Take several photos on iPhone

Question

How do I take for example 25 photos in one second at low resolution?

I want to make a burst mode but with a lot of images at low resolution (640x480)

Later I need to increase to 40fps. I mean, take 40 photos in one second

Answer 1

25 frames per second is very close to the iPhone movie fps of 24.0 − 30 fps. Why not make a movie, then pull out the frames from the movie to get your shots.

Answer 2

The existing camera access in iOS spits out frames at about 30fps. You can't increase that, period. (I assume that this is due to the underlying hardware, but I don't really know.)

You'll also have a hard time with memory. 640x480 * 3 (RGB) * 25 frames ~= 23mb of RAM. Getting that much memory -- much less that much in a second -- in iOS is going to be challenging.

To get started with this, take a look around for AVFoundation sample code -- there's plenty of it to be had -- and experiment a bit to see what you can realistically and reliably get out of a device.