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GonStarTrek
7th May 2004, 15:45
Has anyone bought the new Olympus C770 digital camera or know of a decent Digital Camera forum where it might be discussed? I'm thinking of buying one, but at ukp400+ (us600+) for it, I want to be sure it does things right !

This digital camera is the 1st one that I've come across that can record full-screen MPEG4 video (640x480 @ 30fps) (as well as its normal stills), so I'm curious about its MPEG4 quality: they reckon, with sound, it can record about 5 mins of video on a 128MBxD card, so with a 512MB you are talking 20 minutes (and if xD cards get bigger -I think 8GB is the limit) that would be very powerful. However given these values, it would seem the MPEG4 compression must be pretty high quality considering that most of us can create a high quality encoding of a movie at half that (e.g. 50mb=5mins) or more ! They do not specify what codec is used - only that its MPEG4.

I'd just love to hear from someone who has tried it out and can give the low-down on the vid coded and quality.

Ta
GonStarTrek

scharfis_brain
7th May 2004, 16:02
5 mins on 128 MB means about 3.5 Mbps.

isn't this a little bit much for 640x480@30p

are you sure, this cam is producing not a I-Frame only mpeg-4 compatible stream?

Wilbert
7th May 2004, 16:07
I send them a mail, because I was also curious :) Stupid that they don't specify it on their webpage.

GonStarTrek
7th May 2004, 17:30
Originally posted by scharfis_brain
5 mins on 128 MB means about 3.5 Mbps.

isn't this a little bit much for 640x480@30p

are you sure, this cam is producing not a I-Frame only mpeg-4 compatible stream?

The full specs for a 128MB xD card is 386s 640x480 @30fps video and audio.

If you stick these figures into the Gordian Knot calc you get 2.6 MBits/s, 0.288 bits/(pixel*frame) (assuming uncompressed audio (only info on site is that audio is WAV) so that's about 1MB per minute). That's slightly higher than I would encode a movie (about 50% more).

That's actually about 6.6 minutes rather than 5 minutes.......

GonStarTrek

midi
9th May 2004, 09:27
not like a camera can do dual pass among other things, though, so it needs the extra bitrate...

GonStarTrek
9th May 2004, 12:22
Originally posted by midi
not like a camera can do dual pass among other things, though, so it needs the extra bitrate...

Good point.

GonStarTrek

Wolfman
10th May 2004, 16:25
Well the Olympus c350 also records "movies" in mpeg4 ..actally mov but at low res and without sound .. so its probaly mov

*for the size(320x200)?? the c350 movies arent bad.. but way too short

bb
11th May 2004, 20:41
As far as I know some Sony Cybershot models can record 640x480 MPEG-4 video, too. Does anybody have details?

bb