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/*
* Copyright (C) 2014 The Android Open Source Project
*
* 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.
*/
#ifndef ANDROID_AUDIO_MIXER_OPS_H
#define ANDROID_AUDIO_MIXER_OPS_H
#include <audio_utils/channels.h>
#include <audio_utils/primitives.h>
#include <system/audio.h>
namespace android {
// Hack to make static_assert work in a constexpr
// https://en.cppreference.com/w/cpp/language/if
template <int N>
inline constexpr bool dependent_false = false;
/* MixMul is a multiplication operator to scale an audio input signal
* by a volume gain, with the formula:
*
* O(utput) = I(nput) * V(olume)
*
* The output, input, and volume may have different types.
* There are 27 variants, of which 14 are actually defined in an
* explicitly templated class.
*
* The following type variables and the underlying meaning:
*
* Output type TO: int32_t (Q4.27) or int16_t (Q.15) or float [-1,1]
* Input signal type TI: int32_t (Q4.27) or int16_t (Q.15) or float [-1,1]
* Volume type TV: int32_t (U4.28) or int16_t (U4.12) or float [-1,1]
*
* For high precision audio, only the <TO, TI, TV> = <float, float, float>
* needs to be accelerated. This is perhaps the easiest form to do quickly as well.
*
* A generic version is NOT defined to catch any mistake of using it.
*/
template <typename TO, typename TI, typename TV>
TO MixMul(TI value, TV volume);
template <>
inline int32_t MixMul<int32_t, int16_t, int16_t>(int16_t value, int16_t volume) {
return value * volume;
}
template <>
inline int32_t MixMul<int32_t, int32_t, int16_t>(int32_t value, int16_t volume) {
return (value >> 12) * volume;
}
template <>
inline int32_t MixMul<int32_t, int16_t, int32_t>(int16_t value, int32_t volume) {
return value * (volume >> 16);
}
template <>
inline int32_t MixMul<int32_t, int32_t, int32_t>(int32_t value, int32_t volume) {
return (value >> 12) * (volume >> 16);
}
template <>
inline float MixMul<float, float, int16_t>(float value, int16_t volume) {
static const float norm = 1. / (1 << 12);
return value * volume * norm;
}
template <>
inline float MixMul<float, float, int32_t>(float value, int32_t volume) {
static const float norm = 1. / (1 << 28);
return value * volume * norm;
}
template <>
inline int16_t MixMul<int16_t, float, int16_t>(float value, int16_t volume) {
return clamp16_from_float(MixMul<float, float, int16_t>(value, volume));
}
template <>
inline int16_t MixMul<int16_t, float, int32_t>(float value, int32_t volume) {
return clamp16_from_float(MixMul<float, float, int32_t>(value, volume));
}
template <>
inline float MixMul<float, int16_t, int16_t>(int16_t value, int16_t volume) {
static const float norm = 1. / (1 << (15 + 12));
return static_cast<float>(value) * static_cast<float>(volume) * norm;
}
template <>
inline float MixMul<float, int16_t, int32_t>(int16_t value, int32_t volume) {
static const float norm = 1. / (1ULL << (15 + 28));
return static_cast<float>(value) * static_cast<float>(volume) * norm;
}
template <>
inline int16_t MixMul<int16_t, int16_t, int16_t>(int16_t value, int16_t volume) {
return clamp16(MixMul<int32_t, int16_t, int16_t>(value, volume) >> 12);
}
template <>
inline int16_t MixMul<int16_t, int32_t, int16_t>(int32_t value, int16_t volume) {
return clamp16(MixMul<int32_t, int32_t, int16_t>(value, volume) >> 12);
}
template <>
inline int16_t MixMul<int16_t, int16_t, int32_t>(int16_t value, int32_t volume) {
return clamp16(MixMul<int32_t, int16_t, int32_t>(value, volume) >> 12);
}
template <>
inline int16_t MixMul<int16_t, int32_t, int32_t>(int32_t value, int32_t volume) {
return clamp16(MixMul<int32_t, int32_t, int32_t>(value, volume) >> 12);
}
/* Required for floating point volume. Some are needed for compilation but
* are not needed in execution and should be removed from the final build by
* an optimizing compiler.
*/
template <>
inline float MixMul<float, float, float>(float value, float volume) {
return value * volume;
}
template <>
inline float MixMul<float, int16_t, float>(int16_t value, float volume) {
static const float float_from_q_15 = 1. / (1 << 15);
return value * volume * float_from_q_15;
}
template <>
inline int32_t MixMul<int32_t, int32_t, float>(int32_t value, float volume) {
LOG_ALWAYS_FATAL("MixMul<int32_t, int32_t, float> Runtime Should not be here");
return value * volume;
}
template <>
inline int32_t MixMul<int32_t, int16_t, float>(int16_t value, float volume) {
LOG_ALWAYS_FATAL("MixMul<int32_t, int16_t, float> Runtime Should not be here");
static const float u4_12_from_float = (1 << 12);
return value * volume * u4_12_from_float;
}
template <>
inline int16_t MixMul<int16_t, int16_t, float>(int16_t value, float volume) {
LOG_ALWAYS_FATAL("MixMul<int16_t, int16_t, float> Runtime Should not be here");
return clamp16_from_float(MixMul<float, int16_t, float>(value, volume));
}
template <>
inline int16_t MixMul<int16_t, float, float>(float value, float volume) {
return clamp16_from_float(value * volume);
}
/*
* MixAccum is used to add into an accumulator register of a possibly different
* type. The TO and TI types are the same as MixMul.
*/
template <typename TO, typename TI>
inline void MixAccum(TO *auxaccum, TI value) {
if (!std::is_same_v<TO, TI>) {
LOG_ALWAYS_FATAL("MixAccum type not properly specialized: %zu %zu\n",
sizeof(TO), sizeof(TI));
}
*auxaccum += value;
}
template<>
inline void MixAccum<float, int16_t>(float *auxaccum, int16_t value) {
static constexpr float norm = 1. / (1 << 15);
*auxaccum += norm * value;
}
template<>
inline void MixAccum<float, int32_t>(float *auxaccum, int32_t value) {
static constexpr float norm = 1. / (1 << 27);
*auxaccum += norm * value;
}
template<>
inline void MixAccum<int32_t, int16_t>(int32_t *auxaccum, int16_t value) {
*auxaccum += value << 12;
}
template<>
inline void MixAccum<int32_t, float>(int32_t *auxaccum, float value) {
*auxaccum += clampq4_27_from_float(value);
}
/* MixMulAux is just like MixMul except it combines with
* an accumulator operation MixAccum.
*/
template <typename TO, typename TI, typename TV, typename TA>
inline TO MixMulAux(TI value, TV volume, TA *auxaccum) {
MixAccum<TA, TI>(auxaccum, value);
return MixMul<TO, TI, TV>(value, volume);
}
/* MIXTYPE is used to determine how the samples in the input frame
* are mixed with volume gain into the output frame.
* See the volumeRampMulti functions below for more details.
*/
enum {
MIXTYPE_MULTI,
MIXTYPE_MONOEXPAND,
MIXTYPE_MULTI_SAVEONLY,
MIXTYPE_MULTI_MONOVOL,
MIXTYPE_MULTI_SAVEONLY_MONOVOL,
MIXTYPE_MULTI_STEREOVOL,
MIXTYPE_MULTI_SAVEONLY_STEREOVOL,
MIXTYPE_STEREOEXPAND,
};
/*
* TODO: We should work on non-interleaved streams - the
* complexity of working on interleaved streams is now getting
* too high, and likely limits compiler optimization.
*/
// compile-time function.
constexpr inline bool usesCenterChannel(audio_channel_mask_t mask) {
using namespace audio_utils::channels;
for (size_t i = 0; i < std::size(kSideFromChannelIdx); ++i) {
if ((mask & (1 << i)) != 0 && kSideFromChannelIdx[i] == AUDIO_GEOMETRY_SIDE_CENTER) {
return true;
}
}
return false;
}
/*
* Applies stereo volume to the audio data based on proper left right channel affinity
* (templated channel MASK parameter).
*/
template <int MIXTYPE, audio_channel_mask_t MASK,
typename TO, typename TI, typename TV,
typename F>
void stereoVolumeHelperWithChannelMask(TO*& out, const TI*& in, const TV *vol, F f) {
auto proc = [](auto& a, const auto& b) {
if constexpr (MIXTYPE == MIXTYPE_MULTI_STEREOVOL
|| MIXTYPE == MIXTYPE_STEREOEXPAND
|| MIXTYPE == MIXTYPE_MONOEXPAND) {
a += b;
} else {
a = b;
}
};
auto inp = [&in]() -> const TI& {
if constexpr (MIXTYPE == MIXTYPE_STEREOEXPAND
|| MIXTYPE == MIXTYPE_MONOEXPAND) {
return *in; // note STEREOEXPAND assumes replicated L/R channels (see doc below).
} else {
return *in++;
}
};
std::decay_t<TV> center;
constexpr bool USES_CENTER_CHANNEL = usesCenterChannel(MASK);
if constexpr (USES_CENTER_CHANNEL) {
if constexpr (std::is_floating_point_v<TV>) {
center = (vol[0] + vol[1]) * 0.5; // do not use divide
} else {
center = (vol[0] >> 1) + (vol[1] >> 1); // rounds to 0.
}
}
using namespace audio_utils::channels;
// if LFE and LFE2 are both present, they take left and right volume respectively.
constexpr unsigned LFE_LFE2 = \
AUDIO_CHANNEL_OUT_LOW_FREQUENCY | AUDIO_CHANNEL_OUT_LOW_FREQUENCY_2;
constexpr bool has_LFE_LFE2 = (MASK & LFE_LFE2) == LFE_LFE2;
#pragma push_macro("DO_CHANNEL_POSITION")
#undef DO_CHANNEL_POSITION
#define DO_CHANNEL_POSITION(BIT_INDEX) \
if constexpr ((MASK & (1 << BIT_INDEX)) != 0) { \
constexpr auto side = kSideFromChannelIdx[BIT_INDEX]; \
if constexpr (side == AUDIO_GEOMETRY_SIDE_LEFT || \
has_LFE_LFE2 && (1 << BIT_INDEX) == AUDIO_CHANNEL_OUT_LOW_FREQUENCY) { \
proc(*out++, f(inp(), vol[0])); \
} else if constexpr (side == AUDIO_GEOMETRY_SIDE_RIGHT || \
has_LFE_LFE2 && (1 << BIT_INDEX) == AUDIO_CHANNEL_OUT_LOW_FREQUENCY_2) { \
proc(*out++, f(inp(), vol[1])); \
} else /* constexpr */ { \
proc(*out++, f(inp(), center)); \
} \
}
DO_CHANNEL_POSITION(0);
DO_CHANNEL_POSITION(1);
DO_CHANNEL_POSITION(2);
DO_CHANNEL_POSITION(3);
DO_CHANNEL_POSITION(4);
DO_CHANNEL_POSITION(5);
DO_CHANNEL_POSITION(6);
DO_CHANNEL_POSITION(7);
DO_CHANNEL_POSITION(8);
DO_CHANNEL_POSITION(9);
DO_CHANNEL_POSITION(10);
DO_CHANNEL_POSITION(11);
DO_CHANNEL_POSITION(12);
DO_CHANNEL_POSITION(13);
DO_CHANNEL_POSITION(14);
DO_CHANNEL_POSITION(15);
DO_CHANNEL_POSITION(16);
DO_CHANNEL_POSITION(17);
DO_CHANNEL_POSITION(18);
DO_CHANNEL_POSITION(19);
DO_CHANNEL_POSITION(20);
DO_CHANNEL_POSITION(21);
DO_CHANNEL_POSITION(22);
DO_CHANNEL_POSITION(23);
DO_CHANNEL_POSITION(24);
DO_CHANNEL_POSITION(25);
static_assert(FCC_LIMIT <= FCC_26); // Note: this may need to change.
#pragma pop_macro("DO_CHANNEL_POSITION")
}
// These are the channel position masks we expect from the HAL.
// See audio_channel_out_mask_from_count() but this is constexpr
constexpr inline audio_channel_mask_t canonicalChannelMaskFromCount(size_t channelCount) {
constexpr audio_channel_mask_t canonical[] = {
[0] = AUDIO_CHANNEL_NONE,
[1] = AUDIO_CHANNEL_OUT_MONO,
[2] = AUDIO_CHANNEL_OUT_STEREO,
[3] = AUDIO_CHANNEL_OUT_2POINT1,
[4] = AUDIO_CHANNEL_OUT_QUAD,
[5] = AUDIO_CHANNEL_OUT_PENTA,
[6] = AUDIO_CHANNEL_OUT_5POINT1,
[7] = AUDIO_CHANNEL_OUT_6POINT1,
[8] = AUDIO_CHANNEL_OUT_7POINT1,
[12] = AUDIO_CHANNEL_OUT_7POINT1POINT4,
[14] = AUDIO_CHANNEL_OUT_9POINT1POINT4,
[16] = AUDIO_CHANNEL_OUT_9POINT1POINT6,
[24] = AUDIO_CHANNEL_OUT_22POINT2,
};
return channelCount < std::size(canonical) ? canonical[channelCount] : AUDIO_CHANNEL_NONE;
}
template <int MIXTYPE, int NCHAN,
typename TO, typename TI, typename TV,
typename F>
void stereoVolumeHelper(TO*& out, const TI*& in, const TV *vol, F f) {
static_assert(NCHAN > 0 && NCHAN <= FCC_LIMIT);
static_assert(MIXTYPE == MIXTYPE_MULTI_STEREOVOL
|| MIXTYPE == MIXTYPE_MULTI_SAVEONLY_STEREOVOL
|| MIXTYPE == MIXTYPE_STEREOEXPAND
|| MIXTYPE == MIXTYPE_MONOEXPAND);
constexpr audio_channel_mask_t MASK{canonicalChannelMaskFromCount(NCHAN)};
if constexpr (MASK == AUDIO_CHANNEL_NONE) {
ALOGE("%s: Invalid position count %d", __func__, NCHAN);
return; // not a valid system mask, ignore.
}
stereoVolumeHelperWithChannelMask<MIXTYPE, MASK, TO, TI, TV, F>(out, in, vol, f);
}
/*
* The volumeRampMulti and volumeRamp functions take a MIXTYPE
* which indicates the per-frame mixing and accumulation strategy.
*
* MIXTYPE_MULTI:
* NCHAN represents number of input and output channels.
* TO: int32_t (Q4.27) or float
* TI: int32_t (Q4.27) or int16_t (Q0.15) or float
* TA: int32_t (Q4.27) or float
* TV: int32_t (U4.28) or int16_t (U4.12) or float
* vol: represents a volume array.
*
* This accumulates into the out pointer.
*
* MIXTYPE_MONOEXPAND:
* Single input channel. NCHAN represents number of output channels.
* TO: int32_t (Q4.27) or float
* TI: int32_t (Q4.27) or int16_t (Q0.15) or float
* TA: int32_t (Q4.27) or float
* TV/TAV: int32_t (U4.28) or int16_t (U4.12) or float
* Input channel count is 1.
* vol: represents volume array.
* This uses stereo balanced volume vol[0] and vol[1].
* Before R, this was a full volume array but was called only for channels <= 2.
*
* This accumulates into the out pointer.
*
* MIXTYPE_MULTI_SAVEONLY:
* NCHAN represents number of input and output channels.
* TO: int16_t (Q.15) or float
* TI: int32_t (Q4.27) or int16_t (Q0.15) or float
* TA: int32_t (Q4.27) or float
* TV/TAV: int32_t (U4.28) or int16_t (U4.12) or float
* vol: represents a volume array.
*
* MIXTYPE_MULTI_SAVEONLY does not accumulate into the out pointer.
*
* MIXTYPE_MULTI_MONOVOL:
* Same as MIXTYPE_MULTI, but uses only volume[0].
*
* MIXTYPE_MULTI_SAVEONLY_MONOVOL:
* Same as MIXTYPE_MULTI_SAVEONLY, but uses only volume[0].
*
* MIXTYPE_MULTI_STEREOVOL:
* Same as MIXTYPE_MULTI, but uses only volume[0] and volume[1].
*
* MIXTYPE_MULTI_SAVEONLY_STEREOVOL:
* Same as MIXTYPE_MULTI_SAVEONLY, but uses only volume[0] and volume[1].
*
* MIXTYPE_STEREOEXPAND:
* Stereo input channel. NCHAN represents number of output channels.
* Expand size 2 array "in" and "vol" to multi-channel output. Note
* that the 2 array is assumed to have replicated L+R.
*
*/
template <int MIXTYPE, int NCHAN,
typename TO, typename TI, typename TV, typename TA, typename TAV>
inline void volumeRampMulti(TO* out, size_t frameCount,
const TI* in, TA* aux, TV *vol, const TV *volinc, TAV *vola, TAV volainc)
{
#ifdef ALOGVV
ALOGVV("volumeRampMulti, MIXTYPE:%d\n", MIXTYPE);
#endif
if (aux != NULL) {
do {
TA auxaccum = 0;
if constexpr (MIXTYPE == MIXTYPE_MULTI) {
static_assert(NCHAN <= 2);
for (int i = 0; i < NCHAN; ++i) {
*out++ += MixMulAux<TO, TI, TV, TA>(*in++, vol[i], &auxaccum);
vol[i] += volinc[i];
}
} else if constexpr (MIXTYPE == MIXTYPE_MULTI_SAVEONLY) {
static_assert(NCHAN <= 2);
for (int i = 0; i < NCHAN; ++i) {
*out++ = MixMulAux<TO, TI, TV, TA>(*in++, vol[i], &auxaccum);
vol[i] += volinc[i];
}
} else if constexpr (MIXTYPE == MIXTYPE_MULTI_MONOVOL) {
for (int i = 0; i < NCHAN; ++i) {
*out++ += MixMulAux<TO, TI, TV, TA>(*in++, vol[0], &auxaccum);
}
vol[0] += volinc[0];
} else if constexpr (MIXTYPE == MIXTYPE_MULTI_SAVEONLY_MONOVOL) {
for (int i = 0; i < NCHAN; ++i) {
*out++ = MixMulAux<TO, TI, TV, TA>(*in++, vol[0], &auxaccum);
}
vol[0] += volinc[0];
} else if constexpr (MIXTYPE == MIXTYPE_MULTI_STEREOVOL
|| MIXTYPE == MIXTYPE_MULTI_SAVEONLY_STEREOVOL
|| MIXTYPE == MIXTYPE_MONOEXPAND
|| MIXTYPE == MIXTYPE_STEREOEXPAND) {
stereoVolumeHelper<MIXTYPE, NCHAN>(
out, in, vol, [&auxaccum] (auto &a, const auto &b) {
return MixMulAux<TO, TI, TV, TA>(a, b, &auxaccum);
});
if constexpr (MIXTYPE == MIXTYPE_MONOEXPAND) in += 1;
if constexpr (MIXTYPE == MIXTYPE_STEREOEXPAND) in += 2;
vol[0] += volinc[0];
vol[1] += volinc[1];
} else /* constexpr */ {
static_assert(dependent_false<MIXTYPE>, "invalid mixtype");
}
auxaccum /= NCHAN;
*aux++ += MixMul<TA, TA, TAV>(auxaccum, *vola);
vola[0] += volainc;
} while (--frameCount);
} else {
do {
if constexpr (MIXTYPE == MIXTYPE_MULTI) {
static_assert(NCHAN <= 2);
for (int i = 0; i < NCHAN; ++i) {
*out++ += MixMul<TO, TI, TV>(*in++, vol[i]);
vol[i] += volinc[i];
}
} else if constexpr (MIXTYPE == MIXTYPE_MULTI_SAVEONLY) {
static_assert(NCHAN <= 2);
for (int i = 0; i < NCHAN; ++i) {
*out++ = MixMul<TO, TI, TV>(*in++, vol[i]);
vol[i] += volinc[i];
}
} else if constexpr (MIXTYPE == MIXTYPE_MULTI_MONOVOL) {
for (int i = 0; i < NCHAN; ++i) {
*out++ += MixMul<TO, TI, TV>(*in++, vol[0]);
}
vol[0] += volinc[0];
} else if constexpr (MIXTYPE == MIXTYPE_MULTI_SAVEONLY_MONOVOL) {
for (int i = 0; i < NCHAN; ++i) {
*out++ = MixMul<TO, TI, TV>(*in++, vol[0]);
}
vol[0] += volinc[0];
} else if constexpr (MIXTYPE == MIXTYPE_MULTI_STEREOVOL
|| MIXTYPE == MIXTYPE_MULTI_SAVEONLY_STEREOVOL
|| MIXTYPE == MIXTYPE_MONOEXPAND
|| MIXTYPE == MIXTYPE_STEREOEXPAND) {
stereoVolumeHelper<MIXTYPE, NCHAN>(out, in, vol, [] (auto &a, const auto &b) {
return MixMul<TO, TI, TV>(a, b);
});
if constexpr (MIXTYPE == MIXTYPE_MONOEXPAND) in += 1;
if constexpr (MIXTYPE == MIXTYPE_STEREOEXPAND) in += 2;
vol[0] += volinc[0];
vol[1] += volinc[1];
} else /* constexpr */ {
static_assert(dependent_false<MIXTYPE>, "invalid mixtype");
}
} while (--frameCount);
}
}
template <int MIXTYPE, int NCHAN,
typename TO, typename TI, typename TV, typename TA, typename TAV>
inline void volumeMulti(TO* out, size_t frameCount,
const TI* in, TA* aux, const TV *vol, TAV vola)
{
#ifdef ALOGVV
ALOGVV("volumeMulti MIXTYPE:%d\n", MIXTYPE);
#endif
if (aux != NULL) {
do {
TA auxaccum = 0;
if constexpr (MIXTYPE == MIXTYPE_MULTI) {
static_assert(NCHAN <= 2);
for (int i = 0; i < NCHAN; ++i) {
*out++ += MixMulAux<TO, TI, TV, TA>(*in++, vol[i], &auxaccum);
}
} else if constexpr (MIXTYPE == MIXTYPE_MULTI_SAVEONLY) {
static_assert(NCHAN <= 2);
for (int i = 0; i < NCHAN; ++i) {
*out++ = MixMulAux<TO, TI, TV, TA>(*in++, vol[i], &auxaccum);
}
} else if constexpr (MIXTYPE == MIXTYPE_MULTI_MONOVOL) {
for (int i = 0; i < NCHAN; ++i) {
*out++ += MixMulAux<TO, TI, TV, TA>(*in++, vol[0], &auxaccum);
}
} else if constexpr (MIXTYPE == MIXTYPE_MULTI_SAVEONLY_MONOVOL) {
for (int i = 0; i < NCHAN; ++i) {
*out++ = MixMulAux<TO, TI, TV, TA>(*in++, vol[0], &auxaccum);
}
} else if constexpr (MIXTYPE == MIXTYPE_MULTI_STEREOVOL
|| MIXTYPE == MIXTYPE_MULTI_SAVEONLY_STEREOVOL
|| MIXTYPE == MIXTYPE_MONOEXPAND
|| MIXTYPE == MIXTYPE_STEREOEXPAND) {
stereoVolumeHelper<MIXTYPE, NCHAN>(
out, in, vol, [&auxaccum] (auto &a, const auto &b) {
return MixMulAux<TO, TI, TV, TA>(a, b, &auxaccum);
});
if constexpr (MIXTYPE == MIXTYPE_MONOEXPAND) in += 1;
if constexpr (MIXTYPE == MIXTYPE_STEREOEXPAND) in += 2;
} else /* constexpr */ {
static_assert(dependent_false<MIXTYPE>, "invalid mixtype");
}
auxaccum /= NCHAN;
*aux++ += MixMul<TA, TA, TAV>(auxaccum, vola);
} while (--frameCount);
} else {
do {
// ALOGD("Mixtype:%d NCHAN:%d", MIXTYPE, NCHAN);
if constexpr (MIXTYPE == MIXTYPE_MULTI) {
static_assert(NCHAN <= 2);
for (int i = 0; i < NCHAN; ++i) {
*out++ += MixMul<TO, TI, TV>(*in++, vol[i]);
}
} else if constexpr (MIXTYPE == MIXTYPE_MULTI_SAVEONLY) {
static_assert(NCHAN <= 2);
for (int i = 0; i < NCHAN; ++i) {
*out++ = MixMul<TO, TI, TV>(*in++, vol[i]);
}
} else if constexpr (MIXTYPE == MIXTYPE_MULTI_MONOVOL) {
for (int i = 0; i < NCHAN; ++i) {
*out++ += MixMul<TO, TI, TV>(*in++, vol[0]);
}
} else if constexpr (MIXTYPE == MIXTYPE_MULTI_SAVEONLY_MONOVOL) {
for (int i = 0; i < NCHAN; ++i) {
*out++ = MixMul<TO, TI, TV>(*in++, vol[0]);
}
} else if constexpr (MIXTYPE == MIXTYPE_MULTI_STEREOVOL
|| MIXTYPE == MIXTYPE_MULTI_SAVEONLY_STEREOVOL
|| MIXTYPE == MIXTYPE_MONOEXPAND
|| MIXTYPE == MIXTYPE_STEREOEXPAND) {
stereoVolumeHelper<MIXTYPE, NCHAN>(out, in, vol, [] (auto &a, const auto &b) {
return MixMul<TO, TI, TV>(a, b);
});
if constexpr (MIXTYPE == MIXTYPE_MONOEXPAND) in += 1;
if constexpr (MIXTYPE == MIXTYPE_STEREOEXPAND) in += 2;
} else /* constexpr */ {
static_assert(dependent_false<MIXTYPE>, "invalid mixtype");
}
} while (--frameCount);
}
}
};
#endif /* ANDROID_AUDIO_MIXER_OPS_H */