 0 if one of them was invalid or caused some other failure in the implementation.</p>

<p>OSSL_ENCODER_CTX_add_encoder(), OSSL_ENCODER_CTX_add_extra(), OSSL_ENCODER_CTX_set_construct(), OSSL_ENCODER_CTX_set_construct_data() and OSSL_ENCODER_CTX_set_cleanup() return 1 on success, or 0 on failure.</p>

<p>OSSL_ENCODER_CTX_get_num_encoders() returns the current number of encoders. It returns 0 if <i>ctx</i> is NULL.</p>

<p>OSSL_ENCODER_INSTANCE_get_encoder() returns an <b>OSSL_ENCODER</b> pointer on success, 