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Split DCT-II and DCT-III in different functions, they do not share any code. 

Originally committed as revision 22618 to svn://svn.ffmpeg.org/ffmpeg/trunk
This commit is contained in:
Vitor Sessak 2010-03-21 11:35:05 +00:00
parent e30ab38e94
commit 8305c76b53
1 changed files with 11 additions and 5 deletions
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16
libavcodec/dct.c
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@ -37,12 +37,11 @@
/* cos((M_PI * x / (2*n)) */ /* cos((M_PI * x / (2*n)) */
#define COS(s,n,x) (s->costab[x]) #define COS(s,n,x) (s->costab[x])
static void ff_dct_calc_c(DCTContext *ctx, FFTSample *data) static void ff_dct_calc_III_c(DCTContext *ctx, FFTSample *data)
{ {
int n = 1 << ctx->nbits; int n = 1 << ctx->nbits;
int i; int i;
if (ctx->inverse) {
float next = data[n - 1]; float next = data[n - 1];
float inv_n = 1.0f / n; float inv_n = 1.0f / n;
@ -69,7 +68,12 @@ static void ff_dct_calc_c(DCTContext *ctx, FFTSample *data)
data[i ] = tmp1 + csc; data[i ] = tmp1 + csc;
data[n - i - 1] = tmp1 - csc; data[n - i - 1] = tmp1 - csc;
} }
} else { }
static void ff_dct_calc_II_c(DCTContext *ctx, FFTSample *data)
{
int n = 1 << ctx->nbits;
int i;
float next; float next;
for (i=0; i < n/2; i++) { for (i=0; i < n/2; i++) {
float tmp1 = data[i ]; float tmp1 = data[i ];
@ -101,7 +105,6 @@ static void ff_dct_calc_c(DCTContext *ctx, FFTSample *data)
next += s * inr - c * ini; next += s * inr - c * ini;
} }
} }
}
void ff_dct_calc(DCTContext *s, FFTSample *data) void ff_dct_calc(DCTContext *s, FFTSample *data)
{ {
@ -130,7 +133,10 @@ av_cold int ff_dct_init(DCTContext *s, int nbits, int inverse)
for (i = 0; i < n/2; i++) for (i = 0; i < n/2; i++)
s->csc2[i] = 0.5 / sin((M_PI / (2*n) * (2*i + 1))); s->csc2[i] = 0.5 / sin((M_PI / (2*n) * (2*i + 1)));
s->dct_calc = ff_dct_calc_c; if(inverse) {
s->dct_calc = ff_dct_calc_III_c;
} else
s->dct_calc = ff_dct_calc_II_c;
return 0; return 0;
} }