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/ClipToRange.h b/media/libaaudio/src/flowgraph/ClipToRange.h
new file mode 100644
index 0000000..9eef254
--- /dev/null
+++ b/media/libaaudio/src/flowgraph/ClipToRange.h
@@ -0,0 +1,67 @@
+/*
+ * Copyright 2015 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 FLOWGRAPH_CLIP_TO_RANGE_H
+#define FLOWGRAPH_CLIP_TO_RANGE_H
+
+#include <atomic>
+#include <unistd.h>
+#include <sys/types.h>
+
+#include "AudioProcessorBase.h"
+
+namespace flowgraph {
+
+// This is 3 dB, (10^(3/20)), to match the maximum headroom in AudioTrack for float data.
+// It is designed to allow occasional transient peaks.
+constexpr float kDefaultMaxHeadroom = 1.41253754f;
+constexpr float kDefaultMinHeadroom = -kDefaultMaxHeadroom;
+
+class ClipToRange : public AudioProcessorBase {
+public:
+ explicit ClipToRange(int32_t channelCount);
+
+ virtual ~ClipToRange() = default;
+
+ int32_t onProcess(int64_t framePosition, int32_t numFrames) override;
+
+ void setMinimum(float min) {
+ mMinimum = min;
+ }
+
+ float getMinimum() const {
+ return mMinimum;
+ }
+
+ void setMaximum(float min) {
+ mMaximum = min;
+ }
+
+ float getMaximum() const {
+ return mMaximum;
+ }
+
+ AudioFloatInputPort input;
+ AudioFloatOutputPort output;
+
+private:
+ float mMinimum = kDefaultMinHeadroom;
+ float mMaximum = kDefaultMaxHeadroom;
+};
+
+} /* namespace flowgraph */
+
+#endif //FLOWGRAPH_CLIP_TO_RANGE_H