relation between the preview size and fps in android camera

Question

Hi guys: I am testing the camera fps on android system. I've set up the camera functionality by native android camera, set the preview fps of camera.parameter to its maximum(~28fps), then use onPreviewFrame to extract the image data, processed with standard yuv420sp-to-rgb transformation to get the RGB information I need.

The problem I faced is that different preview size will result in different available fps(the times onPreviewFrame() be called per seconds, instead the fps set by camera parameter), here is the data from Asus Transformer TF101(CPU 1GHz)

(Preview Size,fps) (1024x720,5) (640x480,11) (320x240,28)

It seems that only resolution 320x240 could reach the maximum fps. I wonder if anyone have experience in such situation about PreviewSize vs Fps. I hope to find a direction to increase (or explain) the fps. Thanks in advance!

Answer 1

Yes I have also tried same for my media recorder class, if preview size is larger, lesser will be the fps because internally the resolution will be more(as preview size is larger) so it takes time to capture the frame per seconds. FPS is nothing but frame per second ie number of frames captured per second.

Answer 2

fps和分辨率之间的关系：

fps = clock / (width * height)