in = *over0;			*pcm0 = CLIPTOSHORT( (in - f0 + RND_VAL) >> FBITS_OUT_IMDCT );		pcm0 += nChans;		in = *over1;			*pcm1 = CLIPTOSHORT( (in + f1 + RND_VAL) >> FBITS_OUT_IMDCT );		pcm1 -= nChans;		w0 = *wndCurr++;		w1 = *wndCurr++;			in = *buf1--;		*over1-- = MULSHIFT32(w0, in);		*over0++ = MULSHIFT32(w1, in);	} while (over0 < over1);}/************************************************************************************** * Function:    DecWindowOverlapShort * * Description: apply synthesis window, do overlap-add, clip to 16-bit PCM, *                for winSequence EIGHT-SHORT (does all 8 short blocks) * * Inputs:      input buffer (output of type-IV DCT) *              overlap buffer (saved from last time) *              number of channels *              window type (sin or KBD) for input buffer *              window type (sin or KBD) for overlap buffer * * Outputs:     one channel, one frame of 16-bit PCM, interleaved by nChans * * Return:      none * * Notes:       this processes one channel at a time, but skips every other sample in *                the output buffer (pcm) for stereo interleaving *              this should fit in registers on ARM * * TODO:        ARM5E version with saturating overlap/add (QADD) *              asm code with free pointer updates, better load scheduling **************************************************************************************/ __attribute__ ((section (".data"))) static void DecWindowOverlapShort(int *buf0, int *over0, short *pcm0, int nChans, int winTypeCurr, int winTypePrev){	int i, in, w0, w1, f0, f1;	int *buf1, *over1;	short *pcm1;	const int *wndPrev, *wndCurr;	wndPrev = (winTypePrev == 1 ? kbdWindow + kbdWindowOffset[0] : sinWindow + sinWindowOffset[0]);	wndCurr = (winTypeCurr == 1 ? kbdWindow + kbdWindowOffset[0] : sinWindow + sinWindowOffset[0]);	/* pcm[0-447] = 0 + overlap[0-447] */	i = 448;	do {		f0 = *over0++;		f1 = *over0++;		*pcm0 = CLIPTOSHORT( (f0 + RND_VAL) >> FBITS_OUT_IMDCT );	pcm0 += nChans;		*pcm0 = CLIPTOSHORT( (f1 + RND_VAL) >> FBITS_OUT_IMDCT );	pcm0 += nChans;		i -= 2;	} while (i);	/* pcm[448-575] = Wp[0-127] * block0[0-127] + overlap[448-575] */	pcm1  = pcm0 + (128 - 1) * nChans;	over1 = over0 + 128 - 1;	buf0 += 64;	buf1  = buf0  - 1;	do {		w0 = *wndPrev++;	/* W[0], W[1], ...W[63] */		w1 = *wndPrev++;	/* W[127], W[126], ... W[64] */		in = *buf0++;		f0 = MULSHIFT32(w0, in);		f1 = MULSHIFT32(w1, in);		in = *over0;			*pcm0 = CLIPTOSHORT( (in - f0 + RND_VAL) >> FBITS_OUT_IMDCT );		pcm0 += nChans;		in = *over1;			*pcm1 = CLIPTOSHORT( (in + f1 + RND_VAL) >> FBITS_OUT_IMDCT );		pcm1 -= nChans;		w0 = *wndCurr++;		w1 = *wndCurr++;		in = *buf1--;		/* save over0/over1 for next short block, in the slots just vacated */		*over1-- = MULSHIFT32(w0, in);		*over0++ = MULSHIFT32(w1, in);	} while (over0 < over1);	/* pcm[576-703] = Wc[128-255] * block0[128-255] + Wc[0-127] * block1[0-127] + overlap[576-703] 	 * pcm[704-831] = Wc[128-255] * block1[128-255] + Wc[0-127] * block2[0-127] + overlap[704-831] 	 * pcm[832-959] = Wc[128-255] * block2[128-255] + Wc[0-127] * block3[0-127] + overlap[832-959] 	 */	for (i = 0; i < 3; i++) {		pcm0 += 64 * nChans;		pcm1 = pcm0 + (128 - 1) * nChans;		over0 += 64;		over1 = over0 + 128 - 1;		buf0 += 64;		buf1 = buf0 - 1;		wndCurr -= 128;		do {			w0 = *wndCurr++;	/* W[0], W[1], ...W[63] */			w1 = *wndCurr++;	/* W[127], W[126], ... W[64] */			in = *buf0++;			f0 = MULSHIFT32(w0, in);			f1 = MULSHIFT32(w1, in);			in  = *(over0 - 128);	/* from last short block */			in += *(over0 + 0);		/* from last full frame */			*pcm0 = CLIPTOSHORT( (in - f0 + RND_VAL) >> FBITS_OUT_IMDCT );			pcm0 += nChans;			in  = *(over1 - 128);	/* from last short block */			in += *(over1 + 0);		/* from last full frame */			*pcm1 = CLIPTOSHORT( (in + f1 + RND_VAL) >> FBITS_OUT_IMDCT );			pcm1 -= nChans;			/* save over0/over1 for next short block, in the slots just vacated */			in = *buf1--;			*over1-- = MULSHIFT32(w0, in);			*over0++ = MULSHIFT32(w1, in);		} while (over0 < over1);	}	/* pcm[960-1023] = Wc[128-191] * block3[128-191] + Wc[0-63]   * block4[0-63] + overlap[960-1023]  	 * over[0-63]    = Wc[192-255] * block3[192-255] + Wc[64-127] * block4[64-127]	 */	pcm0 += 64 * nChans;	over0 -= 832;				/* points at overlap[64] */	over1 = over0 + 128 - 1;	/* points at overlap[191] */	buf0 += 64;	buf1 = buf0 - 1;	wndCurr -= 128;	do {		w0 = *wndCurr++;	/* W[0], W[1], ...W[63] */		w1 = *wndCurr++;	/* W[127], W[126], ... W[64] */		in = *buf0++;		f0 = MULSHIFT32(w0, in);		f1 = MULSHIFT32(w1, in);		in  = *(over0 + 768);	/* from last short block */		in += *(over0 + 896);	/* from last full frame */		*pcm0 = CLIPTOSHORT( (in - f0 + RND_VAL) >> FBITS_OUT_IMDCT );		pcm0 += nChans;		in  = *(over1 + 768);	/* from last short block */		*(over1 - 128) = in + f1;		in = *buf1--;		*over1-- = MULSHIFT32(w0, in);	/* save in overlap[128-191] */		*over0++ = MULSHIFT32(w1, in);	/* save in overlap[64-127] */	} while (over0 < over1);		/* over0 now points at overlap[128] */		/* over[64-191]   = Wc[128-255] * block4[128-255] + Wc[0-127] * block5[0-127] 	 * over[192-319]  = Wc[128-255] * block5[128-255] + Wc[0-127] * block6[0-127]	 * over[320-447]  = Wc[128-255] * block6[128-255] + Wc[0-127] * block7[0-127]  	 * over[448-576]  = Wc[128-255] * block7[128-255]	 */	for (i = 0; i < 3; i++) {		over0 += 64;		over1 = over0 + 128 - 1;		buf0 += 64;		buf1 = buf0 - 1;		wndCurr -= 128;		do {			w0 = *wndCurr++;	/* W[0], W[1], ...W[63] */			w1 = *wndCurr++;	/* W[127], W[126], ... W[64] */			in = *buf0++;			f0 = MULSHIFT32(w0, in);			f1 = MULSHIFT32(w1, in);			/* from last short block */			*(over0 - 128) -= f0;			*(over1 - 128)+= f1;			in = *buf1--;			*over1-- = MULSHIFT32(w0, in);			*over0++ = MULSHIFT32(w1, in);		} while (over0 < over1);	}	/* over[576-1024] = 0 */ 	i = 448;	over0 += 64;	do {		*over0++ = 0;		*over0++ = 0;		*over0++ = 0;		*over0++ = 0;		i -= 4;	} while (i);}#endif	/* !AAC_ENABLE_SBR *//************************************************************************************** * Function:    IMDCT * * Description: inverse transform and convert to 16-bit PCM * * Inputs:      valid AACDecInfo struct *              index of current channel (0 for SCE/LFE, 0 or 1 for CPE) *              output channel (range = [0, nChans-1]) * * Outputs:     complete frame of decoded PCM, after inverse transform * * Return:      0 if successful, -1 if error * * Notes:       If AAC_ENABLE_SBR is defined at compile time then window + overlap  *                does NOT clip to 16-bit PCM and does NOT interleave channels *              If AAC_ENABLE_SBR is NOT defined at compile time, then window + overlap  *                does clip to 16-bit PCM and interleaves channels *              If SBR is enabled at compile time, but we don't know whether it is *                actually used for this frame (e.g. the first frame of a stream), *                we need to produce both clipped 16-bit PCM in outbuf AND *                unclipped 32-bit PCM in the SBR input buffer. In this case we make *                a separate pass over the 32-bit PCM to produce 16-bit PCM output. *                This inflicts a slight performance hit when decoding non-SBR files. **************************************************************************************/int IMDCT(AACDecInfo *aacDecInfo, int ch, int chOut, short *outbuf){	int i;	PSInfoBase *psi;	ICSInfo *icsInfo;	/* validate pointers */	if (!aacDecInfo || !aacDecInfo->psInfoBase)		return -1;	psi = (PSInfoBase *)(aacDecInfo->psInfoBase);	icsInfo = (ch == 1 && psi->commonWin == 1) ? &(psi->icsInfo[0]) : &(psi->icsInfo[ch]);	outbuf += chOut;	/* optimized type-IV DCT (operates inplace) */	if (icsInfo->winSequence == 2) {		/* 8 short blocks */		for (i = 0; i < 8; i++)			DCT4(0, psi->coef[ch] + i*128, psi->gbCurrent[ch]);	} else {		/* 1 long block */		DCT4(1, psi->coef[ch], psi->gbCurrent[ch]);	}#ifdef AAC_ENABLE_SBR	/* window, overlap-add, don't clip to short (send to SBR decoder) 	 * store the decoded 32-bit samples in top half (second AAC_MAX_NSAMPS samples) of coef buffer	 */	if (icsInfo->winSequence == 0)		DecWindowOverlapNoClip(psi->coef[ch], psi->overlap[chOut], psi->sbrWorkBuf[ch], icsInfo->winShape, psi->prevWinShape[chOut]);	else if (icsInfo->winSequence == 1)		DecWindowOverlapLongStartNoClip(psi->coef[ch], psi->overlap[chOut], psi->sbrWorkBuf[ch], icsInfo->winShape, psi->prevWinShape[chOut]);	else if (icsInfo->winSequence == 2)		DecWindowOverlapShortNoClip(psi->coef[ch], psi->overlap[chOut], psi->sbrWorkBuf[ch], icsInfo->winShape, psi->prevWinShape[chOut]);	else if (icsInfo->winSequence == 3)		DecWindowOverlapLongStopNoClip(psi->coef[ch], psi->overlap[chOut], psi->sbrWorkBuf[ch], icsInfo->winShape, psi->prevWinShape[chOut]);	if (!aacDecInfo->sbrEnabled) {		for (i = 0; i < AAC_MAX_NSAMPS; i++) {			*outbuf = CLIPTOSHORT((psi->sbrWorkBuf[ch][i] + RND_VAL) >> FBITS_OUT_IMDCT);			outbuf += aacDecInfo->nChans;		}	}	aacDecInfo->rawSampleBuf[ch] = psi->sbrWorkBuf[ch];	aacDecInfo->rawSampleBytes = sizeof(int);	aacDecInfo->rawSampleFBits = FBITS_OUT_IMDCT;#else	/* window, overlap-add, round to PCM - optimized for each window sequence */	if (icsInfo->winSequence == 0)		DecWindowOverlap(psi->coef[ch], psi->overlap[chOut], outbuf, aacDecInfo->nChans, icsInfo->winShape, psi->prevWinShape[chOut]);	else if (icsInfo->winSequence == 1)		DecWindowOverlapLongStart(psi->coef[ch], psi->overlap[chOut], outbuf, aacDecInfo->nChans, icsInfo->winShape, psi->prevWinShape[chOut]);	else if (icsInfo->winSequence == 2)		DecWindowOverlapShort(psi->coef[ch], psi->overlap[chOut], outbuf, aacDecInfo->nChans, icsInfo->winShape, psi->prevWinShape[chOut]);	else if (icsInfo->winSequence == 3)		DecWindowOverlapLongStop(psi->coef[ch], psi->overlap[chOut], outbuf, aacDecInfo->nChans, icsInfo->winShape, psi->prevWinShape[chOut]);	aacDecInfo->rawSampleBuf[ch] = 0;	aacDecInfo->rawSampleBytes = 0;	aacDecInfo->rawSampleFBits = 0;#endif	psi->prevWinShape[chOut] = icsInfo->winShape;	return 0;}