Create a handle with optional choice of decoder (named by a string, see mpg123_decoders() or mpg123_supported_decoders()).
and optional retrieval of an error code to feed to mpg123_plain_strerror().
Optional means: Any of or both the parameters may be NULL.
\param decoder optional choice of decoder variant (NULL for default)
\param error optional address to store error codes
\return Non-NULL pointer to fresh handle when successful.
Create a handle with optional choice of decoder (named by a string, see mpg123_decoders() or mpg123_supported_decoders()). and optional retrieval of an error code to feed to mpg123_plain_strerror(). Optional means: Any of or both the parameters may be NULL.
\param decoder optional choice of decoder variant (NULL for default) \param error optional address to store error codes \return Non-NULL pointer to fresh handle when successful.