Problem with output array size of UYVY format

watchever

Hi, I am a bit confused with the format of the output array receive from capture function. I set UYVY format and my picture definition is 1920x1088 (so total of 2 088 960 pixels). If output format is UYVY I should have an output array of 4 177 920 elements (4 bytes UYVY code 2 pixels), but output array from capture has a size of 3 133 440 elements (2 088 960 x 1.5). Don't really understand the format of this output array. Any idea or help (not sure my explanation is clear) ?
Thanks in advance

veye_xumm

@watchever
I think somehow the data you got has been transferred to YUV420 format.
Please tell me how you got that data.

watchever

I have a IMX432 so as you told me in a previous post it does not support I420. Following is my code, I also force register to UYVY, when I initialize the camera.

buffer_array = self._camera.capture(encoding = 'i422')
output = buffer_array.as_rgb_array

When I make the caputre I have following message on my terminal window :
mmal: capture_buffer_callback data len is 3133440

However getting a I420 format is not a problem, but need to know to manipulate the picture. And also know the order of the elements in the array, because it does not seem to be standard (should be all the Y elements first then U and last V).

Thanks

watchever

Mistake in my code :
buffer_array = self._camera.capture(encoding = 'i422')
output = buffer_array.as_array

veye_xumm

@watchever
I think the data is in the place where the raspberry pie is received, and the format conversion has been completed at the mmal level.
1920, 1088, 1.5, 133, 440.
Why pursue YUV422? I don't think YUV420 has really lost anything.

watchever

I don't mind using I420, however you told me in previous post that IMX432 only support I422 format, so I go that way. Do you confirm IMX432 support I420. I confirm that usinf i420 encoding and i422 does not change output array size. So it also means that yuvseq register is useless.

Any idea how the data are stored in this array. Standards say that I should have 1920x1088 Y elements first in the output array, then (960x544) U elements then (960x544 / 2) V elements, but does not seem to be the case.

watchever

Ok got it. I confirm output format is I420 and array order is correct. Thanks for your help