#ifndef _EEL_MDCT_H_ #define _EEL_MDCT_H_ #include "ns-eel-int.h" #ifdef _WIN32 #include #endif #include #include #include #define EEL_DCT_MINBITLEN 5 #define EEL_DCT_MAXBITLEN 12 #define PI 3.1415926535897932384626433832795 typedef struct { int n; int log2n; EEL_F *trig; int *bitrev; EEL_F scale; EEL_F *window; } mdct_lookup; static void mdct(EEL_F *in, EEL_F *out, int len) { int k; EEL_F pioverlen = PI * 0.5 / (EEL_F)len; for (k = 0; k < len / 2; k ++) { int i; EEL_F d = 0.0; for (i = 0; i < len; i ++) { d += in[i] * cos(pioverlen * (2.0 * i + 1.0 + len * 0.5) * (2.0 * k + 1.0)); } out[k] = (EEL_F)d; } } static void imdct(EEL_F *in, EEL_F *out, int len) { int k; EEL_F fourovern = 4.0 / (EEL_F)len; EEL_F pioverlen = PI * 0.5 / (EEL_F)len; for (k = 0; k < len; k ++) { int i; EEL_F d = 0.0; for (i = 0; i < len / 2; i ++) { d += in[i] * cos(pioverlen * (2.0 * k + 1.0 + len * 0.5) * (2 * i + 1.0)); } out[k] = (EEL_F)(d * fourovern); } } // MDCT/iMDCT borrowed from Vorbis, thanks xiph! #define cPI3_8 .38268343236508977175 #define cPI2_8 .70710678118654752441 #define cPI1_8 .92387953251128675613 #define FLOAT_CONV(x) ((EEL_F) ( x )) #define MULT_NORM(x) (x) #define HALVE(x) ((x)*.5f) /* 8 point butterfly (in place, 4 register) */ static void mdct_butterfly_8(EEL_F *x) { EEL_F r0 = x[6] + x[2]; EEL_F r1 = x[6] - x[2]; EEL_F r2 = x[4] + x[0]; EEL_F r3 = x[4] - x[0]; x[6] = r0 + r2; x[4] = r0 - r2; r0 = x[5] - x[1]; r2 = x[7] - x[3]; x[0] = r1 + r0; x[2] = r1 - r0; r0 = x[5] + x[1]; r1 = x[7] + x[3]; x[3] = r2 + r3; x[1] = r2 - r3; x[7] = r1 + r0; x[5] = r1 - r0; } /* 16 point butterfly (in place, 4 register) */ static void mdct_butterfly_16(EEL_F *x) { EEL_F r0 = x[1] - x[9]; EEL_F r1 = x[0] - x[8]; x[8] += x[0]; x[9] += x[1]; x[0] = MULT_NORM((r0 + r1) * cPI2_8); x[1] = MULT_NORM((r0 - r1) * cPI2_8); r0 = x[3] - x[11]; r1 = x[10] - x[2]; x[10] += x[2]; x[11] += x[3]; x[2] = r0; x[3] = r1; r0 = x[12] - x[4]; r1 = x[13] - x[5]; x[12] += x[4]; x[13] += x[5]; x[4] = MULT_NORM((r0 - r1) * cPI2_8); x[5] = MULT_NORM((r0 + r1) * cPI2_8); r0 = x[14] - x[6]; r1 = x[15] - x[7]; x[14] += x[6]; x[15] += x[7]; x[6] = r0; x[7] = r1; mdct_butterfly_8(x); mdct_butterfly_8(x + 8); } /* 32 point butterfly (in place, 4 register) */ static void mdct_butterfly_32(EEL_F *x) { EEL_F r0 = x[30] - x[14]; EEL_F r1 = x[31] - x[15]; x[30] += x[14]; x[31] += x[15]; x[14] = r0; x[15] = r1; r0 = x[28] - x[12]; r1 = x[29] - x[13]; x[28] += x[12]; x[29] += x[13]; x[12] = MULT_NORM( r0 * cPI1_8 - r1 * cPI3_8 ); x[13] = MULT_NORM( r0 * cPI3_8 + r1 * cPI1_8 ); r0 = x[26] - x[10]; r1 = x[27] - x[11]; x[26] += x[10]; x[27] += x[11]; x[10] = MULT_NORM(( r0 - r1 ) * cPI2_8); x[11] = MULT_NORM(( r0 + r1 ) * cPI2_8); r0 = x[24] - x[8]; r1 = x[25] - x[9]; x[24] += x[8]; x[25] += x[9]; x[8] = MULT_NORM( r0 * cPI3_8 - r1 * cPI1_8 ); x[9] = MULT_NORM( r1 * cPI3_8 + r0 * cPI1_8 ); r0 = x[22] - x[6]; r1 = x[7] - x[23]; x[22] += x[6]; x[23] += x[7]; x[6] = r1; x[7] = r0; r0 = x[4] - x[20]; r1 = x[5] - x[21]; x[20] += x[4]; x[21] += x[5]; x[4] = MULT_NORM( r1 * cPI1_8 + r0 * cPI3_8 ); x[5] = MULT_NORM( r1 * cPI3_8 - r0 * cPI1_8 ); r0 = x[2] - x[18]; r1 = x[3] - x[19]; x[18] += x[2]; x[19] += x[3]; x[2] = MULT_NORM(( r1 + r0 ) * cPI2_8); x[3] = MULT_NORM(( r1 - r0 ) * cPI2_8); r0 = x[0] - x[16]; r1 = x[1] - x[17]; x[16] += x[0]; x[17] += x[1]; x[0] = MULT_NORM( r1 * cPI3_8 + r0 * cPI1_8 ); x[1] = MULT_NORM( r1 * cPI1_8 - r0 * cPI3_8 ); mdct_butterfly_16(x); mdct_butterfly_16(x + 16); } /* N point first stage butterfly (in place, 2 register) */ static void mdct_butterfly_first(EEL_F *T, EEL_F *x, int points) { EEL_F *x1 = x + points - 8; EEL_F *x2 = x + (points >> 1) - 8; EEL_F r0; EEL_F r1; do { r0 = x1[6] - x2[6]; r1 = x1[7] - x2[7]; x1[6] += x2[6]; x1[7] += x2[7]; x2[6] = MULT_NORM(r1 * T[1] + r0 * T[0]); x2[7] = MULT_NORM(r1 * T[0] - r0 * T[1]); r0 = x1[4] - x2[4]; r1 = x1[5] - x2[5]; x1[4] += x2[4]; x1[5] += x2[5]; x2[4] = MULT_NORM(r1 * T[5] + r0 * T[4]); x2[5] = MULT_NORM(r1 * T[4] - r0 * T[5]); r0 = x1[2] - x2[2]; r1 = x1[3] - x2[3]; x1[2] += x2[2]; x1[3] += x2[3]; x2[2] = MULT_NORM(r1 * T[9] + r0 * T[8]); x2[3] = MULT_NORM(r1 * T[8] - r0 * T[9]); r0 = x1[0] - x2[0]; r1 = x1[1] - x2[1]; x1[0] += x2[0]; x1[1] += x2[1]; x2[0] = MULT_NORM(r1 * T[13] + r0 * T[12]); x2[1] = MULT_NORM(r1 * T[12] - r0 * T[13]); x1 -= 8; x2 -= 8; T += 16; } while(x2 >= x); } /* N/stage point generic N stage butterfly (in place, 2 register) */ static void mdct_butterfly_generic(EEL_F *T, EEL_F *x, int points, int trigint) { EEL_F *x1 = x + points - 8; EEL_F *x2 = x + (points >> 1) - 8; EEL_F r0; EEL_F r1; do { r0 = x1[6] - x2[6]; r1 = x1[7] - x2[7]; x1[6] += x2[6]; x1[7] += x2[7]; x2[6] = MULT_NORM(r1 * T[1] + r0 * T[0]); x2[7] = MULT_NORM(r1 * T[0] - r0 * T[1]); T += trigint; r0 = x1[4] - x2[4]; r1 = x1[5] - x2[5]; x1[4] += x2[4]; x1[5] += x2[5]; x2[4] = MULT_NORM(r1 * T[1] + r0 * T[0]); x2[5] = MULT_NORM(r1 * T[0] - r0 * T[1]); T += trigint; r0 = x1[2] - x2[2]; r1 = x1[3] - x2[3]; x1[2] += x2[2]; x1[3] += x2[3]; x2[2] = MULT_NORM(r1 * T[1] + r0 * T[0]); x2[3] = MULT_NORM(r1 * T[0] - r0 * T[1]); T += trigint; r0 = x1[0] - x2[0]; r1 = x1[1] - x2[1]; x1[0] += x2[0]; x1[1] += x2[1]; x2[0] = MULT_NORM(r1 * T[1] + r0 * T[0]); x2[1] = MULT_NORM(r1 * T[0] - r0 * T[1]); T += trigint; x1 -= 8; x2 -= 8; } while(x2 >= x); } static void mdct_butterflies(mdct_lookup *init, EEL_F *x, int points) { EEL_F *T = init->trig; int stages = init->log2n - 5; int i, j; if(--stages > 0) { mdct_butterfly_first(T, x, points); } for(i = 1; --stages > 0; i++) { for(j = 0; j < (1 << i); j++) mdct_butterfly_generic(T, x + (points >> i)*j, points >> i, 4 << i); } for(j = 0; j < points; j += 32) mdct_butterfly_32(x + j); } static void mdct_bitreverse(mdct_lookup *init, EEL_F *x) { int n = init->n; int *bit = init->bitrev; EEL_F *w0 = x; EEL_F *w1 = x = w0 + (n >> 1); EEL_F *T = init->trig + n; do { EEL_F *x0 = x + bit[0]; EEL_F *x1 = x + bit[1]; EEL_F r0 = x0[1] - x1[1]; EEL_F r1 = x0[0] + x1[0]; EEL_F r2 = MULT_NORM(r1 * T[0] + r0 * T[1]); EEL_F r3 = MULT_NORM(r1 * T[1] - r0 * T[0]); w1 -= 4; r0 = HALVE(x0[1] + x1[1]); r1 = HALVE(x0[0] - x1[0]); w0[0] = r0 + r2; w1[2] = r0 - r2; w0[1] = r1 + r3; w1[3] = r3 - r1; x0 = x + bit[2]; x1 = x + bit[3]; r0 = x0[1] - x1[1]; r1 = x0[0] + x1[0]; r2 = MULT_NORM(r1 * T[2] + r0 * T[3]); r3 = MULT_NORM(r1 * T[3] - r0 * T[2]); r0 = HALVE(x0[1] + x1[1]); r1 = HALVE(x0[0] - x1[0]); w0[2] = r0 + r2; w1[0] = r0 - r2; w0[3] = r1 + r3; w1[1] = r3 - r1; T += 4; bit += 4; w0 += 4; } while(w0 < w1); } static void megabuf_mdct_apply_window(void *init, EEL_F *inbuf, EEL_F *outbuf) { mdct_lookup *p = (mdct_lookup *)init; EEL_F *w; int cnt; if (!p) return; w = p->window; if (!w) return; cnt = p->n / 2; while (cnt--) *outbuf++ = *inbuf++ * *w++; cnt = p->n / 2; while (cnt--) *outbuf++ = *inbuf++ * *--w; } static void *megabuf_mdct_init(int n) { mdct_lookup *lookup = (mdct_lookup *)calloc(sizeof(mdct_lookup), 1); int i; EEL_F c = (PI / (EEL_F) n); int *bitrev; EEL_F *T; int n2, log2n; if (!lookup) return 0; lookup->n = n; lookup->window = (EEL_F *)calloc(sizeof(EEL_F), n / 2); if (!lookup->window) return lookup; for (i = 0; i < n / 2; i ++) { lookup->window[i] = sin(c * (i + 0.5)); } if (n <= 32) return lookup; bitrev = (int*)calloc(sizeof(int), (n / 4)); lookup->bitrev = bitrev; if (!bitrev) return lookup; T = (EEL_F*)calloc(sizeof(EEL_F), (n + n / 4)); lookup->trig = T; if (!T) return lookup; n2 = n >> 1; log2n = lookup->log2n = (int)(log((double)n) / log(2.0) + 0.5); /* trig lookups... */ for(i = 0; i < n / 4; i++) { T[i * 2] = FLOAT_CONV(cos((PI / n) * (4 * i))); T[i * 2 + 1] = FLOAT_CONV(-sin((PI / n) * (4 * i))); T[n2 + i * 2] = FLOAT_CONV(cos((PI / (2 * n)) * (2 * i + 1))); T[n2 + i * 2 + 1] = FLOAT_CONV(sin((PI / (2 * n)) * (2 * i + 1))); } for(i = 0; i < n / 8; i++) { T[n + i * 2] = FLOAT_CONV(cos((PI / n) * (4 * i + 2)) * .5); T[n + i * 2 + 1] = FLOAT_CONV(-sin((PI / n) * (4 * i + 2)) * .5); } /* bitreverse lookup... */ { int mask = (1 << (log2n - 1)) - 1, j; int msb = 1 << (log2n - 2); for(i = 0; i < n / 8; i++) { int acc = 0; for(j = 0; msb >> j; j++) if((msb >> j)&i)acc |= 1 << j; bitrev[i * 2] = ((~acc)&mask) - 1; bitrev[i * 2 + 1] = acc; } } lookup->scale = FLOAT_CONV(4.f / n); return lookup; } static void megabuf_mdct_backward(void *init, EEL_F *in, EEL_F *out) { mdct_lookup *lookup = (mdct_lookup *)init; int n, n2, n4; EEL_F *iX, *oX, *T; if (!lookup) return; n = lookup->n; if (n <= 32 || !lookup->bitrev || !lookup->trig) { imdct(in, out, n); return; } n2 = n >> 1; n4 = n >> 2; /* rotate */ iX = in + n2 - 7; oX = out + n2 + n4; T = lookup->trig + n4; do { oX -= 4; oX[0] = MULT_NORM(-iX[2] * T[3] - iX[0] * T[2]); oX[1] = MULT_NORM (iX[0] * T[3] - iX[2] * T[2]); oX[2] = MULT_NORM(-iX[6] * T[1] - iX[4] * T[0]); oX[3] = MULT_NORM (iX[4] * T[1] - iX[6] * T[0]); iX -= 8; T += 4; } while(iX >= in); iX = in + n2 - 8; oX = out + n2 + n4; T = lookup->trig + n4; do { T -= 4; oX[0] = MULT_NORM (iX[4] * T[3] + iX[6] * T[2]); oX[1] = MULT_NORM (iX[4] * T[2] - iX[6] * T[3]); oX[2] = MULT_NORM (iX[0] * T[1] + iX[2] * T[0]); oX[3] = MULT_NORM (iX[0] * T[0] - iX[2] * T[1]); iX -= 8; oX += 4; } while(iX >= in); mdct_butterflies(lookup, out + n2, n2); mdct_bitreverse(lookup, out); /* roatate + window */ { EEL_F *oX1 = out + n2 + n4; EEL_F *oX2 = out + n2 + n4; iX = out; T = lookup->trig + n2; do { oX1 -= 4; oX1[3] = MULT_NORM (iX[0] * T[1] - iX[1] * T[0]); oX2[0] = -MULT_NORM (iX[0] * T[0] + iX[1] * T[1]); oX1[2] = MULT_NORM (iX[2] * T[3] - iX[3] * T[2]); oX2[1] = -MULT_NORM (iX[2] * T[2] + iX[3] * T[3]); oX1[1] = MULT_NORM (iX[4] * T[5] - iX[5] * T[4]); oX2[2] = -MULT_NORM (iX[4] * T[4] + iX[5] * T[5]); oX1[0] = MULT_NORM (iX[6] * T[7] - iX[7] * T[6]); oX2[3] = -MULT_NORM (iX[6] * T[6] + iX[7] * T[7]); oX2 += 4; iX += 8; T += 8; } while(iX < oX1); iX = out + n2 + n4; oX1 = out + n4; oX2 = oX1; do { oX1 -= 4; iX -= 4; oX2[0] = -(oX1[3] = iX[3]); oX2[1] = -(oX1[2] = iX[2]); oX2[2] = -(oX1[1] = iX[1]); oX2[3] = -(oX1[0] = iX[0]); oX2 += 4; } while(oX2 < iX); iX = out + n2 + n4; oX1 = out + n2 + n4; oX2 = out + n2; do { oX1 -= 4; oX1[0] = iX[3]; oX1[1] = iX[2]; oX1[2] = iX[1]; oX1[3] = iX[0]; iX += 4; } while(oX1 > oX2); } } static void megabuf_mdct_forward(void *init, EEL_F *in, EEL_F *out) { mdct_lookup *lookup = (mdct_lookup *)init; int n, n2, n4, n8; EEL_F *w, *w2; if (!lookup) return; n = lookup->n; if (n <= 32 || !lookup->bitrev || !lookup->trig) { mdct(in, out, n); return; } n2 = n >> 1; n4 = n >> 2; n8 = n >> 3; EEL_F oldw[1<trig + n2; int i = 0; for(i = 0; i < n8; i += 2) { x0 -= 4; T -= 2; r0 = x0[2] + x1[0]; r1 = x0[0] + x1[2]; w2[i] = MULT_NORM(r1 * T[1] + r0 * T[0]); w2[i + 1] = MULT_NORM(r1 * T[0] - r0 * T[1]); x1 += 4; } x1 = in + 1; for(; i < n2 - n8; i += 2) { T -= 2; x0 -= 4; r0 = x0[2] - x1[0]; r1 = x0[0] - x1[2]; w2[i] = MULT_NORM(r1 * T[1] + r0 * T[0]); w2[i + 1] = MULT_NORM(r1 * T[0] - r0 * T[1]); x1 += 4; } x0 = in + n; for(; i < n2; i += 2) { T -= 2; x0 -= 4; r0 = -x0[2] - x1[0]; r1 = -x0[0] - x1[2]; w2[i] = MULT_NORM(r1 * T[1] + r0 * T[0]); w2[i + 1] = MULT_NORM(r1 * T[0] - r0 * T[1]); x1 += 4; } mdct_butterflies(lookup, w + n2, n2); mdct_bitreverse(lookup, w); /* roatate + window */ T = lookup->trig + n2; x0 = out + n2; for(i = 0; i < n4; i++) { x0--; out[i] = MULT_NORM((w[0] * T[0] + w[1] * T[1]) * lookup->scale); x0[0] = MULT_NORM((w[0] * T[1] - w[1] * T[0]) * lookup->scale); w += 2; T += 2; } } } #if 0 static void dct(EEL_F *in, EEL_F *out, int len) { int k; EEL_F wk = sqrt(2.0 / len); EEL_F overtwolen = 0.5 / (EEL_F)len; for (k = 0; k < len; k ++) { int n; EEL_F d = 0.0; for (n = 0; n < len; n ++) { int an = n + 1; d += in[n] * cos(PI * (2.0 * n + 1.0) * (EEL_F)k * overtwolen); } if (!k) d /= sqrt(len); else d *= wk; out[k] = (EEL_F)d; } } static void idct(EEL_F *in, EEL_F *out, int len) { int n; EEL_F dd0 = 1.0 / sqrt(len); EEL_F dd1 = sqrt(2.0 / len); EEL_F overtwolen = 0.5 / len; for (n = 0; n < len; n ++) { int k; EEL_F d = 0.0; for (k = 0; k < len; k ++) { EEL_F dd; if (!k) dd = dd0 * in[k]; else dd = dd1 * in[k]; d += dd * cos(PI * (2.0 * n + 1.0) * k * overtwolen); } out[n] = (EEL_F)d; } } #endif // 0 is megabuf blocks // 1 is need_free flag static EEL_F * NSEEL_CGEN_CALL mdct_func(int dir, EEL_F **blocks, EEL_F *start, EEL_F *length) { int l = (int)(*length + 0.0001); int offs = (int)(*start + 0.0001); int bitl = 0; int ilen; int bidx; EEL_F *ptr; while (l > 1 && bitl < EEL_DCT_MAXBITLEN) { bitl++; l >>= 1; } if (bitl < EEL_DCT_MINBITLEN) { return start; } ilen = 1 << bitl; bidx = bitl - EEL_DCT_MINBITLEN; // check to make sure we don't cross a boundary if (offs / NSEEL_RAM_ITEMSPERBLOCK != (offs + ilen * 2 - 1) / NSEEL_RAM_ITEMSPERBLOCK) { return start; } ptr = __NSEEL_RAMAlloc(blocks, offs); if (!ptr || ptr == &nseel_ramalloc_onfail) { return start; } if (ilen > 1) { static void *mdct_ctxs[1 + EEL_DCT_MAXBITLEN - EEL_DCT_MINBITLEN]; if (!mdct_ctxs[bidx]) { NSEEL_HOSTSTUB_EnterMutex(); if (!mdct_ctxs[bidx]) mdct_ctxs[bidx] = megabuf_mdct_init(ilen); NSEEL_HOSTSTUB_LeaveMutex(); } if (mdct_ctxs[bidx]) { EEL_F buf[1 << EEL_DCT_MAXBITLEN]; if (dir < 0) { megabuf_mdct_backward(mdct_ctxs[bidx], ptr, buf); megabuf_mdct_apply_window(mdct_ctxs[bidx], buf, ptr); } else { megabuf_mdct_apply_window(mdct_ctxs[bidx], ptr, buf); megabuf_mdct_forward(mdct_ctxs[bidx], buf, ptr); } } } return start; } static EEL_F * NSEEL_CGEN_CALL megabuf_mdct(EEL_F **blocks, EEL_F *start, EEL_F *length) { return mdct_func(0, blocks, start, length); } static EEL_F * NSEEL_CGEN_CALL megabuf_imdct(EEL_F **blocks, EEL_F *start, EEL_F *length) { return mdct_func(-1, blocks, start, length); } void EEL_mdct_register() { NSEEL_addfunc_retptr("mdct", 2, NSEEL_PProc_RAM, &megabuf_mdct); NSEEL_addfunc_retptr("imdct", 2, NSEEL_PProc_RAM, &megabuf_imdct); } #ifdef EEL_WANT_DOCUMENTATION static const char *eel_mdct_function_reference = "mdct\tbuffer,length\tPerforms a windowed modified DCT, taking length inputs and producing length/2 outputs. buffer must not cross a 65,536 item boundary, and length must be 64, 128, 256, 512, 2048 or 4096.\0" "imdct\tbuffer,length\tPerforms a windowed inverse modified DCT, taking length/2 inputs and producing length outputs. buffer must not cross a 65,536 item boundary, and length must be 64, 128, 256, 512, 2048 or 4096.\0" ; #endif #endif