100 lines
3.3 KiB
C
100 lines
3.3 KiB
C
/***************************************************************************
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* __________ __ ___.
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* Open \______ \ ____ ____ | | _\_ |__ _______ ___
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* Source | _// _ \_/ ___\| |/ /| __ \ / _ \ \/ /
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* Jukebox | | ( <_> ) \___| < | \_\ ( <_> > < <
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* Firmware |____|_ /\____/ \___ >__|_ \|___ /\____/__/\_ \
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* \/ \/ \/ \/ \/
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* $Id$
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*
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* Copyright (C) 2011 by Michael Sevakis
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*
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* This program is free software; you can redistribute it and/or
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* modify it under the terms of the GNU General Public License
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* as published by the Free Software Foundation; either version 2
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* of the License, or (at your option) any later version.
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*
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* This software is distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY
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* KIND, either express or implied.
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*
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****************************************************************************/
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#include "dsp-util.h" /* for clip_sample_16 */
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/* Mix channels' samples and apply gain factors */
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static FORCE_INLINE void mix_samples(uint32_t *out,
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int16_t *src0,
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int32_t src0_amp,
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int16_t *src1,
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int32_t src1_amp,
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size_t size)
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{
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if (src0_amp == MIX_AMP_UNITY && src1_amp == MIX_AMP_UNITY)
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{
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/* Both are unity amplitude */
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do
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{
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int32_t l = *src0++ + *src1++;
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int32_t h = *src0++ + *src1++;
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*out++ = (uint16_t)clip_sample_16(l) | (clip_sample_16(h) << 16);
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}
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while ((size -= 4) > 0);
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}
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else if (src0_amp != MIX_AMP_UNITY && src1_amp != MIX_AMP_UNITY)
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{
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/* Neither are unity amplitude */
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do
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{
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int32_t l = (*src0++ * src0_amp >> 16) + (*src1++ * src1_amp >> 16);
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int32_t h = (*src0++ * src0_amp >> 16) + (*src1++ * src1_amp >> 16);
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*out++ = (uint16_t)clip_sample_16(l) | (clip_sample_16(h) << 16);
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}
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while ((size -= 4) > 0);
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}
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else
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{
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/* One is unity amplitude */
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if (src0_amp != MIX_AMP_UNITY)
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{
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/* Keep unity in src0, amp0 */
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int16_t *src_tmp = src0;
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src0 = src1;
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src1 = src_tmp;
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src1_amp = src0_amp;
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src0_amp = MIX_AMP_UNITY;
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}
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do
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{
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int32_t l = *src0++ + (*src1++ * src1_amp >> 16);
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int32_t h = *src0++ + (*src1++ * src1_amp >> 16);
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*out++ = (uint16_t)clip_sample_16(l) | (clip_sample_16(h) << 16);
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}
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while ((size -= 4) > 0);
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}
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}
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/* Write channel's samples and apply gain factor */
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static FORCE_INLINE void write_samples(uint32_t *out,
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int16_t *src,
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int32_t amp,
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size_t size)
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{
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if (LIKELY(amp == MIX_AMP_UNITY))
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{
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/* Channel is unity amplitude */
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memcpy(out, src, size);
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}
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else
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{
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/* Channel needs amplitude cut */
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do
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{
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int32_t l = *src++ * amp >> 16;
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int32_t h = *src++ * amp & 0xffff0000;
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*out++ = (uint16_t)l | h;
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}
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while ((size -= 4) > 0);
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}
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}
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#endif
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