libaaudio: implement callback
Use AudioTrack and AudioRecord TRANSFER_CALLBACK.
Add FixedBlockAdapter to provide fixed size callbacks.
Bug: 36489240
Test: CTS test_aaudio.cpp
Change-Id: Id2034dd640f878dd27fee6b43ad80a01c627dfd6
Signed-off-by: Phil Burk <philburk@google.com>
diff --git a/media/libaaudio/src/utility/FixedBlockAdapter.h b/media/libaaudio/src/utility/FixedBlockAdapter.h
new file mode 100644
index 0000000..7008b25
--- /dev/null
+++ b/media/libaaudio/src/utility/FixedBlockAdapter.h
@@ -0,0 +1,71 @@
+/*
+ * Copyright (C) 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.
+ */
+
+#ifndef AAUDIO_FIXED_BLOCK_ADAPTER_H
+#define AAUDIO_FIXED_BLOCK_ADAPTER_H
+
+#include <stdio.h>
+
+/**
+ * Interface for a class that needs fixed-size blocks.
+ */
+class FixedBlockProcessor {
+public:
+ virtual ~FixedBlockProcessor() = default;
+ virtual int32_t onProcessFixedBlock(uint8_t *buffer, int32_t numBytes) = 0;
+};
+
+/**
+ * Base class for a variable-to-fixed-size block adapter.
+ */
+class FixedBlockAdapter
+{
+public:
+ FixedBlockAdapter(FixedBlockProcessor &fixedBlockProcessor)
+ : mFixedBlockProcessor(fixedBlockProcessor) {}
+
+ virtual ~FixedBlockAdapter();
+
+ /**
+ * Allocate internal resources needed for buffering data.
+ */
+ virtual int32_t open(int32_t bytesPerFixedBlock);
+
+ /**
+ * Note that if the fixed-sized blocks must be aligned, then the variable-sized blocks
+ * must have the same alignment.
+ * For example, if the fixed-size blocks must be a multiple of 8, then the variable-sized
+ * blocks must also be a multiple of 8.
+ *
+ * @param buffer
+ * @param numBytes
+ * @return zero if OK or a non-zero code
+ */
+ virtual int32_t processVariableBlock(uint8_t *buffer, int32_t numBytes) = 0;
+
+ /**
+ * Free internal resources.
+ */
+ int32_t close();
+
+protected:
+ FixedBlockProcessor &mFixedBlockProcessor;
+ uint8_t *mStorage = nullptr; // Store data here while assembling buffers.
+ int32_t mSize = 0; // Size in bytes of the fixed size buffer.
+ int32_t mPosition = 0; // Offset of the last byte read or written.
+};
+
+#endif /* AAUDIO_FIXED_BLOCK_ADAPTER_H */