audio: Unified audio related header files. [4/7]

PD#SWPL-140847

Problem:
Unified audio related header files.

Solution:
Delete duplicate header files.
Common header files depend on audio hal.

Verify:
Yocto: :AP222

Change-Id: Idd9903a8333ce0b4949829aac28212628ab9ace7
Signed-off-by: xingri.gao <xingri.gao@amlogic.com>
diff --git a/utils/SPDIFEncoderAD.cpp b/utils/SPDIFEncoderAD.cpp
index 4e9f677..2fcde22 100644
--- a/utils/SPDIFEncoderAD.cpp
+++ b/utils/SPDIFEncoderAD.cpp
@@ -21,9 +21,9 @@
 #include <stdint.h>
 #include <cutils/log.h>
 #include <system/audio.h>
-#include <audio_utils/spdif/SPDIFEncoder.h>
 #include <tinyalsa/asoundlib.h>
 #include <cutils/properties.h>
+#include "SPDIFEncoder.h"
 #include "SPDIFEncoderAD.h"
 #include "aml_android_utils.h"
 
diff --git a/utils/include/spdif/FrameScanner.h b/utils/include/spdif/FrameScanner.h
new file mode 100644
index 0000000..6d391ee
--- /dev/null
+++ b/utils/include/spdif/FrameScanner.h
@@ -0,0 +1,130 @@
+/*
+ * 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.
+ */
+
+#ifndef ANDROID_AUDIO_FRAME_SCANNER_H
+#define ANDROID_AUDIO_FRAME_SCANNER_H
+
+#include <stdint.h>
+
+namespace android {
+
+
+/**
+ * Scan a byte stream looking for the start of an encoded frame.
+ * Parse the sample rate and the size of the encoded frame.
+ * Buffer the sync header so it can be prepended to the remaining data.
+ *
+ * This is used directly by the SPDIFEncoder. External clients will
+ * generally not call this class.
+ */
+class FrameScanner {
+public:
+    FrameScanner(int dataType,
+            const uint8_t *syncBytes,
+            uint32_t syncLength,
+            uint32_t headerLength
+            );
+    virtual ~FrameScanner();
+
+    /**
+     * Pass each byte of the encoded stream to this scanner.
+     * @return true if a complete and valid header was detected
+     */
+    virtual bool scan(uint8_t byte);
+
+    /**
+     * @return address of where the sync header was stored by scan()
+     */
+    const uint8_t *getHeaderAddress() const { return mHeaderBuffer; }
+
+    /**
+     * @return number of bytes in sync header stored by scan()
+     */
+    size_t getHeaderSizeBytes() const { return mHeaderLength; }
+
+    /**
+     * @return sample rate of the encoded audio
+     */
+    uint32_t getSampleRate()   const { return mSampleRate; }
+
+    /**
+     * Some formats, for example EAC3, are wrapped in data bursts that have
+     * a sample rate that is a multiple of the encoded sample rate.
+     * The default multiplier is 1.
+     * @return sample rate multiplier for the SP/DIF PCM data bursts
+     */
+    uint32_t getRateMultiplier()   const { return mRateMultiplier; }
+
+    size_t getFrameSizeBytes()     const { return mFrameSizeBytes; }
+
+    /**
+     * dataType is defined by the SPDIF standard for each format
+     */
+    int getDataType()      const { return mDataType; }
+    int getDataTypeInfo()  const { return mDataTypeInfo; }
+
+    virtual int getMaxChannels() const = 0;
+
+    virtual void resetBurst() = 0;
+
+    /**
+     * @return the number of pcm frames that correspond to one encoded frame
+     */
+    virtual int getMaxSampleFramesPerSyncFrame() const = 0;
+    virtual int getSampleFramesPerSyncFrame()    const = 0;
+
+    /**
+     * @return true if this parsed frame must be the first frame in a data burst.
+     */
+    virtual bool isFirstInBurst() = 0;
+
+    /**
+     * If this returns false then the previous frame may or may not be the last frame.
+     * @return true if this parsed frame is definitely the last frame in a data burst.
+     */
+    virtual bool isLastInBurst()  = 0;
+
+    /**
+     * Most compression types use a lengthCode expressed in bits.
+     */
+    virtual uint16_t convertBytesToLengthCode(uint16_t numBytes) const { return numBytes * 8; }
+
+protected:
+    uint32_t  mBytesSkipped;     // how many bytes were skipped looking for the start of a frame
+    const uint8_t *mSyncBytes;   // pointer to the sync word specific to a format
+    uint32_t  mSyncLength;       // number of bytes in sync word
+    uint8_t   mHeaderBuffer[32]; // a place to gather the relevant header bytes for parsing
+    uint32_t  mHeaderLength;     // the number of bytes we need to parse
+    uint32_t  mCursor;           // position in the mHeaderBuffer
+    uint32_t  mFormatDumpCount;  // used to thin out the debug dumps
+    uint32_t  mSampleRate;       // encoded sample rate
+    uint32_t  mRateMultiplier;   // SPDIF output data burst rate = msampleRate * mRateMultiplier
+    size_t    mFrameSizeBytes;   // encoded frame size
+    int       mDataType;         // as defined in IEC61937-2 paragraph 4.2
+    int       mDataTypeInfo;     // as defined in IEC61937-2 paragraph 4.1
+
+    /**
+     * Parse data in mHeaderBuffer.
+     * Sets mDataType, mFrameSizeBytes, mSampleRate, mRateMultiplier.
+     * @return true if the header is valid.
+     */
+    virtual bool parseHeader() = 0;
+
+};
+
+
+}  // namespace android
+#endif  // ANDROID_AUDIO_FRAME_SCANNER_H
diff --git a/utils/include/spdif/SPDIFEncoder.h b/utils/include/spdif/SPDIFEncoder.h
new file mode 100644
index 0000000..6e6a644
--- /dev/null
+++ b/utils/include/spdif/SPDIFEncoder.h
@@ -0,0 +1,113 @@
+/*
+ * 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.
+ */
+
+#ifndef ANDROID_AUDIO_SPDIF_ENCODER_H
+#define ANDROID_AUDIO_SPDIF_ENCODER_H
+
+#include <stdint.h>
+#include "FrameScanner.h"
+
+namespace android {
+
+/**
+ * Scan the incoming byte stream for a frame sync.
+ * Then wrap the encoded frame in a data burst and send it as if it were PCM.
+ * The receiver will see the data burst header and decode the wrapped frame.
+ */
+#define SPDIF_MAX_CHANNELS          8
+#define SPDIF_ENCODED_CHANNEL_COUNT 2
+
+class SPDIFEncoder {
+public:
+
+    explicit SPDIFEncoder(audio_format_t format);
+    // Defaults to AC3 format. Was in original API.
+    SPDIFEncoder();
+
+    virtual ~SPDIFEncoder();
+
+    /**
+     * Write encoded data to be wrapped for SPDIF.
+     * The compressed frames do not have to be aligned.
+     * @return number of bytes written or negative error
+     */
+    ssize_t write( const void* buffer, size_t numBytes );
+
+    /**
+     * Called by SPDIFEncoder when it is ready to output a data burst.
+     * Must be implemented in the subclass.
+     * @return number of bytes written or negative error
+     */
+    virtual ssize_t writeOutput( const void* buffer, size_t numBytes ) = 0;
+
+    /**
+     * Get ratio of the encoded data burst sample rate to the encoded rate.
+     * For example, EAC3 data bursts are 4X the encoded rate.
+     */
+    uint32_t getRateMultiplier() const { return mRateMultiplier; }
+
+    /**
+     * @return number of PCM frames in a data burst
+     */
+    uint32_t getBurstFrames() const { return mBurstFrames; }
+
+    /**
+     * @return number of bytes per PCM frame for the data burst
+     */
+    int      getBytesPerOutputFrame();
+
+    /**
+     * @return  true if we can wrap this format in an SPDIF stream
+     */
+    static bool isFormatSupported(audio_format_t format);
+
+    /**
+     * Discard any data in the buffer. Reset frame scanners.
+     * This should be called when seeking to a new position in the stream.
+     */
+    void reset();
+
+protected:
+    void   clearBurstBuffer();
+    void   writeBurstBufferShorts(const uint16_t* buffer, size_t numBytes);
+    void   writeBurstBufferBytes(const uint8_t* buffer, size_t numBytes);
+    void   sendZeroPad();
+    void   flushBurstBuffer();
+    void   startDataBurst();
+    size_t startSyncFrame();
+
+    // Works with various formats including AC3.
+    FrameScanner *mFramer;
+
+    uint32_t  mSampleRate;
+    size_t    mFrameSize;   // size of sync frame in bytes
+    uint16_t *mBurstBuffer; // ALSA wants to get SPDIF data as shorts.
+    size_t    mBurstBufferSizeBytes;
+    uint32_t  mRateMultiplier;
+    uint32_t  mBurstFrames;
+    size_t    mByteCursor;  // cursor into data burst
+    int       mBitstreamNumber;
+    size_t    mPayloadBytesPending; // number of bytes needed to finish burst
+    // state variable, true if scanning for start of frame
+    bool      mScanning;
+
+    static const uint16_t kSPDIFSync1; // Pa
+    static const uint16_t kSPDIFSync2; // Pb
+};
+
+}  // namespace android
+
+#endif  // ANDROID_AUDIO_SPDIF_ENCODER_H
diff --git a/utils/spdif/AC3FrameScanner.cpp b/utils/spdif/AC3FrameScanner.cpp
new file mode 100644
index 0000000..aa041b3
--- /dev/null
+++ b/utils/spdif/AC3FrameScanner.cpp
@@ -0,0 +1,260 @@
+/*
+ * 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 <cutils/log.h>
+
+#include "FrameScanner.h"
+#include "AC3FrameScanner.h"
+
+namespace android {
+
+// These values are from the AC3 spec. Do not change them.
+
+const uint8_t AC3FrameScanner::kSyncBytes[] = { 0x0B, 0x77 };
+
+const uint16_t AC3FrameScanner::kAC3SampleRateTable[AC3_NUM_SAMPLE_RATE_TABLE_ENTRIES]
+    = { 48000, 44100, 32000 };
+
+// Table contains number of 16-bit words in an AC3 frame.
+// From AC3 spec table 5.13
+const uint16_t AC3FrameScanner::kAC3FrameSizeTable[AC3_NUM_FRAME_SIZE_TABLE_ENTRIES]
+        [AC3_NUM_SAMPLE_RATE_TABLE_ENTRIES] = {
+    { 64, 69, 96 },
+    { 64, 70, 96 },
+    { 80, 87, 120 },
+    { 80, 88, 120 },
+    { 96, 104, 144 },
+    { 96, 105, 144 },
+    { 112, 121, 168 },
+    { 112, 122, 168 },
+    { 128, 139, 192 },
+    { 128, 140, 192 },
+    { 160, 174, 240 },
+    { 160, 175, 240 },
+    { 192, 208, 288 },
+    { 192, 209, 288 },
+    { 224, 243, 336 },
+    { 224, 244, 336 },
+    { 256, 278, 384 },
+    { 256, 279, 384 },
+    { 320, 348, 480 },
+    { 320, 349, 480 },
+    { 384, 417, 576 },
+    { 384, 418, 576 },
+    { 448, 487, 672 },
+    { 448, 488, 672 },
+    { 512, 557, 768 },
+    { 512, 558, 768 },
+    { 640, 696, 960 },
+    { 640, 697, 960 },
+    { 768, 835, 1152 },
+    { 768, 836, 1152 },
+    { 896, 975, 1344 },
+    { 896, 976, 1344 },
+    { 1024, 1114, 1536 },
+    { 1024, 1115, 1536 },
+    { 1152, 1253, 1728 },
+    { 1152, 1254, 1728 },
+    { 1280, 1393, 1920 },
+    { 1280, 1394, 1920 }
+};
+
+const uint16_t AC3FrameScanner::kEAC3ReducedSampleRateTable[AC3_NUM_SAMPLE_RATE_TABLE_ENTRIES]
+        = { 24000, 22050, 16000 };
+
+const uint16_t
+        AC3FrameScanner::kEAC3BlocksPerFrameTable[EAC3_NUM_BLOCKS_PER_FRAME_TABLE_ENTRIES]
+        = { 1, 2, 3, 6 };
+
+// Defined in IEC61937-2
+#define SPDIF_DATA_TYPE_AC3     1
+#define SPDIF_DATA_TYPE_E_AC3  21
+#define AC3_STREAM_TYPE_0       0
+#define AC3_STREAM_TYPE_1       1
+#define AC3_STREAM_TYPE_2       2
+// -----------------------------------------------------------------------------
+
+// Scanner for AC3 byte streams.
+AC3FrameScanner::AC3FrameScanner(audio_format_t format)
+ : FrameScanner(SPDIF_DATA_TYPE_AC3,
+        AC3FrameScanner::kSyncBytes,
+        sizeof(AC3FrameScanner::kSyncBytes), 6)
+ , mStreamType(0)
+ , mSubstreamID(0)
+ , mFormat(format)
+{
+    mAudioBlocksPerSyncFrame = 6;
+    memset(mSubstreamBlockCounts, 0, sizeof(mSubstreamBlockCounts));
+}
+
+AC3FrameScanner::~AC3FrameScanner()
+{
+}
+
+int AC3FrameScanner::getSampleFramesPerSyncFrame() const
+{
+    return mRateMultiplier
+            * AC3_MAX_BLOCKS_PER_SYNC_FRAME_BLOCK * AC3_PCM_FRAMES_PER_BLOCK;
+}
+
+void AC3FrameScanner::resetBurst()
+{
+    for (int i = 0; i < EAC3_MAX_SUBSTREAMS; i++) {
+        if (mSubstreamBlockCounts[i] >= AC3_MAX_BLOCKS_PER_SYNC_FRAME_BLOCK) {
+            mSubstreamBlockCounts[i] -= AC3_MAX_BLOCKS_PER_SYNC_FRAME_BLOCK;
+        } else if (mSubstreamBlockCounts[i] > 0) {
+            ALOGW("EAC3 substream[%d] has only %d audio blocks!",
+                i, mSubstreamBlockCounts[i]);
+            mSubstreamBlockCounts[i] = 0;
+        }
+    }
+}
+
+// Per IEC 61973-3:5.3.3, for E-AC3 burst-length shall be in bytes.
+uint16_t AC3FrameScanner::convertBytesToLengthCode(uint16_t numBytes) const
+{
+    return (mDataType == SPDIF_DATA_TYPE_E_AC3) ? numBytes : numBytes * 8;
+}
+
+// per IEC 61973-3 Paragraph 5.3.3
+// We have to send 6 audio blocks on all active substreams.
+// Substream zero must be the first.
+// We don't know if we have all the blocks we need until we see
+// the 7th block of substream#0.
+bool AC3FrameScanner::isFirstInBurst()
+{
+    if (mDataType == SPDIF_DATA_TYPE_E_AC3) {
+        if (((mStreamType == AC3_STREAM_TYPE_0)
+                || (mStreamType == AC3_STREAM_TYPE_2))
+                && (mSubstreamID == 0)
+                // The ">" is intentional. We have to see the beginning
+                // of the block in the next burst before we can send
+                // the current burst.
+                && (mSubstreamBlockCounts[0] > AC3_MAX_BLOCKS_PER_SYNC_FRAME_BLOCK)) {
+            return true;
+        }
+    }
+    return false;
+}
+
+bool AC3FrameScanner::isLastInBurst()
+{
+    // For EAC3 we don't know if we are the end until we see a
+    // frame that must be at the beginning. See isFirstInBurst().
+    return (mDataType != SPDIF_DATA_TYPE_E_AC3); // Just one AC3 frame per burst.
+}
+
+// TODO Use BitFieldParser
+
+// Parse AC3 header.
+// Detect whether the stream is AC3 or EAC3. Extract data depending on type.
+//
+// @return true if valid
+bool AC3FrameScanner::parseHeader()
+{
+    // Interpret bsid based on paragraph E2.3.1.6 of EAC3 spec.
+    uint32_t bsid = mHeaderBuffer[5] >> 3; // bitstream ID
+    // Check BSID to see if this is EAC3 or regular AC3.
+    // These arbitrary BSID numbers do not have any names in the spec.
+    if ((bsid > 10) && (bsid <= 16)) {
+        mDataType = SPDIF_DATA_TYPE_E_AC3;
+    } else if (bsid <= 8) {
+        mDataType = SPDIF_DATA_TYPE_AC3;
+    } else {
+        ALOGW("AC3 bsid = %d not supported", bsid);
+        return false;
+    }
+
+    // bitstream mode, main, commentary, etc.
+    uint32_t bsmod = mHeaderBuffer[5] & 7;
+    mDataTypeInfo = bsmod; // as per IEC61937-3, table 3.
+
+    // The names fscod, frmsiz are from the AC3 spec.
+    uint32_t fscod = mHeaderBuffer[4] >> 6;
+    if (mDataType == SPDIF_DATA_TYPE_E_AC3) {
+        mStreamType = mHeaderBuffer[2] >> 6; // strmtyp in spec
+        mSubstreamID = (mHeaderBuffer[2] >> 3) & 0x07;
+
+        // Frame size is explicit in EAC3. Paragraph E2.3.1.3
+        uint32_t frmsiz = ((mHeaderBuffer[2] & 0x07) << 8) + mHeaderBuffer[3];
+        mFrameSizeBytes = (frmsiz + 1) * sizeof(int16_t);
+
+        uint32_t numblkscod = 3; // 6 blocks default
+        if (fscod == 3) {
+            uint32_t fscod2 = (mHeaderBuffer[4] >> 4) & 0x03;
+            if (fscod2 >= AC3_NUM_SAMPLE_RATE_TABLE_ENTRIES) {
+                ALOGW("Invalid EAC3 fscod2 = %d", fscod2);
+                return false;
+            } else {
+                mSampleRate = kEAC3ReducedSampleRateTable[fscod2];
+            }
+        } else {
+            mSampleRate = kAC3SampleRateTable[fscod];
+            numblkscod = (mHeaderBuffer[4] >> 4) & 0x03;
+        }
+        mRateMultiplier = EAC3_RATE_MULTIPLIER; // per IEC 61973-3 Paragraph 5.3.3
+        // Don't send data burst until we have 6 blocks per substream.
+        mAudioBlocksPerSyncFrame = kEAC3BlocksPerFrameTable[numblkscod];
+        // Keep track of how many audio blocks we have for each substream.
+        // This should be safe because mSubstreamID is ANDed with 0x07 above.
+        // And the array is allocated as [8].
+        if ((mStreamType == AC3_STREAM_TYPE_0)
+                || (mStreamType == AC3_STREAM_TYPE_2)) {
+            mSubstreamBlockCounts[mSubstreamID] += mAudioBlocksPerSyncFrame;
+        }
+
+        // Print enough so we can see all the substreams.
+        ALOGD_IF((mFormatDumpCount < 3*8 ),
+                "EAC3 mStreamType = %d, mSubstreamID = %d",
+                mStreamType, mSubstreamID);
+    } else { // regular AC3
+        // Extract sample rate and frame size from codes.
+        uint32_t frmsizcod = mHeaderBuffer[4] & 0x3F; // frame size code
+
+        if (fscod >= AC3_NUM_SAMPLE_RATE_TABLE_ENTRIES) {
+            ALOGW("Invalid AC3 sampleRateCode = %d", fscod);
+            return false;
+        } else if (frmsizcod >= AC3_NUM_FRAME_SIZE_TABLE_ENTRIES) {
+            ALOGW("Invalid AC3 frameSizeCode = %d", frmsizcod);
+            return false;
+        } else {
+            mSampleRate = kAC3SampleRateTable[fscod];
+            mRateMultiplier = 1;
+            mFrameSizeBytes = sizeof(uint16_t)
+                    * kAC3FrameSizeTable[frmsizcod][fscod];
+        }
+        mAudioBlocksPerSyncFrame = 6;
+        if (mFormat == AUDIO_FORMAT_E_AC3) {
+            ALOGV("Its a Ac3 substream in EAC3 stream");
+            mStreamType = 2;
+            mSubstreamID = 0;
+            mSubstreamBlockCounts[0] += mAudioBlocksPerSyncFrame;
+            mDataType = SPDIF_DATA_TYPE_E_AC3;
+            mRateMultiplier = EAC3_RATE_MULTIPLIER;
+        }
+    }
+    ALOGI_IF((mFormatDumpCount == 0),
+            "AC3 frame rate = %d * %d, size = %zu, audioBlocksPerSyncFrame = %d",
+            mSampleRate, mRateMultiplier, mFrameSizeBytes, mAudioBlocksPerSyncFrame);
+    mFormatDumpCount++;
+    return true;
+}
+
+}  // namespace android
diff --git a/utils/spdif/AC3FrameScanner.h b/utils/spdif/AC3FrameScanner.h
new file mode 100644
index 0000000..23746a3
--- /dev/null
+++ b/utils/spdif/AC3FrameScanner.h
@@ -0,0 +1,81 @@
+/*
+ * 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.
+ */
+
+#ifndef ANDROID_AUDIO_AC3_FRAME_SCANNER_H
+#define ANDROID_AUDIO_AC3_FRAME_SCANNER_H
+
+#include <stdint.h>
+#include "FrameScanner.h"
+#include "system/audio-base.h"
+
+namespace android {
+
+#define AC3_NUM_SAMPLE_RATE_TABLE_ENTRIES          3
+#define AC3_NUM_FRAME_SIZE_TABLE_ENTRIES          38
+#define AC3_PCM_FRAMES_PER_BLOCK                 256
+#define AC3_MAX_BLOCKS_PER_SYNC_FRAME_BLOCK        6
+#define EAC3_RATE_MULTIPLIER                       4
+#define EAC3_NUM_SAMPLE_RATE_TABLE_ENTRIES         3
+#define EAC3_NUM_BLOCKS_PER_FRAME_TABLE_ENTRIES   38
+#define EAC3_MAX_SUBSTREAMS                        8
+
+class AC3FrameScanner : public FrameScanner
+{
+public:
+    explicit AC3FrameScanner(audio_format_t format);
+    virtual ~AC3FrameScanner();
+
+    virtual int getMaxChannels()   const { return 5 + 1; } // 5.1 surround
+
+    virtual int getMaxSampleFramesPerSyncFrame() const { return EAC3_RATE_MULTIPLIER
+            * AC3_MAX_BLOCKS_PER_SYNC_FRAME_BLOCK * AC3_PCM_FRAMES_PER_BLOCK; }
+    virtual int getSampleFramesPerSyncFrame() const;
+
+    virtual bool isFirstInBurst();
+    virtual bool isLastInBurst();
+    virtual void resetBurst();
+
+    virtual uint16_t convertBytesToLengthCode(uint16_t numBytes) const;
+
+protected:
+    // Keep track of how many of each substream blocks have been accumulated.
+    // We need all of each substream before sending block data burst.
+    uint8_t   mSubstreamBlockCounts[EAC3_MAX_SUBSTREAMS];
+    int       mAudioBlocksPerSyncFrame;
+    // The type of EAC3 stream as per EAC3 spec paragraph 2.3.1.1
+    uint32_t  mStreamType;
+    // substream index
+    uint32_t  mSubstreamID;
+    audio_format_t mFormat;
+
+    // used to recognize the start of an AC3 sync frame
+    static const uint8_t  kSyncBytes[];
+    // sample rates from AC3 spec table 5.1
+    static const uint16_t kAC3SampleRateTable[AC3_NUM_SAMPLE_RATE_TABLE_ENTRIES];
+    // frame sizes from AC3 spec table 5.13
+    static const uint16_t kAC3FrameSizeTable[AC3_NUM_FRAME_SIZE_TABLE_ENTRIES]
+            [AC3_NUM_SAMPLE_RATE_TABLE_ENTRIES];
+    // sample rates from EAC3 spec table E2.3
+    static const uint16_t kEAC3ReducedSampleRateTable[AC3_NUM_SAMPLE_RATE_TABLE_ENTRIES];
+    // audio blocks per frame from EAC3 spec table E2.4
+    static const uint16_t kEAC3BlocksPerFrameTable[EAC3_NUM_BLOCKS_PER_FRAME_TABLE_ENTRIES];
+
+    virtual bool parseHeader();
+};
+
+}  // namespace android
+
+#endif  // ANDROID_AUDIO_AC3_FRAME_SCANNER_H
diff --git a/utils/spdif/BitFieldParser.cpp b/utils/spdif/BitFieldParser.cpp
new file mode 100644
index 0000000..d513320
--- /dev/null
+++ b/utils/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
diff --git a/utils/spdif/BitFieldParser.h b/utils/spdif/BitFieldParser.h
new file mode 100644
index 0000000..1a6d0da
--- /dev/null
+++ b/utils/spdif/BitFieldParser.h
@@ -0,0 +1,57 @@
+/*
+ * 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.
+ */
+
+#ifndef ANDROID_AUDIO_BIT_FIELD_PARSER_H
+#define ANDROID_AUDIO_BIT_FIELD_PARSER_H
+
+#include <stdint.h>
+
+namespace android {
+
+/**
+ * Extract bit fields from a byte array.
+ */
+class BitFieldParser {
+public:
+
+    explicit BitFieldParser(uint8_t *data);
+    virtual ~BitFieldParser();
+
+    /**
+     * Read numBits bits from the data array.
+     * Fields may span byte boundaries but may not exceed 32-bits.
+     * Note that the caller must ensure that there is sufficient data.
+     * Assume data is organized as BigEndian format.
+     */
+    uint32_t readBits(uint32_t numBits);
+
+    /*
+     * When the cursor is zero it points to a position right before
+     * the most significant bit.
+     * When the cursor is seven it points to a position right before
+     * the least significant bit.
+     */
+    uint32_t getBitCursor() const { return mBitCursor; }
+
+private:
+    uint8_t *mData;
+    uint32_t mBitCursor;
+};
+
+
+}  // namespace android
+
+#endif  // ANDROID_AUDIO_BIT_FIELD_PARSER_H
diff --git a/utils/spdif/DTSFrameScanner.cpp b/utils/spdif/DTSFrameScanner.cpp
new file mode 100644
index 0000000..0501fe2
--- /dev/null
+++ b/utils/spdif/DTSFrameScanner.cpp
@@ -0,0 +1,139 @@
+/*
+ * 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 <assert.h>
+#include <string.h>
+
+#include <cutils/log.h>
+
+#include "FrameScanner.h"
+#include "BitFieldParser.h"
+#include "DTSFrameScanner.h"
+
+namespace android {
+
+// TODO Handle termination frames.
+// TODO assert if parse past end of header buffer
+// TODO Handle DTS_HD
+
+const uint8_t DTSFrameScanner::kSyncBytes[] =
+        { 0x7F, 0xFE, 0x80, 0x01 };
+
+const int32_t DTSFrameScanner::kDTSSampleRateTable[DTS_NUM_SAMPLE_RATE_TABLE_ENTRIES]
+        = { -1, 8000, 16000, 32000, -1, -1,
+        11025, 22050, 44100, -1, -1, 12000, 24000, 48000, -1, -1 };
+
+// Defined in IEC61937-2
+#define IEC61937_DATA_TYPE_DTS_I        11
+#define IEC61937_DATA_TYPE_DTS_II       12
+#define IEC61937_DATA_TYPE_DTS_III      13
+#define IEC61937_DATA_TYPE_DTS_IV       17
+
+#define IEC61937_MAX_SAMPLES_TYPE_I    512
+#define IEC61937_MAX_SAMPLES_TYPE_II  1024
+#define IEC61937_MAX_SAMPLES_TYPE_III 2048
+
+// Limits defined in DTS spec paragraph 5.3.1
+#define DTS_MINIMUM_NBLKS                5
+#define DTS_MINIMUM_FSIZE               95
+
+#define DTS_HEADER_BYTES_NEEDED         12
+
+// Scanner for DTS byte streams.
+DTSFrameScanner::DTSFrameScanner()
+ : FrameScanner(IEC61937_DATA_TYPE_DTS_I,
+    DTSFrameScanner::kSyncBytes,
+    sizeof(DTSFrameScanner::kSyncBytes),
+    DTS_HEADER_BYTES_NEEDED)
+ , mSampleFramesPerSyncFrame(0)
+{
+}
+
+DTSFrameScanner::~DTSFrameScanner()
+{
+}
+
+// Parse DTS header.
+// Detect whether the stream is DTS or DTS_HD. Extract data depending on type.
+// Sets mDataType, mFrameSizeBytes,
+//      mSampleRate, mRateMultiplier, mLengthCode.
+//
+// @return true if valid
+bool DTSFrameScanner::parseHeader()
+{
+    BitFieldParser parser(&mHeaderBuffer[mSyncLength]);
+
+    // These variables are named after the fields in the DTS spec 5.3.1
+    // Extract field in order.
+    (void) /* uint32_t ftype = */ parser.readBits(1);
+    (void) /* uint32_t deficit = */ parser.readBits(5); // "short"
+    uint32_t cpf = parser.readBits(1);
+    uint32_t nblks = parser.readBits(7);
+    uint32_t fsize = parser.readBits(14);
+    (void) /* uint32_t amode = */ parser.readBits(6);
+    uint32_t sfreq = parser.readBits(4);
+    // make sure we did not read past collected data
+    ALOG_ASSERT((mSyncLength + ((parser.getBitCursor() + 7) >> 3))
+            <= mHeaderLength);
+
+    // Validate fields.
+    if (cpf != 0) {
+        ALOGE("DTSFrameScanner: ERROR - CPF not zero!");
+        return false;
+    }
+    if (nblks < DTS_MINIMUM_NBLKS) {
+        ALOGE("DTSFrameScanner: ERROR - nblks = %u", nblks);
+        return false;
+    }
+    if (fsize < DTS_MINIMUM_FSIZE) {
+        ALOGE("DTSFrameScanner: ERROR - fsize = %u", fsize);
+        return false;
+    }
+
+    int32_t sampleRate = kDTSSampleRateTable[sfreq];
+    if (sampleRate < 0) {
+        ALOGE("DTSFrameScanner: ERROR - invalid sampleRate[%u] = %d", sfreq, sampleRate);
+        return false;
+    }
+    mSampleRate = (uint32_t) sampleRate;
+
+    mSampleFramesPerSyncFrame = (nblks + 1) * DTS_PCM_FRAMES_PER_BLOCK;
+    if (mSampleFramesPerSyncFrame <= IEC61937_MAX_SAMPLES_TYPE_I) {
+        mDataType = IEC61937_DATA_TYPE_DTS_I;
+    } else if (mSampleFramesPerSyncFrame <= IEC61937_MAX_SAMPLES_TYPE_II) {
+        mDataType = IEC61937_DATA_TYPE_DTS_II;
+    } else if (mSampleFramesPerSyncFrame <= IEC61937_MAX_SAMPLES_TYPE_III) {
+        mDataType = IEC61937_DATA_TYPE_DTS_III;
+    } else {
+        mDataType = IEC61937_DATA_TYPE_DTS_IV;
+        // TODO set bits 8,10
+    }
+
+    mFrameSizeBytes = fsize + 1;
+
+    mRateMultiplier = 1; // TODO what about "frequency extension"?
+    ALOGI_IF((mFormatDumpCount == 0),
+            "DTS frame rate = %d * %d, size = %zu",
+            mSampleRate, mRateMultiplier, mFrameSizeBytes);
+    mFormatDumpCount++;
+    return true;
+}
+
+
+}  // namespace android
diff --git a/utils/spdif/DTSFrameScanner.h b/utils/spdif/DTSFrameScanner.h
new file mode 100644
index 0000000..7a394c3
--- /dev/null
+++ b/utils/spdif/DTSFrameScanner.h
@@ -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.
+ */
+
+#ifndef ANDROID_AUDIO_DTS_FRAME_SCANNER_H
+#define ANDROID_AUDIO_DTS_FRAME_SCANNER_H
+
+#include <stdint.h>
+#include "FrameScanner.h"
+
+namespace android {
+
+#define DTS_NUM_SAMPLE_RATE_TABLE_ENTRIES      16
+#define DTS_PCM_FRAMES_PER_BLOCK               32
+#define DTS_MAX_BLOCKS_PER_SYNC_FRAME_BLOCK   128
+
+class DTSFrameScanner : public FrameScanner
+{
+public:
+    DTSFrameScanner();
+    virtual ~DTSFrameScanner();
+
+    virtual int getMaxChannels()   const { return 5 + 1; }
+
+    virtual int getMaxSampleFramesPerSyncFrame() const {
+        return  DTS_MAX_BLOCKS_PER_SYNC_FRAME_BLOCK * DTS_PCM_FRAMES_PER_BLOCK;
+    }
+
+    virtual int getSampleFramesPerSyncFrame() const {
+        return mSampleFramesPerSyncFrame;
+    }
+
+    virtual bool isFirstInBurst() { return true; }
+    virtual bool isLastInBurst() { return true; }
+    virtual void resetBurst()  { }
+
+protected:
+
+    int mSampleFramesPerSyncFrame;
+
+    virtual bool parseHeader();
+
+    static const uint8_t kSyncBytes[];
+    static const int32_t kDTSSampleRateTable[];
+
+};
+
+}  // namespace android
+#endif  // ANDROID_AUDIO_DTS_FRAME_SCANNER_H
diff --git a/utils/spdif/FrameScanner.cpp b/utils/spdif/FrameScanner.cpp
new file mode 100644
index 0000000..32e5b44
--- /dev/null
+++ b/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 <cutils/log.h>
+#include "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
diff --git a/utils/spdif/MatFrameScanner.cpp b/utils/spdif/MatFrameScanner.cpp
new file mode 100644
index 0000000..6008b28
--- /dev/null
+++ b/utils/spdif/MatFrameScanner.cpp
@@ -0,0 +1,148 @@
+/*
+ * 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"
+//#define LOG_NDEBUG 0
+
+#include <string.h>
+#include <assert.h>
+
+#include <cutils/log.h>
+#include "FrameScanner.h"
+
+#include "MatFrameScanner.h"
+
+namespace android {
+
+// MAT Transport stream sync word
+const uint8_t MatFrameScanner::kSyncBytes[] = { 0x07, 0x9E };
+
+// Defined in IEC61937-9
+#define SPDIF_DATA_TYPE_MAT 22
+
+#define MAT_MAX_CHUNK_SIZE 30720
+
+// MAT transport format
+// { Syncword (16 bits) }
+// { metadata_payload_length   (16 bits), Metadata Payload, Payload CRC (16 bits) }
+// { top_of_channels_length    (16 bits), Top of Channels Audio Chunk, Payload CRC (16 bits) }
+// { bottom_of_channels_length (16 bits), Bottom of Channels Audio Chunk, Payload CRC (16 bits) }
+// Length does not include bytes for length itself and the CRC after payload.
+
+// For frame parsing, we use three frame chunks for a single IEC61937 frame
+// 1. {syncword, metadata_payload_length, Metadata Payload}
+// 2. {metadata_payload_crc, top_of_channels_length, Top of Channels Audio Chunk}
+// 3. {Top channels chunk crc, bottom_of_channels_length, Bottom of Channels Audio Chunk, Bottom Channels Chunk crc}
+// such that the header buffer for the three "virtual" frames have fixed 4 bytes size (mHeaderLength = 4)
+// and we can control the frame size to collect in each chunk state.
+
+#define CHUNK_TYPE_METADATA 0
+#define CHUNK_TYPE_TOP      1
+#define CHUNK_TYPE_BOTTOM   2
+
+MatFrameScanner::MatFrameScanner()
+ : FrameScanner(SPDIF_DATA_TYPE_MAT,
+        MatFrameScanner::kSyncBytes,
+        sizeof(MatFrameScanner::kSyncBytes), 4)
+ , mChunkType(CHUNK_TYPE_METADATA)
+ , mLastChunk(false)
+{
+}
+
+MatFrameScanner::~MatFrameScanner()
+{
+}
+
+void MatFrameScanner::resetBurst()
+{
+    mChunkType = CHUNK_TYPE_METADATA;
+}
+
+// Per IEC 61973-9:5.3.1, for MAT burst-length shall be in bytes.
+uint16_t MatFrameScanner::convertBytesToLengthCode(uint16_t numBytes) const
+{
+    return numBytes;
+}
+
+bool MatFrameScanner::isLastInBurst()
+{
+    return mLastChunk;
+}
+
+bool MatFrameScanner::parseHeader()
+{
+    size_t payload_length = ((size_t)(mHeaderBuffer[2]) << 8) | mHeaderBuffer[3];
+
+    if ((payload_length <= 0) || (payload_length > MAT_MAX_CHUNK_SIZE))
+        return false;
+
+    payload_length <<= 1;   // convert to bytes
+
+    if (mChunkType == CHUNK_TYPE_METADATA) {
+        mFrameSizeBytes = mHeaderLength;    // sync word, metadata length
+        mFrameSizeBytes += payload_length;
+        mChunkType = CHUNK_TYPE_TOP;
+        mLastChunk = false;
+    } else if (mChunkType == CHUNK_TYPE_TOP) {
+        mFrameSizeBytes = mHeaderLength;    // metadata crc, top length
+        mFrameSizeBytes += payload_length;
+        mChunkType = CHUNK_TYPE_BOTTOM;
+        mLastChunk = false;
+    } else {
+        mFrameSizeBytes = mHeaderLength;    // top crc, bottom length
+        mFrameSizeBytes += payload_length;
+        mFrameSizeBytes += 2;               // bottom crc
+        mChunkType = CHUNK_TYPE_METADATA;
+        mLastChunk = true;
+    }
+
+    return true;
+}
+
+// State machine that scans for headers in a byte stream.
+// @return true if we have detected a complete and valid header.
+bool MatFrameScanner::scan(uint8_t byte)
+{
+    bool result = false;
+
+    //ALOGV("MatFrameScanner: byte = 0x%02X, mCursor = %d", byte, mCursor);
+    assert(mCursor < sizeof(mHeaderBuffer));
+
+    if ((mChunkType == CHUNK_TYPE_METADATA) && (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 metadata payload length
+        mHeaderBuffer[mCursor++] = byte;
+        if (mCursor >= mHeaderLength) {
+            if (parseHeader()) {
+                result = true;
+            } else {
+                ALOGE("MatFrameScanner: ERROR - parseHeader() failed.");
+            }
+            mCursor = 0;
+        }
+    }
+
+    return result;
+}
+
+}  // namespace android
diff --git a/utils/spdif/MatFrameScanner.h b/utils/spdif/MatFrameScanner.h
new file mode 100644
index 0000000..f51f528
--- /dev/null
+++ b/utils/spdif/MatFrameScanner.h
@@ -0,0 +1,59 @@
+/*
+ * 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.
+ */
+
+#ifndef ANDROID_AUDIO_MAT_FRAME_SCANNER_H
+#define ANDROID_AUDIO_MAT_FRAME_SCANNER_H
+
+#include <stdint.h>
+#include "FrameScanner.h"
+
+namespace android {
+
+#define MAT_PCM_FRAMES                          1536
+#define MAT_RATE_MULTIPLIER                       10
+
+class MatFrameScanner : public FrameScanner
+{
+public:
+    MatFrameScanner();
+    virtual ~MatFrameScanner();
+
+    virtual int getMaxChannels()   const { return 5 + 1 + 2; } // 5.1.2 surround
+
+    virtual int getMaxSampleFramesPerSyncFrame() const { return MAT_RATE_MULTIPLIER
+            * MAT_PCM_FRAMES; }
+    virtual int getSampleFramesPerSyncFrame() const { return MAT_RATE_MULTIPLIER
+            * MAT_PCM_FRAMES; }
+
+    virtual bool isFirstInBurst() { return false; }
+    virtual bool isLastInBurst();
+    virtual void resetBurst();
+
+    virtual uint16_t convertBytesToLengthCode(uint16_t numBytes) const;
+    virtual bool scan(uint8_t byte);
+
+protected:
+    // used to recognize the start of a MAT sync frame
+    static const uint8_t kSyncBytes[];
+    int mChunkType;
+    bool mLastChunk;
+
+    virtual bool parseHeader();
+};
+
+}  // namespace android
+
+#endif  // ANDROID_AUDIO_MAT_FRAME_SCANNER_H
diff --git a/utils/spdif/SPDIFEncoder.cpp b/utils/spdif/SPDIFEncoder.cpp
new file mode 100644
index 0000000..6bd1a08
--- /dev/null
+++ b/utils/spdif/SPDIFEncoder.cpp
@@ -0,0 +1,281 @@
+/*
+ * 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.
+ */
+
+#include <stdint.h>
+#include <string.h>
+
+#define LOG_TAG "AudioSPDIF"
+#include <cutils/log.h>
+
+#include "system/audio-base.h"
+#include "SPDIFEncoder.h"
+#include "AC3FrameScanner.h"
+#include "DTSFrameScanner.h"
+#include "MatFrameScanner.h"
+
+namespace android {
+
+// Burst Preamble defined in IEC61937-1
+const uint16_t SPDIFEncoder::kSPDIFSync1 = 0xF872; // Pa
+const uint16_t SPDIFEncoder::kSPDIFSync2 = 0x4E1F; // Pb
+
+static int32_t sEndianDetector = 1;
+#define isLittleEndian()  (*((uint8_t *)&sEndianDetector))
+
+SPDIFEncoder::SPDIFEncoder(audio_format_t format)
+  : mFramer(NULL)
+  , mSampleRate(48000)
+  , mBurstBuffer(NULL)
+  , mBurstBufferSizeBytes(0)
+  , mRateMultiplier(1)
+  , mBurstFrames(0)
+  , mByteCursor(0)
+  , mBitstreamNumber(0)
+  , mPayloadBytesPending(0)
+  , mScanning(true)
+  , mFrameSize(0)
+{
+    switch (format) {
+        case AUDIO_FORMAT_AC3:
+        case AUDIO_FORMAT_E_AC3:
+            mFramer = new AC3FrameScanner(format);
+            break;
+        case AUDIO_FORMAT_DTS:
+        case AUDIO_FORMAT_DTS_HD:
+            mFramer = new DTSFrameScanner();
+            break;
+        case AUDIO_FORMAT_MAT:
+            mFramer = new MatFrameScanner();
+            break;
+        default:
+            break;
+    }
+
+    // This a programmer error. Call isFormatSupported() first.
+    LOG_ALWAYS_FATAL_IF((mFramer == NULL),
+        "SPDIFEncoder: invalid audio format = 0x%08X", format);
+
+    mBurstBufferSizeBytes = sizeof(uint16_t)
+            * SPDIF_ENCODED_CHANNEL_COUNT
+            * mFramer->getMaxSampleFramesPerSyncFrame();
+
+    ALOGI("SPDIFEncoder: mBurstBufferSizeBytes = %zu, littleEndian = %d",
+            mBurstBufferSizeBytes, isLittleEndian());
+    mBurstBuffer = new uint16_t[mBurstBufferSizeBytes >> 1];
+    clearBurstBuffer();
+}
+
+SPDIFEncoder::SPDIFEncoder()
+    : SPDIFEncoder(AUDIO_FORMAT_AC3)
+{
+}
+
+SPDIFEncoder::~SPDIFEncoder()
+{
+    delete[] mBurstBuffer;
+    delete mFramer;
+}
+
+bool SPDIFEncoder::isFormatSupported(audio_format_t format)
+{
+    switch (format) {
+        case AUDIO_FORMAT_AC3:
+        case AUDIO_FORMAT_E_AC3:
+        case AUDIO_FORMAT_DTS:
+        case AUDIO_FORMAT_DTS_HD:
+            return true;
+        default:
+            return false;
+    }
+}
+
+int SPDIFEncoder::getBytesPerOutputFrame()
+{
+    return SPDIF_ENCODED_CHANNEL_COUNT * sizeof(int16_t);
+}
+
+void SPDIFEncoder::writeBurstBufferShorts(const uint16_t *buffer, size_t numShorts)
+{
+    // avoid static analyser warning
+    LOG_ALWAYS_FATAL_IF((mBurstBuffer == NULL), "mBurstBuffer never allocated");
+    mByteCursor = (mByteCursor + 1) & ~1; // round up to even byte
+    size_t bytesToWrite = numShorts * sizeof(uint16_t);
+    if ((mByteCursor + bytesToWrite) > mBurstBufferSizeBytes) {
+        ALOGE("SPDIFEncoder: Burst buffer overflow!");
+        reset();
+        return;
+    }
+    memcpy(&mBurstBuffer[mByteCursor >> 1], buffer, bytesToWrite);
+    mByteCursor += bytesToWrite;
+}
+
+// Pack the bytes into the short buffer in the order:
+//   byte[0] -> short[0] MSB
+//   byte[1] -> short[0] LSB
+//   byte[2] -> short[1] MSB
+//   byte[3] -> short[1] LSB
+//   etcetera
+// This way they should come out in the correct order for SPDIF on both
+// Big and Little Endian CPUs.
+void SPDIFEncoder::writeBurstBufferBytes(const uint8_t *buffer, size_t numBytes)
+{
+    size_t bytesToWrite = numBytes;
+    if ((mByteCursor + bytesToWrite) > mBurstBufferSizeBytes) {
+        ALOGE("SPDIFEncoder: Burst buffer overflow!");
+        clearBurstBuffer();
+        return;
+    }
+    uint16_t pad = mBurstBuffer[mByteCursor >> 1];
+    for (size_t i = 0; i < bytesToWrite; i++) {
+        if (mByteCursor & 1 ) {
+            pad |= *buffer++; // put second byte in LSB
+            mBurstBuffer[mByteCursor >> 1] = pad;
+            pad = 0;
+        } else {
+            pad |= (*buffer++) << 8; // put first byte in MSB
+        }
+        mByteCursor++;
+    }
+    // Save partially filled short.
+    if (mByteCursor & 1) {
+        mBurstBuffer[mByteCursor >> 1] = pad;
+    }
+}
+
+void SPDIFEncoder::sendZeroPad()
+{
+    // Pad remainder of burst with zeros.
+    size_t burstSize = mFramer->getSampleFramesPerSyncFrame() * sizeof(uint16_t)
+            * SPDIF_ENCODED_CHANNEL_COUNT;
+    if (mByteCursor > burstSize) {
+        ALOGE("SPDIFEncoder: Burst buffer, contents too large!");
+        clearBurstBuffer();
+    } else {
+        // We don't have to write zeros because buffer already set to zero
+        // by clearBurstBuffer(). Just pretend we wrote zeros by
+        // incrementing cursor.
+        mByteCursor = burstSize;
+    }
+}
+
+void SPDIFEncoder::reset()
+{
+    ALOGV("SPDIFEncoder: reset()");
+    clearBurstBuffer();
+    if (mFramer != NULL) {
+        mFramer->resetBurst();
+    }
+    mPayloadBytesPending = 0;
+    mScanning = true;
+}
+
+void SPDIFEncoder::flushBurstBuffer()
+{
+    const int preambleSize = 4 * sizeof(uint16_t);
+    if (mByteCursor > preambleSize) {
+        // Set lengthCode for valid payload before zeroPad.
+        uint16_t numBytes = (mByteCursor - preambleSize);
+        mBurstBuffer[3] = mFramer->convertBytesToLengthCode(numBytes);
+
+        sendZeroPad();
+        writeOutput(mBurstBuffer, mByteCursor);
+    }
+    reset();
+}
+
+void SPDIFEncoder::clearBurstBuffer()
+{
+    if (mBurstBuffer) {
+        memset(mBurstBuffer, 0, mBurstBufferSizeBytes);
+    }
+    mByteCursor = 0;
+}
+
+void SPDIFEncoder::startDataBurst()
+{
+    // Encode IEC61937-1 Burst Preamble
+    uint16_t preamble[4];
+
+    uint16_t burstInfo = (mBitstreamNumber << 13)
+        | (mFramer->getDataTypeInfo() << 8)
+        | mFramer->getDataType();
+
+    mRateMultiplier = mFramer->getRateMultiplier();
+
+    preamble[0] = kSPDIFSync1;
+    preamble[1] = kSPDIFSync2;
+    preamble[2] = burstInfo;
+    preamble[3] = 0; // lengthCode - This will get set after the buffer is full.
+    writeBurstBufferShorts(preamble, 4);
+}
+
+size_t SPDIFEncoder::startSyncFrame()
+{
+    // Write start of encoded frame that was buffered in frame detector.
+    size_t syncSize = mFramer->getHeaderSizeBytes();
+    writeBurstBufferBytes(mFramer->getHeaderAddress(), syncSize);
+    return mFramer->getFrameSizeBytes() - syncSize;
+}
+
+// Wraps raw encoded data into a data burst.
+ssize_t SPDIFEncoder::write( const void *buffer, size_t numBytes )
+{
+    size_t bytesLeft = numBytes;
+    const uint8_t *data = (const uint8_t *)buffer;
+    ALOGV("SPDIFEncoder: mScanning = %d, write(buffer[0] = 0x%02X, numBytes = %zu)",
+        mScanning, (uint) *data, numBytes);
+    while (bytesLeft > 0) {
+        if (mScanning) {
+        // Look for beginning of next encoded frame.
+            if (mFramer->scan(*data)) {
+                if (mByteCursor == 0) {
+                    startDataBurst();
+                } else if (mFramer->isFirstInBurst()) {
+                    // Make sure that this frame is at the beginning of the data burst.
+                    flushBurstBuffer();
+                    startDataBurst();
+                }
+                mPayloadBytesPending = startSyncFrame();
+                mScanning = false;
+            }
+            data++;
+            bytesLeft--;
+        } else {
+            // Write payload until we hit end of frame.
+            size_t bytesToWrite = bytesLeft;
+            // Only write as many as we need to finish the frame.
+            if (bytesToWrite > mPayloadBytesPending) {
+                bytesToWrite = mPayloadBytesPending;
+            }
+            writeBurstBufferBytes(data, bytesToWrite);
+
+            data += bytesToWrite;
+            bytesLeft -= bytesToWrite;
+            mPayloadBytesPending -= bytesToWrite;
+
+            // If we have all the payload then send a data burst.
+            if (mPayloadBytesPending == 0) {
+                if (mFramer->isLastInBurst()) {
+                    flushBurstBuffer();
+                }
+                mScanning = true;
+            }
+        }
+    }
+    return numBytes;
+}
+
+}  // namespace android
diff --git a/utils/spdifenc_wrap.cpp b/utils/spdifenc_wrap.cpp
index b2561b6..a757d78 100644
--- a/utils/spdifenc_wrap.cpp
+++ b/utils/spdifenc_wrap.cpp
@@ -25,8 +25,8 @@
 #include <sound/asound.h>
 #include <cutils/log.h>
 #include <system/audio.h>
-#include <audio_utils/spdif/SPDIFEncoder.h>
 
+#include "SPDIFEncoder.h"
 #include <tinyalsa/asoundlib.h>
 #include <cutils/properties.h>
 #include <string.h>