/* ***** 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] PROGMEM = { /* 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; } } }