[FFmpeg-devel] [PATCH] 1D DCT for dsputil

[Loren Merritt]

On Mon, 18 Jan 2010, Vitor Sessak wrote:

>+ data[i    ] =   COS(s,n,i) * val1 + SIN(s,n,i) * val2;
>+ data[i + 1] =   SIN(s,n,i) * val1 - COS(s,n,i) * val2;

data aliases costab, so the SIN/COS loads will be duplicated.

>+ float tmp1 = data[i        ] * (1./n);
>+ float tmp2 = data[n - i - 1] * (1./n);
>+ float sin1 = 0.5/SIN(s,n,2*i+1);

division?

>+typedef struct {
>+    int nbits;
>+    int inverse;
>+    FFTSample *data;
>+    RDFTContext rdft;
>+    const float *costab
>+} DCTContext;

libavcodec/dsputil.h:902: warning: no semicolon at end of struct or union

--Loren Merritt