;

int OSSL_DECODER_CTX_set_selection(OSSL_DECODER_CTX *ctx, int selection);
int OSSL_DECODER_CTX_set_input_type(OSSL_DECODER_CTX *ctx,
                                    const char *input_type);
int OSSL_DECODER_CTX_set_input_structure(OSSL_DECODER_CTX *ctx,
                                         const char *input_structure);
int OSSL_DECODER_CTX_add_decoder(OSSL_DECODER_CTX *ctx, OSSL_DECODER *decoder);
int OSSL_DECODER_CTX_add_extra(OSSL_DECODER_CTX *ctx, 
                               OSSL_LIB_CTX *