iPhone video buffer

Question

I'm trying to build a video recorder without jailbreaking my iPhone (i've a Developer license). I began using PhotoLibrary private framework, but i can only reach 2ftp (too slow). Cycoder app have a fps of 15, i think it uses a different approach. I tried to create a bitmap from the previewView of the CameraController, but it always returns e black bitmap.

I wonder if there's a way to directly access the video buffer, maybe with IOKit framework.

Thanks Marco

Answer 1

That is the big problem. So far i've solved using some temp fixed size buffers and detach a thread for every buffer when is full. The thread will save the buffer content in the Flash memory. Launching some heavy threads, heavy beacause each thread access the flash, will slow the device down and the refresh of the camera view. Buffers cannot be big, because you will get memory warning, and cannot be small because you will freeze the device, because of too many threads and accesses to the flash memory at a time. The solution resides in balancing buffer size and number of threads.

I haven't already tried to use sqlite3 db to store images binary data, but i don't if will be a better solution.

PS: to speed up class methods call, avoid the common solution [object method] because of how method call works, but try to get and save the method address as below.

From Apple ObjC doc:

"The example below shows how the procedure that implements the setFilled: method might be called:

void (*setter)(id, SEL, BOOL); 
int i; 
setter = (void (*)(id, SEL, BOOL))[target methodForSelector:@selector(setFilled:)]; 
for ( i = 0; i < 1000, i++ ) 
setter(targetList[i], @selector(setFilled:), YES); "

Marco