Function adapt_for_encode_explicit 

pub fn adapt_for_encode_explicit<'a>(
    data: &'a [u8],
    descriptor: PixelDescriptor,
    width: u32,
    rows: u32,
    stride: usize,
    supported: &[PixelDescriptor],
    options: &ConvertOptions,
) -> Result<Adapted<'a>, At<ConvertError>>

Negotiate format and convert with explicit policies.

Like adapt_for_encode, but enforces ConvertOptions policies on the conversion. Returns an error if a policy forbids the required conversion.