diff options
Diffstat (limited to 'libavcodec/avfft.h')
-rw-r--r-- | libavcodec/avfft.h | 18 |
1 files changed, 14 insertions, 4 deletions
diff --git a/libavcodec/avfft.h b/libavcodec/avfft.h index d0babc0909..623f0a33b5 100644 --- a/libavcodec/avfft.h +++ b/libavcodec/avfft.h @@ -77,12 +77,22 @@ void av_rdft_end(RDFTContext *s); typedef struct DCTContext DCTContext; +enum DCTTransformType { + DCT_II = 0, + DCT_III, + DCT_I, + DST_I, +}; + /** - * Set up (Inverse)DCT. - * @param nbits log2 of the length of the input array - * @param inverse >0 forward transform, <0 inverse transform + * Sets up DCT. + * @param nbits size of the input array: + * (1 << nbits) for DCT-II, DCT-III and DST-I + * (1 << nbits) + 1 for DCT-I + * + * @note the first element of the input of DST-I is ignored */ -DCTContext *av_dct_init(int nbits, int inverse); +DCTContext *av_dct_init(int nbits, enum DCTTransformType type); void av_dct_calc(DCTContext *s, FFTSample *data); void av_dct_end (DCTContext *s); |