[enhance][AYUV][render target]Request for a render target for AYUV

[fulinjie]

Request for a new render target for AYUV:
VA_RT_FORMAT_AYUV for 4:4:4 8 bit hardware decode support.

Requested by community:
https://patchwork.ffmpeg.org/patch/13728/

[fulinjie]

Also, request for a new render target for Y410, since Y410 has alpha channel, but the render_target format YUV444_10 doesn't have one.
https://patchwork.ffmpeg.org/patch/15008/

[fulinjie]

Collected some information:

1. in CreateDecAttributes and MediaLibvaCaps::CheckEncRTFormat,
   VA_RT_FORMAT_YUV444 and VA_RT_FORMAT_YUV444_10 are used for MAIN444 and MAIN444_10:

https://github.com/intel/media-driver/blob/cf80fa0e3c81361696ada1285ea17a417114be47/media_driver/linux/gen11/ddi/media_libva_caps_g11.cpp#L1189

https://github.com/intel/media-driver/blob/cf80fa0e3c81361696ada1285ea17a417114be47/media_driver/linux/common/ddi/media_libva_caps.cpp#L350

2.DDI_MEDIA_FORMAT mediaFmt = DdiMedia_OsFormatToMediaFormat(expected_fourcc,format);

mediaFmt is decided by expected_fourcc (firstly decided by the RT_FORMAT, then by the attrib value)

Which will be queried:
case VASurfaceAttribPixelFormat:
DDI_ASSERT(attrib_list[i].value.type == VAGenericValueTypeInteger);
expected_fourcc = attrib_list[i].value.value.i;

https://github.com/intel/media-driver/blob/cf80fa0e3c81361696ada1285ea17a417114be47/media_driver/linux/common/ddi/media_libva.cpp#L2222

3. VA_RT_Format describes the sampling format, different fourcc may have the some rt_format:
   I420, NV12,YV12 has the same RT_FORMAT.

As to AYUV and Y410, YUV444 and YUV444_10 are able to present the sampling format well.

[fulinjie]

Hi @XinfengZhang , any comments?