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author | Matthias P. Braendli <matthias.braendli@mpb.li> | 2016-02-15 02:44:20 +0100 |
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committer | Matthias P. Braendli <matthias.braendli@mpb.li> | 2016-02-15 02:44:20 +0100 |
commit | 22f1fce330059ef8a383cf327a023d6a9da5ad3e (patch) | |
tree | 6893f158dcaaaa1b9f1317923c32a841ba31f768 /libtoolame-dab/fft.c | |
parent | 891bb2592944aa2be2d81e1583e73e632e70537f (diff) | |
download | fdk-aac-22f1fce330059ef8a383cf327a023d6a9da5ad3e.tar.gz fdk-aac-22f1fce330059ef8a383cf327a023d6a9da5ad3e.tar.bz2 fdk-aac-22f1fce330059ef8a383cf327a023d6a9da5ad3e.zip |
Include toolame-dab as library
Diffstat (limited to 'libtoolame-dab/fft.c')
-rw-r--r-- | libtoolame-dab/fft.c | 1296 |
1 files changed, 1296 insertions, 0 deletions
diff --git a/libtoolame-dab/fft.c b/libtoolame-dab/fft.c new file mode 100644 index 0000000..985bdd4 --- /dev/null +++ b/libtoolame-dab/fft.c @@ -0,0 +1,1296 @@ +/* +** FFT and FHT routines +** Copyright 1988, 1993; Ron Mayer +** +** fht(fz,n); +** Does a hartley transform of "n" points in the array "fz". +** +** NOTE: This routine uses at least 2 patented algorithms, and may be +** under the restrictions of a bunch of different organizations. +** Although I wrote it completely myself; it is kind of a derivative +** of a routine I once authored and released under the GPL, so it +** may fall under the free software foundation's restrictions; +** it was worked on as a Stanford Univ project, so they claim +** some rights to it; it was further optimized at work here, so +** I think this company claims parts of it. The patents are +** held by R. Bracewell (the FHT algorithm) and O. Buneman (the +** trig generator), both at Stanford Univ. +** If it were up to me, I'd say go do whatever you want with it; +** but it would be polite to give credit to the following people +** if you use this anywhere: +** Euler - probable inventor of the fourier transform. +** Gauss - probable inventor of the FFT. +** Hartley - probable inventor of the hartley transform. +** Buneman - for a really cool trig generator +** Mayer(me) - for authoring this particular version and +** including all the optimizations in one package. +** Thanks, +** Ron Mayer; mayer@acuson.com +** +*/ +#include <stdio.h> +#include <math.h> +#include "common.h" +#include "fft.h" +#define SQRT2 1.4142135623730951454746218587388284504414 + + +static FLOAT costab[20] = { + .00000000000000000000000000000000000000000000000000, + .70710678118654752440084436210484903928483593768847, + .92387953251128675612818318939678828682241662586364, + .98078528040323044912618223613423903697393373089333, + .99518472667219688624483695310947992157547486872985, + .99879545620517239271477160475910069444320361470461, + .99969881869620422011576564966617219685006108125772, + .99992470183914454092164649119638322435060646880221, + .99998117528260114265699043772856771617391725094433, + .99999529380957617151158012570011989955298763362218, + .99999882345170190992902571017152601904826792288976, + .99999970586288221916022821773876567711626389934930, + .99999992646571785114473148070738785694820115568892, + .99999998161642929380834691540290971450507605124278, + .99999999540410731289097193313960614895889430318945, + .99999999885102682756267330779455410840053741619428 +}; +static FLOAT sintab[20] = { + 1.0000000000000000000000000000000000000000000000000, + .70710678118654752440084436210484903928483593768846, + .38268343236508977172845998403039886676134456248561, + .19509032201612826784828486847702224092769161775195, + .09801714032956060199419556388864184586113667316749, + .04906767432741801425495497694268265831474536302574, + .02454122852291228803173452945928292506546611923944, + .01227153828571992607940826195100321214037231959176, + .00613588464915447535964023459037258091705788631738, + .00306795676296597627014536549091984251894461021344, + .00153398018628476561230369715026407907995486457522, + .00076699031874270452693856835794857664314091945205, + .00038349518757139558907246168118138126339502603495, + .00019174759731070330743990956198900093346887403385, + .00009587379909597734587051721097647635118706561284, + .00004793689960306688454900399049465887274686668768 +}; + +/* This is a simplified version for n an even power of 2 */ +/* MFC: In the case of LayerII encoding, n==1024 always. */ + +static void fht (FLOAT * fz) +{ + int i, k, k1, k2, k3, k4, kx; + FLOAT *fi, *fn, *gi; + FLOAT t_c, t_s; + + FLOAT a; + static const struct { + unsigned short k1, k2; + } k1k2tab[8 * 62] = { + { + 0x020, 0x010} + , { + 0x040, 0x008} + , { + 0x050, 0x028} + , { + 0x060, 0x018} + , { + 0x068, 0x058} + , { + 0x070, 0x038} + , { + 0x080, 0x004} + , { + 0x088, 0x044} + , { + 0x090, 0x024} + , { + 0x098, 0x064} + , { + 0x0a0, 0x014} + , { + 0x0a4, 0x094} + , { + 0x0a8, 0x054} + , { + 0x0b0, 0x034} + , { + 0x0b8, 0x074} + , { + 0x0c0, 0x00c} + , { + 0x0c4, 0x08c} + , { + 0x0c8, 0x04c} + , { + 0x0d0, 0x02c} + , { + 0x0d4, 0x0ac} + , { + 0x0d8, 0x06c} + , { + 0x0e0, 0x01c} + , { + 0x0e4, 0x09c} + , { + 0x0e8, 0x05c} + , { + 0x0ec, 0x0dc} + , { + 0x0f0, 0x03c} + , { + 0x0f4, 0x0bc} + , { + 0x0f8, 0x07c} + , { + 0x100, 0x002} + , { + 0x104, 0x082} + , { + 0x108, 0x042} + , { + 0x10c, 0x0c2} + , { + 0x110, 0x022} + , { + 0x114, 0x0a2} + , { + 0x118, 0x062} + , { + 0x11c, 0x0e2} + , { + 0x120, 0x012} + , { + 0x122, 0x112} + , { + 0x124, 0x092} + , { + 0x128, 0x052} + , { + 0x12c, 0x0d2} + , { + 0x130, 0x032} + , { + 0x134, 0x0b2} + , { + 0x138, 0x072} + , { + 0x13c, 0x0f2} + , { + 0x140, 0x00a} + , { + 0x142, 0x10a} + , { + 0x144, 0x08a} + , { + 0x148, 0x04a} + , { + 0x14c, 0x0ca} + , { + 0x150, 0x02a} + , { + 0x152, 0x12a} + , { + 0x154, 0x0aa} + , { + 0x158, 0x06a} + , { + 0x15c, 0x0ea} + , { + 0x160, 0x01a} + , { + 0x162, 0x11a} + , { + 0x164, 0x09a} + , { + 0x168, 0x05a} + , { + 0x16a, 0x15a} + , { + 0x16c, 0x0da} + , { + 0x170, 0x03a} + , { + 0x172, 0x13a} + , { + 0x174, 0x0ba} + , { + 0x178, 0x07a} + , { + 0x17c, 0x0fa} + , { + 0x180, 0x006} + , { + 0x182, 0x106} + , { + 0x184, 0x086} + , { + 0x188, 0x046} + , { + 0x18a, 0x146} + , { + 0x18c, 0x0c6} + , { + 0x190, 0x026} + , { + 0x192, 0x126} + , { + 0x194, 0x0a6} + , { + 0x198, 0x066} + , { + 0x19a, 0x166} + , { + 0x19c, 0x0e6} + , { + 0x1a0, 0x016} + , { + 0x1a2, 0x116} + , { + 0x1a4, 0x096} + , { + 0x1a6, 0x196} + , { + 0x1a8, 0x056} + , { + 0x1aa, 0x156} + , { + 0x1ac, 0x0d6} + , { + 0x1b0, 0x036} + , { + 0x1b2, 0x136} + , { + 0x1b4, 0x0b6} + , { + 0x1b8, 0x076} + , { + 0x1ba, 0x176} + , { + 0x1bc, 0x0f6} + , { + 0x1c0, 0x00e} + , { + 0x1c2, 0x10e} + , { + 0x1c4, 0x08e} + , { + 0x1c6, 0x18e} + , { + 0x1c8, 0x04e} + , { + 0x1ca, 0x14e} + , { + 0x1cc, 0x0ce} + , { + 0x1d0, 0x02e} + , { + 0x1d2, 0x12e} + , { + 0x1d4, 0x0ae} + , { + 0x1d6, 0x1ae} + , { + 0x1d8, 0x06e} + , { + 0x1da, 0x16e} + , { + 0x1dc, 0x0ee} + , { + 0x1e0, 0x01e} + , { + 0x1e2, 0x11e} + , { + 0x1e4, 0x09e} + , { + 0x1e6, 0x19e} + , { + 0x1e8, 0x05e} + , { + 0x1ea, 0x15e} + , { + 0x1ec, 0x0de} + , { + 0x1ee, 0x1de} + , { + 0x1f0, 0x03e} + , { + 0x1f2, 0x13e} + , { + 0x1f4, 0x0be} + , { + 0x1f6, 0x1be} + , { + 0x1f8, 0x07e} + , { + 0x1fa, 0x17e} + , { + 0x1fc, 0x0fe} + , { + 0x200, 0x001} + , { + 0x202, 0x101} + , { + 0x204, 0x081} + , { + 0x206, 0x181} + , { + 0x208, 0x041} + , { + 0x20a, 0x141} + , { + 0x20c, 0x0c1} + , { + 0x20e, 0x1c1} + , { + 0x210, 0x021} + , { + 0x212, 0x121} + , { + 0x214, 0x0a1} + , { + 0x216, 0x1a1} + , { + 0x218, 0x061} + , { + 0x21a, 0x161} + , { + 0x21c, 0x0e1} + , { + 0x21e, 0x1e1} + , { + 0x220, 0x011} + , { + 0x221, 0x211} + , { + 0x222, 0x111} + , { + 0x224, 0x091} + , { + 0x226, 0x191} + , { + 0x228, 0x051} + , { + 0x22a, 0x151} + , { + 0x22c, 0x0d1} + , { + 0x22e, 0x1d1} + , { + 0x230, 0x031} + , { + 0x232, 0x131} + , { + 0x234, 0x0b1} + , { + 0x236, 0x1b1} + , { + 0x238, 0x071} + , { + 0x23a, 0x171} + , { + 0x23c, 0x0f1} + , { + 0x23e, 0x1f1} + , { + 0x240, 0x009} + , { + 0x241, 0x209} + , { + 0x242, 0x109} + , { + 0x244, 0x089} + , { + 0x246, 0x189} + , { + 0x248, 0x049} + , { + 0x24a, 0x149} + , { + 0x24c, 0x0c9} + , { + 0x24e, 0x1c9} + , { + 0x250, 0x029} + , { + 0x251, 0x229} + , { + 0x252, 0x129} + , { + 0x254, 0x0a9} + , { + 0x256, 0x1a9} + , { + 0x258, 0x069} + , { + 0x25a, 0x169} + , { + 0x25c, 0x0e9} + , { + 0x25e, 0x1e9} + , { + 0x260, 0x019} + , { + 0x261, 0x219} + , { + 0x262, 0x119} + , { + 0x264, 0x099} + , { + 0x266, 0x199} + , { + 0x268, 0x059} + , { + 0x269, 0x259} + , { + 0x26a, 0x159} + , { + 0x26c, 0x0d9} + , { + 0x26e, 0x1d9} + , { + 0x270, 0x039} + , { + 0x271, 0x239} + , { + 0x272, 0x139} + , { + 0x274, 0x0b9} + , { + 0x276, 0x1b9} + , { + 0x278, 0x079} + , { + 0x27a, 0x179} + , { + 0x27c, 0x0f9} + , { + 0x27e, 0x1f9} + , { + 0x280, 0x005} + , { + 0x281, 0x205} + , { + 0x282, 0x105} + , { + 0x284, 0x085} + , { + 0x286, 0x185} + , { + 0x288, 0x045} + , { + 0x289, 0x245} + , { + 0x28a, 0x145} + , { + 0x28c, 0x0c5} + , { + 0x28e, 0x1c5} + , { + 0x290, 0x025} + , { + 0x291, 0x225} + , { + 0x292, 0x125} + , { + 0x294, 0x0a5} + , { + 0x296, 0x1a5} + , { + 0x298, 0x065} + , { + 0x299, 0x265} + , { + 0x29a, 0x165} + , { + 0x29c, 0x0e5} + , { + 0x29e, 0x1e5} + , { + 0x2a0, 0x015} + , { + 0x2a1, 0x215} + , { + 0x2a2, 0x115} + , { + 0x2a4, 0x095} + , { + 0x2a5, 0x295} + , { + 0x2a6, 0x195} + , { + 0x2a8, 0x055} + , { + 0x2a9, 0x255} + , { + 0x2aa, 0x155} + , { + 0x2ac, 0x0d5} + , { + 0x2ae, 0x1d5} + , { + 0x2b0, 0x035} + , { + 0x2b1, 0x235} + , { + 0x2b2, 0x135} + , { + 0x2b4, 0x0b5} + , { + 0x2b6, 0x1b5} + , { + 0x2b8, 0x075} + , { + 0x2b9, 0x275} + , { + 0x2ba, 0x175} + , { + 0x2bc, 0x0f5} + , { + 0x2be, 0x1f5} + , { + 0x2c0, 0x00d} + , { + 0x2c1, 0x20d} + , { + 0x2c2, 0x10d} + , { + 0x2c4, 0x08d} + , { + 0x2c5, 0x28d} + , { + 0x2c6, 0x18d} + , { + 0x2c8, 0x04d} + , { + 0x2c9, 0x24d} + , { + 0x2ca, 0x14d} + , { + 0x2cc, 0x0cd} + , { + 0x2ce, 0x1cd} + , { + 0x2d0, 0x02d} + , { + 0x2d1, 0x22d} + , { + 0x2d2, 0x12d} + , { + 0x2d4, 0x0ad} + , { + 0x2d5, 0x2ad} + , { + 0x2d6, 0x1ad} + , { + 0x2d8, 0x06d} + , { + 0x2d9, 0x26d} + , { + 0x2da, 0x16d} + , { + 0x2dc, 0x0ed} + , { + 0x2de, 0x1ed} + , { + 0x2e0, 0x01d} + , { + 0x2e1, 0x21d} + , { + 0x2e2, 0x11d} + , { + 0x2e4, 0x09d} + , { + 0x2e5, 0x29d} + , { + 0x2e6, 0x19d} + , { + 0x2e8, 0x05d} + , { + 0x2e9, 0x25d} + , { + 0x2ea, 0x15d} + , { + 0x2ec, 0x0dd} + , { + 0x2ed, 0x2dd} + , { + 0x2ee, 0x1dd} + , { + 0x2f0, 0x03d} + , { + 0x2f1, 0x23d} + , { + 0x2f2, 0x13d} + , { + 0x2f4, 0x0bd} + , { + 0x2f5, 0x2bd} + , { + 0x2f6, 0x1bd} + , { + 0x2f8, 0x07d} + , { + 0x2f9, 0x27d} + , { + 0x2fa, 0x17d} + , { + 0x2fc, 0x0fd} + , { + 0x2fe, 0x1fd} + , { + 0x300, 0x003} + , { + 0x301, 0x203} + , { + 0x302, 0x103} + , { + 0x304, 0x083} + , { + 0x305, 0x283} + , { + 0x306, 0x183} + , { + 0x308, 0x043} + , { + 0x309, 0x243} + , { + 0x30a, 0x143} + , { + 0x30c, 0x0c3} + , { + 0x30d, 0x2c3} + , { + 0x30e, 0x1c3} + , { + 0x310, 0x023} + , { + 0x311, 0x223} + , { + 0x312, 0x123} + , { + 0x314, 0x0a3} + , { + 0x315, 0x2a3} + , { + 0x316, 0x1a3} + , { + 0x318, 0x063} + , { + 0x319, 0x263} + , { + 0x31a, 0x163} + , { + 0x31c, 0x0e3} + , { + 0x31d, 0x2e3} + , { + 0x31e, 0x1e3} + , { + 0x320, 0x013} + , { + 0x321, 0x213} + , { + 0x322, 0x113} + , { + 0x323, 0x313} + , { + 0x324, 0x093} + , { + 0x325, 0x293} + , { + 0x326, 0x193} + , { + 0x328, 0x053} + , { + 0x329, 0x253} + , { + 0x32a, 0x153} + , { + 0x32c, 0x0d3} + , { + 0x32d, 0x2d3} + , { + 0x32e, 0x1d3} + , { + 0x330, 0x033} + , { + 0x331, 0x233} + , { + 0x332, 0x133} + , { + 0x334, 0x0b3} + , { + 0x335, 0x2b3} + , { + 0x336, 0x1b3} + , { + 0x338, 0x073} + , { + 0x339, 0x273} + , { + 0x33a, 0x173} + , { + 0x33c, 0x0f3} + , { + 0x33d, 0x2f3} + , { + 0x33e, 0x1f3} + , { + 0x340, 0x00b} + , { + 0x341, 0x20b} + , { + 0x342, 0x10b} + , { + 0x343, 0x30b} + , { + 0x344, 0x08b} + , { + 0x345, 0x28b} + , { + 0x346, 0x18b} + , { + 0x348, 0x04b} + , { + 0x349, 0x24b} + , { + 0x34a, 0x14b} + , { + 0x34c, 0x0cb} + , { + 0x34d, 0x2cb} + , { + 0x34e, 0x1cb} + , { + 0x350, 0x02b} + , { + 0x351, 0x22b} + , { + 0x352, 0x12b} + , { + 0x353, 0x32b} + , { + 0x354, 0x0ab} + , { + 0x355, 0x2ab} + , { + 0x356, 0x1ab} + , { + 0x358, 0x06b} + , { + 0x359, 0x26b} + , { + 0x35a, 0x16b} + , { + 0x35c, 0x0eb} + , { + 0x35d, 0x2eb} + , { + 0x35e, 0x1eb} + , { + 0x360, 0x01b} + , { + 0x361, 0x21b} + , { + 0x362, 0x11b} + , { + 0x363, 0x31b} + , { + 0x364, 0x09b} + , { + 0x365, 0x29b} + , { + 0x366, 0x19b} + , { + 0x368, 0x05b} + , { + 0x369, 0x25b} + , { + 0x36a, 0x15b} + , { + 0x36b, 0x35b} + , { + 0x36c, 0x0db} + , { + 0x36d, 0x2db} + , { + 0x36e, 0x1db} + , { + 0x370, 0x03b} + , { + 0x371, 0x23b} + , { + 0x372, 0x13b} + , { + 0x373, 0x33b} + , { + 0x374, 0x0bb} + , { + 0x375, 0x2bb} + , { + 0x376, 0x1bb} + , { + 0x378, 0x07b} + , { + 0x379, 0x27b} + , { + 0x37a, 0x17b} + , { + 0x37c, 0x0fb} + , { + 0x37d, 0x2fb} + , { + 0x37e, 0x1fb} + , { + 0x380, 0x007} + , { + 0x381, 0x207} + , { + 0x382, 0x107} + , { + 0x383, 0x307} + , { + 0x384, 0x087} + , { + 0x385, 0x287} + , { + 0x386, 0x187} + , { + 0x388, 0x047} + , { + 0x389, 0x247} + , { + 0x38a, 0x147} + , { + 0x38b, 0x347} + , { + 0x38c, 0x0c7} + , { + 0x38d, 0x2c7} + , { + 0x38e, 0x1c7} + , { + 0x390, 0x027} + , { + 0x391, 0x227} + , { + 0x392, 0x127} + , { + 0x393, 0x327} + , { + 0x394, 0x0a7} + , { + 0x395, 0x2a7} + , { + 0x396, 0x1a7} + , { + 0x398, 0x067} + , { + 0x399, 0x267} + , { + 0x39a, 0x167} + , { + 0x39b, 0x367} + , { + 0x39c, 0x0e7} + , { + 0x39d, 0x2e7} + , { + 0x39e, 0x1e7} + , { + 0x3a0, 0x017} + , { + 0x3a1, 0x217} + , { + 0x3a2, 0x117} + , { + 0x3a3, 0x317} + , { + 0x3a4, 0x097} + , { + 0x3a5, 0x297} + , { + 0x3a6, 0x197} + , { + 0x3a7, 0x397} + , { + 0x3a8, 0x057} + , { + 0x3a9, 0x257} + , { + 0x3aa, 0x157} + , { + 0x3ab, 0x357} + , { + 0x3ac, 0x0d7} + , { + 0x3ad, 0x2d7} + , { + 0x3ae, 0x1d7} + , { + 0x3b0, 0x037} + , { + 0x3b1, 0x237} + , { + 0x3b2, 0x137} + , { + 0x3b3, 0x337} + , { + 0x3b4, 0x0b7} + , { + 0x3b5, 0x2b7} + , { + 0x3b6, 0x1b7} + , { + 0x3b8, 0x077} + , { + 0x3b9, 0x277} + , { + 0x3ba, 0x177} + , { + 0x3bb, 0x377} + , { + 0x3bc, 0x0f7} + , { + 0x3bd, 0x2f7} + , { + 0x3be, 0x1f7} + , { + 0x3c0, 0x00f} + , { + 0x3c1, 0x20f} + , { + 0x3c2, 0x10f} + , { + 0x3c3, 0x30f} + , { + 0x3c4, 0x08f} + , { + 0x3c5, 0x28f} + , { + 0x3c6, 0x18f} + , { + 0x3c7, 0x38f} + , { + 0x3c8, 0x04f} + , { + 0x3c9, 0x24f} + , { + 0x3ca, 0x14f} + , { + 0x3cb, 0x34f} + , { + 0x3cc, 0x0cf} + , { + 0x3cd, 0x2cf} + , { + 0x3ce, 0x1cf} + , { + 0x3d0, 0x02f} + , { + 0x3d1, 0x22f} + , { + 0x3d2, 0x12f} + , { + 0x3d3, 0x32f} + , { + 0x3d4, 0x0af} + , { + 0x3d5, 0x2af} + , { + 0x3d6, 0x1af} + , { + 0x3d7, 0x3af} + , { + 0x3d8, 0x06f} + , { + 0x3d9, 0x26f} + , { + 0x3da, 0x16f} + , { + 0x3db, 0x36f} + , { + 0x3dc, 0x0ef} + , { + 0x3dd, 0x2ef} + , { + 0x3de, 0x1ef} + , { + 0x3e0, 0x01f} + , { + 0x3e1, 0x21f} + , { + 0x3e2, 0x11f} + , { + 0x3e3, 0x31f} + , { + 0x3e4, 0x09f} + , { + 0x3e5, 0x29f} + , { + 0x3e6, 0x19f} + , { + 0x3e7, 0x39f} + , { + 0x3e8, 0x05f} + , { + 0x3e9, 0x25f} + , { + 0x3ea, 0x15f} + , { + 0x3eb, 0x35f} + , { + 0x3ec, 0x0df} + , { + 0x3ed, 0x2df} + , { + 0x3ee, 0x1df} + , { + 0x3ef, 0x3df} + , { + 0x3f0, 0x03f} + , { + 0x3f1, 0x23f} + , { + 0x3f2, 0x13f} + , { + 0x3f3, 0x33f} + , { + 0x3f4, 0x0bf} + , { + 0x3f5, 0x2bf} + , { + 0x3f6, 0x1bf} + , { + 0x3f7, 0x3bf} + , { + 0x3f8, 0x07f} + , { + 0x3f9, 0x27f} + , { + 0x3fa, 0x17f} + , { + 0x3fb, 0x37f} + , { + 0x3fc, 0x0ff} + , { + 0x3fd, 0x2ff} + , { + 0x3fe, 0x1ff} + }; + { + int i; + for (i = 0; i < sizeof k1k2tab / sizeof k1k2tab[0]; ++i) { + k1 = k1k2tab[i].k1; + k2 = k1k2tab[i].k2; + a = fz[k1]; + fz[k1] = fz[k2]; + fz[k2] = a; + } + } + + for (fi = fz, fn = fz + 1024; fi < fn; fi += 4) { + FLOAT f0, f1, f2, f3; + f1 = fi[0] - fi[1]; + f0 = fi[0] + fi[1]; + f3 = fi[2] - fi[3]; + f2 = fi[2] + fi[3]; + fi[2] = (f0 - f2); + fi[0] = (f0 + f2); + fi[3] = (f1 - f3); + fi[1] = (f1 + f3); + } + + k = 0; + do { + FLOAT s1, c1; + k += 2; + k1 = 1 << k; + k2 = k1 << 1; + k4 = k2 << 1; + k3 = k2 + k1; + kx = k1 >> 1; + fi = fz; + gi = fi + kx; + fn = fz + 1024; + do { + FLOAT g0, f0, f1, g1, f2, g2, f3, g3; + f1 = fi[0] - fi[k1]; + f0 = fi[0] + fi[k1]; + f3 = fi[k2] - fi[k3]; + f2 = fi[k2] + fi[k3]; + fi[k2] = f0 - f2; + fi[0] = f0 + f2; + fi[k3] = f1 - f3; + fi[k1] = f1 + f3; + g1 = gi[0] - gi[k1]; + g0 = gi[0] + gi[k1]; + g3 = SQRT2 * gi[k3]; + g2 = SQRT2 * gi[k2]; + gi[k2] = g0 - g2; + gi[0] = g0 + g2; + gi[k3] = g1 - g3; + gi[k1] = g1 + g3; + gi += k4; + fi += k4; + } + while (fi < fn); + t_c = costab[k]; + t_s = sintab[k]; + c1 = 1; + s1 = 0; + for (i = 1; i < kx; i++) { + FLOAT c2, s2; + FLOAT t = c1; + c1 = t * t_c - s1 * t_s; + s1 = t * t_s + s1 * t_c; + c2 = c1 * c1 - s1 * s1; + s2 = 2 * (c1 * s1); + fn = fz + 1024; + fi = fz + i; + gi = fz + k1 - i; + do { + FLOAT a, b, g0, f0, f1, g1, f2, g2, f3, g3; + b = s2 * fi[k1] - c2 * gi[k1]; + a = c2 * fi[k1] + s2 * gi[k1]; + f1 = fi[0] - a; + f0 = fi[0] + a; + g1 = gi[0] - b; + g0 = gi[0] + b; + b = s2 * fi[k3] - c2 * gi[k3]; + a = c2 * fi[k3] + s2 * gi[k3]; + f3 = fi[k2] - a; + f2 = fi[k2] + a; + g3 = gi[k2] - b; + g2 = gi[k2] + b; + b = s1 * f2 - c1 * g3; + a = c1 * f2 + s1 * g3; + fi[k2] = f0 - a; + fi[0] = f0 + a; + gi[k3] = g1 - b; + gi[k1] = g1 + b; + b = c1 * g2 - s1 * f3; + a = s1 * g2 + c1 * f3; + gi[k2] = g0 - a; + gi[0] = g0 + a; + fi[k3] = f1 - b; + fi[k1] = f1 + b; + gi += k4; + fi += k4; + } + while (fi < fn); + } + } + while (k4 < 1024); +} + +#ifdef NEWATAN +#define ATANSIZE 2000 +#define ATANSCALE 50.0 + static FLOAT atan_t[ATANSIZE]; + +FLOAT atan_table(FLOAT y, FLOAT x) { + int index; + double index_d = ATANSCALE * fabs(y/x); + + // Don't cast an infinite to an int, that's undefined behaviour + if (isfinite(index_d)) { + index = (int)(ATANSCALE * fabs(y/x)); + } + else { + index = ATANSIZE-1; + } + + if (index>=ATANSIZE) + index = ATANSIZE-1; + + if (y>0 && x<0) + return( PI - atan_t[index] ); + + if (y<0 && x>0) + return( -atan_t[index] ); + + if (y<0 && x<0) + return( atan_t[index] - PI ); + + return(atan_t[index]); +} + +void atan_table_init(void) { + int i; + for (i=0;i<ATANSIZE;i++) + atan_t[i] = atan((double)i/ATANSCALE); +} + +#endif //NEWATAN + +/* For variations on psycho model 2: + N always equals 1024 + BUT in the returned values, no energy/phi is used at or above an index of 513 */ +void psycho_2_fft (FLOAT * x_real, FLOAT * energy, FLOAT * phi) + /* got rid of size "N" argument as it is always 1024 for layerII */ +{ + FLOAT a, b; + int i, j; +#ifdef NEWATAN + static int init=0; + + if (!init) { + atan_table_init(); + init++; + } +#endif + + + fht (x_real); + + + energy[0] = x_real[0] * x_real[0]; + + for (i = 1, j = 1023; i < 512; i++, j--) { + a = x_real[i]; + b = x_real[j]; + /* MFC FIXME Mar03 Why is this divided by 2.0? + if a and b are the real and imaginary components then + r = sqrt(a^2 + b^2), + but, back in the psycho2 model, they calculate r=sqrt(energy), + which, if you look at the original equation below is different */ + energy[i] = (a * a + b * b) / 2.0; + if (energy[i] < 0.0005) { + energy[i] = 0.0005; + phi[i] = 0; + } else +#ifdef NEWATAN + { + phi[i] = atan_table(-a, b) + PI/4; + } +#else + { + phi[i] = atan2(-(double)a, (double)b) + PI/4; + } +#endif + } + energy[512] = x_real[512] * x_real[512]; + phi[512] = atan2 (0.0, (double) x_real[512]); +} + + +void psycho_1_fft (FLOAT * x_real, FLOAT * energy, int N) +{ + FLOAT a, b; + int i, j; + + fht (x_real); + + energy[0] = x_real[0] * x_real[0]; + + for (i = 1, j = N - 1; i < N / 2; i++, j--) { + a = x_real[i]; + b = x_real[j]; + energy[i] = (a * a + b * b) / 2.0; + } + energy[N / 2] = x_real[N / 2] * x_real[N / 2]; +} + + + |