| /* |
| ** Copyright 2003-2010, VisualOn, Inc. |
| ** |
| ** Licensed under the Apache License, Version 2.0 (the "License"); |
| ** you may not use this file except in compliance with the License. |
| ** You may obtain a copy of the License at |
| ** |
| ** http://www.apache.org/licenses/LICENSE-2.0 |
| ** |
| ** Unless required by applicable law or agreed to in writing, software |
| ** distributed under the License is distributed on an "AS IS" BASIS, |
| ** WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
| ** See the License for the specific language governing permissions and |
| ** limitations under the License. |
| */ |
| /******************************************************************************* |
| File: transform.c |
| |
| Content: MDCT Transform functionss |
| |
| *******************************************************************************/ |
| |
| #include "basic_op.h" |
| #include "psy_const.h" |
| #include "transform.h" |
| #include "aac_rom.h" |
| |
| |
| #define LS_TRANS ((FRAME_LEN_LONG-FRAME_LEN_SHORT)/2) /* 448 */ |
| #define SQRT1_2 0x5a82799a /* sqrt(1/2) in Q31 */ |
| #define swap2(p0,p1) \ |
| t = p0; t1 = *(&(p0)+1); \ |
| p0 = p1; *(&(p0)+1) = *(&(p1)+1); \ |
| p1 = t; *(&(p1)+1) = t1 |
| |
| /********************************************************************************* |
| * |
| * function name: Shuffle |
| * description: Shuffle points prepared function for fft |
| * |
| **********************************************************************************/ |
| static void Shuffle(int *buf, int num, const unsigned char* bitTab) |
| { |
| int *part0, *part1; |
| int i, j; |
| int t, t1; |
| |
| part0 = buf; |
| part1 = buf + num; |
| |
| while ((i = *bitTab++) != 0) { |
| j = *bitTab++; |
| |
| swap2(part0[4*i+0], part0[4*j+0]); |
| swap2(part0[4*i+2], part1[4*j+0]); |
| swap2(part1[4*i+0], part0[4*j+2]); |
| swap2(part1[4*i+2], part1[4*j+2]); |
| } |
| |
| do { |
| swap2(part0[4*i+2], part1[4*i+0]); |
| } while ((i = *bitTab++) != 0); |
| } |
| |
| #if !defined(ARMV5E) && !defined(ARMV7Neon) |
| |
| /***************************************************************************** |
| * |
| * function name: Radix4First |
| * description: Radix 4 point prepared function for fft |
| * |
| **********************************************************************************/ |
| static void Radix4First(int *buf, int num) |
| { |
| int r0, r1, r2, r3; |
| int r4, r5, r6, r7; |
| |
| for (; num != 0; num--) |
| { |
| r0 = buf[0] + buf[2]; |
| r1 = buf[1] + buf[3]; |
| r2 = buf[0] - buf[2]; |
| r3 = buf[1] - buf[3]; |
| r4 = buf[4] + buf[6]; |
| r5 = buf[5] + buf[7]; |
| r6 = buf[4] - buf[6]; |
| r7 = buf[5] - buf[7]; |
| |
| buf[0] = r0 + r4; |
| buf[1] = r1 + r5; |
| buf[4] = r0 - r4; |
| buf[5] = r1 - r5; |
| buf[2] = r2 + r7; |
| buf[3] = r3 - r6; |
| buf[6] = r2 - r7; |
| buf[7] = r3 + r6; |
| |
| buf += 8; |
| } |
| } |
| |
| /***************************************************************************** |
| * |
| * function name: Radix8First |
| * description: Radix 8 point prepared function for fft |
| * |
| **********************************************************************************/ |
| static void Radix8First(int *buf, int num) |
| { |
| int r0, r1, r2, r3; |
| int i0, i1, i2, i3; |
| int r4, r5, r6, r7; |
| int i4, i5, i6, i7; |
| int t0, t1, t2, t3; |
| |
| for ( ; num != 0; num--) |
| { |
| r0 = buf[0] + buf[2]; |
| i0 = buf[1] + buf[3]; |
| r1 = buf[0] - buf[2]; |
| i1 = buf[1] - buf[3]; |
| r2 = buf[4] + buf[6]; |
| i2 = buf[5] + buf[7]; |
| r3 = buf[4] - buf[6]; |
| i3 = buf[5] - buf[7]; |
| |
| r4 = (r0 + r2) >> 1; |
| i4 = (i0 + i2) >> 1; |
| r5 = (r0 - r2) >> 1; |
| i5 = (i0 - i2) >> 1; |
| r6 = (r1 - i3) >> 1; |
| i6 = (i1 + r3) >> 1; |
| r7 = (r1 + i3) >> 1; |
| i7 = (i1 - r3) >> 1; |
| |
| r0 = buf[ 8] + buf[10]; |
| i0 = buf[ 9] + buf[11]; |
| r1 = buf[ 8] - buf[10]; |
| i1 = buf[ 9] - buf[11]; |
| r2 = buf[12] + buf[14]; |
| i2 = buf[13] + buf[15]; |
| r3 = buf[12] - buf[14]; |
| i3 = buf[13] - buf[15]; |
| |
| t0 = (r0 + r2) >> 1; |
| t1 = (i0 + i2) >> 1; |
| t2 = (r0 - r2) >> 1; |
| t3 = (i0 - i2) >> 1; |
| |
| buf[ 0] = r4 + t0; |
| buf[ 1] = i4 + t1; |
| buf[ 8] = r4 - t0; |
| buf[ 9] = i4 - t1; |
| buf[ 4] = r5 + t3; |
| buf[ 5] = i5 - t2; |
| buf[12] = r5 - t3; |
| buf[13] = i5 + t2; |
| |
| r0 = r1 - i3; |
| i0 = i1 + r3; |
| r2 = r1 + i3; |
| i2 = i1 - r3; |
| |
| t0 = MULHIGH(SQRT1_2, r0 - i0); |
| t1 = MULHIGH(SQRT1_2, r0 + i0); |
| t2 = MULHIGH(SQRT1_2, r2 - i2); |
| t3 = MULHIGH(SQRT1_2, r2 + i2); |
| |
| buf[ 6] = r6 - t0; |
| buf[ 7] = i6 - t1; |
| buf[14] = r6 + t0; |
| buf[15] = i6 + t1; |
| buf[ 2] = r7 + t3; |
| buf[ 3] = i7 - t2; |
| buf[10] = r7 - t3; |
| buf[11] = i7 + t2; |
| |
| buf += 16; |
| } |
| } |
| |
| /***************************************************************************** |
| * |
| * function name: Radix4FFT |
| * description: Radix 4 point fft core function |
| * |
| **********************************************************************************/ |
| static void Radix4FFT(int *buf, int num, int bgn, int *twidTab) |
| { |
| int r0, r1, r2, r3; |
| int r4, r5, r6, r7; |
| int t0, t1; |
| int sinx, cosx; |
| int i, j, step; |
| int *xptr, *csptr; |
| |
| for (num >>= 2; num != 0; num >>= 2) |
| { |
| step = 2*bgn; |
| xptr = buf; |
| |
| for (i = num; i != 0; i--) |
| { |
| csptr = twidTab; |
| |
| for (j = bgn; j != 0; j--) |
| { |
| r0 = xptr[0]; |
| r1 = xptr[1]; |
| xptr += step; |
| |
| t0 = xptr[0]; |
| t1 = xptr[1]; |
| cosx = csptr[0]; |
| sinx = csptr[1]; |
| r2 = MULHIGH(cosx, t0) + MULHIGH(sinx, t1); /* cos*br + sin*bi */ |
| r3 = MULHIGH(cosx, t1) - MULHIGH(sinx, t0); /* cos*bi - sin*br */ |
| xptr += step; |
| |
| t0 = r0 >> 2; |
| t1 = r1 >> 2; |
| r0 = t0 - r2; |
| r1 = t1 - r3; |
| r2 = t0 + r2; |
| r3 = t1 + r3; |
| |
| t0 = xptr[0]; |
| t1 = xptr[1]; |
| cosx = csptr[2]; |
| sinx = csptr[3]; |
| r4 = MULHIGH(cosx, t0) + MULHIGH(sinx, t1); /* cos*cr + sin*ci */ |
| r5 = MULHIGH(cosx, t1) - MULHIGH(sinx, t0); /* cos*ci - sin*cr */ |
| xptr += step; |
| |
| t0 = xptr[0]; |
| t1 = xptr[1]; |
| cosx = csptr[4]; |
| sinx = csptr[5]; |
| r6 = MULHIGH(cosx, t0) + MULHIGH(sinx, t1); /* cos*cr + sin*ci */ |
| r7 = MULHIGH(cosx, t1) - MULHIGH(sinx, t0); /* cos*ci - sin*cr */ |
| csptr += 6; |
| |
| t0 = r4; |
| t1 = r5; |
| r4 = t0 + r6; |
| r5 = r7 - t1; |
| r6 = t0 - r6; |
| r7 = r7 + t1; |
| |
| xptr[0] = r0 + r5; |
| xptr[1] = r1 + r6; |
| xptr -= step; |
| |
| xptr[0] = r2 - r4; |
| xptr[1] = r3 - r7; |
| xptr -= step; |
| |
| xptr[0] = r0 - r5; |
| xptr[1] = r1 - r6; |
| xptr -= step; |
| |
| xptr[0] = r2 + r4; |
| xptr[1] = r3 + r7; |
| xptr += 2; |
| } |
| xptr += 3*step; |
| } |
| twidTab += 3*step; |
| bgn <<= 2; |
| } |
| } |
| |
| /********************************************************************************* |
| * |
| * function name: PreMDCT |
| * description: prepare MDCT process for next FFT compute |
| * |
| **********************************************************************************/ |
| static void PreMDCT(int *buf0, int num, const int *csptr) |
| { |
| int i; |
| int tr1, ti1, tr2, ti2; |
| int cosa, sina, cosb, sinb; |
| int *buf1; |
| |
| buf1 = buf0 + num - 1; |
| |
| for(i = num >> 2; i != 0; i--) |
| { |
| cosa = *csptr++; |
| sina = *csptr++; |
| cosb = *csptr++; |
| sinb = *csptr++; |
| |
| tr1 = *(buf0 + 0); |
| ti2 = *(buf0 + 1); |
| tr2 = *(buf1 - 1); |
| ti1 = *(buf1 + 0); |
| |
| *buf0++ = MULHIGH(cosa, tr1) + MULHIGH(sina, ti1); |
| *buf0++ = MULHIGH(cosa, ti1) - MULHIGH(sina, tr1); |
| |
| *buf1-- = MULHIGH(cosb, ti2) - MULHIGH(sinb, tr2); |
| *buf1-- = MULHIGH(cosb, tr2) + MULHIGH(sinb, ti2); |
| } |
| } |
| |
| /********************************************************************************* |
| * |
| * function name: PostMDCT |
| * description: post MDCT process after next FFT for MDCT |
| * |
| **********************************************************************************/ |
| static void PostMDCT(int *buf0, int num, const int *csptr) |
| { |
| int i; |
| int tr1, ti1, tr2, ti2; |
| int cosa, sina, cosb, sinb; |
| int *buf1; |
| |
| buf1 = buf0 + num - 1; |
| |
| for(i = num >> 2; i != 0; i--) |
| { |
| cosa = *csptr++; |
| sina = *csptr++; |
| cosb = *csptr++; |
| sinb = *csptr++; |
| |
| tr1 = *(buf0 + 0); |
| ti1 = *(buf0 + 1); |
| ti2 = *(buf1 + 0); |
| tr2 = *(buf1 - 1); |
| |
| *buf0++ = MULHIGH(cosa, tr1) + MULHIGH(sina, ti1); |
| *buf1-- = MULHIGH(sina, tr1) - MULHIGH(cosa, ti1); |
| |
| *buf0++ = MULHIGH(sinb, tr2) - MULHIGH(cosb, ti2); |
| *buf1-- = MULHIGH(cosb, tr2) + MULHIGH(sinb, ti2); |
| } |
| } |
| #endif |
| |
| |
| /********************************************************************************** |
| * |
| * function name: Mdct_Long |
| * description: the long block mdct, include long_start block, end_long block |
| * |
| **********************************************************************************/ |
| void Mdct_Long(int *buf) |
| { |
| PreMDCT(buf, 1024, cossintab + 128); |
| |
| Shuffle(buf, 512, bitrevTab + 17); |
| Radix8First(buf, 512 >> 3); |
| Radix4FFT(buf, 512 >> 3, 8, (int *)twidTab512); |
| |
| PostMDCT(buf, 1024, cossintab + 128); |
| } |
| |
| |
| /********************************************************************************** |
| * |
| * function name: Mdct_Short |
| * description: the short block mdct |
| * |
| **********************************************************************************/ |
| void Mdct_Short(int *buf) |
| { |
| PreMDCT(buf, 128, cossintab); |
| |
| Shuffle(buf, 64, bitrevTab); |
| Radix4First(buf, 64 >> 2); |
| Radix4FFT(buf, 64 >> 2, 4, (int *)twidTab64); |
| |
| PostMDCT(buf, 128, cossintab); |
| } |
| |
| |
| /***************************************************************************** |
| * |
| * function name: shiftMdctDelayBuffer |
| * description: the mdct delay buffer has a size of 1600, |
| * so the calculation of LONG,STOP must be spilt in two |
| * passes with 1024 samples and a mid shift, |
| * the SHORT transforms can be completed in the delay buffer, |
| * and afterwards a shift |
| * |
| **********************************************************************************/ |
| static void shiftMdctDelayBuffer(Word16 *mdctDelayBuffer, /*! start of mdct delay buffer */ |
| Word16 *timeSignal, /*! pointer to new time signal samples, interleaved */ |
| Word16 chIncrement /*! number of channels */ |
| ) |
| { |
| Word32 i; |
| Word16 *srBuf = mdctDelayBuffer; |
| Word16 *dsBuf = mdctDelayBuffer+FRAME_LEN_LONG; |
| |
| for(i = 0; i < BLOCK_SWITCHING_OFFSET-FRAME_LEN_LONG; i+= 8) |
| { |
| *srBuf++ = *dsBuf++; *srBuf++ = *dsBuf++; |
| *srBuf++ = *dsBuf++; *srBuf++ = *dsBuf++; |
| *srBuf++ = *dsBuf++; *srBuf++ = *dsBuf++; |
| *srBuf++ = *dsBuf++; *srBuf++ = *dsBuf++; |
| } |
| |
| srBuf = mdctDelayBuffer + BLOCK_SWITCHING_OFFSET-FRAME_LEN_LONG; |
| dsBuf = timeSignal; |
| |
| for(i=0; i<FRAME_LEN_LONG; i+=8) |
| { |
| *srBuf++ = *dsBuf; dsBuf += chIncrement; |
| *srBuf++ = *dsBuf; dsBuf += chIncrement; |
| *srBuf++ = *dsBuf; dsBuf += chIncrement; |
| *srBuf++ = *dsBuf; dsBuf += chIncrement; |
| *srBuf++ = *dsBuf; dsBuf += chIncrement; |
| *srBuf++ = *dsBuf; dsBuf += chIncrement; |
| *srBuf++ = *dsBuf; dsBuf += chIncrement; |
| *srBuf++ = *dsBuf; dsBuf += chIncrement; |
| } |
| } |
| |
| |
| /***************************************************************************** |
| * |
| * function name: getScalefactorOfShortVectorStride |
| * description: Calculate max possible scale factor for input vector of shorts |
| * returns: Maximum scale factor |
| * |
| **********************************************************************************/ |
| static Word16 getScalefactorOfShortVectorStride(const Word16 *vector, /*!< Pointer to input vector */ |
| Word16 len, /*!< Length of input vector */ |
| Word16 stride) /*!< Stride of input vector */ |
| { |
| Word16 maxVal = 0; |
| Word16 absVal; |
| Word16 i; |
| |
| for(i=0; i<len; i++){ |
| absVal = abs_s(vector[i*stride]); |
| maxVal |= absVal; |
| } |
| |
| return( maxVal ? norm_s(maxVal) : 15); |
| } |
| |
| |
| /***************************************************************************** |
| * |
| * function name: Transform_Real |
| * description: Calculate transform filter for input vector of shorts |
| * returns: TRUE if success |
| * |
| **********************************************************************************/ |
| void Transform_Real(Word16 *mdctDelayBuffer, |
| Word16 *timeSignal, |
| Word16 chIncrement, |
| Word32 *realOut, |
| Word16 *mdctScale, |
| Word16 blockType |
| ) |
| { |
| Word32 i,w; |
| Word32 timeSignalSample; |
| Word32 ws1,ws2; |
| Word16 *dctIn0, *dctIn1; |
| Word32 *outData0, *outData1; |
| Word32 *winPtr; |
| |
| Word32 delayBufferSf,timeSignalSf,minSf; |
| Word32 headRoom=0; |
| |
| switch(blockType){ |
| |
| |
| case LONG_WINDOW: |
| /* |
| we access BLOCK_SWITCHING_OFFSET (1600 ) delay buffer samples + 448 new timeSignal samples |
| and get the biggest scale factor for next calculate more precise |
| */ |
| delayBufferSf = getScalefactorOfShortVectorStride(mdctDelayBuffer,BLOCK_SWITCHING_OFFSET,1); |
| timeSignalSf = getScalefactorOfShortVectorStride(timeSignal,2*FRAME_LEN_LONG-BLOCK_SWITCHING_OFFSET,chIncrement); |
| minSf = min(delayBufferSf,timeSignalSf); |
| minSf = min(minSf,14); |
| |
| dctIn0 = mdctDelayBuffer; |
| dctIn1 = mdctDelayBuffer + FRAME_LEN_LONG - 1; |
| outData0 = realOut + FRAME_LEN_LONG/2; |
| |
| /* add windows and pre add for mdct to last buffer*/ |
| winPtr = (int *)LongWindowKBD; |
| for(i=0;i<FRAME_LEN_LONG/2;i++){ |
| timeSignalSample = (*dctIn0++) << minSf; |
| ws1 = timeSignalSample * (*winPtr >> 16); |
| timeSignalSample = (*dctIn1--) << minSf; |
| ws2 = timeSignalSample * (*winPtr & 0xffff); |
| winPtr ++; |
| /* shift 2 to avoid overflow next */ |
| *outData0++ = (ws1 >> 2) - (ws2 >> 2); |
| } |
| |
| shiftMdctDelayBuffer(mdctDelayBuffer,timeSignal,chIncrement); |
| |
| /* add windows and pre add for mdct to new buffer*/ |
| dctIn0 = mdctDelayBuffer; |
| dctIn1 = mdctDelayBuffer + FRAME_LEN_LONG - 1; |
| outData0 = realOut + FRAME_LEN_LONG/2 - 1; |
| winPtr = (int *)LongWindowKBD; |
| for(i=0;i<FRAME_LEN_LONG/2;i++){ |
| timeSignalSample = (*dctIn0++) << minSf; |
| ws1 = timeSignalSample * (*winPtr & 0xffff); |
| timeSignalSample = (*dctIn1--) << minSf; |
| ws2 = timeSignalSample * (*winPtr >> 16); |
| winPtr++; |
| /* shift 2 to avoid overflow next */ |
| *outData0-- = -((ws1 >> 2) + (ws2 >> 2)); |
| } |
| |
| Mdct_Long(realOut); |
| /* update scale factor */ |
| minSf = 14 - minSf; |
| *mdctScale=minSf; |
| break; |
| |
| case START_WINDOW: |
| /* |
| we access BLOCK_SWITCHING_OFFSET (1600 ) delay buffer samples + no timeSignal samples |
| and get the biggest scale factor for next calculate more precise |
| */ |
| minSf = getScalefactorOfShortVectorStride(mdctDelayBuffer,BLOCK_SWITCHING_OFFSET,1); |
| minSf = min(minSf,14); |
| |
| dctIn0 = mdctDelayBuffer; |
| dctIn1 = mdctDelayBuffer + FRAME_LEN_LONG - 1; |
| outData0 = realOut + FRAME_LEN_LONG/2; |
| winPtr = (int *)LongWindowKBD; |
| |
| /* add windows and pre add for mdct to last buffer*/ |
| for(i=0;i<FRAME_LEN_LONG/2;i++){ |
| timeSignalSample = (*dctIn0++) << minSf; |
| ws1 = timeSignalSample * (*winPtr >> 16); |
| timeSignalSample = (*dctIn1--) << minSf; |
| ws2 = timeSignalSample * (*winPtr & 0xffff); |
| winPtr ++; |
| *outData0++ = (ws1 >> 2) - (ws2 >> 2); /* shift 2 to avoid overflow next */ |
| } |
| |
| shiftMdctDelayBuffer(mdctDelayBuffer,timeSignal,chIncrement); |
| |
| outData0 = realOut + FRAME_LEN_LONG/2 - 1; |
| for(i=0;i<LS_TRANS;i++){ |
| *outData0-- = -mdctDelayBuffer[i] << (15 - 2 + minSf); |
| } |
| |
| /* add windows and pre add for mdct to new buffer*/ |
| dctIn0 = mdctDelayBuffer + LS_TRANS; |
| dctIn1 = mdctDelayBuffer + FRAME_LEN_LONG - 1 - LS_TRANS; |
| outData0 = realOut + FRAME_LEN_LONG/2 - 1 -LS_TRANS; |
| winPtr = (int *)ShortWindowSine; |
| for(i=0;i<FRAME_LEN_SHORT/2;i++){ |
| timeSignalSample= (*dctIn0++) << minSf; |
| ws1 = timeSignalSample * (*winPtr & 0xffff); |
| timeSignalSample= (*dctIn1--) << minSf; |
| ws2 = timeSignalSample * (*winPtr >> 16); |
| winPtr++; |
| *outData0-- = -((ws1 >> 2) + (ws2 >> 2)); /* shift 2 to avoid overflow next */ |
| } |
| |
| Mdct_Long(realOut); |
| /* update scale factor */ |
| minSf = 14 - minSf; |
| *mdctScale= minSf; |
| break; |
| |
| case STOP_WINDOW: |
| /* |
| we access BLOCK_SWITCHING_OFFSET-LS_TRANS (1600-448 ) delay buffer samples + 448 new timeSignal samples |
| and get the biggest scale factor for next calculate more precise |
| */ |
| delayBufferSf = getScalefactorOfShortVectorStride(mdctDelayBuffer+LS_TRANS,BLOCK_SWITCHING_OFFSET-LS_TRANS,1); |
| timeSignalSf = getScalefactorOfShortVectorStride(timeSignal,2*FRAME_LEN_LONG-BLOCK_SWITCHING_OFFSET,chIncrement); |
| minSf = min(delayBufferSf,timeSignalSf); |
| minSf = min(minSf,13); |
| |
| outData0 = realOut + FRAME_LEN_LONG/2; |
| dctIn1 = mdctDelayBuffer + FRAME_LEN_LONG - 1; |
| for(i=0;i<LS_TRANS;i++){ |
| *outData0++ = -(*dctIn1--) << (15 - 2 + minSf); |
| } |
| |
| /* add windows and pre add for mdct to last buffer*/ |
| dctIn0 = mdctDelayBuffer + LS_TRANS; |
| dctIn1 = mdctDelayBuffer + FRAME_LEN_LONG - 1 - LS_TRANS; |
| outData0 = realOut + FRAME_LEN_LONG/2 + LS_TRANS; |
| winPtr = (int *)ShortWindowSine; |
| for(i=0;i<FRAME_LEN_SHORT/2;i++){ |
| timeSignalSample = (*dctIn0++) << minSf; |
| ws1 = timeSignalSample * (*winPtr >> 16); |
| timeSignalSample= (*dctIn1--) << minSf; |
| ws2 = timeSignalSample * (*winPtr & 0xffff); |
| winPtr++; |
| *outData0++ = (ws1 >> 2) - (ws2 >> 2); /* shift 2 to avoid overflow next */ |
| } |
| |
| shiftMdctDelayBuffer(mdctDelayBuffer,timeSignal,chIncrement); |
| |
| /* add windows and pre add for mdct to new buffer*/ |
| dctIn0 = mdctDelayBuffer; |
| dctIn1 = mdctDelayBuffer + FRAME_LEN_LONG - 1; |
| outData0 = realOut + FRAME_LEN_LONG/2 - 1; |
| winPtr = (int *)LongWindowKBD; |
| for(i=0;i<FRAME_LEN_LONG/2;i++){ |
| timeSignalSample= (*dctIn0++) << minSf; |
| ws1 = timeSignalSample *(*winPtr & 0xffff); |
| timeSignalSample= (*dctIn1--) << minSf; |
| ws2 = timeSignalSample * (*winPtr >> 16); |
| *outData0-- = -((ws1 >> 2) + (ws2 >> 2)); /* shift 2 to avoid overflow next */ |
| winPtr++; |
| } |
| |
| Mdct_Long(realOut); |
| minSf = 14 - minSf; |
| *mdctScale= minSf; /* update scale factor */ |
| break; |
| |
| case SHORT_WINDOW: |
| /* |
| we access BLOCK_SWITCHING_OFFSET (1600 ) delay buffer samples + no new timeSignal samples |
| and get the biggest scale factor for next calculate more precise |
| */ |
| minSf = getScalefactorOfShortVectorStride(mdctDelayBuffer+TRANSFORM_OFFSET_SHORT,9*FRAME_LEN_SHORT,1); |
| minSf = min(minSf,10); |
| |
| |
| for(w=0;w<TRANS_FAC;w++){ |
| dctIn0 = mdctDelayBuffer+w*FRAME_LEN_SHORT+TRANSFORM_OFFSET_SHORT; |
| dctIn1 = mdctDelayBuffer+w*FRAME_LEN_SHORT+TRANSFORM_OFFSET_SHORT + FRAME_LEN_SHORT-1; |
| outData0 = realOut + FRAME_LEN_SHORT/2; |
| outData1 = realOut + FRAME_LEN_SHORT/2 - 1; |
| |
| winPtr = (int *)ShortWindowSine; |
| for(i=0;i<FRAME_LEN_SHORT/2;i++){ |
| timeSignalSample= *dctIn0 << minSf; |
| ws1 = timeSignalSample * (*winPtr >> 16); |
| timeSignalSample= *dctIn1 << minSf; |
| ws2 = timeSignalSample * (*winPtr & 0xffff); |
| *outData0++ = (ws1 >> 2) - (ws2 >> 2); /* shift 2 to avoid overflow next */ |
| |
| timeSignalSample= *(dctIn0 + FRAME_LEN_SHORT) << minSf; |
| ws1 = timeSignalSample * (*winPtr & 0xffff); |
| timeSignalSample= *(dctIn1 + FRAME_LEN_SHORT) << minSf; |
| ws2 = timeSignalSample * (*winPtr >> 16); |
| *outData1-- = -((ws1 >> 2) + (ws2 >> 2)); /* shift 2 to avoid overflow next */ |
| |
| winPtr++; |
| dctIn0++; |
| dctIn1--; |
| } |
| |
| Mdct_Short(realOut); |
| realOut += FRAME_LEN_SHORT; |
| } |
| |
| minSf = 11 - minSf; |
| *mdctScale = minSf; /* update scale factor */ |
| |
| shiftMdctDelayBuffer(mdctDelayBuffer,timeSignal,chIncrement); |
| break; |
| } |
| } |
| |