diff options
Diffstat (limited to 'circuitpython/lib/mp3/src/dct32.c')
| -rw-r--r-- | circuitpython/lib/mp3/src/dct32.c | 280 |
1 files changed, 280 insertions, 0 deletions
diff --git a/circuitpython/lib/mp3/src/dct32.c b/circuitpython/lib/mp3/src/dct32.c new file mode 100644 index 0000000..d29a18e --- /dev/null +++ b/circuitpython/lib/mp3/src/dct32.c @@ -0,0 +1,280 @@ +/* ***** BEGIN LICENSE BLOCK ***** + * Version: RCSL 1.0/RPSL 1.0 + * + * Portions Copyright (c) 1995-2002 RealNetworks, Inc. All Rights Reserved. + * + * The contents of this file, and the files included with this file, are + * subject to the current version of the RealNetworks Public Source License + * Version 1.0 (the "RPSL") available at + * http://www.helixcommunity.org/content/rpsl unless you have licensed + * the file under the RealNetworks Community Source License Version 1.0 + * (the "RCSL") available at http://www.helixcommunity.org/content/rcsl, + * in which case the RCSL will apply. You may also obtain the license terms + * directly from RealNetworks. You may not use this file except in + * compliance with the RPSL or, if you have a valid RCSL with RealNetworks + * applicable to this file, the RCSL. Please see the applicable RPSL or + * RCSL for the rights, obligations and limitations governing use of the + * contents of the file. + * + * This file is part of the Helix DNA Technology. RealNetworks is the + * developer of the Original Code and owns the copyrights in the portions + * it created. + * + * This file, and the files included with this file, is distributed and made + * available on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER + * EXPRESS OR IMPLIED, AND REALNETWORKS HEREBY DISCLAIMS ALL SUCH WARRANTIES, + * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY, FITNESS + * FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT. + * + * Technology Compatibility Kit Test Suite(s) Location: + * http://www.helixcommunity.org/content/tck + * + * Contributor(s): + * + * ***** END LICENSE BLOCK ***** */ + +/************************************************************************************** + * Fixed-point MP3 decoder + * Jon Recker (jrecker@real.com), Ken Cooke (kenc@real.com) + * June 2003 + * + * dct32.c - optimized implementations of 32-point DCT for matrixing stage of + * polyphase filter + **************************************************************************************/ + +#include "coder.h" +#include "assembly.h" + +#define COS0_0 0x4013c251 /* Q31 */ +#define COS0_1 0x40b345bd /* Q31 */ +#define COS0_2 0x41fa2d6d /* Q31 */ +#define COS0_3 0x43f93421 /* Q31 */ +#define COS0_4 0x46cc1bc4 /* Q31 */ +#define COS0_5 0x4a9d9cf0 /* Q31 */ +#define COS0_6 0x4fae3711 /* Q31 */ +#define COS0_7 0x56601ea7 /* Q31 */ +#define COS0_8 0x5f4cf6eb /* Q31 */ +#define COS0_9 0x6b6fcf26 /* Q31 */ +#define COS0_10 0x7c7d1db3 /* Q31 */ +#define COS0_11 0x4ad81a97 /* Q30 */ +#define COS0_12 0x5efc8d96 /* Q30 */ +#define COS0_13 0x41d95790 /* Q29 */ +#define COS0_14 0x6d0b20cf /* Q29 */ +#define COS0_15 0x518522fb /* Q27 */ + +#define COS1_0 0x404f4672 /* Q31 */ +#define COS1_1 0x42e13c10 /* Q31 */ +#define COS1_2 0x48919f44 /* Q31 */ +#define COS1_3 0x52cb0e63 /* Q31 */ +#define COS1_4 0x64e2402e /* Q31 */ +#define COS1_5 0x43e224a9 /* Q30 */ +#define COS1_6 0x6e3c92c1 /* Q30 */ +#define COS1_7 0x519e4e04 /* Q28 */ + +#define COS2_0 0x4140fb46 /* Q31 */ +#define COS2_1 0x4cf8de88 /* Q31 */ +#define COS2_2 0x73326bbf /* Q31 */ +#define COS2_3 0x52036742 /* Q29 */ + +#define COS3_0 0x4545e9ef /* Q31 */ +#define COS3_1 0x539eba45 /* Q30 */ + +#define COS4_0 0x5a82799a /* Q31 */ + +// faster in ROM +static const int dcttab[48] = { + /* first pass */ + COS0_0, COS0_15, COS1_0, /* 31, 27, 31 */ + COS0_1, COS0_14, COS1_1, /* 31, 29, 31 */ + COS0_2, COS0_13, COS1_2, /* 31, 29, 31 */ + COS0_3, COS0_12, COS1_3, /* 31, 30, 31 */ + COS0_4, COS0_11, COS1_4, /* 31, 30, 31 */ + COS0_5, COS0_10, COS1_5, /* 31, 31, 30 */ + COS0_6, COS0_9, COS1_6, /* 31, 31, 30 */ + COS0_7, COS0_8, COS1_7, /* 31, 31, 28 */ + /* second pass */ + COS2_0, COS2_3, COS3_0, /* 31, 29, 31 */ + COS2_1, COS2_2, COS3_1, /* 31, 31, 30 */ + -COS2_0, -COS2_3, COS3_0, /* 31, 29, 31 */ + -COS2_1, -COS2_2, COS3_1, /* 31, 31, 30 */ + COS2_0, COS2_3, COS3_0, /* 31, 29, 31 */ + COS2_1, COS2_2, COS3_1, /* 31, 31, 30 */ + -COS2_0, -COS2_3, COS3_0, /* 31, 29, 31 */ + -COS2_1, -COS2_2, COS3_1, /* 31, 31, 30 */ +}; + +#define D32FP(i, s0, s1, s2) { \ + a0 = buf[i]; a3 = buf[31-i]; \ + a1 = buf[15-i]; a2 = buf[16+i]; \ + b0 = a0 + a3; b3 = MULSHIFT32(*cptr++, a0 - a3) << (s0); \ + b1 = a1 + a2; b2 = MULSHIFT32(*cptr++, a1 - a2) << (s1); \ + buf[i] = b0 + b1; buf[15-i] = MULSHIFT32(*cptr, b0 - b1) << (s2); \ + buf[16+i] = b2 + b3; buf[31-i] = MULSHIFT32(*cptr++, b3 - b2) << (s2); \ +} + +/************************************************************************************** + * Function: FDCT32 + * + * Description: Ken's highly-optimized 32-point DCT (radix-4 + radix-8) + * + * Inputs: input buffer, length = 32 samples + * require at least 6 guard bits in input vector x to avoid possibility + * of overflow in internal calculations (see bbtest_imdct test app) + * buffer offset and oddblock flag for polyphase filter input buffer + * number of guard bits in input + * + * Outputs: output buffer, data copied and interleaved for polyphase filter + * no guarantees about number of guard bits in output + * + * Return: none + * + * Notes: number of muls = 4*8 + 12*4 = 80 + * final stage of DCT is hardcoded to shuffle data into the proper order + * for the polyphase filterbank + * fully unrolled stage 1, for max precision (scale the 1/cos() factors + * differently, depending on magnitude) + * guard bit analysis verified by exhaustive testing of all 2^32 + * combinations of max pos/max neg values in x[] + * + * TODO: code organization and optimization for ARM + * possibly interleave stereo (cut # of coef loads in half - may not have + * enough registers) + **************************************************************************************/ +// about 1ms faster in RAM +/*__attribute__ ((section (".data")))*/ void FDCT32(int *buf, int *dest, int offset, int oddBlock, int gb) +{ + int i, s, tmp, es; + const int *cptr = dcttab; + int a0, a1, a2, a3, a4, a5, a6, a7; + int b0, b1, b2, b3, b4, b5, b6, b7; + int *d; + + /* scaling - ensure at least 6 guard bits for DCT + * (in practice this is already true 99% of time, so this code is + * almost never triggered) + */ + es = 0; + if (gb < 6) { + es = 6 - gb; + for (i = 0; i < 32; i++) + buf[i] >>= es; + } + + /* first pass */ + D32FP(0, 1, 5, 1); + D32FP(1, 1, 3, 1); + D32FP(2, 1, 3, 1); + D32FP(3, 1, 2, 1); + D32FP(4, 1, 2, 1); + D32FP(5, 1, 1, 2); + D32FP(6, 1, 1, 2); + D32FP(7, 1, 1, 4); + + /* second pass */ + for (i = 4; i > 0; i--) { + a0 = buf[0]; a7 = buf[7]; a3 = buf[3]; a4 = buf[4]; + b0 = a0 + a7; b7 = MULSHIFT32(*cptr++, a0 - a7) << 1; + b3 = a3 + a4; b4 = MULSHIFT32(*cptr++, a3 - a4) << 3; + a0 = b0 + b3; a3 = MULSHIFT32(*cptr, b0 - b3) << 1; + a4 = b4 + b7; a7 = MULSHIFT32(*cptr++, b7 - b4) << 1; + + a1 = buf[1]; a6 = buf[6]; a2 = buf[2]; a5 = buf[5]; + b1 = a1 + a6; b6 = MULSHIFT32(*cptr++, a1 - a6) << 1; + b2 = a2 + a5; b5 = MULSHIFT32(*cptr++, a2 - a5) << 1; + a1 = b1 + b2; a2 = MULSHIFT32(*cptr, b1 - b2) << 2; + a5 = b5 + b6; a6 = MULSHIFT32(*cptr++, b6 - b5) << 2; + + b0 = a0 + a1; b1 = MULSHIFT32(COS4_0, a0 - a1) << 1; + b2 = a2 + a3; b3 = MULSHIFT32(COS4_0, a3 - a2) << 1; + buf[0] = b0; buf[1] = b1; + buf[2] = b2 + b3; buf[3] = b3; + + b4 = a4 + a5; b5 = MULSHIFT32(COS4_0, a4 - a5) << 1; + b6 = a6 + a7; b7 = MULSHIFT32(COS4_0, a7 - a6) << 1; + b6 += b7; + buf[4] = b4 + b6; buf[5] = b5 + b7; + buf[6] = b5 + b6; buf[7] = b7; + + buf += 8; + } + buf -= 32; /* reset */ + + /* sample 0 - always delayed one block */ + d = dest + 64*16 + ((offset - oddBlock) & 7) + (oddBlock ? 0 : VBUF_LENGTH); + s = buf[ 0]; d[0] = d[8] = s; + + /* samples 16 to 31 */ + d = dest + offset + (oddBlock ? VBUF_LENGTH : 0); + + s = buf[ 1]; d[0] = d[8] = s; d += 64; + + tmp = buf[25] + buf[29]; + s = buf[17] + tmp; d[0] = d[8] = s; d += 64; + s = buf[ 9] + buf[13]; d[0] = d[8] = s; d += 64; + s = buf[21] + tmp; d[0] = d[8] = s; d += 64; + + tmp = buf[29] + buf[27]; + s = buf[ 5]; d[0] = d[8] = s; d += 64; + s = buf[21] + tmp; d[0] = d[8] = s; d += 64; + s = buf[13] + buf[11]; d[0] = d[8] = s; d += 64; + s = buf[19] + tmp; d[0] = d[8] = s; d += 64; + + tmp = buf[27] + buf[31]; + s = buf[ 3]; d[0] = d[8] = s; d += 64; + s = buf[19] + tmp; d[0] = d[8] = s; d += 64; + s = buf[11] + buf[15]; d[0] = d[8] = s; d += 64; + s = buf[23] + tmp; d[0] = d[8] = s; d += 64; + + tmp = buf[31]; + s = buf[ 7]; d[0] = d[8] = s; d += 64; + s = buf[23] + tmp; d[0] = d[8] = s; d += 64; + s = buf[15]; d[0] = d[8] = s; d += 64; + s = tmp; d[0] = d[8] = s; + + /* samples 16 to 1 (sample 16 used again) */ + d = dest + 16 + ((offset - oddBlock) & 7) + (oddBlock ? 0 : VBUF_LENGTH); + + s = buf[ 1]; d[0] = d[8] = s; d += 64; + + tmp = buf[30] + buf[25]; + s = buf[17] + tmp; d[0] = d[8] = s; d += 64; + s = buf[14] + buf[ 9]; d[0] = d[8] = s; d += 64; + s = buf[22] + tmp; d[0] = d[8] = s; d += 64; + s = buf[ 6]; d[0] = d[8] = s; d += 64; + + tmp = buf[26] + buf[30]; + s = buf[22] + tmp; d[0] = d[8] = s; d += 64; + s = buf[10] + buf[14]; d[0] = d[8] = s; d += 64; + s = buf[18] + tmp; d[0] = d[8] = s; d += 64; + s = buf[ 2]; d[0] = d[8] = s; d += 64; + + tmp = buf[28] + buf[26]; + s = buf[18] + tmp; d[0] = d[8] = s; d += 64; + s = buf[12] + buf[10]; d[0] = d[8] = s; d += 64; + s = buf[20] + tmp; d[0] = d[8] = s; d += 64; + s = buf[ 4]; d[0] = d[8] = s; d += 64; + + tmp = buf[24] + buf[28]; + s = buf[20] + tmp; d[0] = d[8] = s; d += 64; + s = buf[ 8] + buf[12]; d[0] = d[8] = s; d += 64; + s = buf[16] + tmp; d[0] = d[8] = s; + + /* this is so rarely invoked that it's not worth making two versions of the output + * shuffle code (one for no shift, one for clip + variable shift) like in IMDCT + * here we just load, clip, shift, and store on the rare instances that es != 0 + */ + if (es) { + d = dest + 64*16 + ((offset - oddBlock) & 7) + (oddBlock ? 0 : VBUF_LENGTH); + s = d[0]; CLIP_2N(s, 31 - es); d[0] = d[8] = (s << es); + + d = dest + offset + (oddBlock ? VBUF_LENGTH : 0); + for (i = 16; i <= 31; i++) { + s = d[0]; CLIP_2N(s, 31 - es); d[0] = d[8] = (s << es); d += 64; + } + + d = dest + 16 + ((offset - oddBlock) & 7) + (oddBlock ? 0 : VBUF_LENGTH); + for (i = 15; i >= 0; i--) { + s = d[0]; CLIP_2N(s, 31 - es); d[0] = d[8] = (s << es); d += 64; + } + } +} |