aml_amaudioutils: audio hal utilities library [1/1]
PD#SWPL-17555
Problem:
This is the initial import of the utility library
to support audio hal implementation on Linux.
Solution:
This library is added on Linux for:
1. The resampler routines from speex
2. The Android SPDIF encoder
3. Partial Android libcutils support needed
as dependencies for audio hal.
Verify:
Local
Change-Id: I28cbc154c82bf6c395aba2f066a2fe0e6f6349db
Signed-off-by: Tim Yao <tim.yao@amlogic.com>
diff --git a/src/spdif/BitFieldParser.cpp b/src/spdif/BitFieldParser.cpp
new file mode 100644
index 0000000..d513320
--- /dev/null
+++ b/src/spdif/BitFieldParser.cpp
@@ -0,0 +1,61 @@
+/*
+ * 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.
+ */
+
+#define LOG_TAG "AudioSPDIF"
+//#define LOG_NDEBUG 0
+
+#include <string.h>
+#include <assert.h>
+
+#include <cutils/log.h>
+#include "BitFieldParser.h"
+
+namespace android {
+
+BitFieldParser::BitFieldParser(uint8_t *data)
+ : mData(data)
+ , mBitCursor(0)
+{
+}
+
+BitFieldParser::~BitFieldParser()
+{
+}
+
+uint32_t BitFieldParser::readBits(uint32_t numBits)
+{
+ ALOG_ASSERT(numBits <= 32);
+
+ // Extract some bits from the current byte.
+ uint32_t byteCursor = mBitCursor >> 3; // 8 bits per byte
+ uint8_t byte = mData[byteCursor];
+
+ uint32_t bitsLeftInByte = 8 - (mBitCursor & 7);
+ uint32_t bitsFromByte = (bitsLeftInByte < numBits) ? bitsLeftInByte : numBits;
+ uint32_t result = byte >> (bitsLeftInByte - bitsFromByte);
+ result &= (1 << bitsFromByte) - 1; // mask
+ mBitCursor += bitsFromByte;
+
+ uint32_t bitsRemaining = numBits - bitsFromByte;
+ if (bitsRemaining == 0) {
+ return result;
+ } else {
+ // Use recursion to get remaining bits.
+ return (result << bitsRemaining) | readBits(bitsRemaining);
+ }
+}
+
+} // namespace android