dear all:
I am now using dm355 for capturing 640x480(30
frame / second) picture and displayed in svga mode 800x600(60 frame / second)
by ths8200.if i used edma to translated data from v4l2 caputured buffer to
frame buffer, It will emerge noised pictures,i have set PBBPR register with
value 30 .but if i change to displayed in vga mode 640x480(60 f/s),it seem
ok!it seemed the ddr speed(171M) is not enough! but My project GUI(osd) must be
set as 800x600,So i have to change displaying to svga.I don't want to used edma,
then can i give the displayer driver(fbdev or v4l2) my caputre buffer address
directly for display?
I have
studied the v4l2 display driver,it supported V4L2_MEMORY_USERPTR mothod,it
seemed can accept a buffer address but it must be mmaped to the display buffer
first,So the captured buffer datas must translate to the mmaped buffer,so the
result is equal to mmap display buffer directly.
V4L2_MEMORY_MMAP : v4l2 capture
buffer->address1(mmaped) -> EDMA-> address2 (mmaped)<-v4l2 or
fbdev buffer
V4L2_MEMORY_USERPTR :v4l2 capture
buffer->address1(mmaped) -> EDMA-> address2 (mmaped)->v4l2 or
fbdev buffer
