A hardware workaround for RGBX was added to the standalone libpisp convert utility. There is also a software workaround in libcamera. However neither of those is currently included in the gstreamer plugin. I will have a look to see if this can be better factorized.
There is indeed an issue converting YCbCr back to RGB on BCM2712C1, due to insufficient range of the +constant terms. Akwardly, the RGBX hardware workaround potentially interacts with colour conversion too! But it might be hackable.
It's currently considered a "bonus" rather than core functionality, and some use cases were given more attention than others; but I do agree that libpisp should not be offering conversions that it can't support.
There is indeed an issue converting YCbCr back to RGB on BCM2712C1, due to insufficient range of the +constant terms. Akwardly, the RGBX hardware workaround potentially interacts with colour conversion too! But it might be hackable.
It's currently considered a "bonus" rather than core functionality, and some use cases were given more attention than others; but I do agree that libpisp should not be offering conversions that it can't support.
Statistics: Posted by njh — Mon Jul 27, 2026 10:43 am
