aaudio: apply volume in the MMAP data path
The volume scaling is in AudioStreamInternal and not the mixer
because we will need volume scaling in EXCLUSIVE mode too.
Bug: 37518243
Test: play a tone using NativeOboe app then press volume keys
Change-Id: Ibbac9770ea4493f8ade64681be86f109a92803cd
Signed-off-by: Phil Burk <philburk@google.com>
diff --git a/media/libaaudio/src/utility/LinearRamp.cpp b/media/libaaudio/src/utility/LinearRamp.cpp
new file mode 100644
index 0000000..1714bbf
--- /dev/null
+++ b/media/libaaudio/src/utility/LinearRamp.cpp
@@ -0,0 +1,50 @@
+/*
+ * Copyright 2017 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 "LinearRamp.h"
+
+bool LinearRamp::isRamping() {
+ float target = mTarget.load();
+ if (target != mLevelTo) {
+ // Update target. Continue from previous level.
+ mLevelTo = target;
+ mRemaining = mLengthInFrames;
+ return true;
+ } else {
+ return mRemaining > 0;
+ }
+}
+
+bool LinearRamp::nextSegment(int32_t frames, float *levelFrom, float *levelTo) {
+ bool ramping = isRamping();
+ *levelFrom = mLevelFrom;
+ if (ramping) {
+ float level;
+ if (frames >= mRemaining) {
+ level = mLevelTo;
+ mRemaining = 0;
+ } else {
+ // Interpolate to a point along the full ramp.
+ level = mLevelFrom + (frames * (mLevelTo - mLevelFrom) / mRemaining);
+ mRemaining -= frames;
+ }
+ mLevelFrom = level; // for next ramp
+ *levelTo = level;
+ } else {
+ *levelTo = mLevelTo;
+ }
+ return ramping;
+}
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