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Diffstat (limited to 'circuitpython/lib/mp3/src/stproc.c')
| -rw-r--r-- | circuitpython/lib/mp3/src/stproc.c | 296 |
1 files changed, 296 insertions, 0 deletions
diff --git a/circuitpython/lib/mp3/src/stproc.c b/circuitpython/lib/mp3/src/stproc.c new file mode 100644 index 0000000..4f6a751 --- /dev/null +++ b/circuitpython/lib/mp3/src/stproc.c @@ -0,0 +1,296 @@ +/* ***** 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 + * + * stproc.c - mid-side and intensity (MPEG1 and MPEG2) stereo processing + **************************************************************************************/ + +#include "coder.h" +#include "assembly.h" + +/************************************************************************************** + * Function: MidSideProc + * + * Description: sum-difference stereo reconstruction + * + * Inputs: vector x with dequantized samples from left and right channels + * number of non-zero samples (MAX of left and right) + * assume 1 guard bit in input + * guard bit mask (left and right channels) + * + * Outputs: updated sample vector x + * updated guard bit mask + * + * Return: none + * + * Notes: assume at least 1 GB in input + **************************************************************************************/ +void MidSideProc(int x[MAX_NCHAN][MAX_NSAMP], int nSamps, int mOut[2]) +{ + int i, xr, xl, mOutL, mOutR; + + /* L = (M+S)/sqrt(2), R = (M-S)/sqrt(2) + * NOTE: 1/sqrt(2) done in DequantChannel() - see comments there + */ + mOutL = mOutR = 0; + for(i = 0; i < nSamps; i++) { + xl = x[0][i]; + xr = x[1][i]; + x[0][i] = xl + xr; + x[1][i] = xl - xr; + mOutL |= FASTABS(x[0][i]); + mOutR |= FASTABS(x[1][i]); + } + mOut[0] |= mOutL; + mOut[1] |= mOutR; +} + +/************************************************************************************** + * Function: IntensityProcMPEG1 + * + * Description: intensity stereo processing for MPEG1 + * + * Inputs: vector x with dequantized samples from left and right channels + * number of non-zero samples in left channel + * valid FrameHeader struct + * two each of ScaleFactorInfoSub, CriticalBandInfo structs (both channels) + * flags indicating midSide on/off, mixedBlock on/off + * guard bit mask (left and right channels) + * + * Outputs: updated sample vector x + * updated guard bit mask + * + * Return: none + * + * Notes: assume at least 1 GB in input + * + * TODO: combine MPEG1/2 into one function (maybe) + * make sure all the mixed-block and IIP logic is right + **************************************************************************************/ +void IntensityProcMPEG1(int x[MAX_NCHAN][MAX_NSAMP], int nSamps, FrameHeader *fh, ScaleFactorInfoSub *sfis, + CriticalBandInfo *cbi, int midSideFlag, int mixFlag, int mOut[2]) +{ + int i=0, j=0, n=0, cb=0, w=0; + int sampsLeft, isf, mOutL, mOutR, xl, xr; + int fl, fr, fls[3], frs[3]; + int cbStartL=0, cbStartS=0, cbEndL=0, cbEndS=0; + int *isfTab; + + /* NOTE - this works fine for mixed blocks, as long as the switch point starts in the + * short block section (i.e. on or after sample 36 = sfBand->l[8] = 3*sfBand->s[3] + * is this a safe assumption? + * TODO - intensity + mixed not quite right (diff = 11 on he_mode) + * figure out correct implementation (spec ambiguous about when to do short block reorder) + */ + if (cbi[1].cbType == 0) { + /* long block */ + cbStartL = cbi[1].cbEndL + 1; + cbEndL = cbi[0].cbEndL + 1; + cbStartS = cbEndS = 0; + i = fh->sfBand->l[cbStartL]; + } else if (cbi[1].cbType == 1 || cbi[1].cbType == 2) { + /* short or mixed block */ + cbStartS = cbi[1].cbEndSMax + 1; + cbEndS = cbi[0].cbEndSMax + 1; + cbStartL = cbEndL = 0; + i = 3 * fh->sfBand->s[cbStartS]; + } + + sampsLeft = nSamps - i; /* process to length of left */ + isfTab = (int *)ISFMpeg1[midSideFlag]; + mOutL = mOutR = 0; + + /* long blocks */ + for (cb = cbStartL; cb < cbEndL && sampsLeft > 0; cb++) { + isf = sfis->l[cb]; + if (isf == 7) { + fl = ISFIIP[midSideFlag][0]; + fr = ISFIIP[midSideFlag][1]; + } else { + fl = isfTab[isf]; + fr = isfTab[6] - isfTab[isf]; + } + + n = fh->sfBand->l[cb + 1] - fh->sfBand->l[cb]; + for (j = 0; j < n && sampsLeft > 0; j++, i++) { + xr = MULSHIFT32(fr, x[0][i]) << 2; x[1][i] = xr; mOutR |= FASTABS(xr); + xl = MULSHIFT32(fl, x[0][i]) << 2; x[0][i] = xl; mOutL |= FASTABS(xl); + sampsLeft--; + } + } + + /* short blocks */ + for (cb = cbStartS; cb < cbEndS && sampsLeft >= 3; cb++) { + for (w = 0; w < 3; w++) { + isf = sfis->s[cb][w]; + if (isf == 7) { + fls[w] = ISFIIP[midSideFlag][0]; + frs[w] = ISFIIP[midSideFlag][1]; + } else { + fls[w] = isfTab[isf]; + frs[w] = isfTab[6] - isfTab[isf]; + } + } + + n = fh->sfBand->s[cb + 1] - fh->sfBand->s[cb]; + for (j = 0; j < n && sampsLeft >= 3; j++, i+=3) { + xr = MULSHIFT32(frs[0], x[0][i+0]) << 2; x[1][i+0] = xr; mOutR |= FASTABS(xr); + xl = MULSHIFT32(fls[0], x[0][i+0]) << 2; x[0][i+0] = xl; mOutL |= FASTABS(xl); + xr = MULSHIFT32(frs[1], x[0][i+1]) << 2; x[1][i+1] = xr; mOutR |= FASTABS(xr); + xl = MULSHIFT32(fls[1], x[0][i+1]) << 2; x[0][i+1] = xl; mOutL |= FASTABS(xl); + xr = MULSHIFT32(frs[2], x[0][i+2]) << 2; x[1][i+2] = xr; mOutR |= FASTABS(xr); + xl = MULSHIFT32(fls[2], x[0][i+2]) << 2; x[0][i+2] = xl; mOutL |= FASTABS(xl); + sampsLeft -= 3; + } + } + mOut[0] = mOutL; + mOut[1] = mOutR; + + return; +} + +/************************************************************************************** + * Function: IntensityProcMPEG2 + * + * Description: intensity stereo processing for MPEG2 + * + * Inputs: vector x with dequantized samples from left and right channels + * number of non-zero samples in left channel + * valid FrameHeader struct + * two each of ScaleFactorInfoSub, CriticalBandInfo structs (both channels) + * ScaleFactorJS struct with joint stereo info from UnpackSFMPEG2() + * flags indicating midSide on/off, mixedBlock on/off + * guard bit mask (left and right channels) + * + * Outputs: updated sample vector x + * updated guard bit mask + * + * Return: none + * + * Notes: assume at least 1 GB in input + * + * TODO: combine MPEG1/2 into one function (maybe) + * make sure all the mixed-block and IIP logic is right + * probably redo IIP logic to be simpler + **************************************************************************************/ +void IntensityProcMPEG2(int x[MAX_NCHAN][MAX_NSAMP], int nSamps, FrameHeader *fh, ScaleFactorInfoSub *sfis, + CriticalBandInfo *cbi, ScaleFactorJS *sfjs, int midSideFlag, int mixFlag, int mOut[2]) +{ + int i, j, k, n, r, cb, w; + int fl, fr, mOutL, mOutR, xl, xr; + int sampsLeft; + int isf, sfIdx, tmp, il[23]; + int *isfTab; + int cbStartL, cbStartS, cbEndL, cbEndS; + + isfTab = (int *)ISFMpeg2[sfjs->intensityScale][midSideFlag]; + mOutL = mOutR = 0; + + /* fill buffer with illegal intensity positions (depending on slen) */ + for (k = r = 0; r < 4; r++) { + tmp = (1 << sfjs->slen[r]) - 1; + for (j = 0; j < sfjs->nr[r]; j++, k++) + il[k] = tmp; + } + + if (cbi[1].cbType == 0) { + /* long blocks */ + il[21] = il[22] = 1; + cbStartL = cbi[1].cbEndL + 1; /* start at end of right */ + cbEndL = cbi[0].cbEndL + 1; /* process to end of left */ + i = fh->sfBand->l[cbStartL]; + sampsLeft = nSamps - i; + + for(cb = cbStartL; cb < cbEndL; cb++) { + sfIdx = sfis->l[cb]; + if (sfIdx == il[cb]) { + fl = ISFIIP[midSideFlag][0]; + fr = ISFIIP[midSideFlag][1]; + } else { + isf = (sfis->l[cb] + 1) >> 1; + fl = isfTab[(sfIdx & 0x01 ? isf : 0)]; + fr = isfTab[(sfIdx & 0x01 ? 0 : isf)]; + } + n = MIN(fh->sfBand->l[cb + 1] - fh->sfBand->l[cb], sampsLeft); + + for(j = 0; j < n; j++, i++) { + xr = MULSHIFT32(fr, x[0][i]) << 2; x[1][i] = xr; mOutR |= FASTABS(xr); + xl = MULSHIFT32(fl, x[0][i]) << 2; x[0][i] = xl; mOutL |= FASTABS(xl); + } + + /* early exit once we've used all the non-zero samples */ + sampsLeft -= n; + if (sampsLeft == 0) + break; + } + } else { + /* short or mixed blocks */ + il[12] = 1; + + for(w = 0; w < 3; w++) { + cbStartS = cbi[1].cbEndS[w] + 1; /* start at end of right */ + cbEndS = cbi[0].cbEndS[w] + 1; /* process to end of left */ + i = 3 * fh->sfBand->s[cbStartS] + w; + + /* skip through sample array by 3, so early-exit logic would be more tricky */ + for(cb = cbStartS; cb < cbEndS; cb++) { + sfIdx = sfis->s[cb][w]; + if (sfIdx == il[cb]) { + fl = ISFIIP[midSideFlag][0]; + fr = ISFIIP[midSideFlag][1]; + } else { + isf = (sfis->s[cb][w] + 1) >> 1; + fl = isfTab[(sfIdx & 0x01 ? isf : 0)]; + fr = isfTab[(sfIdx & 0x01 ? 0 : isf)]; + } + n = fh->sfBand->s[cb + 1] - fh->sfBand->s[cb]; + + for(j = 0; j < n; j++, i+=3) { + xr = MULSHIFT32(fr, x[0][i]) << 2; x[1][i] = xr; mOutR |= FASTABS(xr); + xl = MULSHIFT32(fl, x[0][i]) << 2; x[0][i] = xl; mOutL |= FASTABS(xl); + } + } + } + } + mOut[0] = mOutL; + mOut[1] = mOutR; + + return; +} + |