Convert the format_str string into the drm fourcc value. The modifier is also parsed if we want. Please note that the format_str should follow the fourcc:modifier kind style, such as NV12:0x0100000000000002
a drm format string
Return the modifier in format or null to ignore.
The drm fourcc value or DRM_FORMAT_INVALID if format_str is invalid.
Convert the format_str string into the drm fourcc value. The modifier is also parsed if we want. Please note that the format_str should follow the fourcc:modifier kind style, such as NV12:0x0100000000000002