Unable to encode JPEG

[uartie]

The yami encoder tries to call vaCreateConfig for profile=VAProfileJPEGBaseline and entrypoint=VAEntrypointEncPicture with a VAConfigAttribRateControl=VA_RC_CQP config attribute. VAConfigAttribRateControl is an unsupported config attribute for JPEG encode. Recently, the intel-vaapi-driver (intel/intel-vaapi-driver@336d891) enforces strict VAConfigAttribRateControl config attributes and will not allow user/app to specify it if it is unsupported for the given profile/entrypoint.

This prevents libyami from creating a jpeg encoder.

The yami encoder should call vaGetConfigAttributes to determine whether VAConfigAttribRateControl is supported or not and avoid sending VAConfigAttribRateControl if it is VA_ATTRIB_NOT_SUPPORTED.

[uartie]

intel/intel-vaapi-driver#345 allows VA_RC_CQP for JPEG now...

However, the bigger issue is that libyami should actually query supported/unsupported attributes instead of hard-coding assumptions about the driver. Thus, this bug is still relevant since a simple driver query would have prevented this problem in the first place.