AudioMixer: Multichannel handling of stereo volume
Assign left/right volume to 22.2 channels.
Test: mixerops_benchmark
Test: mixerops_tests
Bug: 193275879
Change-Id: Iea4dd08b34b2e1e5c17d7563702e1510d2f961e4
diff --git a/media/libaudioprocessing/tests/mixerops_tests.cpp b/media/libaudioprocessing/tests/mixerops_tests.cpp
new file mode 100644
index 0000000..2500ba9
--- /dev/null
+++ b/media/libaudioprocessing/tests/mixerops_tests.cpp
@@ -0,0 +1,175 @@
+/*
+ * Copyright (C) 2021 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.
+ */
+
+//#define LOG_NDEBUG 0
+#define LOG_TAG "mixerop_tests"
+#include <log/log.h>
+
+#include <inttypes.h>
+#include <type_traits>
+
+#include <../AudioMixerOps.h>
+#include <gtest/gtest.h>
+
+using namespace android;
+
+// Note: gtest templated tests require typenames, not integers.
+template <int MIXTYPE, int NCHAN>
+class MixerOpsBasicTest {
+public:
+ static void testStereoVolume() {
+ using namespace android::audio_utils::channels;
+
+ constexpr size_t FRAME_COUNT = 1000;
+ constexpr size_t SAMPLE_COUNT = FRAME_COUNT * NCHAN;
+
+ const float in[SAMPLE_COUNT] = {[0 ... (SAMPLE_COUNT - 1)] = 1.f};
+
+ AUDIO_GEOMETRY_SIDE sides[NCHAN];
+ size_t i = 0;
+ unsigned channel = canonicalChannelMaskFromCount(NCHAN);
+ constexpr unsigned LFE_LFE2 =
+ AUDIO_CHANNEL_OUT_LOW_FREQUENCY | AUDIO_CHANNEL_OUT_LOW_FREQUENCY_2;
+ bool has_LFE_LFE2 = (channel & LFE_LFE2) == LFE_LFE2;
+ while (channel != 0) {
+ const int index = __builtin_ctz(channel);
+ if (has_LFE_LFE2 && (1 << index) == AUDIO_CHANNEL_OUT_LOW_FREQUENCY) {
+ sides[i++] = AUDIO_GEOMETRY_SIDE_LEFT; // special case
+ } else if (has_LFE_LFE2 && (1 << index) == AUDIO_CHANNEL_OUT_LOW_FREQUENCY_2) {
+ sides[i++] = AUDIO_GEOMETRY_SIDE_RIGHT; // special case
+ } else {
+ sides[i++] = sideFromChannelIdx(index);
+ }
+ channel &= ~(1 << index);
+ }
+
+ float vola[2] = {1.f, 0.f}; // left volume at max.
+ float out[SAMPLE_COUNT]{};
+ float aux[FRAME_COUNT]{};
+ float volaux = 0.5;
+ {
+ volumeMulti<MIXTYPE, NCHAN>(out, FRAME_COUNT, in, aux, vola, volaux);
+ const float *outp = out;
+ const float *auxp = aux;
+ const float left = vola[0];
+ const float center = (vola[0] + vola[1]) * 0.5;
+ const float right = vola[1];
+ for (size_t i = 0; i < FRAME_COUNT; ++i) {
+ for (size_t j = 0; j < NCHAN; ++j) {
+ const float audio = *outp++;
+ if (sides[j] == AUDIO_GEOMETRY_SIDE_LEFT) {
+ EXPECT_EQ(left, audio);
+ } else if (sides[j] == AUDIO_GEOMETRY_SIDE_CENTER) {
+ EXPECT_EQ(center, audio);
+ } else {
+ EXPECT_EQ(right, audio);
+ }
+ }
+ EXPECT_EQ(volaux, *auxp++); // works if all channels contain 1.f
+ }
+ }
+ float volb[2] = {0.f, 0.5f}; // right volume at half max.
+ {
+ // this accumulates into out, aux.
+ // float out[SAMPLE_COUNT]{};
+ // float aux[FRAME_COUNT]{};
+ volumeMulti<MIXTYPE, NCHAN>(out, FRAME_COUNT, in, aux, volb, volaux);
+ const float *outp = out;
+ const float *auxp = aux;
+ const float left = vola[0] + volb[0];
+ const float center = (vola[0] + vola[1] + volb[0] + volb[1]) * 0.5;
+ const float right = vola[1] + volb[1];
+ for (size_t i = 0; i < FRAME_COUNT; ++i) {
+ for (size_t j = 0; j < NCHAN; ++j) {
+ const float audio = *outp++;
+ if (sides[j] == AUDIO_GEOMETRY_SIDE_LEFT) {
+ EXPECT_EQ(left, audio);
+ } else if (sides[j] == AUDIO_GEOMETRY_SIDE_CENTER) {
+ EXPECT_EQ(center, audio);
+ } else {
+ EXPECT_EQ(right, audio);
+ }
+ }
+ // aux is accumulated so 2x the amplitude
+ EXPECT_EQ(volaux * 2.f, *auxp++); // works if all channels contain 1.f
+ }
+ }
+
+ { // test aux as derived from out.
+ // AUX channel is the weighted sum of all of the output channels prior to volume
+ // adjustment. We must set L and R to the same volume to allow computation
+ // of AUX from the output values.
+ const float volmono = 0.25f;
+ const float vollr[2] = {volmono, volmono}; // all the same.
+ float out[SAMPLE_COUNT]{};
+ float aux[FRAME_COUNT]{};
+ volumeMulti<MIXTYPE, NCHAN>(out, FRAME_COUNT, in, aux, vollr, volaux);
+ const float *outp = out;
+ const float *auxp = aux;
+ for (size_t i = 0; i < FRAME_COUNT; ++i) {
+ float accum = 0.f;
+ for (size_t j = 0; j < NCHAN; ++j) {
+ accum += *outp++;
+ }
+ EXPECT_EQ(accum / NCHAN * volaux / volmono, *auxp++);
+ }
+ }
+ }
+};
+
+TEST(mixerops, stereovolume_1) { // Note: mono not used for output sinks yet.
+ MixerOpsBasicTest<MIXTYPE_MULTI_STEREOVOL, 1>::testStereoVolume();
+}
+TEST(mixerops, stereovolume_2) {
+ MixerOpsBasicTest<MIXTYPE_MULTI_STEREOVOL, 2>::testStereoVolume();
+}
+TEST(mixerops, stereovolume_3) {
+ MixerOpsBasicTest<MIXTYPE_MULTI_STEREOVOL, 3>::testStereoVolume();
+}
+TEST(mixerops, stereovolume_4) {
+ MixerOpsBasicTest<MIXTYPE_MULTI_STEREOVOL, 4>::testStereoVolume();
+}
+TEST(mixerops, stereovolume_5) {
+ MixerOpsBasicTest<MIXTYPE_MULTI_STEREOVOL, 5>::testStereoVolume();
+}
+TEST(mixerops, stereovolume_6) {
+ MixerOpsBasicTest<MIXTYPE_MULTI_STEREOVOL, 6>::testStereoVolume();
+}
+TEST(mixerops, stereovolume_7) {
+ MixerOpsBasicTest<MIXTYPE_MULTI_STEREOVOL, 7>::testStereoVolume();
+}
+TEST(mixerops, stereovolume_8) {
+ MixerOpsBasicTest<MIXTYPE_MULTI_STEREOVOL, 8>::testStereoVolume();
+}
+TEST(mixerops, stereovolume_12) {
+ if constexpr (FCC_LIMIT >= 12) { // NOTE: FCC_LIMIT is an enum, so can't #if
+ MixerOpsBasicTest<MIXTYPE_MULTI_STEREOVOL, 12>::testStereoVolume();
+ }
+}
+TEST(mixerops, stereovolume_24) {
+ if constexpr (FCC_LIMIT >= 24) {
+ MixerOpsBasicTest<MIXTYPE_MULTI_STEREOVOL, 24>::testStereoVolume();
+ }
+}
+TEST(mixerops, channel_equivalence) {
+ // we must match the constexpr function with the system determined channel mask from count.
+ for (size_t i = 0; i < FCC_LIMIT; ++i) {
+ const audio_channel_mask_t actual = canonicalChannelMaskFromCount(i);
+ const audio_channel_mask_t system = audio_channel_out_mask_from_count(i);
+ if (system == AUDIO_CHANNEL_INVALID) continue;
+ EXPECT_EQ(system, actual);
+ }
+}