reading and writing movie files of of . y4m extension

Hi everyone I have two questions

1-How to read and write movie files (of . y4m extension) with matlab

2-I want simple movies (.avi extension) with little frames with size(256X256) or size(512X512)

Regards

Answer 1

[Walter Roberson]

Reading y4m: see http://www.mathworks.com/matlabcentral/fileexchange/50690-yuv4mpeg-reader

For writing y4m files I do not see code available (but I do see it listed as an Extra Credit project at a couple of universities.)

For writing .avi see VideoWriter

[Majid Al-Sirafi]

Firstly, thank you for your recoomedation

secondly in question 2 I want AVI movies with size (512*512)

regards

[Walter Roberson]

If you want AVI movies with frame size 512 x 512, then write 512 x 512 frames. If your frame would be a different size than that, then imresize() or crop it to be the size you want.

[Majid Al-Sirafi]

thank you very much

regards

Majid

[Meenakshi kollati]

Normally video contains resolution of width to height of aspect ratio of 4/3 or 16/9. It is a silly question K.Meenakshi

[Walter Roberson]

video contains whatever resolution is needed for the purpose. When doing image analysis it is not uncommon to encounter algorithms which use mathematics that require square matrices.

[Meenakshi kollati]

Is this operation performed on frame by frame basis or video.

[Walter Roberson]

Image analysis that requires square matrices would typically be analyzing frame by frame, but the information calculated might be tracked through multiple frames.

[sendja450]

I'm using the function you mentioned in your answer, it worked for me. Now I want to divide each frame into 64x64 block and build an histogram for each block created. Could you help me on that ?

[Walter Roberson]

mat2cell() to break into blocks, and then histogram each. Or, alternately, you might be able to use blockproc()