Spec for getSourceEncodings and getTargetEncodings methods of javax.sound.sampled.spi.FormatConversionProvider class should allow to return empty arrays (arrays of length 0).
Current spec says: "The array will always have a length of at least 1."
This definition is fine for pure-java conversion probiders, but it's is very inconvenient for providers which doesn't implement convertor by itself, but is wrapper for external convertor. In case external provider is not available (for example some library is not installed), current spec force conversion provider to implement some fake convertor (for example convertor which just keep audio formats)