topic PXP Rotation with destination offsets not divisible by BLOCK_SIZE? in i.MX RT Crossover MCUs

PXP Rotation with destination offsets not divisible by BLOCK_SIZE?

AndyCapon — Sat, 03 Apr 2021 09:09:18 GMT

Hi Guys,

If I do a PXP rotate to coordinates divisible by the BLOCK_SIZE then everything looks good. I am using a block size of 8x8, coords = 128, 128:

IMG_0029.jpg

coords = 132, 132. Not so good:

IMG_0030.jpg

I am setting the ps buffer config

.bufferAddr = (uint32_t)s_psBufferPxp - uSourceOffset

Where:

uint16_t uSourceOffset = (uXTop%8) * 2;

Is it possible to rotate to offsets within the blocks or does PXP only support rotation to coordinates divisible by the block size?

Cheers

Andy

Re: PXP Rotation with destination offsets not divisible by BLOCK_SIZE?

AndyCapon — Sat, 03 Apr 2021 09:06:00 GMT

Ok I "Fixed" the issue by calculating the destination address and changing outputBufferConfig.buffer0Addr.

Then setting outputBufferConfig.height to the width of my source buffer.

And using PXP_SetProcessSurfacePosition() with a an upper x and y of 0 and the lower x and y set to height and width.

This all seems a bit strange, am I misunderstanding what PXP_SetProcessSurfacePosition does?

This approach seems to be 1.4 times faster and works!

Re: PXP Rotation with destination offsets not divisible by BLOCK_SIZE?

Alexis_A — Wed, 07 Apr 2021 16:53:36 GMT

Hello @AndyCapon,

I think this problem shown is addressed in section 36.4.26 of the RM, not calculating the surface position correctly could cause one of the two following cases:

Alexis_A_0-1617810749419.png

Best Regards,

Alexis Andalon