upload android base code part6

android/system/media/audio_utils/spdif/FrameScanner.cpp

@@ -0,0 +1,79 @@
+/*
+ * Copyright 2014, 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"
+
+#include <string.h>
+#include <assert.h>
+
+#include <utils/Log.h>
+#include <audio_utils/spdif/FrameScanner.h>
+
+namespace android {
+
+FrameScanner::FrameScanner(int dataType,
+            const uint8_t *syncBytes,
+            uint32_t syncLength,
+            uint32_t headerLength)
+ : mBytesSkipped(0)
+ , mSyncBytes(syncBytes)
+ , mSyncLength(syncLength)
+ , mHeaderLength(headerLength)
+ , mCursor(0)
+ , mFormatDumpCount(0)
+ , mSampleRate(0)
+ , mRateMultiplier(1)
+ , mFrameSizeBytes(0)
+ , mDataType(dataType)
+ , mDataTypeInfo(0)
+{
+}
+
+FrameScanner::~FrameScanner()
+{
+}
+
+// State machine that scans for headers in a byte stream.
+// @return true if we have detected a complete and valid header.
+bool FrameScanner::scan(uint8_t byte)
+{
+    bool result = false;
+    ALOGV("FrameScanner: byte = 0x%02X, mCursor = %d", byte, mCursor);
+    assert(mCursor < sizeof(mHeaderBuffer));
+    if (mCursor < mSyncLength) {
+        // match sync word
+        if (byte == mSyncBytes[mCursor]) {
+            mHeaderBuffer[mCursor++] = byte;
+        } else {
+            mBytesSkipped += 1; // skip unsynchronized data
+            mCursor = 0;
+        }
+    } else if (mCursor < mHeaderLength) {
+        // gather header for parsing
+        mHeaderBuffer[mCursor++] = byte;
+        if (mCursor >= mHeaderLength) {
+            if (parseHeader()) {
+                result = true;
+            } else {
+                ALOGE("FrameScanner: ERROR - parseHeader() failed.");
+            }
+            mCursor = 0;
+        }
+    }
+    return result;
+}
+
+}  // namespace android