aaudio: add simple flowgraph system
Implement a simple data flow model that can be used to
chain various processing modules including:
data format conversion
volume ramping
channel conversion
Bug: 65067568
Test: test_flowgraph.cpp
Change-Id: I81a5655406cfa8c1c7d7cef4d933879f823939a5
diff --git a/media/libaaudio/src/flowgraph/SourceI24.cpp b/media/libaaudio/src/flowgraph/SourceI24.cpp
new file mode 100644
index 0000000..f319880
--- /dev/null
+++ b/media/libaaudio/src/flowgraph/SourceI24.cpp
@@ -0,0 +1,65 @@
+/*
+ * Copyright 2018 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.
+ */
+
+#include <algorithm>
+#include <unistd.h>
+
+#ifdef __ANDROID__
+#include <audio_utils/primitives.h>
+#endif
+
+#include "AudioProcessorBase.h"
+#include "SourceI24.h"
+
+using namespace flowgraph;
+
+constexpr int kBytesPerI24Packed = 3;
+
+SourceI24::SourceI24(int32_t channelCount)
+ : AudioSource(channelCount) {
+}
+
+int32_t SourceI24::onProcess(int64_t framePosition, int32_t numFrames) {
+ float *floatData = output.getBlock();
+ int32_t channelCount = output.getSamplesPerFrame();
+
+ int32_t framesLeft = mSizeInFrames - mFrameIndex;
+ int32_t framesToProcess = std::min(numFrames, framesLeft);
+ int32_t numSamples = framesToProcess * channelCount;
+
+ const uint8_t *byteBase = (uint8_t *) mData;
+ const uint8_t *byteData = &byteBase[mFrameIndex * channelCount * kBytesPerI24Packed];
+
+#ifdef __ANDROID__
+ memcpy_to_float_from_p24(floatData, byteData, numSamples);
+#else
+ static const float scale = 1. / (float)(1UL << 31);
+ for (int i = 0; i < numSamples; i++) {
+ // Assemble the data assuming Little Endian format.
+ int32_t pad = byteData[2];
+ pad <<= 8;
+ pad |= byteData[1];
+ pad <<= 8;
+ pad |= byteData[0];
+ pad <<= 8; // Shift to 32 bit data so the sign is correct.
+ byteData += kBytesPerI24Packed;
+ *floatData++ = pad * scale; // scale to range -1.0 to 1.0
+ }
+#endif
+
+ mFrameIndex += framesToProcess;
+ return framesToProcess;
+}
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