// Non-factorized reference version (section A.3.3 of the JPEG standard).
void idct_reference(const int16_t* input, const uint32_t* quant_table, uint8_t* output);
+// Floating-point IDCT due to Arai, Agui and Nakajima (also known as AA&N).
+// See idct.c for more details.
+void idct_float(const int16_t* input, const uint32_t* quant_table, uint8_t* output);
+
#endif /* !defined(_IDCT_H) */