liboboe: oboe MMAP client interface
Bug: 33347409
Test: test_oboe_api
Change-Id: I2ff3e9b57c91839c6debe91903b3e4b92e82d681
Signed-off-by: Phil Burk <philburk@google.com>
diff --git a/media/liboboe/src/client/IsochronousClockModel.h b/media/liboboe/src/client/IsochronousClockModel.h
new file mode 100644
index 0000000..97be325
--- /dev/null
+++ b/media/liboboe/src/client/IsochronousClockModel.h
@@ -0,0 +1,111 @@
+/*
+ * Copyright (C) 2016 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 OBOE_ISOCHRONOUSCLOCKMODEL_H
+#define OBOE_ISOCHRONOUSCLOCKMODEL_H
+
+#include <stdint.h>
+#include <oboe/OboeAudio.h>
+
+namespace oboe {
+
+/**
+ * Model an isochronous data stream using occasional timestamps as input.
+ * This can be used to predict the position of the stream at a given time.
+ *
+ * This class is not thread safe and should only be called from one thread.
+ */
+class IsochronousClockModel {
+
+public:
+ IsochronousClockModel();
+ virtual ~IsochronousClockModel();
+
+ void start(oboe_nanoseconds_t nanoTime);
+ void stop(oboe_nanoseconds_t nanoTime);
+
+ void processTimestamp(oboe_position_frames_t framePosition, oboe_nanoseconds_t nanoTime);
+
+ /**
+ * @param sampleRate rate of the stream in frames per second
+ */
+ void setSampleRate(oboe_sample_rate_t sampleRate);
+
+ oboe_sample_rate_t getSampleRate() const {
+ return mSampleRate;
+ }
+
+ /**
+ * This must be set accurately in order to track the isochronous stream.
+ *
+ * @param framesPerBurst number of frames that stream advance at one time.
+ */
+ void setFramesPerBurst(oboe_size_frames_t framesPerBurst);
+
+ oboe_size_frames_t getFramesPerBurst() const {
+ return mFramesPerBurst;
+ }
+
+ /**
+ * Calculate an estimated time when the stream will be at that position.
+ *
+ * @param framePosition position of the stream in frames
+ * @return time in nanoseconds
+ */
+ oboe_nanoseconds_t convertPositionToTime(oboe_position_frames_t framePosition) const;
+
+ /**
+ * Calculate an estimated position where the stream will be at the specified time.
+ *
+ * @param nanoTime time of interest
+ * @return position in frames
+ */
+ oboe_position_frames_t convertTimeToPosition(oboe_nanoseconds_t nanoTime) const;
+
+ /**
+ * @param framesDelta difference in frames
+ * @return duration in nanoseconds
+ */
+ oboe_nanoseconds_t convertDeltaPositionToTime(oboe_position_frames_t framesDelta) const;
+
+ /**
+ * @param nanosDelta duration in nanoseconds
+ * @return frames that stream will advance in that time
+ */
+ oboe_position_frames_t convertDeltaTimeToPosition(oboe_nanoseconds_t nanosDelta) const;
+
+private:
+ enum clock_model_state_t {
+ STATE_STOPPED,
+ STATE_STARTING,
+ STATE_SYNCING,
+ STATE_RUNNING
+ };
+
+ oboe_sample_rate_t mSampleRate;
+ oboe_size_frames_t mFramesPerBurst;
+ int32_t mMaxLatenessInNanos;
+ oboe_position_frames_t mMarkerFramePosition;
+ oboe_nanoseconds_t mMarkerNanoTime;
+ int32_t mTimestampCount;
+ clock_model_state_t mState;
+
+ void update();
+};
+
+} /* namespace oboe */
+
+#endif //OBOE_ISOCHRONOUSCLOCKMODEL_H