for #738, parse mp4 udta(user data) box.

@@ -189,6 +189,7 @@ int SrsMp4Box::discovery(SrsBuffer* buf, SrsMp4Box** ppbox)
         case SrsMp4BoxTypeAVCC: box = new SrsMp4AvccBox(); break;
         case SrsMp4BoxTypeMP4A: box = new SrsMp4AudioSampleEntry(); break;
         case SrsMp4BoxTypeESDS: box = new SrsMp4EsdsBox(); break;
+        case SrsMp4BoxTypeUDTA: box = new SrsMp4UserDataBox(); break;
         default:
             ret = ERROR_MP4_BOX_ILLEGAL_TYPE;
             srs_error("MP4 illegal box type=%d. ret=%d", type, ret);
@@ -624,6 +625,21 @@ SrsMp4MovieBox::~SrsMp4MovieBox()
 {
 }
 
+int SrsMp4MovieBox::nb_header()
+{
+    return SrsMp4Box::nb_header();
+}
+
+int SrsMp4MovieBox::encode_header(SrsBuffer* buf)
+{
+    return SrsMp4Box::encode_header(buf);
+}
+
+int SrsMp4MovieBox::decode_header(SrsBuffer* buf)
+{
+    return SrsMp4Box::decode_header(buf);
+}
+
 SrsMp4MovieHeaderBox::SrsMp4MovieHeaderBox()
 {
     type = SrsMp4BoxTypeMVHD;
@@ -2621,6 +2637,55 @@ int SrsMp4SampleSizeBox::decode_header(SrsBuffer* buf)
     return ret;
 }
 
+SrsMp4UserDataBox::SrsMp4UserDataBox()
+{
+    type = SrsMp4BoxTypeUDTA;
+    nb_data = 0;
+    data = NULL;
+}
+
+SrsMp4UserDataBox::~SrsMp4UserDataBox()
+{
+    srs_freepa(data);
+}
+
+int SrsMp4UserDataBox::nb_header()
+{
+    return SrsMp4Box::nb_header()+nb_data;
+}
+
+int SrsMp4UserDataBox::encode_header(SrsBuffer* buf)
+{
+    int ret = ERROR_SUCCESS;
+    
+    if ((ret = SrsMp4Box::encode_header(buf)) != ERROR_SUCCESS) {
+        return ret;
+    }
+    
+    if (nb_data) {
+        buf->write_bytes((char*)data, nb_data);
+    }
+    
+    return ret;
+}
+
+int SrsMp4UserDataBox::decode_header(SrsBuffer* buf)
+{
+    int ret = ERROR_SUCCESS;
+    
+    if ((ret = SrsMp4Box::decode_header(buf)) != ERROR_SUCCESS) {
+        return ret;
+    }
+    
+    nb_data = left_space(buf);
+    if (nb_data) {
+        data = new uint8_t[nb_data];
+        buf->read_bytes((char*)data, nb_data);
+    }
+    
+    return ret;
+}
+
 #define SRS_MP4_BUF_SIZE 4096
 
 SrsMp4Decoder::SrsMp4Decoder()
@@ -2693,6 +2758,14 @@ int SrsMp4Decoder::initialize(ISrsReader* r)
         return ret;
     }
     
+    // Parse the MOOV.
+    SrsMp4MovieBox* moov = dynamic_cast<SrsMp4MovieBox*>(box);
+    return parse_moov(moov);
+}
+
+int SrsMp4Decoder::parse_moov(SrsMp4MovieBox* moov)
+{
+    int ret = ERROR_SUCCESS;
     return ret;
 }
 

@@ -80,6 +80,7 @@ enum SrsMp4BoxType
     SrsMp4BoxTypeAVCC = 0x61766343, // 'avcC'
     SrsMp4BoxTypeMP4A = 0x6d703461, // 'mp4a'
     SrsMp4BoxTypeESDS = 0x65736473, // 'esds'
+    SrsMp4BoxTypeUDTA = 0x75647461, // 'udta'
     
     SrsMp4BoxTypeVIDE = 0x76696465, // 'vide'
     SrsMp4BoxTypeSOUN = 0x736f756e, // 'soun'
@@ -262,6 +263,10 @@ class SrsMp4MovieBox : public SrsMp4Box
 public:
     SrsMp4MovieBox();
     virtual ~SrsMp4MovieBox();
+protected:
+    virtual int nb_header();
+    virtual int encode_header(SrsBuffer* buf);
+    virtual int decode_header(SrsBuffer* buf);
 };
 
 /**
@@ -1206,6 +1211,26 @@ protected:
 };
 
 /**
+ * 8.10.1 User Data Box (udta)
+ * ISO_IEC_14496-12-base-format-2012.pdf, page 78
+ * This box contains objects that declare user information about the containing box and its data (presentation or
+ * track).
+ */
+class SrsMp4UserDataBox : public SrsMp4Box
+{
+public:
+    int nb_data;
+    uint8_t* data;
+public:
+    SrsMp4UserDataBox();
+    virtual ~SrsMp4UserDataBox();
+protected:
+    virtual int nb_header();
+    virtual int encode_header(SrsBuffer* buf);
+    virtual int decode_header(SrsBuffer* buf);
+};
+
+/**
  * The MP4 demuxer.
  */
 class SrsMp4Decoder
@@ -1229,6 +1254,8 @@ public:
      */
     virtual int initialize(ISrsReader* r);
 private:
+    virtual int parse_moov(SrsMp4MovieBox* box);
+private:
     // Load the next box from reader.
     // @param required_box_type The box type required, 0 for any box.
     virtual int load_next_box(SrsMp4Box** ppbox, uint32_t required_box_type);