diff --git a/trunk/doc/ISO_IEC_14496-1-System-2010.pdf b/trunk/doc/ISO_IEC_14496-1-System-2010.pdf
new file mode 100644
index 000000000..d804ac825
Binary files /dev/null and b/trunk/doc/ISO_IEC_14496-1-System-2010.pdf differ
diff --git a/trunk/src/kernel/srs_kernel_mp4.cpp b/trunk/src/kernel/srs_kernel_mp4.cpp
index 54bbc58b8..db7eed4f4 100644
--- a/trunk/src/kernel/srs_kernel_mp4.cpp
+++ b/trunk/src/kernel/srs_kernel_mp4.cpp
@@ -232,6 +232,7 @@ int SrsMp4Box::discovery(SrsBuffer* buf, SrsMp4Box** ppbox)
         case SRS_MP4_BOX_AVC1: box = new SrsMp4VisualSampleEntry(); break;
         case SRS_MP4_BOX_AVCC: box = new SrsMp4AvccBox(); break;
         case SRS_MP4_BOX_MP4A: box = new SrsMp4AudioSampleEntry(); break;
+        case SRS_MP4_BOX_ESDS: box = new SrsMp4EsdsBox(); break;
         default:
             ret = ERROR_MP4_BOX_ILLEGAL_TYPE;
             srs_error("MP4 illegal box type=%d. ret=%d", type, ret);
@@ -1721,6 +1722,298 @@ int SrsMp4AudioSampleEntry::decode_header(SrsBuffer* buf)
     return ret;
 }
 
+SrsMp4BaseDescriptor::SrsMp4BaseDescriptor()
+{
+    tag = SRS_MP4_ES_TAG_ES_forbidden;
+}
+
+SrsMp4BaseDescriptor::~SrsMp4BaseDescriptor()
+{
+}
+
+int SrsMp4BaseDescriptor::nb_bytes()
+{
+    // 1 byte tag.
+    int size = 1;
+    
+    // 1-3 bytes size.
+    uint32_t length = nb_payload();
+    if (length > 0x1fffff) {
+        size += 4;
+    } else if (length > 0x3fff) {
+        size += 3;
+    } else if (length > 0x7f) {
+        size += 2;
+    } else {
+        size += 1;
+    }
+    
+    // length bytes payload.
+    size += length;
+    
+    return size;
+}
+
+int SrsMp4BaseDescriptor::encode(SrsBuffer* buf)
+{
+    int ret = ERROR_SUCCESS;
+    
+    int size = nb_bytes();
+    if (!buf->require(size)) {
+        ret = ERROR_MP4_BOX_REQUIRE_SPACE;
+        srs_error("MP4 ES requires %d bytes space. ret=%d", size, ret);
+        return ret;
+    }
+    
+    buf->write_1bytes((uint8_t)tag);
+    
+    // As an expandable class the size of each class instance in bytes is encoded and accessible
+    // through the instance variable sizeOfInstance (see 8.3.3).
+    uint32_t length = nb_payload(); // bit(8) to bit(32)
+    
+    return ret;
+}
+
+int SrsMp4BaseDescriptor::decode(SrsBuffer* buf)
+{
+    int ret = ERROR_SUCCESS;
+    
+    int size = nb_bytes();
+    if (!buf->require(size)) {
+        ret = ERROR_MP4_BOX_REQUIRE_SPACE;
+        srs_error("MP4 ES requires %d bytes space. ret=%d", size, ret);
+        return ret;
+    }
+    
+    tag = (SRS_MP4_ES_TAG_ES)buf->read_1bytes();
+    return ret;
+}
+
+SrsMp4DecoderConfigDescriptor::SrsMp4DecoderConfigDescriptor()
+{
+    tag = SRS_MP4_ES_TAG_ES_DecoderConfigDescrTag;
+}
+
+SrsMp4DecoderConfigDescriptor::~SrsMp4DecoderConfigDescriptor()
+{
+}
+
+uint32_t SrsMp4DecoderConfigDescriptor::nb_payload()
+{
+    return 0;
+}
+
+int SrsMp4DecoderConfigDescriptor::encode_payload(SrsBuffer* buf)
+{
+    int ret = ERROR_SUCCESS;
+    return ret;
+}
+
+int SrsMp4DecoderConfigDescriptor::decode_payload(SrsBuffer* buf)
+{
+    int ret = ERROR_SUCCESS;
+    return ret;
+}
+
+SrsMp4SLConfigDescriptor::SrsMp4SLConfigDescriptor()
+{
+    tag = SRS_MP4_ES_TAG_ES_SLConfigDescrTag;
+}
+
+SrsMp4SLConfigDescriptor::~SrsMp4SLConfigDescriptor()
+{
+}
+
+uint32_t SrsMp4SLConfigDescriptor::nb_payload()
+{
+    return 0;
+}
+
+int SrsMp4SLConfigDescriptor::encode_payload(SrsBuffer* buf)
+{
+    int ret = ERROR_SUCCESS;
+    return ret;
+}
+
+int SrsMp4SLConfigDescriptor::decode_payload(SrsBuffer* buf)
+{
+    int ret = ERROR_SUCCESS;
+    return ret;
+}
+
+SrsMp4ES_Descriptor::SrsMp4ES_Descriptor()
+{
+    tag = SRS_MP4_ES_TAG_ES_DescrTag;
+    streamDependenceFlag = URL_Flag = OCRstreamFlag = 0;
+    URLlength = 0;
+    URLstring = NULL;
+}
+
+SrsMp4ES_Descriptor::~SrsMp4ES_Descriptor()
+{
+    srs_freepa(URLstring);
+}
+
+uint32_t SrsMp4ES_Descriptor::nb_payload()
+{
+    int size = 2 +1;
+    size += streamDependenceFlag? 2:0;
+    if (URL_Flag) {
+        size += 1 + URLlength;
+    }
+    size += OCRstreamFlag? 2:0;
+    size += decConfigDescr.nb_bytes() +slConfigDescr.nb_bytes();
+    return size;
+}
+
+int SrsMp4ES_Descriptor::encode_payload(SrsBuffer* buf)
+{
+    int ret = ERROR_SUCCESS;
+    
+    buf->write_2bytes(ES_ID);
+    
+    uint8_t v = streamPriority & 0x1f;
+    v |= (streamDependenceFlag & 0x01) << 7;
+    v |= (URL_Flag & 0x01) << 6;
+    v |= (OCRstreamFlag & 0x01) << 5;
+    buf->write_1bytes(v);
+    
+    if (streamDependenceFlag) {
+        buf->write_2bytes(dependsOn_ES_ID);
+    }
+    
+    if (URL_Flag && URLlength) {
+        buf->write_1bytes(URLlength);
+        buf->write_bytes((char*)URLstring, URLlength);
+    }
+    
+    if (OCRstreamFlag) {
+        buf->write_2bytes(OCR_ES_Id);
+    }
+    
+    if ((ret = decConfigDescr.encode(buf)) != ERROR_SUCCESS) {
+        return ret;
+    }
+    
+    if ((ret = slConfigDescr.encode(buf)) != ERROR_SUCCESS) {
+        return ret;
+    }
+    
+    return ret;
+}
+
+int SrsMp4ES_Descriptor::decode_payload(SrsBuffer* buf)
+{
+    int ret = ERROR_SUCCESS;
+    
+    ES_ID = buf->read_2bytes();
+    
+    uint8_t v = buf->read_1bytes();
+    streamPriority = v & 0x1f;
+    streamDependenceFlag = (v >> 7) & 0x01;
+    URL_Flag = (v >> 6) & 0x01;
+    OCRstreamFlag = (v >> 5) & 0x01;
+    
+    if (streamDependenceFlag) {
+        if (!buf->require(2)) {
+            ret = ERROR_MP4_BOX_REQUIRE_SPACE;
+            srs_error("MP4 ES requires 2 bytes space. ret=%d", ret);
+            return ret;
+        }
+        dependsOn_ES_ID = buf->read_2bytes();
+    }
+    
+    if (URL_Flag) {
+        if (!buf->require(1)) {
+            ret = ERROR_MP4_BOX_REQUIRE_SPACE;
+            srs_error("MP4 ES requires 1 byte space. ret=%d", ret);
+            return ret;
+        }
+        URLlength = buf->read_1bytes();
+        
+        if (!buf->require(URLlength)) {
+            ret = ERROR_MP4_BOX_REQUIRE_SPACE;
+            srs_error("MP4 ES requires %d bytes space. ret=%d", URLlength, ret);
+            return ret;
+        }
+        URLstring = new uint8_t[URLlength];
+        buf->read_bytes((char*)URLstring, URLlength);
+    }
+    
+    if (OCRstreamFlag) {
+        if (!buf->require(2)) {
+            ret = ERROR_MP4_BOX_REQUIRE_SPACE;
+            srs_error("MP4 ES requires 2 bytes space. ret=%d", ret);
+            return ret;
+        }
+        OCR_ES_Id = buf->read_2bytes();
+    }
+    
+    if ((ret = decConfigDescr.decode(buf)) != ERROR_SUCCESS) {
+        return ret;
+    }
+    
+    if ((ret = slConfigDescr.decode(buf)) != ERROR_SUCCESS) {
+        return ret;
+    }
+    
+    return ret;
+}
+
+SrsMp4EsdsBox::SrsMp4EsdsBox()
+{
+    type = SRS_MP4_BOX_ESDS;
+    es = new SrsMp4ES_Descriptor();
+}
+
+SrsMp4EsdsBox::~SrsMp4EsdsBox()
+{
+    srs_freep(es);
+}
+
+int SrsMp4EsdsBox::nb_header()
+{
+    return SrsMp4FullBox::nb_header() + es->nb_bytes();
+}
+
+int SrsMp4EsdsBox::encode_header(SrsBuffer* buf)
+{
+    int ret = ERROR_SUCCESS;
+    
+    if ((ret = SrsMp4FullBox::encode_header(buf)) != ERROR_SUCCESS) {
+        return ret;
+    }
+    
+    int left = left_space(buf);
+    SrsBuffer buffer(buf->data() + buf->pos(), left);
+    if ((ret = es->encode(&buffer)) != ERROR_SUCCESS) {
+        return ret;
+    }
+    
+    buf->skip(buffer.pos());
+    
+    return ret;
+}
+
+int SrsMp4EsdsBox::decode_header(SrsBuffer* buf)
+{
+    int ret = ERROR_SUCCESS;
+    
+    if ((ret = SrsMp4FullBox::decode_header(buf)) != ERROR_SUCCESS) {
+        return ret;
+    }
+    
+    int left = left_space(buf);
+    SrsBuffer buffer(buf->data() + buf->pos(), left);
+    if ((ret = es->decode(&buffer)) != ERROR_SUCCESS) {
+        return ret;
+    }
+    
+    buf->skip(buffer.pos());
+    
+    return ret;
+}
+
 SrsMp4SampleDescriptionBox::SrsMp4SampleDescriptionBox()
 {
     type = SRS_MP4_BOX_STSD;
diff --git a/trunk/src/kernel/srs_kernel_mp4.hpp b/trunk/src/kernel/srs_kernel_mp4.hpp
index 03c3c50b9..dc2c299d3 100644
--- a/trunk/src/kernel/srs_kernel_mp4.hpp
+++ b/trunk/src/kernel/srs_kernel_mp4.hpp
@@ -724,6 +724,159 @@ protected:
     virtual int decode_header(SrsBuffer* buf);
 };
 
+// Table 1 — List of Class Tags for Descriptors
+// ISO_IEC_14496-1-System-2010.pdf, page 31
+enum SRS_MP4_ES_TAG_ES {
+    SRS_MP4_ES_TAG_ES_forbidden = 0x00,
+    SRS_MP4_ES_TAG_ES_ObjectDescrTag = 0x01,
+    SRS_MP4_ES_TAG_ES_InitialObjectDescrTag = 0x02,
+    SRS_MP4_ES_TAG_ES_DescrTag = 0x03,
+    SRS_MP4_ES_TAG_ES_DecoderConfigDescrTag = 0x04,
+    SRS_MP4_ES_TAG_ES_DecSpecificInfoTag = 0x05,
+    SRS_MP4_ES_TAG_ES_SLConfigDescrTag = 0x06,
+    SRS_MP4_ES_TAG_ES_ExtSLConfigDescrTag = 0x064,
+};
+
+/**
+ * 7.2.2.2 BaseDescriptor
+ * ISO_IEC_14496-1-System-2010.pdf, page 32
+ */
+class SrsMp4BaseDescriptor : public ISrsCodec
+{
+public:
+    // The values of the class tags are
+    // defined in Table 2. As an expandable class the size of each class instance in bytes is encoded and accessible
+    // through the instance variable sizeOfInstance (see 8.3.3).
+    SRS_MP4_ES_TAG_ES tag; // bit(8)
+public:
+    SrsMp4BaseDescriptor();
+    virtual ~SrsMp4BaseDescriptor();
+// Interface ISrsCodec
+public:
+    virtual int nb_bytes();
+    virtual int encode(SrsBuffer* buf);
+    virtual int decode(SrsBuffer* buf);
+protected:
+    virtual uint32_t nb_payload() = 0;
+    virtual int encode_payload(SrsBuffer* buf) = 0;
+    virtual int decode_payload(SrsBuffer* buf) = 0;
+};
+
+/**
+ * 7.2.6.6 DecoderConfigDescriptor
+ * ISO_IEC_14496-1-System-2010.pdf, page 48
+ */
+class SrsMp4DecoderConfigDescriptor : public SrsMp4BaseDescriptor
+{
+public:
+    uint8_t objectTypeIndication;
+    uint8_t streamType; // bit(6)
+    uint8_t upStream; // bit(1)
+    uint8_t reserved; // bit(1)
+    uint32_t bufferSizeDB; // bit(24)
+    uint32_t maxBitrate;
+    uint32_t avgBitrate;
+public:
+    SrsMp4DecoderConfigDescriptor();
+    virtual ~SrsMp4DecoderConfigDescriptor();
+protected:
+    virtual uint32_t nb_payload();
+    virtual int encode_payload(SrsBuffer* buf);
+    virtual int decode_payload(SrsBuffer* buf);
+};
+
+/**
+ * 7.3.2.3 SL Packet Header Configuration
+ * ISO_IEC_14496-1-System-2010.pdf, page 92
+ */
+class SrsMp4SLConfigDescriptor : public SrsMp4BaseDescriptor
+{
+public:
+    uint8_t predefined;
+    // if (predefined==0)
+    uint8_t useAccessUnitStartFlag; // bit(1)
+    uint8_t useAccessUnitEndFlag; // bit(1)
+    uint8_t useRandomAccessPointFlag; // bit(1)
+    uint8_t hasRandomAccessUnitsOnlyFlag; // bit(1)
+    uint8_t usePaddingFlag; // bit(1)
+    uint8_t useTimeStampsFlag; // bit(1)
+    uint8_t useIdleFlag; // bit(1)
+    uint8_t durationFlag; // bit(1)
+    uint32_t timeStampResolution;
+    uint32_t OCRResolution;
+    uint8_t timeStampLength; // must be ≤ 64
+    uint8_t OCRLength; // must be ≤ 64
+    uint8_t AU_Length; // must be ≤ 32
+    uint8_t instantBitrateLength;
+    uint8_t degradationPriorityLength; // bit(4)
+    uint8_t AU_seqNumLength; // bit(5) // must be ≤ 16
+    uint8_t packetSeqNumLength; // bit(5) // must be ≤ 16
+    uint8_t reserved; // bit(2) // 0b11
+    // if (durationFlag)
+    uint32_t timeScale;
+    uint16_t accessUnitDuration;
+    uint16_t compositionUnitDuration;
+    // if (!useTimeStampsFlag)
+    uint64_t startDecodingTimeStamp; // bit(timeStampLength)
+    uint64_t startCompositionTimeStamp; // bit(timeStampLength)
+public:
+    SrsMp4SLConfigDescriptor();
+    virtual ~SrsMp4SLConfigDescriptor();
+protected:
+    virtual uint32_t nb_payload();
+    virtual int encode_payload(SrsBuffer* buf);
+    virtual int decode_payload(SrsBuffer* buf);
+};
+
+/**
+ * 7.2.6.5 ES_Descriptor
+ * ISO_IEC_14496-1-System-2010.pdf, page 47
+ */
+class SrsMp4ES_Descriptor : public SrsMp4BaseDescriptor
+{
+public:
+    uint16_t ES_ID;
+    uint8_t streamDependenceFlag; // bit(1)
+    uint8_t URL_Flag; // bit(1)
+    uint8_t OCRstreamFlag; // bit(1)
+    uint8_t streamPriority; // bit(5)
+    // if (streamDependenceFlag)
+    uint16_t dependsOn_ES_ID;
+    // if (URL_Flag)
+    uint8_t URLlength;
+    uint8_t* URLstring;
+    // if (OCRstreamFlag)
+    uint16_t OCR_ES_Id;
+    SrsMp4DecoderConfigDescriptor decConfigDescr;
+    SrsMp4SLConfigDescriptor slConfigDescr;
+public:
+    SrsMp4ES_Descriptor();
+    virtual ~SrsMp4ES_Descriptor();
+protected:
+    virtual uint32_t nb_payload();
+    virtual int encode_payload(SrsBuffer* buf);
+    virtual int decode_payload(SrsBuffer* buf);
+};
+
+/**
+ * 5.6 Sample Description Boxes
+ * Elementary Stream Descriptors (esds)
+ * ISO_IEC_14496-14-MP4-2003.pdf, page 15
+ * @see http://www.mp4ra.org/codecs.html
+ */
+class SrsMp4EsdsBox : public SrsMp4FullBox
+{
+public:
+    SrsMp4ES_Descriptor* es;
+public:
+    SrsMp4EsdsBox();
+    virtual ~SrsMp4EsdsBox();
+protected:
+    virtual int nb_header();
+    virtual int encode_header(SrsBuffer* buf);
+    virtual int decode_header(SrsBuffer* buf);
+};
+
 /**
  * 8.5.2 Sample Description Box (stsd), for Audio/Video.
  * ISO_IEC_14496-12-base-format-2012.pdf, page 40