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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
namespace android {
/* Behavior of is_same<>::value is true if the types are identical,
* false otherwise. Identical to the STL std::is_same.
*/
template<typename T, typename U>
struct is_same
{
static const bool value = false;
};
template<typename T>
struct is_same<T, T> // partial specialization
{
static const bool value = true;
};
/* 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.
*/
template <typename TO, typename TI, typename TV>
inline TO MixMul(TI value, TV volume) {
COMPILE_TIME_ASSERT_FUNCTION_SCOPE(false);
// should not be here :-).
// To avoid mistakes, this template is always specialized.
return value * 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 value * volume;
}
template <>
inline int16_t MixMul<int16_t, float, float>(float value, float volume) {
static const float q_15_from_float = (1 << 15);
return value * volume * q_15_from_float;
}
/*
* 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 (!is_same<TO, TI>::value) {
LOG_ALWAYS_FATAL("MixAccum type not properly specialized: %d %d\n",
sizeof(TO), sizeof(TI));
}
*auxaccum += value;
}
template<>
inline void MixAccum<float, int16_t>(float *auxaccum, int16_t value) {
static const float norm = 1. / (1 << 15);
*auxaccum += norm * value;
}
template<>
inline void MixAccum<float, int32_t>(float *auxaccum, int32_t value) {
static const 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,
};
/*
* 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
* 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
* TV: int32_t (U4.28) or int16_t (U4.12) or float
* Input channel count is 1.
* vol: represents volume array.
*
* 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
* TV: 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.
*/
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;
switch (MIXTYPE) {
case MIXTYPE_MULTI:
for (int i = 0; i < NCHAN; ++i) {
*out++ += MixMulAux<TO, TI, TV, TA>(*in++, vol[i], &auxaccum);
vol[i] += volinc[i];
}
break;
case MIXTYPE_MULTI_SAVEONLY:
for (int i = 0; i < NCHAN; ++i) {
*out++ = MixMulAux<TO, TI, TV, TA>(*in++, vol[i], &auxaccum);
vol[i] += volinc[i];
}
break;
case MIXTYPE_MONOEXPAND:
for (int i = 0; i < NCHAN; ++i) {
*out++ += MixMulAux<TO, TI, TV, TA>(*in, vol[i], &auxaccum);
vol[i] += volinc[i];
}
in++;
break;
default:
LOG_ALWAYS_FATAL("invalid mixtype %d", MIXTYPE);
break;
}
auxaccum /= NCHAN;
*aux++ += MixMul<TA, TA, TAV>(auxaccum, *vola);
vola[0] += volainc;
} while (--frameCount);
} else {
do {
switch (MIXTYPE) {
case MIXTYPE_MULTI:
for (int i = 0; i < NCHAN; ++i) {
*out++ += MixMul<TO, TI, TV>(*in++, vol[i]);
vol[i] += volinc[i];
}
break;
case MIXTYPE_MULTI_SAVEONLY:
for (int i = 0; i < NCHAN; ++i) {
*out++ = MixMul<TO, TI, TV>(*in++, vol[i]);
vol[i] += volinc[i];
}
break;
case MIXTYPE_MONOEXPAND:
for (int i = 0; i < NCHAN; ++i) {
*out++ += MixMul<TO, TI, TV>(*in, vol[i]);
vol[i] += volinc[i];
}
in++;
break;
default:
LOG_ALWAYS_FATAL("invalid mixtype %d", MIXTYPE);
break;
}
} 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;
switch (MIXTYPE) {
case MIXTYPE_MULTI:
for (int i = 0; i < NCHAN; ++i) {
*out++ += MixMulAux<TO, TI, TV, TA>(*in++, vol[i], &auxaccum);
}
break;
case MIXTYPE_MULTI_SAVEONLY:
for (int i = 0; i < NCHAN; ++i) {
*out++ = MixMulAux<TO, TI, TV, TA>(*in++, vol[i], &auxaccum);
}
break;
case MIXTYPE_MONOEXPAND:
for (int i = 0; i < NCHAN; ++i) {
*out++ += MixMulAux<TO, TI, TV, TA>(*in, vol[i], &auxaccum);
}
in++;
break;
default:
LOG_ALWAYS_FATAL("invalid mixtype %d", MIXTYPE);
break;
}
auxaccum /= NCHAN;
*aux++ += MixMul<TA, TA, TAV>(auxaccum, vola);
} while (--frameCount);
} else {
do {
switch (MIXTYPE) {
case MIXTYPE_MULTI:
for (int i = 0; i < NCHAN; ++i) {
*out++ += MixMul<TO, TI, TV>(*in++, vol[i]);
}
break;
case MIXTYPE_MULTI_SAVEONLY:
for (int i = 0; i < NCHAN; ++i) {
*out++ = MixMul<TO, TI, TV>(*in++, vol[i]);
}
break;
case MIXTYPE_MONOEXPAND:
for (int i = 0; i < NCHAN; ++i) {
*out++ += MixMul<TO, TI, TV>(*in, vol[i]);
}
in++;
break;
default:
LOG_ALWAYS_FATAL("invalid mixtype %d", MIXTYPE);
break;
}
} while (--frameCount);
}
}
};
#endif /* ANDROID_AUDIO_MIXER_OPS_H */
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