. in other words black
art where settings for clip 1 will not work for clip 2.

general simple advice: if you seriously want to be able to do this
easily get Cleaner. expensive but this is one of the things that it is
designed for.

> you know, is there anyway we can double the image size that most of us
> have
> right now?
> from 320×480 to ????
> how big can we make the screen?

up to you. QT's full screen mode goes full screen in relation to
current screen resolution.
> my last video was 10MB which is probably too big for most people.
> but is this true?

no it isn't. yes it is 🙂 If they want it, they'll survive it. But
does it need it? Lots of questions in there.

at the moment i reckon 1mb=1minute is a good approximate rule of thumb,
but that requires broadband, but on homeband a 2min movie would take
only a few minutes to arrive, which is doable. in this scenario 10mb is
a long wait.

on broadband it isn't. but if i've got a cheap Australian broadband
deal (AUD30.00 month *but* only for 200MB – I know, it's immoral), then
watching your video has used up 5% of my monthly limit. From that point
of view I'd like to think it was 5% 🙂

> what's the limit going to be?

varies. People happily downloaded gigabytes of a Star Wars clip at
highest quality that I think was an 80MB file. But what can you afford?
I've got a pdf on my server (a computer games essay) that got
slashdotted over 18 months ago. it still clocks up 50+ downloads a day
and in the first 3 days after slashdotting clocked up 3 or 4gig of
downloads. file size is only 150kb, but at that point the limit is not
what do my clients want to pay but how much am I willign to pay.

Adrian Miles
……………………………………………………….. ||
interactive networked video ||
research blog ||