rockbox/firmware/asm/pcm-mixer.c

116 lines
3.6 KiB
C

/***************************************************************************
* __________ __ ___.
* Open \______ \ ____ ____ | | _\_ |__ _______ ___
* Source | _// _ \_/ ___\| |/ /| __ \ / _ \ \/ /
* Jukebox | | ( <_> ) \___| < | \_\ ( <_> > < <
* Firmware |____|_ /\____/ \___ >__|_ \|___ /\____/__/\_ \
* \/ \/ \/ \/ \/
* $Id$
*
* Copyright (C) 2011 by Michael Sevakis
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License
* as published by the Free Software Foundation; either version 2
* of the License, or (at your option) any later version.
*
* This software is distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY
* KIND, either express or implied.
*
****************************************************************************/
#if defined(CPU_ARM)
#include "arm/pcm-mixer.c"
#elif defined(CPU_COLDFIRE)
#include "m68k/pcm-mixer.c"
#else
#include "dsp-util.h" /* for clip_sample_16 */
/* Mix channels' samples and apply gain factors */
static FORCE_INLINE void mix_samples(int16_t *out,
const int16_t *src0,
int32_t src0_amp,
const int16_t *src1,
int32_t src1_amp,
size_t size)
{
if (src0_amp == MIX_AMP_UNITY && src1_amp == MIX_AMP_UNITY)
{
/* Both are unity amplitude */
do
{
int32_t l = *src0++ + *src1++;
int32_t h = *src0++ + *src1++;
*out++ = clip_sample_16(l);
*out++ = clip_sample_16(h);
}
while ((size -= 2*sizeof(int16_t)) > 0);
}
else if (src0_amp != MIX_AMP_UNITY && src1_amp != MIX_AMP_UNITY)
{
/* Neither are unity amplitude */
do
{
int32_t l = (*src0++ * src0_amp >> 16) + (*src1++ * src1_amp >> 16);
int32_t h = (*src0++ * src0_amp >> 16) + (*src1++ * src1_amp >> 16);
*out++ = clip_sample_16(l);
*out++ = clip_sample_16(h);
}
while ((size -= 2*sizeof(int16_t)) > 0);
}
else
{
/* One is unity amplitude */
if (src0_amp != MIX_AMP_UNITY)
{
/* Keep unity in src0, amp0 */
const int16_t *src_tmp = src0;
src0 = src1;
src1 = src_tmp;
src1_amp = src0_amp;
src0_amp = MIX_AMP_UNITY;
}
do
{
int32_t l = *src0++ + (*src1++ * src1_amp >> 16);
int32_t h = *src0++ + (*src1++ * src1_amp >> 16);
*out++ = clip_sample_16(l);
*out++ = clip_sample_16(h);
}
while ((size -= 2*sizeof(int16_t)) > 0);
}
}
/* Write channel's samples and apply gain factor */
static FORCE_INLINE void write_samples(int16_t *out,
const int16_t *src,
int32_t amp,
size_t size)
{
if (LIKELY(amp == MIX_AMP_UNITY))
{
/* Channel is unity amplitude */
memcpy(out, src, size);
}
else
{
/* Channel needs amplitude cut */
do
{
int32_t l = *src++ * amp >> 16;
int32_t h = *src++ * amp >> 16;
*out++ = l;
*out++ = h;
}
while ((size -= 2*sizeof(int16_t)) > 0);
}
}
#endif /* CPU_* */
#ifndef mixer_buffer_callback_exit
#define mixer_buffer_callback_exit() do{}while(0)
#endif