vaCreateContext() doesn't need |render_targets| nor |num_render_targets| parameters

[yell0wd0g]

According to this email thread, vaCreateContext() doesn't need the render_targets nor num_render_targets parameters: consider removing them or adding an overloaded function or a numbered vaCreateContext2() method without those.

@rosetta-jpn

[XinfengZhang]

@YellowDoge , you can use render_targets to register ref/recon surface , you also can set the render_targets to be nullptr and num_render_targets to 0. I dont understand why we need to remove it.
another concern is , if you want to use one surface as reference, you should ensure that it is decoded/encoded. so actually it is combined. one surface can be combined with 2 or more contexts. but in one context, when it is used as reference, it must be decoded/encoded in this context.

[uartie]

@YellowDoge if @XinfengZhang reply does not satisfy your question, feel free to reopen.

[linjiling]

so how do i combine one surface with one context if num_render_targets is zero ?