DIFFERENT SIZE AND FRAMERATE VIDEO

fudgey

1705
a570is

Re: DIFFERENT SIZE AND FRAMERATE VIDEO

« Reply #10 on: 13 / January / 2008, 05:05:52 »

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Quote

The A570 IS can shoot 640x480 at 60fps, but it may be the only one.

No, it can't. It can do 640x480 at 30 or 15 fps, but the 60 fps mode is fixed to 320x240.

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GrAnd

916
[A610, S3IS]

Re: DIFFERENT SIZE AND FRAMERATE VIDEO

« Reply #11 on: 13 / January / 2008, 05:16:52 »

It seems many sites erroneously mention the 640x480x60fps mode for A570. But the spec on the official site does not have such mode.

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CHDK Developer.

a710is

250
A710 IS

Re: DIFFERENT SIZE AND FRAMERATE VIDEO

« Reply #12 on: 13 / January / 2008, 05:35:49 »

why did you write that higher resolution video requires changes in hardware? I mean don't these cameras take pictures with the v MP sensor and resize each one to x by y pixels at z fps ?
is there no hope that you can get the camera to resize the pictures to some other dimensions and use a custom framerate?
the G7 even films at 1024 x 768 / 15 fps.
720p video (or even 1280 by 960/1024) at whatever framerate would be nice...
so howcome you're stating that the cameras require changes in hardware as opposed to software?

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fudgey

1705
a570is

Re: DIFFERENT SIZE AND FRAMERATE VIDEO

« Reply #13 on: 13 / January / 2008, 11:27:49 »

I'm guessing the cameras use hardware jpeg/mjpeg codecs (chips or ip blocks) and their thruput may be limited in hardware by either the codec itself or by CPU speed or available RAM. The memory card (and the interface writing to it) is an obious limit as well. Different models may of course have somewhat different hardware even if the operating system is the same.

In any case it could obivously be possible to record a movie in full resolution at 2 fps as you can beat that in regular continous mode when saving jpegs. Note that the MJPEG video used by Canon (in at least my A570IS) is really not that much different from having a tarball of separate jpeg files on the card. Afaik frames in mjpeg are independent of each other unlike in mpeg4 used by many other camera brands nowadays.

I have no clue whether CHDK could be able to touch these things without modifying the camera's firmware.

Similarly, I'd really like to see my A570IS being able to record audio using a higher sample rate (I hear it's possible in some other models). It only records in uncompressed 8-bit mono 11 kHz, which is just plain apalling down to the point where speech is often incomprehensible.

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m2tk

50
Sheet happens ...

Re: DIFFERENT SIZE AND FRAMERATE VIDEO

« Reply #14 on: 13 / January / 2008, 13:54:45 »

Quote from: GrAnd on 11 / January / 2008, 12:48:34

Quote from: Woodsman on 11 / January / 2008, 11:41:00
I think many of the newer ones do. I know that the S3 IS has 60 fps at 320x240 resolution.

Quite the contrary. The newer cameras may not have such mode. The S5 does not have.
But it seems that the whole A-series has.

S5IS does have it (320x240x60fps )!
It doesn't have any of 15fps mode.

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S5IS 1.01bc