Stagefright: added WebM muxer.

Change-Id: I50bbf9c6f089b205d5ecef1371bfdd2028b3b358

16 files changed, 2284 insertions, 6 deletions

diff --git a/include/media/stagefright/MediaMuxer.h b/include/media/stagefright/MediaMuxer.h
index ff6a66e..bbe4303 100644
--- a/include/media/stagefright/MediaMuxer.h
+++ b/include/media/stagefright/MediaMuxer.h
@@ -30,7 +30,7 @@ struct MediaAdapter;
 struct MediaBuffer;
 struct MediaSource;
 struct MetaData;
-struct MPEG4Writer;
+struct MediaWriter;
 
 // MediaMuxer is used to mux multiple tracks into a video. Currently, we only
 // support a mp4 file as the output.
@@ -44,6 +44,7 @@ public:
     // OutputFormat is updated.
     enum OutputFormat {
         OUTPUT_FORMAT_MPEG_4 = 0,
+        OUTPUT_FORMAT_WEBM   = 1,
         OUTPUT_FORMAT_LIST_END // must be last - used to validate format type
     };
 
@@ -115,7 +116,8 @@ public:
                              int64_t timeUs, uint32_t flags) ;
 
 private:
-    sp<MPEG4Writer> mWriter;
+    const OutputFormat mFormat;
+    sp<MediaWriter> mWriter;
     Vector< sp<MediaAdapter> > mTrackList;  // Each track has its MediaAdapter.
     sp<MetaData> mFileMeta;  // Metadata for the whole file.
 
diff --git a/media/libstagefright/Android.mk b/media/libstagefright/Android.mk
index 0fd1e69..714b5e0 100644
--- a/media/libstagefright/Android.mk
+++ b/media/libstagefright/Android.mk
@@ -97,6 +97,7 @@ LOCAL_STATIC_LIBRARIES := \
         libstagefright_color_conversion \
         libstagefright_aacenc \
         libstagefright_matroska \
+        libstagefright_webm \
         libstagefright_timedtext \
         libvpx \
         libwebm \
diff --git a/media/libstagefright/MediaMuxer.cpp b/media/libstagefright/MediaMuxer.cpp
index d87e910..90335ee 100644
--- a/media/libstagefright/MediaMuxer.cpp
+++ b/media/libstagefright/MediaMuxer.cpp
@@ -16,6 +16,9 @@
 
 //#define LOG_NDEBUG 0
 #define LOG_TAG "MediaMuxer"
+
+#include "webm/WebmWriter.h"
+
 #include <utils/Log.h>
 
 #include <media/stagefright/MediaMuxer.h>
@@ -36,19 +39,30 @@
 namespace android {
 
 MediaMuxer::MediaMuxer(const char *path, OutputFormat format)
-    : mState(UNINITIALIZED) {
+    : mFormat(format),
+      mState(UNINITIALIZED) {
     if (format == OUTPUT_FORMAT_MPEG_4) {
         mWriter = new MPEG4Writer(path);
+    } else if (format == OUTPUT_FORMAT_WEBM) {
+        mWriter = new WebmWriter(path);
+    }
+
+    if (mWriter != NULL) {
         mFileMeta = new MetaData;
         mState = INITIALIZED;
     }
-
 }
 
 MediaMuxer::MediaMuxer(int fd, OutputFormat format)
-    : mState(UNINITIALIZED) {
+    : mFormat(format),
+      mState(UNINITIALIZED) {
     if (format == OUTPUT_FORMAT_MPEG_4) {
         mWriter = new MPEG4Writer(fd);
+    } else if (format == OUTPUT_FORMAT_WEBM) {
+        mWriter = new WebmWriter(fd);
+    }
+
+    if (mWriter != NULL) {
         mFileMeta = new MetaData;
         mState = INITIALIZED;
     }
@@ -109,8 +123,13 @@ status_t MediaMuxer::setLocation(int latitude, int longitude) {
         ALOGE("setLocation() must be called before start().");
         return INVALID_OPERATION;
     }
+    if (mFormat != OUTPUT_FORMAT_MPEG_4) {
+        ALOGE("setLocation() is only supported for .mp4 output.");
+        return INVALID_OPERATION;
+    }
+
     ALOGV("Setting location: latitude = %d, longitude = %d", latitude, longitude);
-    return mWriter->setGeoData(latitude, longitude);
+    return static_cast<MPEG4Writer*>(mWriter.get())->setGeoData(latitude, longitude);
 }
 
 status_t MediaMuxer::start() {
diff --git a/media/libstagefright/webm/Android.mk b/media/libstagefright/webm/Android.mk
new file mode 100644
index 0000000..7081463
--- /dev/null
+++ b/media/libstagefright/webm/Android.mk
@@ -0,0 +1,23 @@
+LOCAL_PATH:= $(call my-dir)
+include $(CLEAR_VARS)
+
+LOCAL_CPPFLAGS += -D__STDINT_LIMITS \
+                  -Werror
+
+LOCAL_SRC_FILES:= EbmlUtil.cpp        \
+                  WebmElement.cpp     \
+                  WebmFrame.cpp       \
+                  WebmFrameThread.cpp \
+                  WebmWriter.cpp
+
+
+LOCAL_C_INCLUDES += $(TOP)/frameworks/av/include
+
+LOCAL_SHARED_LIBRARIES += libstagefright_foundation \
+                          libstagefright \
+                          libutils \
+                          liblog
+
+LOCAL_MODULE:= libstagefright_webm
+
+include $(BUILD_STATIC_LIBRARY)
diff --git a/media/libstagefright/webm/EbmlUtil.cpp b/media/libstagefright/webm/EbmlUtil.cpp
new file mode 100644
index 0000000..449fec6
--- /dev/null
+++ b/media/libstagefright/webm/EbmlUtil.cpp
@@ -0,0 +1,108 @@
+/*
+ * Copyright (C) 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>
+
+namespace {
+
+// Table for Seal's algorithm for Number of Trailing Zeros. Hacker's Delight
+// online, Figure 5-18 (http://www.hackersdelight.org/revisions.pdf)
+// The entries whose value is -1 are never referenced.
+int NTZ_TABLE[] = {
+    32,  0,  1, 12,  2,  6, -1, 13,   3, -1,  7, -1, -1, -1, -1, 14,
+    10,  4, -1, -1,  8, -1, -1, 25,  -1, -1, -1, -1, -1, 21, 27, 15,
+    31, 11,  5, -1, -1, -1, -1, -1,   9, -1, -1, 24, -1, -1, 20, 26,
+    30, -1, -1, -1, -1, 23, -1, 19,  29, -1, 22, 18, 28, 17, 16, -1
+};
+
+int numberOfTrailingZeros32(int32_t i) {
+    uint32_t u = (i & -i) * 0x0450FBAF;
+    return NTZ_TABLE[(u) >> 26];
+}
+
+uint64_t highestOneBit(uint64_t n) {
+    n |= (n >> 1);
+    n |= (n >> 2);
+    n |= (n >> 4);
+    n |= (n >> 8);
+    n |= (n >> 16);
+    n |= (n >> 32);
+    return n - (n >> 1);
+}
+
+uint64_t _powerOf2(uint64_t u) {
+    uint64_t powerOf2 = highestOneBit(u);
+    return powerOf2 ? powerOf2 : 1;
+}
+
+// Based on Long.numberOfTrailingZeros in Long.java
+int numberOfTrailingZeros(uint64_t u) {
+    int32_t low = u;
+    return low !=0 ? numberOfTrailingZeros32(low)
+                   : 32 + numberOfTrailingZeros32((int32_t) (u >> 32));
+}
+}
+
+namespace webm {
+
+// Encode the id and/or size of an EBML element bytes by setting a leading length descriptor bit:
+//
+//   1xxxxxxx                                                                - 1-byte values
+//   01xxxxxx xxxxxxxx                                                       -
+//   001xxxxx xxxxxxxx xxxxxxxx                                              -
+//   0001xxxx xxxxxxxx xxxxxxxx xxxxxxxx                                     - ...
+//   00001xxx xxxxxxxx xxxxxxxx xxxxxxxx xxxxxxxx                            -
+//   000001xx xxxxxxxx xxxxxxxx xxxxxxxx xxxxxxxx xxxxxxxx                   -
+//   0000001x xxxxxxxx xxxxxxxx xxxxxxxx xxxxxxxx xxxxxxxx xxxxxxxx          -
+//   00000001 xxxxxxxx xxxxxxxx xxxxxxxx xxxxxxxx xxxxxxxx xxxxxxxx xxxxxxxx - 8-byte values
+//
+// This function uses the least the number of bytes possible.
+uint64_t encodeUnsigned(uint64_t u) {
+    uint64_t powerOf2 = _powerOf2(u);
+    if (u + 1 == powerOf2 << 1)
+        powerOf2 <<= 1;
+    int shiftWidth = (7 + numberOfTrailingZeros(powerOf2)) / 7 * 7;
+    long lengthDescriptor = 1 << shiftWidth;
+    return lengthDescriptor | u;
+}
+
+// Like above but pads the input value with leading zeros up to the specified width. The length
+// descriptor is calculated based on width.
+uint64_t encodeUnsigned(uint64_t u, int width) {
+    int shiftWidth = 7 * width;
+    uint64_t lengthDescriptor = 1;
+    lengthDescriptor <<= shiftWidth;
+    return lengthDescriptor | u;
+}
+
+// Calculate the length of an EBML coded id or size from its length descriptor.
+int sizeOf(uint64_t u) {
+    uint64_t powerOf2 = _powerOf2(u);
+    int unsignedLength = numberOfTrailingZeros(powerOf2) / 8 + 1;
+    return unsignedLength;
+}
+
+// Serialize an EBML coded id or size in big-endian order.
+int serializeCodedUnsigned(uint64_t u, uint8_t* bary) {
+    int unsignedLength = sizeOf(u);
+    for (int i = unsignedLength - 1; i >= 0; i--) {
+        bary[i] = u & 0xff;
+        u >>= 8;
+    }
+    return unsignedLength;
+}
+
+}
diff --git a/media/libstagefright/webm/EbmlUtil.h b/media/libstagefright/webm/EbmlUtil.h
new file mode 100644
index 0000000..eb9c37c
--- /dev/null
+++ b/media/libstagefright/webm/EbmlUtil.h
@@ -0,0 +1,50 @@
+/*
+ * Copyright (C) 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 EBMLUTIL_H_
+#define EBMLUTIL_H_
+
+#include <stdint.h>
+
+namespace webm {
+
+// Encode the id and/or size of an EBML element bytes by setting a leading length descriptor bit:
+//
+//   1xxxxxxx                                                                - 1-byte values
+//   01xxxxxx xxxxxxxx                                                       -
+//   001xxxxx xxxxxxxx xxxxxxxx                                              -
+//   0001xxxx xxxxxxxx xxxxxxxx xxxxxxxx                                     - ...
+//   00001xxx xxxxxxxx xxxxxxxx xxxxxxxx xxxxxxxx                            -
+//   000001xx xxxxxxxx xxxxxxxx xxxxxxxx xxxxxxxx xxxxxxxx                   -
+//   0000001x xxxxxxxx xxxxxxxx xxxxxxxx xxxxxxxx xxxxxxxx xxxxxxxx          -
+//   00000001 xxxxxxxx xxxxxxxx xxxxxxxx xxxxxxxx xxxxxxxx xxxxxxxx xxxxxxxx - 8-byte values
+//
+// This function uses the least the number of bytes possible.
+uint64_t encodeUnsigned(uint64_t u);
+
+// Like above but pads the input value with leading zeros up to the specified width. The length
+// descriptor is calculated based on width.
+uint64_t encodeUnsigned(uint64_t u, int width);
+
+// Serialize an EBML coded id or size in big-endian order.
+int serializeCodedUnsigned(uint64_t u, uint8_t* bary);
+
+// Calculate the length of an EBML coded id or size from its length descriptor.
+int sizeOf(uint64_t u);
+
+}
+
+#endif /* EBMLUTIL_H_ */
diff --git a/media/libstagefright/webm/LinkedBlockingQueue.h b/media/libstagefright/webm/LinkedBlockingQueue.h
new file mode 100644
index 0000000..0b6a9a1
--- /dev/null
+++ b/media/libstagefright/webm/LinkedBlockingQueue.h
@@ -0,0 +1,79 @@
+/*
+ * Copyright (C) 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 LINKEDBLOCKINGQUEUE_H_
+#define LINKEDBLOCKINGQUEUE_H_
+
+#include <utils/List.h>
+#include <utils/Mutex.h>
+#include <utils/Condition.h>
+
+namespace android {
+
+template<typename T>
+class LinkedBlockingQueue {
+    List<T> mList;
+    Mutex mLock;
+    Condition mContentAvailableCondition;
+
+    T front(bool remove) {
+        Mutex::Autolock autolock(mLock);
+        while (mList.empty()) {
+            mContentAvailableCondition.wait(mLock);
+        }
+        T e = *(mList.begin());
+        if (remove) {
+            mList.erase(mList.begin());
+        }
+        return e;
+    }
+
+    DISALLOW_EVIL_CONSTRUCTORS(LinkedBlockingQueue);
+
+public:
+    LinkedBlockingQueue() {
+    }
+
+    ~LinkedBlockingQueue() {
+    }
+
+    bool empty() {
+        Mutex::Autolock autolock(mLock);
+        return mList.empty();
+    }
+
+    void clear() {
+        Mutex::Autolock autolock(mLock);
+        mList.clear();
+    }
+
+    T peek() {
+        return front(false);
+    }
+
+    T take() {
+        return front(true);
+    }
+
+    void push(T e) {
+        Mutex::Autolock autolock(mLock);
+        mList.push_back(e);
+        mContentAvailableCondition.signal();
+    }
+};
+
+} /* namespace android */
+#endif /* LINKEDBLOCKINGQUEUE_H_ */
diff --git a/media/libstagefright/webm/WebmConstants.h b/media/libstagefright/webm/WebmConstants.h
new file mode 100644
index 0000000..c53f458
--- /dev/null
+++ b/media/libstagefright/webm/WebmConstants.h
@@ -0,0 +1,133 @@
+/*
+ * Copyright (C) 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 WEBMCONSTANTS_H_
+#define WEBMCONSTANTS_H_
+
+#include <stdint.h>
+
+namespace webm {
+
+const int kMinEbmlVoidSize = 2;
+const int64_t kMaxMetaSeekSize = 64;
+const int64_t kMkvUnknownLength = 0x01ffffffffffffffl;
+
+// EBML element id's from http://matroska.org/technical/specs/index.html
+enum Mkv {
+    kMkvEbml = 0x1A45DFA3,
+    kMkvEbmlVersion = 0x4286,
+    kMkvEbmlReadVersion = 0x42F7,
+    kMkvEbmlMaxIdlength = 0x42F2,
+    kMkvEbmlMaxSizeLength = 0x42F3,
+    kMkvDocType = 0x4282,
+    kMkvDocTypeVersion = 0x4287,
+    kMkvDocTypeReadVersion = 0x4285,
+    kMkvVoid = 0xEC,
+    kMkvSignatureSlot = 0x1B538667,
+    kMkvSignatureAlgo = 0x7E8A,
+    kMkvSignatureHash = 0x7E9A,
+    kMkvSignaturePublicKey = 0x7EA5,
+    kMkvSignature = 0x7EB5,
+    kMkvSignatureElements = 0x7E5B,
+    kMkvSignatureElementList = 0x7E7B,
+    kMkvSignedElement = 0x6532,
+    kMkvSegment = 0x18538067,
+    kMkvSeekHead = 0x114D9B74,
+    kMkvSeek = 0x4DBB,
+    kMkvSeekId = 0x53AB,
+    kMkvSeekPosition = 0x53AC,
+    kMkvInfo = 0x1549A966,
+    kMkvTimecodeScale = 0x2AD7B1,
+    kMkvSegmentDuration = 0x4489,
+    kMkvDateUtc = 0x4461,
+    kMkvMuxingApp = 0x4D80,
+    kMkvWritingApp = 0x5741,
+    kMkvCluster = 0x1F43B675,
+    kMkvTimecode = 0xE7,
+    kMkvPrevSize = 0xAB,
+    kMkvBlockGroup = 0xA0,
+    kMkvBlock = 0xA1,
+    kMkvBlockAdditions = 0x75A1,
+    kMkvBlockMore = 0xA6,
+    kMkvBlockAddId = 0xEE,
+    kMkvBlockAdditional = 0xA5,
+    kMkvBlockDuration = 0x9B,
+    kMkvReferenceBlock = 0xFB,
+    kMkvLaceNumber = 0xCC,
+    kMkvSimpleBlock = 0xA3,
+    kMkvTracks = 0x1654AE6B,
+    kMkvTrackEntry = 0xAE,
+    kMkvTrackNumber = 0xD7,
+    kMkvTrackUid = 0x73C5,
+    kMkvTrackType = 0x83,
+    kMkvFlagEnabled = 0xB9,
+    kMkvFlagDefault = 0x88,
+    kMkvFlagForced = 0x55AA,
+    kMkvFlagLacing = 0x9C,
+    kMkvDefaultDuration = 0x23E383,
+    kMkvMaxBlockAdditionId = 0x55EE,
+    kMkvName = 0x536E,
+    kMkvLanguage = 0x22B59C,
+    kMkvCodecId = 0x86,
+    kMkvCodecPrivate = 0x63A2,
+    kMkvCodecName = 0x258688,
+    kMkvVideo = 0xE0,
+    kMkvFlagInterlaced = 0x9A,
+    kMkvStereoMode = 0x53B8,
+    kMkvAlphaMode = 0x53C0,
+    kMkvPixelWidth = 0xB0,
+    kMkvPixelHeight = 0xBA,
+    kMkvPixelCropBottom = 0x54AA,
+    kMkvPixelCropTop = 0x54BB,
+    kMkvPixelCropLeft = 0x54CC,
+    kMkvPixelCropRight = 0x54DD,
+    kMkvDisplayWidth = 0x54B0,
+    kMkvDisplayHeight = 0x54BA,
+    kMkvDisplayUnit = 0x54B2,
+    kMkvAspectRatioType = 0x54B3,
+    kMkvFrameRate = 0x2383E3,
+    kMkvAudio = 0xE1,
+    kMkvSamplingFrequency = 0xB5,
+    kMkvOutputSamplingFrequency = 0x78B5,
+    kMkvChannels = 0x9F,
+    kMkvBitDepth = 0x6264,
+    kMkvCues = 0x1C53BB6B,
+    kMkvCuePoint = 0xBB,
+    kMkvCueTime = 0xB3,
+    kMkvCueTrackPositions = 0xB7,
+    kMkvCueTrack = 0xF7,
+    kMkvCueClusterPosition = 0xF1,
+    kMkvCueBlockNumber = 0x5378
+};
+
+enum TrackTypes {
+    kInvalidType = -1,
+    kVideoType = 0x1,
+    kAudioType = 0x2,
+    kComplexType = 0x3,
+    kLogoType = 0x10,
+    kSubtitleType = 0x11,
+    kButtonsType = 0x12,
+    kControlType = 0x20
+};
+
+enum TrackNum {
+    kVideoTrackNum = 0x1,
+    kAudioTrackNum = 0x2
+};
+}
+
+#endif /* WEBMCONSTANTS_H_ */
diff --git a/media/libstagefright/webm/WebmElement.cpp b/media/libstagefright/webm/WebmElement.cpp
new file mode 100644
index 0000000..c978966
--- /dev/null
+++ b/media/libstagefright/webm/WebmElement.cpp
@@ -0,0 +1,367 @@
+/*
+ * Copyright (C) 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_NDEBUG 0
+#define LOG_TAG "WebmElement"
+
+#include "EbmlUtil.h"
+#include "WebmElement.h"
+#include "WebmConstants.h"
+
+#include <media/stagefright/foundation/ADebug.h>
+#include <utils/Log.h>
+
+#include <string.h>
+#include <unistd.h>
+#include <errno.h>
+#include <fcntl.h>
+#include <sys/mman.h>
+
+using namespace android;
+using namespace webm;
+
+namespace {
+
+int64_t voidSize(int64_t totalSize) {
+    if (totalSize < 2) {
+        return -1;
+    }
+    if (totalSize < 9) {
+        return totalSize - 2;
+    }
+    return totalSize - 9;
+}
+
+uint64_t childrenSum(const List<sp<WebmElement> >& children) {
+    uint64_t total = 0;
+    for (List<sp<WebmElement> >::const_iterator it = children.begin();
+            it != children.end(); ++it) {
+        total += (*it)->totalSize();
+    }
+    return total;
+}
+
+void populateCommonTrackEntries(
+        int num,
+        uint64_t uid,
+        bool lacing,
+        const char *lang,
+        const char *codec,
+        TrackTypes type,
+        List<sp<WebmElement> > &ls) {
+    ls.push_back(new WebmUnsigned(kMkvTrackNumber, num));
+    ls.push_back(new WebmUnsigned(kMkvTrackUid, uid));
+    ls.push_back(new WebmUnsigned(kMkvFlagLacing, lacing));
+    ls.push_back(new WebmString(kMkvLanguage, lang));
+    ls.push_back(new WebmString(kMkvCodecId, codec));
+    ls.push_back(new WebmUnsigned(kMkvTrackType, type));
+}
+}
+
+namespace android {
+
+WebmElement::WebmElement(uint64_t id, uint64_t size)
+    : mId(id), mSize(size) {
+}
+
+WebmElement::~WebmElement() {
+}
+
+int WebmElement::serializePayloadSize(uint8_t *buf) {
+    return serializeCodedUnsigned(encodeUnsigned(mSize), buf);
+}
+
+uint64_t WebmElement::serializeInto(uint8_t *buf) {
+    uint8_t *cur = buf;
+    int head = serializeCodedUnsigned(mId, cur);
+    cur += head;
+    int neck = serializePayloadSize(cur);
+    cur += neck;
+    serializePayload(cur);
+    cur += mSize;
+    return cur - buf;
+}
+
+uint64_t WebmElement::totalSize() {
+    uint8_t buf[8];
+    //............... + sizeOf(encodeUnsigned(size))
+    return sizeOf(mId) + serializePayloadSize(buf) + mSize;
+}
+
+uint8_t *WebmElement::serialize(uint64_t& size) {
+    size = totalSize();
+    uint8_t *buf = new uint8_t[size];
+    serializeInto(buf);
+    return buf;
+}
+
+int WebmElement::write(int fd, uint64_t& size) {
+    uint8_t buf[8];
+    size = totalSize();
+    off64_t off = ::lseek64(fd, (size - 1), SEEK_CUR) - (size - 1);
+    ::write(fd, buf, 1); // extend file
+
+    off64_t curOff = off + size;
+    off64_t alignedOff = off & ~(::sysconf(_SC_PAGE_SIZE) - 1);
+    off64_t mapSize = curOff - alignedOff;
+    off64_t pageOff = off - alignedOff;
+    void *dst = ::mmap64(NULL, mapSize, PROT_WRITE, MAP_SHARED, fd, alignedOff);
+    if ((int) dst == -1) {
+        ALOGE("mmap64 failed; errno = %d", errno);
+        ALOGE("fd %d; flags: %o", fd, ::fcntl(fd, F_GETFL, 0));
+        return errno;
+    } else {
+        serializeInto((uint8_t*) dst + pageOff);
+        ::msync(dst, mapSize, MS_SYNC);
+        return ::munmap(dst, mapSize);
+    }
+}
+
+//=================================================================================================
+
+WebmUnsigned::WebmUnsigned(uint64_t id, uint64_t value)
+    : WebmElement(id, sizeOf(value)), mValue(value) {
+}
+
+void WebmUnsigned::serializePayload(uint8_t *buf) {
+    serializeCodedUnsigned(mValue, buf);
+}
+
+//=================================================================================================
+
+WebmFloat::WebmFloat(uint64_t id, double value)
+    : WebmElement(id, sizeof(double)), mValue(value) {
+}
+
+WebmFloat::WebmFloat(uint64_t id, float value)
+    : WebmElement(id, sizeof(float)), mValue(value) {
+}
+
+void WebmFloat::serializePayload(uint8_t *buf) {
+    uint64_t data;
+    if (mSize == sizeof(float)) {
+        float f = mValue;
+        data = *reinterpret_cast<const uint32_t*>(&f);
+    } else {
+        data = *reinterpret_cast<const uint64_t*>(&mValue);
+    }
+    for (int i = mSize - 1; i >= 0; --i) {
+        buf[i] = data & 0xff;
+        data >>= 8;
+    }
+}
+
+//=================================================================================================
+
+WebmBinary::WebmBinary(uint64_t id, const sp<ABuffer> &ref)
+    : WebmElement(id, ref->size()), mRef(ref) {
+}
+
+void WebmBinary::serializePayload(uint8_t *buf) {
+    memcpy(buf, mRef->data(), mRef->size());
+}
+
+//=================================================================================================
+
+WebmString::WebmString(uint64_t id, const char *str)
+    : WebmElement(id, strlen(str)), mStr(str) {
+}
+
+void WebmString::serializePayload(uint8_t *buf) {
+    memcpy(buf, mStr, strlen(mStr));
+}
+
+//=================================================================================================
+
+WebmSimpleBlock::WebmSimpleBlock(
+        int trackNum,
+        int16_t relTimecode,
+        bool key,
+        const sp<ABuffer>& orig)
+    // ............................ trackNum*1 + timecode*2 + flags*1
+    //                                ^^^
+    // Only the least significant byte of trackNum is encoded
+    : WebmElement(kMkvSimpleBlock, orig->size() + 4),
+      mTrackNum(trackNum),
+      mRelTimecode(relTimecode),
+      mKey(key),
+      mRef(orig) {
+}
+
+void WebmSimpleBlock::serializePayload(uint8_t *buf) {
+    serializeCodedUnsigned(encodeUnsigned(mTrackNum), buf);
+    buf[1] = (mRelTimecode & 0xff00) >> 8;
+    buf[2] = mRelTimecode & 0xff;
+    buf[3] = mKey ? 0x80 : 0;
+    memcpy(buf + 4, mRef->data(), mSize - 4);
+}
+
+//=================================================================================================
+
+EbmlVoid::EbmlVoid(uint64_t totalSize)
+    : WebmElement(kMkvVoid, voidSize(totalSize)),
+      mSizeWidth(totalSize - sizeOf(kMkvVoid) - voidSize(totalSize)) {
+    CHECK_GE(voidSize(totalSize), 0);
+}
+
+int EbmlVoid::serializePayloadSize(uint8_t *buf) {
+    return serializeCodedUnsigned(encodeUnsigned(mSize, mSizeWidth), buf);
+}
+
+void EbmlVoid::serializePayload(uint8_t *buf) {
+    ::memset(buf, 0, mSize);
+    return;
+}
+
+//=================================================================================================
+
+WebmMaster::WebmMaster(uint64_t id, const List<sp<WebmElement> >& children)
+    : WebmElement(id, childrenSum(children)), mChildren(children) {
+}
+
+WebmMaster::WebmMaster(uint64_t id)
+    : WebmElement(id, 0) {
+}
+
+int WebmMaster::serializePayloadSize(uint8_t *buf) {
+    if (mSize == 0){
+        return serializeCodedUnsigned(kMkvUnknownLength, buf);
+    }
+    return WebmElement::serializePayloadSize(buf);
+}
+
+void WebmMaster::serializePayload(uint8_t *buf) {
+    uint64_t off = 0;
+    for (List<sp<WebmElement> >::const_iterator it = mChildren.begin(); it != mChildren.end();
+            ++it) {
+        sp<WebmElement> child = (*it);
+        child->serializeInto(buf + off);
+        off += child->totalSize();
+    }
+}
+
+//=================================================================================================
+
+sp<WebmElement> WebmElement::CuePointEntry(uint64_t time, int track, uint64_t off) {
+    List<sp<WebmElement> > cuePointEntryFields;
+    cuePointEntryFields.push_back(new WebmUnsigned(kMkvCueTrack, track));
+    cuePointEntryFields.push_back(new WebmUnsigned(kMkvCueClusterPosition, off));
+    WebmElement *cueTrackPositions = new WebmMaster(kMkvCueTrackPositions, cuePointEntryFields);
+
+    cuePointEntryFields.clear();
+    cuePointEntryFields.push_back(new WebmUnsigned(kMkvCueTime, time));
+    cuePointEntryFields.push_back(cueTrackPositions);
+    return new WebmMaster(kMkvCuePoint, cuePointEntryFields);
+}
+
+sp<WebmElement> WebmElement::SeekEntry(uint64_t id, uint64_t off) {
+    List<sp<WebmElement> > seekEntryFields;
+    seekEntryFields.push_back(new WebmUnsigned(kMkvSeekId, id));
+    seekEntryFields.push_back(new WebmUnsigned(kMkvSeekPosition, off));
+    return new WebmMaster(kMkvSeek, seekEntryFields);
+}
+
+sp<WebmElement> WebmElement::EbmlHeader(
+        int ver,
+        int readVer,
+        int maxIdLen,
+        int maxSizeLen,
+        int docVer,
+        int docReadVer) {
+    List<sp<WebmElement> > headerFields;
+    headerFields.push_back(new WebmUnsigned(kMkvEbmlVersion, ver));
+    headerFields.push_back(new WebmUnsigned(kMkvEbmlReadVersion, readVer));
+    headerFields.push_back(new WebmUnsigned(kMkvEbmlMaxIdlength, maxIdLen));
+    headerFields.push_back(new WebmUnsigned(kMkvEbmlMaxSizeLength, maxSizeLen));
+    headerFields.push_back(new WebmString(kMkvDocType, "webm"));
+    headerFields.push_back(new WebmUnsigned(kMkvDocTypeVersion, docVer));
+    headerFields.push_back(new WebmUnsigned(kMkvDocTypeReadVersion, docReadVer));
+    return new WebmMaster(kMkvEbml, headerFields);
+}
+
+sp<WebmElement> WebmElement::SegmentInfo(uint64_t scale, double dur) {
+    List<sp<WebmElement> > segmentInfo;
+    // place duration first; easier to patch
+    segmentInfo.push_back(new WebmFloat(kMkvSegmentDuration, dur));
+    segmentInfo.push_back(new WebmUnsigned(kMkvTimecodeScale, scale));
+    segmentInfo.push_back(new WebmString(kMkvMuxingApp, "android"));
+    segmentInfo.push_back(new WebmString(kMkvWritingApp, "android"));
+    return new WebmMaster(kMkvInfo, segmentInfo);
+}
+
+sp<WebmElement> WebmElement::AudioTrackEntry(
+        int chans,
+        double rate,
+        const sp<ABuffer> &buf,
+        int bps,
+        uint64_t uid,
+        bool lacing,
+        const char *lang) {
+    if (uid == 0) {
+        uid = kAudioTrackNum;
+    }
+
+    List<sp<WebmElement> > trackEntryFields;
+    populateCommonTrackEntries(
+            kAudioTrackNum,
+            uid,
+            lacing,
+            lang,
+            "A_VORBIS",
+            kAudioType,
+            trackEntryFields);
+
+    List<sp<WebmElement> > audioInfo;
+    audioInfo.push_back(new WebmUnsigned(kMkvChannels, chans));
+    audioInfo.push_back(new WebmFloat(kMkvSamplingFrequency, rate));
+    if (bps) {
+        WebmElement *bitDepth = new WebmUnsigned(kMkvBitDepth, bps);
+        audioInfo.push_back(bitDepth);
+    }
+
+    trackEntryFields.push_back(new WebmMaster(kMkvAudio, audioInfo));
+    trackEntryFields.push_back(new WebmBinary(kMkvCodecPrivate, buf));
+    return new WebmMaster(kMkvTrackEntry, trackEntryFields);
+}
+
+sp<WebmElement> WebmElement::VideoTrackEntry(
+        uint64_t width,
+        uint64_t height,
+        uint64_t uid,
+        bool lacing,
+        const char *lang) {
+    if (uid == 0) {
+        uid = kVideoTrackNum;
+    }
+
+    List<sp<WebmElement> > trackEntryFields;
+    populateCommonTrackEntries(
+            kVideoTrackNum,
+            uid,
+            lacing,
+            lang,
+            "V_VP8",
+            kVideoType,
+            trackEntryFields);
+
+    List<sp<WebmElement> > videoInfo;
+    videoInfo.push_back(new WebmUnsigned(kMkvPixelWidth, width));
+    videoInfo.push_back(new WebmUnsigned(kMkvPixelHeight, height));
+
+    trackEntryFields.push_back(new WebmMaster(kMkvVideo, videoInfo));
+    return new WebmMaster(kMkvTrackEntry, trackEntryFields);
+}
+} /* namespace android */
diff --git a/media/libstagefright/webm/WebmElement.h b/media/libstagefright/webm/WebmElement.h
new file mode 100644
index 0000000..f19933e
--- /dev/null
+++ b/media/libstagefright/webm/WebmElement.h
@@ -0,0 +1,127 @@
+/*
+ * Copyright (C) 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 WEBMELEMENT_H_
+#define WEBMELEMENT_H_
+
+#include <media/stagefright/MediaBuffer.h>
+#include <media/stagefright/foundation/ABase.h>
+#include <media/stagefright/foundation/ABuffer.h>
+#include <utils/List.h>
+
+namespace android {
+
+struct WebmElement : public LightRefBase<WebmElement> {
+    const uint64_t mId, mSize;
+
+    WebmElement(uint64_t id, uint64_t size);
+    virtual ~WebmElement();
+
+    virtual int serializePayloadSize(uint8_t *buf);
+    virtual void serializePayload(uint8_t *buf)=0;
+    uint64_t totalSize();
+    uint64_t serializeInto(uint8_t *buf);
+    uint8_t *serialize(uint64_t& size);
+    int write(int fd, uint64_t& size);
+
+    static sp<WebmElement> EbmlHeader(
+            int ver = 1,
+            int readVer = 1,
+            int maxIdLen = 4,
+            int maxSizeLen = 8,
+            int docVer = 2,
+            int docReadVer = 2);
+
+    static sp<WebmElement> SegmentInfo(uint64_t scale = 1000000, double dur = 0);
+
+    static sp<WebmElement> AudioTrackEntry(
+            int chans,
+            double rate,
+            const sp<ABuffer> &buf,
+            int bps = 0,
+            uint64_t uid = 0,
+            bool lacing = false,
+            const char *lang = "und");
+
+    static sp<WebmElement> VideoTrackEntry(
+            uint64_t width,
+            uint64_t height,
+            uint64_t uid = 0,
+            bool lacing = false,
+            const char *lang = "und");
+
+    static sp<WebmElement> SeekEntry(uint64_t id, uint64_t off);
+    static sp<WebmElement> CuePointEntry(uint64_t time, int track, uint64_t off);
+    static sp<WebmElement> SimpleBlock(
+            int trackNum,
+            int16_t timecode,
+            bool key,
+            const uint8_t *data,
+            uint64_t dataSize);
+};
+
+struct WebmUnsigned : public WebmElement {
+    WebmUnsigned(uint64_t id, uint64_t value);
+    const uint64_t mValue;
+    void serializePayload(uint8_t *buf);
+};
+
+struct WebmFloat : public WebmElement {
+    const double mValue;
+    WebmFloat(uint64_t id, float value);
+    WebmFloat(uint64_t id, double value);
+    void serializePayload(uint8_t *buf);
+};
+
+struct WebmBinary : public WebmElement {
+    const sp<ABuffer> mRef;
+    WebmBinary(uint64_t id, const sp<ABuffer> &ref);
+    void serializePayload(uint8_t *buf);
+};
+
+struct WebmString : public WebmElement {
+    const char *const mStr;
+    WebmString(uint64_t id, const char *str);
+    void serializePayload(uint8_t *buf);
+};
+
+struct WebmSimpleBlock : public WebmElement {
+    const int mTrackNum;
+    const int16_t mRelTimecode;
+    const bool mKey;
+    const sp<ABuffer> mRef;
+
+    WebmSimpleBlock(int trackNum, int16_t timecode, bool key, const sp<ABuffer>& orig);
+    void serializePayload(uint8_t *buf);
+};
+
+struct EbmlVoid : public WebmElement {
+    const uint64_t mSizeWidth;
+    EbmlVoid(uint64_t totalSize);
+    int serializePayloadSize(uint8_t *buf);
+    void serializePayload(uint8_t *buf);
+};
+
+struct WebmMaster : public WebmElement {
+    const List<sp<WebmElement> > mChildren;
+    WebmMaster(uint64_t id);
+    WebmMaster(uint64_t id, const List<sp<WebmElement> > &children);
+    int serializePayloadSize(uint8_t *buf);
+    void serializePayload(uint8_t *buf);
+};
+
+} /* namespace android */
+#endif /* WEBMELEMENT_H_ */
diff --git a/media/libstagefright/webm/WebmFrame.cpp b/media/libstagefright/webm/WebmFrame.cpp
new file mode 100644
index 0000000..e5134ed
--- /dev/null
+++ b/media/libstagefright/webm/WebmFrame.cpp
@@ -0,0 +1,83 @@
+/*
+ * Copyright (C) 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_NDEBUG 0
+#define LOG_TAG "WebmFrame"
+
+#include "WebmFrame.h"
+#include "WebmConstants.h"
+
+#include <media/stagefright/foundation/ADebug.h>
+#include <unistd.h>
+
+using namespace android;
+using namespace webm;
+
+namespace {
+sp<ABuffer> toABuffer(MediaBuffer *mbuf) {
+    sp<ABuffer> abuf = new ABuffer(mbuf->range_length());
+    memcpy(abuf->data(), (uint8_t*) mbuf->data() + mbuf->range_offset(), mbuf->range_length());
+    return abuf;
+}
+}
+
+namespace android {
+
+const sp<WebmFrame> WebmFrame::EOS = new WebmFrame();
+
+WebmFrame::WebmFrame()
+    : mType(kInvalidType),
+      mKey(false),
+      mAbsTimecode(UINT64_MAX),
+      mData(new ABuffer(0)),
+      mEos(true) {
+}
+
+WebmFrame::WebmFrame(int type, bool key, uint64_t absTimecode, MediaBuffer *mbuf)
+    : mType(type),
+      mKey(key),
+      mAbsTimecode(absTimecode),
+      mData(toABuffer(mbuf)),
+      mEos(false) {
+}
+
+sp<WebmElement> WebmFrame::SimpleBlock(uint64_t baseTimecode) const {
+    return new WebmSimpleBlock(
+            mType == kVideoType ? kVideoTrackNum : kAudioTrackNum,
+            mAbsTimecode - baseTimecode,
+            mKey,
+            mData);
+}
+
+bool WebmFrame::operator<(const WebmFrame &other) const {
+    if (this->mEos) {
+        return false;
+    }
+    if (other.mEos) {
+        return true;
+    }
+    if (this->mAbsTimecode == other.mAbsTimecode) {
+        if (this->mType == kAudioType && other.mType == kVideoType) {
+            return true;
+        }
+        if (this->mType == kVideoType && other.mType == kAudioType) {
+            return false;
+        }
+        return false;
+    }
+    return this->mAbsTimecode < other.mAbsTimecode;
+}
+} /* namespace android */
diff --git a/media/libstagefright/webm/WebmFrame.h b/media/libstagefright/webm/WebmFrame.h
new file mode 100644
index 0000000..4f0b055
--- /dev/null
+++ b/media/libstagefright/webm/WebmFrame.h
@@ -0,0 +1,46 @@
+/*
+ * Copyright (C) 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 WEBMFRAME_H_
+#define WEBMFRAME_H_
+
+#include "WebmElement.h"
+
+namespace android {
+
+struct WebmFrame : LightRefBase<WebmFrame> {
+public:
+    const int mType;
+    const bool mKey;
+    const uint64_t mAbsTimecode;
+    const sp<ABuffer> mData;
+    const bool mEos;
+
+    WebmFrame();
+    WebmFrame(int type, bool key, uint64_t absTimecode, MediaBuffer *buf);
+    ~WebmFrame() {}
+
+    sp<WebmElement> SimpleBlock(uint64_t baseTimecode) const;
+
+    bool operator<(const WebmFrame &other) const;
+
+    static const sp<WebmFrame> EOS;
+private:
+    DISALLOW_EVIL_CONSTRUCTORS(WebmFrame);
+};
+
+} /* namespace android */
+#endif /* WEBMFRAME_H_ */
diff --git a/media/libstagefright/webm/WebmFrameThread.cpp b/media/libstagefright/webm/WebmFrameThread.cpp
new file mode 100644
index 0000000..5addd3c
--- /dev/null
+++ b/media/libstagefright/webm/WebmFrameThread.cpp
@@ -0,0 +1,399 @@
+/*
+ * Copyright (C) 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_NDEBUG 0
+#define LOG_TAG "WebmFrameThread"
+
+#include "WebmConstants.h"
+#include "WebmFrameThread.h"
+
+#include <media/stagefright/MetaData.h>
+#include <media/stagefright/foundation/ADebug.h>
+
+#include <utils/Log.h>
+#include <inttypes.h>
+
+using namespace webm;
+
+namespace android {
+
+void *WebmFrameThread::wrap(void *arg) {
+    WebmFrameThread *worker = reinterpret_cast<WebmFrameThread*>(arg);
+    worker->run();
+    return NULL;
+}
+
+status_t WebmFrameThread::start() {
+    pthread_attr_t attr;
+    pthread_attr_init(&attr);
+    pthread_attr_setdetachstate(&attr, PTHREAD_CREATE_JOINABLE);
+    pthread_create(&mThread, &attr, WebmFrameThread::wrap, this);
+    pthread_attr_destroy(&attr);
+    return OK;
+}
+
+status_t WebmFrameThread::stop() {
+    void *status;
+    pthread_join(mThread, &status);
+    return (status_t) status;
+}
+
+//=================================================================================================
+
+WebmFrameSourceThread::WebmFrameSourceThread(
+    int type,
+    LinkedBlockingQueue<const sp<WebmFrame> >& sink)
+    : mType(type), mSink(sink) {
+}
+
+//=================================================================================================
+
+WebmFrameSinkThread::WebmFrameSinkThread(
+        const int& fd,
+        const uint64_t& off,
+        sp<WebmFrameSourceThread> videoThread,
+        sp<WebmFrameSourceThread> audioThread,
+        List<sp<WebmElement> >& cues)
+    : mFd(fd),
+      mSegmentDataStart(off),
+      mVideoFrames(videoThread->mSink),
+      mAudioFrames(audioThread->mSink),
+      mCues(cues),
+      mDone(true) {
+}
+
+WebmFrameSinkThread::WebmFrameSinkThread(
+        const int& fd,
+        const uint64_t& off,
+        LinkedBlockingQueue<const sp<WebmFrame> >& videoSource,
+        LinkedBlockingQueue<const sp<WebmFrame> >& audioSource,
+        List<sp<WebmElement> >& cues)
+    : mFd(fd),
+      mSegmentDataStart(off),
+      mVideoFrames(videoSource),
+      mAudioFrames(audioSource),
+      mCues(cues),
+      mDone(true) {
+}
+
+// Initializes a webm cluster with its starting timecode.
+//
+// frames:
+//   sequence of input audio/video frames received from the source.
+//
+// clusterTimecodeL:
+//   the starting timecode of the cluster; this is the timecode of the first
+//   frame since frames are ordered by timestamp.
+//
+// children:
+//   list to hold child elements in a webm cluster (start timecode and
+//   simple blocks).
+//
+// static
+void WebmFrameSinkThread::initCluster(
+    List<const sp<WebmFrame> >& frames,
+    uint64_t& clusterTimecodeL,
+    List<sp<WebmElement> >& children) {
+    CHECK(!frames.empty() && children.empty());
+
+    const sp<WebmFrame> f = *(frames.begin());
+    clusterTimecodeL = f->mAbsTimecode;
+    WebmUnsigned *clusterTimecode = new WebmUnsigned(kMkvTimecode, clusterTimecodeL);
+    children.clear();
+    children.push_back(clusterTimecode);
+}
+
+void WebmFrameSinkThread::writeCluster(List<sp<WebmElement> >& children) {
+    // children must contain at least one simpleblock and its timecode
+    CHECK_GE(children.size(), 2);
+
+    uint64_t size;
+    sp<WebmElement> cluster = new WebmMaster(kMkvCluster, children);
+    cluster->write(mFd, size);
+    children.clear();
+}
+
+// Write out (possibly multiple) webm cluster(s) from frames split on video key frames.
+//
+// last:
+//   current flush is triggered by EOS instead of a second outstanding video key frame.
+void WebmFrameSinkThread::flushFrames(List<const sp<WebmFrame> >& frames, bool last) {
+    if (frames.empty()) {
+        return;
+    }
+
+    uint64_t clusterTimecodeL;
+    List<sp<WebmElement> > children;
+    initCluster(frames, clusterTimecodeL, children);
+
+    uint64_t cueTime = clusterTimecodeL;
+    off_t fpos = ::lseek(mFd, 0, SEEK_CUR);
+    size_t n = frames.size();
+    if (!last) {
+        // If we are not flushing the last sequence of outstanding frames, flushFrames
+        // must have been called right after we have pushed a second outstanding video key
+        // frame (the last frame), which belongs to the next cluster; also hold back on
+        // flushing the second to last frame before we check its type. A audio frame
+        // should precede the aforementioned video key frame in the next sequence, a video
+        // frame should be the last frame in the current (to-be-flushed) sequence.
+        CHECK_GE(n, 2);
+        n -= 2;
+    }
+
+    for (size_t i = 0; i < n; i++) {
+        const sp<WebmFrame> f = *(frames.begin());
+        if (f->mType == kVideoType && f->mKey) {
+            cueTime = f->mAbsTimecode;
+        }
+
+        if (f->mAbsTimecode - clusterTimecodeL > INT16_MAX) {
+            writeCluster(children);
+            initCluster(frames, clusterTimecodeL, children);
+        }
+
+        frames.erase(frames.begin());
+        children.push_back(f->SimpleBlock(clusterTimecodeL));
+    }
+
+    // equivalent to last==false
+    if (!frames.empty()) {
+        // decide whether to write out the second to last frame.
+        const sp<WebmFrame> secondLastFrame = *(frames.begin());
+        if (secondLastFrame->mType == kVideoType) {
+            frames.erase(frames.begin());
+            children.push_back(secondLastFrame->SimpleBlock(clusterTimecodeL));
+        }
+    }
+
+    writeCluster(children);
+    sp<WebmElement> cuePoint = WebmElement::CuePointEntry(cueTime, 1, fpos - mSegmentDataStart);
+    mCues.push_back(cuePoint);
+}
+
+status_t WebmFrameSinkThread::start() {
+    mDone = false;
+    return WebmFrameThread::start();
+}
+
+status_t WebmFrameSinkThread::stop() {
+    mDone = true;
+    mVideoFrames.push(WebmFrame::EOS);
+    mAudioFrames.push(WebmFrame::EOS);
+    return WebmFrameThread::stop();
+}
+
+void WebmFrameSinkThread::run() {
+    int numVideoKeyFrames = 0;
+    List<const sp<WebmFrame> > outstandingFrames;
+    while (!mDone) {
+        ALOGV("wait v frame");
+        const sp<WebmFrame> videoFrame = mVideoFrames.peek();
+        ALOGV("v frame: %p", videoFrame.get());
+
+        ALOGV("wait a frame");
+        const sp<WebmFrame> audioFrame = mAudioFrames.peek();
+        ALOGV("a frame: %p", audioFrame.get());
+
+        if (videoFrame->mEos && audioFrame->mEos) {
+            break;
+        }
+
+        if (*audioFrame < *videoFrame) {
+            ALOGV("take a frame");
+            mAudioFrames.take();
+            outstandingFrames.push_back(audioFrame);
+        } else {
+            ALOGV("take v frame");
+            mVideoFrames.take();
+            outstandingFrames.push_back(videoFrame);
+            if (videoFrame->mKey)
+                numVideoKeyFrames++;
+        }
+
+        if (numVideoKeyFrames == 2) {
+            flushFrames(outstandingFrames, /* last = */ false);
+            numVideoKeyFrames--;
+        }
+    }
+    ALOGV("flushing last cluster (size %zu)", outstandingFrames.size());
+    flushFrames(outstandingFrames, /* last = */ true);
+    mDone = true;
+}
+
+//=================================================================================================
+
+static const int64_t kInitialDelayTimeUs = 700000LL;
+
+void WebmFrameMediaSourceThread::clearFlags() {
+    mDone = false;
+    mPaused = false;
+    mResumed = false;
+    mStarted = false;
+    mReachedEOS = false;
+}
+
+WebmFrameMediaSourceThread::WebmFrameMediaSourceThread(
+        const sp<MediaSource>& source,
+        int type,
+        LinkedBlockingQueue<const sp<WebmFrame> >& sink,
+        uint64_t timeCodeScale,
+        int64_t startTimeRealUs,
+        int32_t startTimeOffsetMs,
+        int numTracks,
+        bool realTimeRecording)
+    : WebmFrameSourceThread(type, sink),
+      mSource(source),
+      mTimeCodeScale(timeCodeScale),
+      mTrackDurationUs(0) {
+    clearFlags();
+    mStartTimeUs = startTimeRealUs;
+    if (realTimeRecording && numTracks > 1) {
+        /*
+         * Copied from MPEG4Writer
+         *
+         * This extra delay of accepting incoming audio/video signals
+         * helps to align a/v start time at the beginning of a recording
+         * session, and it also helps eliminate the "recording" sound for
+         * camcorder applications.
+         *
+         * If client does not set the start time offset, we fall back to
+         * use the default initial delay value.
+         */
+        int64_t startTimeOffsetUs = startTimeOffsetMs * 1000LL;
+        if (startTimeOffsetUs < 0) {  // Start time offset was not set
+            startTimeOffsetUs = kInitialDelayTimeUs;
+        }
+        mStartTimeUs += startTimeOffsetUs;
+        ALOGI("Start time offset: %" PRId64 " us", startTimeOffsetUs);
+    }
+}
+
+status_t WebmFrameMediaSourceThread::start() {
+    sp<MetaData> meta = new MetaData;
+    meta->setInt64(kKeyTime, mStartTimeUs);
+    status_t err = mSource->start(meta.get());
+    if (err != OK) {
+        mDone = true;
+        mReachedEOS = true;
+        return err;
+    } else {
+        mStarted = true;
+        return WebmFrameThread::start();
+    }
+}
+
+status_t WebmFrameMediaSourceThread::resume() {
+    if (!mDone && mPaused) {
+        mPaused = false;
+        mResumed = true;
+    }
+    return OK;
+}
+
+status_t WebmFrameMediaSourceThread::pause() {
+    if (mStarted) {
+        mPaused = true;
+    }
+    return OK;
+}
+
+status_t WebmFrameMediaSourceThread::stop() {
+    if (mStarted) {
+        mStarted = false;
+        mDone = true;
+        mSource->stop();
+        return WebmFrameThread::stop();
+    }
+    return OK;
+}
+
+void WebmFrameMediaSourceThread::run() {
+    int32_t count = 0;
+    int64_t timestampUs = 0xdeadbeef;
+    int64_t lastTimestampUs = 0; // Previous sample time stamp
+    int64_t lastDurationUs = 0; // Previous sample duration
+    int64_t previousPausedDurationUs = 0;
+
+    const uint64_t kUninitialized = 0xffffffffffffffffL;
+    mStartTimeUs = kUninitialized;
+
+    status_t err = OK;
+    MediaBuffer *buffer;
+    while (!mDone && (err = mSource->read(&buffer, NULL)) == OK) {
+        if (buffer->range_length() == 0) {
+            buffer->release();
+            buffer = NULL;
+            continue;
+        }
+
+        sp<MetaData> md = buffer->meta_data();
+        CHECK(md->findInt64(kKeyTime, &timestampUs));
+        if (mStartTimeUs == kUninitialized) {
+            mStartTimeUs = timestampUs;
+        }
+        timestampUs -= mStartTimeUs;
+
+        if (mPaused && !mResumed) {
+            lastDurationUs = timestampUs - lastTimestampUs;
+            lastTimestampUs = timestampUs;
+            buffer->release();
+            buffer = NULL;
+            continue;
+        }
+        ++count;
+
+        // adjust time-stamps after pause/resume
+        if (mResumed) {
+            int64_t durExcludingEarlierPausesUs = timestampUs - previousPausedDurationUs;
+            CHECK_GE(durExcludingEarlierPausesUs, 0ll);
+            int64_t pausedDurationUs = durExcludingEarlierPausesUs - mTrackDurationUs;
+            CHECK_GE(pausedDurationUs, lastDurationUs);
+            previousPausedDurationUs += pausedDurationUs - lastDurationUs;
+            mResumed = false;
+        }
+        timestampUs -= previousPausedDurationUs;
+        CHECK_GE(timestampUs, 0ll);
+
+        int32_t isSync = false;
+        md->findInt32(kKeyIsSyncFrame, &isSync);
+        const sp<WebmFrame> f = new WebmFrame(
+            mType,
+            isSync,
+            timestampUs * 1000 / mTimeCodeScale,
+            buffer);
+        mSink.push(f);
+
+        ALOGV(
+            "%s %s frame at %" PRId64 " size %zu\n",
+            mType == kVideoType ? "video" : "audio",
+            isSync ? "I" : "P",
+            timestampUs * 1000 / mTimeCodeScale,
+            buffer->range_length());
+
+        buffer->release();
+        buffer = NULL;
+
+        if (timestampUs > mTrackDurationUs) {
+            mTrackDurationUs = timestampUs;
+        }
+        lastDurationUs = timestampUs - lastTimestampUs;
+        lastTimestampUs = timestampUs;
+    }
+
+    mTrackDurationUs += lastDurationUs;
+    mSink.push(WebmFrame::EOS);
+}
+}
diff --git a/media/libstagefright/webm/WebmFrameThread.h b/media/libstagefright/webm/WebmFrameThread.h
new file mode 100644
index 0000000..d65d9b7
--- /dev/null
+++ b/media/libstagefright/webm/WebmFrameThread.h
@@ -0,0 +1,160 @@
+/*
+ * Copyright (C) 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 WEBMFRAMETHREAD_H_
+#define WEBMFRAMETHREAD_H_
+
+#include "WebmFrame.h"
+#include "LinkedBlockingQueue.h"
+
+#include <media/stagefright/FileSource.h>
+#include <media/stagefright/MediaSource.h>
+
+#include <utils/List.h>
+#include <utils/Errors.h>
+
+#include <pthread.h>
+
+namespace android {
+
+class WebmFrameThread : public LightRefBase<WebmFrameThread> {
+public:
+    virtual void run() = 0;
+    virtual bool running() { return false; }
+    virtual status_t start();
+    virtual status_t pause() { return OK; }
+    virtual status_t resume() { return OK; }
+    virtual status_t stop();
+    virtual ~WebmFrameThread() { stop(); }
+    static void *wrap(void *arg);
+
+protected:
+    WebmFrameThread()
+        : mThread(0) {
+    }
+
+private:
+    pthread_t mThread;
+    DISALLOW_EVIL_CONSTRUCTORS(WebmFrameThread);
+};
+
+//=================================================================================================
+
+class WebmFrameSourceThread;
+class WebmFrameSinkThread : public WebmFrameThread {
+public:
+    WebmFrameSinkThread(
+            const int& fd,
+            const uint64_t& off,
+            sp<WebmFrameSourceThread> videoThread,
+            sp<WebmFrameSourceThread> audioThread,
+            List<sp<WebmElement> >& cues);
+
+    WebmFrameSinkThread(
+            const int& fd,
+            const uint64_t& off,
+            LinkedBlockingQueue<const sp<WebmFrame> >& videoSource,
+            LinkedBlockingQueue<const sp<WebmFrame> >& audioSource,
+            List<sp<WebmElement> >& cues);
+
+    void run();
+    bool running() {
+        return !mDone;
+    }
+    status_t start();
+    status_t stop();
+
+private:
+    const int& mFd;
+    const uint64_t& mSegmentDataStart;
+    LinkedBlockingQueue<const sp<WebmFrame> >& mVideoFrames;
+    LinkedBlockingQueue<const sp<WebmFrame> >& mAudioFrames;
+    List<sp<WebmElement> >& mCues;
+
+    volatile bool mDone;
+
+    static void initCluster(
+            List<const sp<WebmFrame> >& frames,
+            uint64_t& clusterTimecodeL,
+            List<sp<WebmElement> >& children);
+    void writeCluster(List<sp<WebmElement> >& children);
+    void flushFrames(List<const sp<WebmFrame> >& frames, bool last);
+};
+
+//=================================================================================================
+
+class WebmFrameSourceThread : public WebmFrameThread {
+public:
+    WebmFrameSourceThread(int type, LinkedBlockingQueue<const sp<WebmFrame> >& sink);
+    virtual int64_t getDurationUs() = 0;
+protected:
+    const int mType;
+    LinkedBlockingQueue<const sp<WebmFrame> >& mSink;
+
+    friend class WebmFrameSinkThread;
+};
+
+//=================================================================================================
+
+class WebmFrameEmptySourceThread : public WebmFrameSourceThread {
+public:
+    WebmFrameEmptySourceThread(int type, LinkedBlockingQueue<const sp<WebmFrame> >& sink)
+        : WebmFrameSourceThread(type, sink) {
+    }
+    void run() { mSink.push(WebmFrame::EOS); }
+    int64_t getDurationUs() { return 0; }
+};
+
+//=================================================================================================
+
+class WebmFrameMediaSourceThread: public WebmFrameSourceThread {
+public:
+    WebmFrameMediaSourceThread(
+            const sp<MediaSource>& source,
+            int type,
+            LinkedBlockingQueue<const sp<WebmFrame> >& sink,
+            uint64_t timeCodeScale,
+            int64_t startTimeRealUs,
+            int32_t startTimeOffsetMs,
+            int numPeers,
+            bool realTimeRecording);
+
+    void run();
+    status_t start();
+    status_t resume();
+    status_t pause();
+    status_t stop();
+    int64_t getDurationUs() {
+        return mTrackDurationUs;
+    }
+
+private:
+    const sp<MediaSource> mSource;
+    const uint64_t mTimeCodeScale;
+    uint64_t mStartTimeUs;
+
+    volatile bool mDone;
+    volatile bool mPaused;
+    volatile bool mResumed;
+    volatile bool mStarted;
+    volatile bool mReachedEOS;
+    int64_t mTrackDurationUs;
+
+    void clearFlags();
+};
+} /* namespace android */
+
+#endif /* WEBMFRAMETHREAD_H_ */
diff --git a/media/libstagefright/webm/WebmWriter.cpp b/media/libstagefright/webm/WebmWriter.cpp
new file mode 100644
index 0000000..03cf92a
--- /dev/null
+++ b/media/libstagefright/webm/WebmWriter.cpp
@@ -0,0 +1,551 @@
+/*
+ * Copyright (C) 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_NDEBUG 0
+#define LOG_TAG "WebmWriter"
+
+#include "EbmlUtil.h"
+#include "WebmWriter.h"
+
+#include <media/stagefright/MetaData.h>
+#include <media/stagefright/MediaDefs.h>
+#include <media/stagefright/foundation/ADebug.h>
+
+#include <utils/Errors.h>
+
+#include <unistd.h>
+#include <fcntl.h>
+#include <sys/stat.h>
+#include <inttypes.h>
+
+using namespace webm;
+
+namespace {
+size_t XiphLaceCodeLen(size_t size) {
+    return size / 0xff + 1;
+}
+
+size_t XiphLaceEnc(uint8_t *buf, size_t size) {
+    size_t i;
+    for (i = 0; size >= 0xff; ++i, size -= 0xff) {
+        buf[i] = 0xff;
+    }
+    buf[i++] = size;
+    return i;
+}
+}
+
+namespace android {
+
+static const int64_t kMinStreamableFileSizeInBytes = 5 * 1024 * 1024;
+
+WebmWriter::WebmWriter(int fd)
+    : mFd(dup(fd)),
+      mInitCheck(mFd < 0 ? NO_INIT : OK),
+      mTimeCodeScale(1000000),
+      mStartTimestampUs(0),
+      mStartTimeOffsetMs(0),
+      mSegmentOffset(0),
+      mSegmentDataStart(0),
+      mInfoOffset(0),
+      mInfoSize(0),
+      mTracksOffset(0),
+      mCuesOffset(0),
+      mPaused(false),
+      mStarted(false),
+      mIsFileSizeLimitExplicitlyRequested(false),
+      mIsRealTimeRecording(false),
+      mStreamableFile(true),
+      mEstimatedCuesSize(0) {
+    mStreams[kAudioIndex] = WebmStream(kAudioType, "Audio", &WebmWriter::audioTrack);
+    mStreams[kVideoIndex] = WebmStream(kVideoType, "Video", &WebmWriter::videoTrack);
+    mSinkThread = new WebmFrameSinkThread(
+            mFd,
+            mSegmentDataStart,
+            mStreams[kVideoIndex].mSink,
+            mStreams[kAudioIndex].mSink,
+            mCuePoints);
+}
+
+WebmWriter::WebmWriter(const char *filename)
+    : mInitCheck(NO_INIT),
+      mTimeCodeScale(1000000),
+      mStartTimestampUs(0),
+      mStartTimeOffsetMs(0),
+      mSegmentOffset(0),
+      mSegmentDataStart(0),
+      mInfoOffset(0),
+      mInfoSize(0),
+      mTracksOffset(0),
+      mCuesOffset(0),
+      mPaused(false),
+      mStarted(false),
+      mIsFileSizeLimitExplicitlyRequested(false),
+      mIsRealTimeRecording(false),
+      mStreamableFile(true),
+      mEstimatedCuesSize(0) {
+    mFd = open(filename, O_CREAT | O_LARGEFILE | O_TRUNC | O_RDWR, S_IRUSR | S_IWUSR);
+    if (mFd >= 0) {
+        ALOGV("fd %d; flags: %o", mFd, fcntl(mFd, F_GETFL, 0));
+        mInitCheck = OK;
+    }
+    mStreams[kAudioIndex] = WebmStream(kAudioType, "Audio", &WebmWriter::audioTrack);
+    mStreams[kVideoIndex] = WebmStream(kVideoType, "Video", &WebmWriter::videoTrack);
+    mSinkThread = new WebmFrameSinkThread(
+            mFd,
+            mSegmentDataStart,
+            mStreams[kVideoIndex].mSink,
+            mStreams[kAudioIndex].mSink,
+            mCuePoints);
+}
+
+// static
+sp<WebmElement> WebmWriter::videoTrack(const sp<MetaData>& md) {
+    int32_t width, height;
+    CHECK(md->findInt32(kKeyWidth, &width));
+    CHECK(md->findInt32(kKeyHeight, &height));
+    return WebmElement::VideoTrackEntry(width, height);
+}
+
+// static
+sp<WebmElement> WebmWriter::audioTrack(const sp<MetaData>& md) {
+    int32_t nChannels, samplerate;
+    uint32_t type;
+    const void *headerData1;
+    const char headerData2[] = { 3, 'v', 'o', 'r', 'b', 'i', 's', 7, 0, 0, 0,
+            'a', 'n', 'd', 'r', 'o', 'i', 'd', 0, 0, 0, 0, 1 };
+    const void *headerData3;
+    size_t headerSize1, headerSize2 = sizeof(headerData2), headerSize3;
+
+    CHECK(md->findInt32(kKeyChannelCount, &nChannels));
+    CHECK(md->findInt32(kKeySampleRate, &samplerate));
+    CHECK(md->findData(kKeyVorbisInfo, &type, &headerData1, &headerSize1));
+    CHECK(md->findData(kKeyVorbisBooks, &type, &headerData3, &headerSize3));
+
+    size_t codecPrivateSize = 1;
+    codecPrivateSize += XiphLaceCodeLen(headerSize1);
+    codecPrivateSize += XiphLaceCodeLen(headerSize2);
+    codecPrivateSize += headerSize1 + headerSize2 + headerSize3;
+
+    off_t off = 0;
+    sp<ABuffer> codecPrivateBuf = new ABuffer(codecPrivateSize);
+    uint8_t *codecPrivateData = codecPrivateBuf->data();
+    codecPrivateData[off++] = 2;
+
+    off += XiphLaceEnc(codecPrivateData + off, headerSize1);
+    off += XiphLaceEnc(codecPrivateData + off, headerSize2);
+
+    memcpy(codecPrivateData + off, headerData1, headerSize1);
+    off += headerSize1;
+    memcpy(codecPrivateData + off, headerData2, headerSize2);
+    off += headerSize2;
+    memcpy(codecPrivateData + off, headerData3, headerSize3);
+
+    sp<WebmElement> entry = WebmElement::AudioTrackEntry(
+            nChannels,
+            samplerate,
+            codecPrivateBuf);
+    return entry;
+}
+
+size_t WebmWriter::numTracks() {
+    Mutex::Autolock autolock(mLock);
+
+    size_t numTracks = 0;
+    for (size_t i = 0; i < kMaxStreams; ++i) {
+        if (mStreams[i].mTrackEntry != NULL) {
+            numTracks++;
+        }
+    }
+
+    return numTracks;
+}
+
+uint64_t WebmWriter::estimateCuesSize(int32_t bitRate) {
+    // This implementation is based on estimateMoovBoxSize in MPEG4Writer.
+    //
+    // Statistical analysis shows that metadata usually accounts
+    // for a small portion of the total file size, usually < 0.6%.
+
+    // The default MIN_MOOV_BOX_SIZE is set to 0.6% x 1MB / 2,
+    // where 1MB is the common file size limit for MMS application.
+    // The default MAX _MOOV_BOX_SIZE value is based on about 3
+    // minute video recording with a bit rate about 3 Mbps, because
+    // statistics also show that most of the video captured are going
+    // to be less than 3 minutes.
+
+    // If the estimation is wrong, we will pay the price of wasting
+    // some reserved space. This should not happen so often statistically.
+    static const int32_t factor = 2;
+    static const int64_t MIN_CUES_SIZE = 3 * 1024;  // 3 KB
+    static const int64_t MAX_CUES_SIZE = (180 * 3000000 * 6LL / 8000);
+    int64_t size = MIN_CUES_SIZE;
+
+    // Max file size limit is set
+    if (mMaxFileSizeLimitBytes != 0 && mIsFileSizeLimitExplicitlyRequested) {
+        size = mMaxFileSizeLimitBytes * 6 / 1000;
+    }
+
+    // Max file duration limit is set
+    if (mMaxFileDurationLimitUs != 0) {
+        if (bitRate > 0) {
+            int64_t size2 = ((mMaxFileDurationLimitUs * bitRate * 6) / 1000 / 8000000);
+            if (mMaxFileSizeLimitBytes != 0 && mIsFileSizeLimitExplicitlyRequested) {
+                // When both file size and duration limits are set,
+                // we use the smaller limit of the two.
+                if (size > size2) {
+                    size = size2;
+                }
+            } else {
+                // Only max file duration limit is set
+                size = size2;
+            }
+        }
+    }
+
+    if (size < MIN_CUES_SIZE) {
+        size = MIN_CUES_SIZE;
+    }
+
+    // Any long duration recording will be probably end up with
+    // non-streamable webm file.
+    if (size > MAX_CUES_SIZE) {
+        size = MAX_CUES_SIZE;
+    }
+
+    ALOGV("limits: %" PRId64 "/%" PRId64 " bytes/us,"
+            " bit rate: %d bps and the estimated cues size %" PRId64 " bytes",
+            mMaxFileSizeLimitBytes, mMaxFileDurationLimitUs, bitRate, size);
+    return factor * size;
+}
+
+void WebmWriter::initStream(size_t idx) {
+    if (mStreams[idx].mThread != NULL) {
+        return;
+    }
+    if (mStreams[idx].mSource == NULL) {
+        ALOGV("adding dummy source ... ");
+        mStreams[idx].mThread = new WebmFrameEmptySourceThread(
+                mStreams[idx].mType, mStreams[idx].mSink);
+    } else {
+        ALOGV("adding source %p", mStreams[idx].mSource.get());
+        mStreams[idx].mThread = new WebmFrameMediaSourceThread(
+                mStreams[idx].mSource,
+                mStreams[idx].mType,
+                mStreams[idx].mSink,
+                mTimeCodeScale,
+                mStartTimestampUs,
+                mStartTimeOffsetMs,
+                numTracks(),
+                mIsRealTimeRecording);
+    }
+}
+
+void WebmWriter::release() {
+    close(mFd);
+    mFd = -1;
+    mInitCheck = NO_INIT;
+    mStarted = false;
+}
+
+status_t WebmWriter::reset() {
+    if (mInitCheck != OK) {
+        return OK;
+    } else {
+        if (!mStarted) {
+            release();
+            return OK;
+        }
+    }
+
+    status_t err = OK;
+    int64_t maxDurationUs = 0;
+    int64_t minDurationUs = 0x7fffffffffffffffLL;
+    for (int i = 0; i < kMaxStreams; ++i) {
+        if (mStreams[i].mThread == NULL) {
+            continue;
+        }
+
+        status_t status = mStreams[i].mThread->stop();
+        if (err == OK && status != OK) {
+            err = status;
+        }
+
+        int64_t durationUs = mStreams[i].mThread->getDurationUs();
+        if (durationUs > maxDurationUs) {
+            maxDurationUs = durationUs;
+        }
+        if (durationUs < minDurationUs) {
+            minDurationUs = durationUs;
+        }
+    }
+
+    if (numTracks() > 1) {
+        ALOGD("Duration from tracks range is [%" PRId64 ", %" PRId64 "] us", minDurationUs, maxDurationUs);
+    }
+
+    mSinkThread->stop();
+
+    // Do not write out movie header on error.
+    if (err != OK) {
+        release();
+        return err;
+    }
+
+    sp<WebmElement> cues = new WebmMaster(kMkvCues, mCuePoints);
+    uint64_t cuesSize = cues->totalSize();
+    // TRICKY Even when the cues do fit in the space we reserved, if they do not fit
+    // perfectly, we still need to check if there is enough "extra space" to write an
+    // EBML void element.
+    if (cuesSize != mEstimatedCuesSize && cuesSize > mEstimatedCuesSize - kMinEbmlVoidSize) {
+        mCuesOffset = ::lseek(mFd, 0, SEEK_CUR);
+        cues->write(mFd, cuesSize);
+    } else {
+        uint64_t spaceSize;
+        ::lseek(mFd, mCuesOffset, SEEK_SET);
+        cues->write(mFd, cuesSize);
+        sp<WebmElement> space = new EbmlVoid(mEstimatedCuesSize - cuesSize);
+        space->write(mFd, spaceSize);
+    }
+
+    mCuePoints.clear();
+    mStreams[kVideoIndex].mSink.clear();
+    mStreams[kAudioIndex].mSink.clear();
+
+    uint8_t bary[sizeof(uint64_t)];
+    uint64_t totalSize = ::lseek(mFd, 0, SEEK_END);
+    uint64_t segmentSize = totalSize - mSegmentDataStart;
+    ::lseek(mFd, mSegmentOffset + sizeOf(kMkvSegment), SEEK_SET);
+    uint64_t segmentSizeCoded = encodeUnsigned(segmentSize, sizeOf(kMkvUnknownLength));
+    serializeCodedUnsigned(segmentSizeCoded, bary);
+    ::write(mFd, bary, sizeOf(kMkvUnknownLength));
+
+    uint64_t size;
+    uint64_t durationOffset = mInfoOffset + sizeOf(kMkvInfo) + sizeOf(mInfoSize)
+        + sizeOf(kMkvSegmentDuration) + sizeOf(sizeof(double));
+    sp<WebmElement> duration = new WebmFloat(
+            kMkvSegmentDuration,
+            (double) (maxDurationUs * 1000 / mTimeCodeScale));
+    duration->serializePayload(bary);
+    ::lseek(mFd, durationOffset, SEEK_SET);
+    ::write(mFd, bary, sizeof(double));
+
+    List<sp<WebmElement> > seekEntries;
+    seekEntries.push_back(WebmElement::SeekEntry(kMkvInfo, mInfoOffset - mSegmentDataStart));
+    seekEntries.push_back(WebmElement::SeekEntry(kMkvTracks, mTracksOffset - mSegmentDataStart));
+    seekEntries.push_back(WebmElement::SeekEntry(kMkvCues, mCuesOffset - mSegmentDataStart));
+    sp<WebmElement> seekHead = new WebmMaster(kMkvSeekHead, seekEntries);
+
+    uint64_t metaSeekSize;
+    ::lseek(mFd, mSegmentDataStart, SEEK_SET);
+    seekHead->write(mFd, metaSeekSize);
+
+    uint64_t spaceSize;
+    sp<WebmElement> space = new EbmlVoid(kMaxMetaSeekSize - metaSeekSize);
+    space->write(mFd, spaceSize);
+
+    release();
+    return err;
+}
+
+status_t WebmWriter::addSource(const sp<MediaSource> &source) {
+    Mutex::Autolock l(mLock);
+    if (mStarted) {
+        ALOGE("Attempt to add source AFTER recording is started");
+        return UNKNOWN_ERROR;
+    }
+
+    // At most 2 tracks can be supported.
+    if (mStreams[kVideoIndex].mTrackEntry != NULL
+            && mStreams[kAudioIndex].mTrackEntry != NULL) {
+        ALOGE("Too many tracks (2) to add");
+        return ERROR_UNSUPPORTED;
+    }
+
+    CHECK(source != NULL);
+
+    // A track of type other than video or audio is not supported.
+    const char *mime;
+    source->getFormat()->findCString(kKeyMIMEType, &mime);
+    const char *vp8 = MEDIA_MIMETYPE_VIDEO_VP8;
+    const char *vorbis = MEDIA_MIMETYPE_AUDIO_VORBIS;
+
+    size_t streamIndex;
+    if (!strncasecmp(mime, vp8, strlen(vp8))) {
+        streamIndex = kVideoIndex;
+    } else if (!strncasecmp(mime, vorbis, strlen(vorbis))) {
+        streamIndex = kAudioIndex;
+    } else {
+        ALOGE("Track (%s) other than %s or %s is not supported", mime, vp8, vorbis);
+        return ERROR_UNSUPPORTED;
+    }
+
+    // No more than one video or one audio track is supported.
+    if (mStreams[streamIndex].mTrackEntry != NULL) {
+        ALOGE("%s track already exists", mStreams[streamIndex].mName);
+        return ERROR_UNSUPPORTED;
+    }
+
+    // This is the first track of either audio or video.
+    // Go ahead to add the track.
+    mStreams[streamIndex].mSource = source;
+    mStreams[streamIndex].mTrackEntry = mStreams[streamIndex].mMakeTrack(source->getFormat());
+
+    return OK;
+}
+
+status_t WebmWriter::start(MetaData *params) {
+    if (mInitCheck != OK) {
+        return UNKNOWN_ERROR;
+    }
+
+    if (mStreams[kVideoIndex].mTrackEntry == NULL
+            && mStreams[kAudioIndex].mTrackEntry == NULL) {
+        ALOGE("No source added");
+        return INVALID_OPERATION;
+    }
+
+    if (mMaxFileSizeLimitBytes != 0) {
+        mIsFileSizeLimitExplicitlyRequested = true;
+    }
+
+    if (params) {
+        int32_t isRealTimeRecording;
+        params->findInt32(kKeyRealTimeRecording, &isRealTimeRecording);
+        mIsRealTimeRecording = isRealTimeRecording;
+    }
+
+    if (mStarted) {
+        if (mPaused) {
+            mPaused = false;
+            mStreams[kAudioIndex].mThread->resume();
+            mStreams[kVideoIndex].mThread->resume();
+        }
+        return OK;
+    }
+
+    if (params) {
+        int32_t tcsl;
+        if (params->findInt32(kKeyTimeScale, &tcsl)) {
+            mTimeCodeScale = tcsl;
+        }
+    }
+    CHECK_GT(mTimeCodeScale, 0);
+    ALOGV("movie time scale: %" PRIu64, mTimeCodeScale);
+
+    /*
+     * When the requested file size limit is small, the priority
+     * is to meet the file size limit requirement, rather than
+     * to make the file streamable. mStreamableFile does not tell
+     * whether the actual recorded file is streamable or not.
+     */
+    mStreamableFile = (!mMaxFileSizeLimitBytes)
+        || (mMaxFileSizeLimitBytes >= kMinStreamableFileSizeInBytes);
+
+    /*
+     * Write various metadata.
+     */
+    sp<WebmElement> ebml, segment, info, seekHead, tracks, cues;
+    ebml = WebmElement::EbmlHeader();
+    segment = new WebmMaster(kMkvSegment);
+    seekHead = new EbmlVoid(kMaxMetaSeekSize);
+    info = WebmElement::SegmentInfo(mTimeCodeScale, 0);
+
+    List<sp<WebmElement> > children;
+    for (size_t i = 0; i < kMaxStreams; ++i) {
+        if (mStreams[i].mTrackEntry != NULL) {
+            children.push_back(mStreams[i].mTrackEntry);
+        }
+    }
+    tracks = new WebmMaster(kMkvTracks, children);
+
+    if (!mStreamableFile) {
+        cues = NULL;
+    } else {
+        int32_t bitRate = -1;
+        if (params) {
+            params->findInt32(kKeyBitRate, &bitRate);
+        }
+        mEstimatedCuesSize = estimateCuesSize(bitRate);
+        CHECK_GE(mEstimatedCuesSize, 8);
+        cues = new EbmlVoid(mEstimatedCuesSize);
+    }
+
+    sp<WebmElement> elems[] = { ebml, segment, seekHead, info, tracks, cues };
+    size_t nElems = sizeof(elems) / sizeof(elems[0]);
+    uint64_t offsets[nElems];
+    uint64_t sizes[nElems];
+    for (uint32_t i = 0; i < nElems; i++) {
+        WebmElement *e = elems[i].get();
+        if (!e) {
+            continue;
+        }
+
+        uint64_t size;
+        offsets[i] = ::lseek(mFd, 0, SEEK_CUR);
+        sizes[i] = e->mSize;
+        e->write(mFd, size);
+    }
+
+    mSegmentOffset = offsets[1];
+    mSegmentDataStart = offsets[2];
+    mInfoOffset = offsets[3];
+    mInfoSize = sizes[3];
+    mTracksOffset = offsets[4];
+    mCuesOffset = offsets[5];
+
+    // start threads
+    if (params) {
+        params->findInt64(kKeyTime, &mStartTimestampUs);
+    }
+
+    initStream(kAudioIndex);
+    initStream(kVideoIndex);
+
+    mStreams[kAudioIndex].mThread->start();
+    mStreams[kVideoIndex].mThread->start();
+    mSinkThread->start();
+
+    mStarted = true;
+    return OK;
+}
+
+status_t WebmWriter::pause() {
+    if (mInitCheck != OK) {
+        return OK;
+    }
+    mPaused = true;
+    status_t err = OK;
+    for (int i = 0; i < kMaxStreams; ++i) {
+        if (mStreams[i].mThread == NULL) {
+            continue;
+        }
+        status_t status = mStreams[i].mThread->pause();
+        if (status != OK) {
+            err = status;
+        }
+    }
+    return err;
+}
+
+status_t WebmWriter::stop() {
+    return reset();
+}
+
+bool WebmWriter::reachedEOS() {
+    return !mSinkThread->running();
+}
+} /* namespace android */
diff --git a/media/libstagefright/webm/WebmWriter.h b/media/libstagefright/webm/WebmWriter.h
new file mode 100644
index 0000000..529dec8
--- /dev/null
+++ b/media/libstagefright/webm/WebmWriter.h
@@ -0,0 +1,130 @@
+/*
+ * Copyright (C) 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 WEBMWRITER_H_
+#define WEBMWRITER_H_
+
+#include "WebmConstants.h"
+#include "WebmFrameThread.h"
+#include "LinkedBlockingQueue.h"
+
+#include <media/stagefright/MediaSource.h>
+#include <media/stagefright/MediaWriter.h>
+
+#include <utils/Errors.h>
+#include <utils/Mutex.h>
+#include <utils/StrongPointer.h>
+
+#include <stdint.h>
+
+using namespace webm;
+
+namespace android {
+
+class WebmWriter : public MediaWriter {
+public:
+    WebmWriter(int fd);
+    WebmWriter(const char *filename);
+    ~WebmWriter() { reset(); }
+
+
+    status_t addSource(const sp<MediaSource> &source);
+    status_t start(MetaData *param = NULL);
+    status_t stop();
+    status_t pause();
+    bool reachedEOS();
+
+    void setStartTimeOffsetMs(int ms) { mStartTimeOffsetMs = ms; }
+    int32_t getStartTimeOffsetMs() const { return mStartTimeOffsetMs; }
+
+private:
+    int mFd;
+    status_t mInitCheck;
+
+    uint64_t mTimeCodeScale;
+    int64_t mStartTimestampUs;
+    int32_t mStartTimeOffsetMs;
+
+    uint64_t mSegmentOffset;
+    uint64_t mSegmentDataStart;
+    uint64_t mInfoOffset;
+    uint64_t mInfoSize;
+    uint64_t mTracksOffset;
+    uint64_t mCuesOffset;
+
+    bool mPaused;
+    bool mStarted;
+    bool mIsFileSizeLimitExplicitlyRequested;
+    bool mIsRealTimeRecording;
+    bool mStreamableFile;
+    uint64_t mEstimatedCuesSize;
+
+    Mutex mLock;
+    List<sp<WebmElement> > mCuePoints;
+
+    enum {
+        kAudioIndex     =  0,
+        kVideoIndex     =  1,
+        kMaxStreams     =  2,
+    };
+
+    struct WebmStream {
+        int mType;
+        const char *mName;
+        sp<WebmElement> (*mMakeTrack)(const sp<MetaData>&);
+
+        sp<MediaSource> mSource;
+        sp<WebmElement> mTrackEntry;
+        sp<WebmFrameSourceThread> mThread;
+        LinkedBlockingQueue<const sp<WebmFrame> > mSink;
+
+        WebmStream()
+            : mType(kInvalidType),
+              mName("Invalid"),
+              mMakeTrack(NULL) {
+        }
+
+        WebmStream(int type, const char *name, sp<WebmElement> (*makeTrack)(const sp<MetaData>&))
+            : mType(type),
+              mName(name),
+              mMakeTrack(makeTrack) {
+        }
+
+        WebmStream &operator=(const WebmStream &other) {
+            mType = other.mType;
+            mName = other.mName;
+            mMakeTrack = other.mMakeTrack;
+            return *this;
+        }
+    };
+    WebmStream mStreams[kMaxStreams];
+
+    sp<WebmFrameSinkThread> mSinkThread;
+
+    size_t numTracks();
+    uint64_t estimateCuesSize(int32_t bitRate);
+    void initStream(size_t idx);
+    void release();
+    status_t reset();
+
+    static sp<WebmElement> videoTrack(const sp<MetaData>& md);
+    static sp<WebmElement> audioTrack(const sp<MetaData>& md);
+
+    DISALLOW_EVIL_CONSTRUCTORS(WebmWriter);
+};
+
+} /* namespace android */
+#endif /* WEBMWRITER_H_ */