jpeg_data: buffer with input / output jpeg
len: Length of jpeg buffer
itype: Y4M_ILACE_NONE: Not interlaced
Y4M_ILACE_TOP_FIRST: Interlaced, top-field-first
Y4M_ILACE_BOTTOM_FIRST: Interlaced, bottom-field-first
ctype Chroma format for decompression.
Currently always 420 and hence ignored.
raw0 buffer with input / output raw Y channel
raw1 buffer with input / output raw U/Cb channel
raw2 buffer with input / output raw V/Cr channel
width width of Y channel (width of U/V is width/2)
height height of Y channel (height of U/V is height/2)