diff --git a/trunk/src/app/srs_app_caster_flv.cpp b/trunk/src/app/srs_app_caster_flv.cpp
index 53f183364..fe515f0ff 100644
--- a/trunk/src/app/srs_app_caster_flv.cpp
+++ b/trunk/src/app/srs_app_caster_flv.cpp
@@ -280,7 +280,7 @@ void SrsHttpFileReader::skip(int64_t /*size*/)
 {
 }
 
-int64_t SrsHttpFileReader::lseek(int64_t offset)
+int64_t SrsHttpFileReader::seek2(int64_t offset)
 {
     return offset;
 }
@@ -324,4 +324,10 @@ int SrsHttpFileReader::read(void* buf, size_t count, ssize_t* pnread)
     return ret;
 }
 
+int SrsHttpFileReader::lseek(off_t offset, int whence, off_t* seeked)
+{
+    // TODO: FIXME: Use HTTP range for seek.
+    return ERROR_SUCCESS;
+}
+
 #endif
diff --git a/trunk/src/app/srs_app_caster_flv.hpp b/trunk/src/app/srs_app_caster_flv.hpp
index d48900155..d1320546c 100644
--- a/trunk/src/app/srs_app_caster_flv.hpp
+++ b/trunk/src/app/srs_app_caster_flv.hpp
@@ -120,14 +120,11 @@ public:
     virtual bool is_open();
     virtual int64_t tellg();
     virtual void skip(int64_t size);
-    virtual int64_t lseek(int64_t offset);
+    virtual int64_t seek2(int64_t offset);
     virtual int64_t filesize();
 public:
-    /**
-     * read from file.
-     * @param pnread the output nb_read, NULL to ignore.
-     */
     virtual int read(void* buf, size_t count, ssize_t* pnread);
+    virtual int lseek(off_t offset, int whence, off_t* seeked);
 };
 
 #endif
diff --git a/trunk/src/app/srs_app_dvr.cpp b/trunk/src/app/srs_app_dvr.cpp
index a3739451d..77f7a8bf5 100644
--- a/trunk/src/app/srs_app_dvr.cpp
+++ b/trunk/src/app/srs_app_dvr.cpp
@@ -370,7 +370,7 @@ int SrsFlvSegment::update_flv_metadata()
     }
 
     // update the flesize.
-    fs->lseek(filesize_offset);
+    fs->seek2(filesize_offset);
     if ((ret = fs->write(buf, SrsAmf0Size::number(), NULL)) != ERROR_SUCCESS) {
         return ret;
     }
@@ -385,13 +385,13 @@ int SrsFlvSegment::update_flv_metadata()
     }
 
     // update the duration
-    fs->lseek(duration_offset);
+    fs->seek2(duration_offset);
     if ((ret = fs->write(buf, SrsAmf0Size::number(), NULL)) != ERROR_SUCCESS) {
         return ret;
     }
 
     // reset the offset.
-    fs->lseek(cur);
+    fs->seek2(cur);
 
     return ret;
 }
diff --git a/trunk/src/app/srs_app_http_static.cpp b/trunk/src/app/srs_app_http_static.cpp
index e039922ee..620cbbcb3 100644
--- a/trunk/src/app/srs_app_http_static.cpp
+++ b/trunk/src/app/srs_app_http_static.cpp
@@ -131,7 +131,7 @@ int SrsVodStream::serve_flv_stream(ISrsHttpResponseWriter* w, ISrsHttpMessage* r
     }
     
     // write body.
-    if ((ret = ffd.lseek(offset)) != ERROR_SUCCESS) {
+    if ((ret = ffd.seek2(offset)) != ERROR_SUCCESS) {
         return ret;
     }
     
@@ -186,7 +186,7 @@ int SrsVodStream::serve_mp4_stream(ISrsHttpResponseWriter* w, ISrsHttpMessage* r
     w->header()->set("Content-Range", content_range.str());
     
     // write body.
-    fs.lseek(start);
+    fs.seek2(start);
     
     // send data
     if ((ret = copy(w, &fs, r, (int)left)) != ERROR_SUCCESS) {
diff --git a/trunk/src/kernel/srs_kernel_error.hpp b/trunk/src/kernel/srs_kernel_error.hpp
index 6528ce320..909aeef72 100644
--- a/trunk/src/kernel/srs_kernel_error.hpp
+++ b/trunk/src/kernel/srs_kernel_error.hpp
@@ -248,9 +248,8 @@ CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
 #define ERROR_MP4_BOX_ILLEGAL_SCHEMA        3072
 #define ERROR_MP4_BOX_STRING                3073
 #define ERROR_MP4_BOX_ILLEGAL_BRAND         3074
-#define ERROR_MP4_NOT_NON_SEEKABLE          3075
-#define ERROR_MP4_ESDS_SL_Config            3076
-#define ERROR_MP4_ILLEGAL_MOOV              3077
+#define ERROR_MP4_ESDS_SL_Config            3075
+#define ERROR_MP4_ILLEGAL_MOOV              3076
 
 ///////////////////////////////////////////////////////
 // HTTP/StreamCaster/KAFKA protocol error.
diff --git a/trunk/src/kernel/srs_kernel_file.cpp b/trunk/src/kernel/srs_kernel_file.cpp
index 777b4f415..5c50b5ce9 100644
--- a/trunk/src/kernel/srs_kernel_file.cpp
+++ b/trunk/src/kernel/srs_kernel_file.cpp
@@ -117,7 +117,7 @@ bool SrsFileWriter::is_open()
     return fd > 0;
 }
 
-void SrsFileWriter::lseek(int64_t offset)
+void SrsFileWriter::seek2(int64_t offset)
 {
     ::lseek(fd, (off_t)offset, SEEK_SET);
 }
@@ -167,6 +167,19 @@ int SrsFileWriter::writev(const iovec* iov, int iovcnt, ssize_t* pnwrite)
     return ret;
 }
 
+int SrsFileWriter::lseek(off_t offset, int whence, off_t* seeked)
+{
+    off_t sk = ::lseek(fd, offset, whence);
+    if (sk < 0) {
+        return ERROR_SYSTEM_FILE_SEEK;
+    }
+    
+    if (seeked) {
+        *seeked = sk;
+    }
+    return ERROR_SUCCESS;
+}
+
 SrsFileReader::SrsFileReader()
 {
     fd = -1;
@@ -231,7 +244,7 @@ void SrsFileReader::skip(int64_t size)
     ::lseek(fd, (off_t)size, SEEK_CUR);
 }
 
-int64_t SrsFileReader::lseek(int64_t offset)
+int64_t SrsFileReader::seek2(int64_t offset)
 {
     return (int64_t)::lseek(fd, (off_t)offset, SEEK_SET);
 }
@@ -268,3 +281,16 @@ int SrsFileReader::read(void* buf, size_t count, ssize_t* pnread)
     return ret;
 }
 
+int SrsFileReader::lseek(off_t offset, int whence, off_t* seeked)
+{
+    off_t sk = ::lseek(fd, offset, whence);
+    if (sk < 0) {
+        return ERROR_SYSTEM_FILE_SEEK;
+    }
+    
+    if (seeked) {
+        *seeked = sk;
+    }
+    return ERROR_SUCCESS;
+}
+
diff --git a/trunk/src/kernel/srs_kernel_file.hpp b/trunk/src/kernel/srs_kernel_file.hpp
index bf34035f9..9b92bf62f 100644
--- a/trunk/src/kernel/srs_kernel_file.hpp
+++ b/trunk/src/kernel/srs_kernel_file.hpp
@@ -41,7 +41,7 @@ CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
 /**
 * file writer, to write to file.
 */
-class SrsFileWriter : public ISrsWriter
+class SrsFileWriter : public ISrsWriteSeeker
 {
 private:
     std::string path;
@@ -67,25 +67,19 @@ public:
     virtual void close();
 public:
     virtual bool is_open();
-    virtual void lseek(int64_t offset);
+    virtual void seek2(int64_t offset);
     virtual int64_t tellg();
+// Interface ISrsWriteSeeker
 public:
-    /**
-    * write to file. 
-    * @param pnwrite the output nb_write, NULL to ignore.
-    */
     virtual int write(void* buf, size_t count, ssize_t* pnwrite);
-    /**
-     * for the HTTP FLV, to writev to improve performance.
-     * @see https://github.com/ossrs/srs/issues/405
-     */
     virtual int writev(const iovec* iov, int iovcnt, ssize_t* pnwrite);
+    virtual int lseek(off_t offset, int whence, off_t* seeked);
 };
 
 /**
 * file reader, to read from file.
 */
-class SrsFileReader : public ISrsReader
+class SrsFileReader : public ISrsReadSeeker
 {
 private:
     std::string path;
@@ -109,14 +103,12 @@ public:
     virtual bool is_open();
     virtual int64_t tellg();
     virtual void skip(int64_t size);
-    virtual int64_t lseek(int64_t offset);
+    virtual int64_t seek2(int64_t offset);
     virtual int64_t filesize();
+// Interface ISrsReadSeeker
 public:
-    /**
-    * read from file. 
-    * @param pnread the output nb_read, NULL to ignore.
-    */
     virtual int read(void* buf, size_t count, ssize_t* pnread);
+    virtual int lseek(off_t offset, int whence, off_t* seeked);
 };
 
 #endif
diff --git a/trunk/src/kernel/srs_kernel_flv.cpp b/trunk/src/kernel/srs_kernel_flv.cpp
index ada330915..a25fdcd6d 100644
--- a/trunk/src/kernel/srs_kernel_flv.cpp
+++ b/trunk/src/kernel/srs_kernel_flv.cpp
@@ -949,7 +949,7 @@ int SrsFlvVodStreamDecoder::read_sequence_header_summary(int64_t* pstart, int* p
     
     // seek to the sequence header start offset.
     if (av_sequence_offset_start > 0) {
-        reader->lseek(av_sequence_offset_start);
+        reader->seek2(av_sequence_offset_start);
         *pstart = av_sequence_offset_start;
         *psize = (int)(av_sequence_offset_end - av_sequence_offset_start);
     }
@@ -957,7 +957,7 @@ int SrsFlvVodStreamDecoder::read_sequence_header_summary(int64_t* pstart, int* p
     return ret;
 }
 
-int SrsFlvVodStreamDecoder::lseek(int64_t offset)
+int SrsFlvVodStreamDecoder::seek2(int64_t offset)
 {
     int ret = ERROR_SUCCESS;
     
@@ -969,7 +969,7 @@ int SrsFlvVodStreamDecoder::lseek(int64_t offset)
         return ret;
     }
     
-    if (reader->lseek(offset) < 0) {
+    if (reader->seek2(offset) < 0) {
         ret = ERROR_SYSTEM_FILE_SEEK;
         srs_warn("flv fast decoder seek error, "
             "size=%"PRId64", offset=%"PRId64", ret=%d", 
diff --git a/trunk/src/kernel/srs_kernel_flv.hpp b/trunk/src/kernel/srs_kernel_flv.hpp
index 097c87af2..90ab7e816 100644
--- a/trunk/src/kernel/srs_kernel_flv.hpp
+++ b/trunk/src/kernel/srs_kernel_flv.hpp
@@ -597,7 +597,7 @@ public:
     /**
     * for start offset, seed to this position and response flv stream.
     */
-    virtual int lseek(int64_t offset);
+    virtual int seek2(int64_t offset);
 };
 
 #endif
diff --git a/trunk/src/kernel/srs_kernel_io.cpp b/trunk/src/kernel/srs_kernel_io.cpp
index 5b604e79c..3f1c188eb 100644
--- a/trunk/src/kernel/srs_kernel_io.cpp
+++ b/trunk/src/kernel/srs_kernel_io.cpp
@@ -31,6 +31,22 @@ ISrsReader::~ISrsReader()
 {
 }
 
+ISrsSeeker::ISrsSeeker()
+{
+}
+
+ISrsSeeker::~ISrsSeeker()
+{
+}
+
+ISrsReadSeeker::ISrsReadSeeker()
+{
+}
+
+ISrsReadSeeker::~ISrsReadSeeker()
+{
+}
+
 ISrsStreamWriter::ISrsStreamWriter()
 {
 }
@@ -55,3 +71,11 @@ ISrsWriter::~ISrsWriter()
 {
 }
 
+ISrsWriteSeeker::ISrsWriteSeeker()
+{
+}
+
+ISrsWriteSeeker::~ISrsWriteSeeker()
+{
+}
+
diff --git a/trunk/src/kernel/srs_kernel_io.hpp b/trunk/src/kernel/srs_kernel_io.hpp
index f2a18d04a..0e62f4de3 100644
--- a/trunk/src/kernel/srs_kernel_io.hpp
+++ b/trunk/src/kernel/srs_kernel_io.hpp
@@ -51,6 +51,37 @@ public:
     virtual int read(void* buf, size_t size, ssize_t* nread) = 0;
 };
 
+/**
+ * The seeker to seek with a device.
+ */
+class ISrsSeeker
+{
+public:
+    ISrsSeeker();
+    virtual ~ISrsSeeker();
+public:
+    /**
+     * The lseek() function repositions the offset of the file descriptor fildes to the argument offset, according to the 
+     * directive whence. lseek() repositions the file pointer fildes as follows:
+     *      If whence is SEEK_SET, the offset is set to offset bytes.
+     *      If whence is SEEK_CUR, the offset is set to its current location plus offset bytes.
+     *      If whence is SEEK_END, the offset is set to the size of the file plus offset bytes.
+     * @param seeked Upon successful completion, lseek() returns the resulting offset location as measured in bytes from
+     *      the beginning of the file. NULL to ignore.
+     */
+    virtual int lseek(off_t offset, int whence, off_t* seeked) = 0;
+};
+
+/**
+ * The reader and seeker.
+ */
+class ISrsReadSeeker : virtual public ISrsReader, virtual public ISrsSeeker
+{
+public:
+    ISrsReadSeeker();
+    virtual ~ISrsReadSeeker();
+};
+
 /**
  * The writer to write stream data to channel.
  */
@@ -79,6 +110,8 @@ public:
     /**
      * write iov over writer.
      * @nwrite the actual written bytes. NULL to ignore.
+     * @remark for the HTTP FLV, to writev to improve performance.
+     *      @see https://github.com/ossrs/srs/issues/405
      */
     virtual int writev(const iovec *iov, int iov_size, ssize_t* nwrite) = 0;
 };
@@ -93,5 +126,15 @@ public:
     virtual ~ISrsWriter();
 };
 
+/**
+ * The writer and seeker.
+ */
+class ISrsWriteSeeker : virtual public ISrsWriter, virtual public ISrsSeeker
+{
+public:
+    ISrsWriteSeeker();
+    virtual ~ISrsWriteSeeker();
+};
+
 #endif
 
diff --git a/trunk/src/kernel/srs_kernel_mp4.cpp b/trunk/src/kernel/srs_kernel_mp4.cpp
index ad09dcf16..15c22b373 100644
--- a/trunk/src/kernel/srs_kernel_mp4.cpp
+++ b/trunk/src/kernel/srs_kernel_mp4.cpp
@@ -2959,7 +2959,8 @@ int SrsMp4UserDataBox::decode_header(SrsBuffer* buf)
 
 SrsMp4Decoder::SrsMp4Decoder()
 {
-    reader = NULL;
+    rsio = NULL;
+    brand = SrsMp4BoxBrandForbidden;
     buf = new char[SRS_MP4_BUF_SIZE];
     stream = new SrsSimpleStream();
 }
@@ -2970,66 +2971,83 @@ SrsMp4Decoder::~SrsMp4Decoder()
     srs_freep(stream);
 }
 
-int SrsMp4Decoder::initialize(ISrsReader* r)
+int SrsMp4Decoder::initialize(ISrsReadSeeker* rs)
 {
     int ret = ERROR_SUCCESS;
     
-    srs_assert(r);
-    reader = r;
+    srs_assert(rs);
+    rsio = rs;
     
-    // File Type Box (ftyp)
-    if (true) {
+    // For mdat before moov, we must reset the io.
+    off_t offset = -1;
+    
+    while (true) {
         SrsMp4Box* box = NULL;
-        SrsAutoFree(SrsMp4Box, box);
         
-        if ((ret = load_next_box(&box, SrsMp4BoxTypeFTYP)) != ERROR_SUCCESS) {
+        if ((ret = load_next_box(&box, 0)) != ERROR_SUCCESS) {
             return ret;
         }
-        SrsMp4FileTypeBox* ftyp = dynamic_cast<SrsMp4FileTypeBox*>(box);
         
-        bool legal_brand = false;
-        static SrsMp4BoxBrand legal_brands[] = {
-            SrsMp4BoxBrandISOM, SrsMp4BoxBrandISO2, SrsMp4BoxBrandAVC1, SrsMp4BoxBrandMP41
-        };
-        for (int i = 0; i < sizeof(legal_brands)/sizeof(SrsMp4BoxBrand); i++) {
-            if (ftyp->major_brand == legal_brands[i]) {
-                legal_brand = true;
-                break;
+        if (box->is_ftyp()) {
+            SrsMp4FileTypeBox* ftyp = dynamic_cast<SrsMp4FileTypeBox*>(box);
+            if ((ret = parse_ftyp(ftyp)) != ERROR_SUCCESS) {
+                return ret;
             }
+        } else if (box->is_mdat()) {
+            off_t cur = 0;
+            if ((ret = rsio->lseek(0, SEEK_CUR, &cur)) != ERROR_SUCCESS) {
+                return ret;
+            }
+            offset = off_t(cur - box->sz());
+        } else if (box->is_moov()) {
+            SrsMp4MovieBox* moov = dynamic_cast<SrsMp4MovieBox*>(box);
+            if ((ret = parse_moov(moov)) != ERROR_SUCCESS) {
+                return ret;
+            }
+            break;
         }
-        if (!legal_brand) {
-            ret = ERROR_MP4_BOX_ILLEGAL_BRAND;
-            srs_error("MP4 brand is illegal, brand=%d. ret=%d", ftyp->major_brand, ret);
-            return ret;
-        }
+        
+        srs_freep(box);
     }
     
-    // Media Data Box (mdat) or Movie Box (moov)
-    SrsMp4Box* box = NULL;
-    SrsAutoFree(SrsMp4Box, box);
-    while (true) {
-        if ((ret = load_next_box(&box, 0)) != ERROR_SUCCESS) {
-            return ret;
-        }
-        
-        if (!box->is_mdat() && !box->is_moov()) {
-            srs_freep(box);
-            continue;
-        }
-        break;
+    if (brand == SrsMp4BoxBrandForbidden) {
+        ret = ERROR_MP4_BOX_ILLEGAL_SCHEMA;
+        srs_error("MP4 missing ftyp. ret=%d", ret);
+        return ret;
     }
     
-    // Only support non-seek mp4, that is, mdat should never before moov.
-    // @see https://github.com/ossrs/srs/issues/738#issuecomment-276343669
-    if (box->is_mdat()) {
-        ret = ERROR_MP4_NOT_NON_SEEKABLE;
-        srs_error("MP4 is not non-seekable. ret=%d", ret);
+    // Reset the io to the start to reparse the general MP4.
+    if (offset >= 0) {
+        return rsio->lseek(offset, SEEK_SET, NULL);
+    }
+    
+    return ret;
+}
+
+int SrsMp4Decoder::parse_ftyp(SrsMp4FileTypeBox* ftyp)
+{
+    int ret = ERROR_SUCCESS;
+    
+    // File Type Box (ftyp)
+    bool legal_brand = false;
+    static SrsMp4BoxBrand legal_brands[] = {
+        SrsMp4BoxBrandISOM, SrsMp4BoxBrandISO2, SrsMp4BoxBrandAVC1, SrsMp4BoxBrandMP41
+    };
+    for (int i = 0; i < sizeof(legal_brands)/sizeof(SrsMp4BoxBrand); i++) {
+        if (ftyp->major_brand == legal_brands[i]) {
+            legal_brand = true;
+            break;
+        }
+    }
+    if (!legal_brand) {
+        ret = ERROR_MP4_BOX_ILLEGAL_BRAND;
+        srs_error("MP4 brand is illegal, brand=%d. ret=%d", ftyp->major_brand, ret);
         return ret;
     }
     
-    // Parse the Movie Header Box(moov).
-    SrsMp4MovieBox* moov = dynamic_cast<SrsMp4MovieBox*>(box);
-    return parse_moov(moov);
+    brand = ftyp->major_brand;
+    
+    return ret;
 }
 
 int SrsMp4Decoder::parse_moov(SrsMp4MovieBox* moov)
@@ -3110,7 +3128,7 @@ int SrsMp4Decoder::do_load_next_box(SrsMp4Box** ppbox, uint32_t required_box_typ
         uint64_t required = box? box->sz():4;
         while (stream->length() < required) {
             ssize_t nread;
-            if ((ret = reader->read(buf, SRS_MP4_BUF_SIZE, &nread)) != ERROR_SUCCESS) {
+            if ((ret = rsio->read(buf, SRS_MP4_BUF_SIZE, &nread)) != ERROR_SUCCESS) {
                 srs_error("MP4 load failed, nread=%d, required=%d. ret=%d", nread, required, ret);
                 return ret;
             }
@@ -3131,18 +3149,36 @@ int SrsMp4Decoder::do_load_next_box(SrsMp4Box** ppbox, uint32_t required_box_typ
             return ret;
         }
         
-        // Decode util we can demux the whole box.
-        if (!buffer->require((int)box->sz())) {
-            continue;
-        }
+        // For mdat, skip the content.
+        if (box->is_mdat()) {
+            // Never load the mdat box content, instead we skip it, for it's too large.
+            // The demuxer use seeker to read sample one by one.
+            if (box->is_mdat()) {
+                int offset = (int)(box->sz() - stream->length());
+                if (offset < 0) {
+                    stream->erase(stream->length() + offset);
+                } else {
+                    stream->erase(stream->length());
+                }
+                if (offset > 0 && (ret = rsio->lseek(offset, SEEK_CUR, NULL)) != ERROR_SUCCESS) {
+                    return ret;
+                }
+            }
+        } else {
+            // Util we can demux the whole box.
+            if (!buffer->require((int)box->sz())) {
+                continue;
+            }
+            
+            // Decode the matched box or any box is matched.
+            if (!required_box_type || box->type == required_box_type) {
+                ret = box->decode(buffer);
+            }
         
-        if (!required_box_type || box->type == required_box_type) {
-            ret = box->decode(buffer);
+            // Remove the consumed bytes.
+            stream->erase((int)box->sz());
         }
         
-        // Remove the consumed bytes.
-        stream->erase((int)box->sz());
-        
         if (ret != ERROR_SUCCESS) {
             srs_freep(box);
         } else {
diff --git a/trunk/src/kernel/srs_kernel_mp4.hpp b/trunk/src/kernel/srs_kernel_mp4.hpp
index b05bf4406..b82b4c01f 100644
--- a/trunk/src/kernel/srs_kernel_mp4.hpp
+++ b/trunk/src/kernel/srs_kernel_mp4.hpp
@@ -35,7 +35,7 @@ CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
 #include <string>
 #include <vector>
 
-class ISrsReader;
+class ISrsReadSeeker;
 class SrsMp4TrackBox;
 class SrsMp4MediaBox;
 class SrsSimpleStream;
@@ -1342,8 +1342,12 @@ protected:
 class SrsMp4Decoder
 {
 private:
-    // Underlayer reader.
-    ISrsReader* reader;
+    // The major brand of decoder, parse from ftyp.
+    SrsMp4BoxBrand brand;
+private:
+    // Underlayer reader and seeker.
+    // @remark The demuxer must use seeker for general MP4 to seek the moov.
+    ISrsReadSeeker* rsio;
     // The stream used to demux the boxes.
     // TODO: FIXME: refine for performance issue.
     SrsSimpleStream* stream;
@@ -1358,13 +1362,15 @@ public:
      * @param r The underlayer io reader, user must manage it for decoder never open/free it,
      *      the decoder just read data from the reader.
      */
-    virtual int initialize(ISrsReader* r);
+    virtual int initialize(ISrsReadSeeker* rs);
 private:
-    virtual int parse_moov(SrsMp4MovieBox* box);
+    virtual int parse_ftyp(SrsMp4FileTypeBox* ftyp);
+    virtual int parse_moov(SrsMp4MovieBox* moov);
 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);
+    // @remark Never load the mdat box content, for it's too large.
     virtual int do_load_next_box(SrsMp4Box** ppbox, uint32_t required_box_type);
 };
 
diff --git a/trunk/src/libs/srs_librtmp.cpp b/trunk/src/libs/srs_librtmp.cpp
index 941d9d990..d15d1b670 100644
--- a/trunk/src/libs/srs_librtmp.cpp
+++ b/trunk/src/libs/srs_librtmp.cpp
@@ -1755,7 +1755,7 @@ int64_t srs_flv_tellg(srs_flv_t flv)
 void srs_flv_lseek(srs_flv_t flv, int64_t offset)
 {
     FlvContext* context = (FlvContext*)flv;
-    context->reader.lseek(offset);
+    context->reader.seek2(offset);
 }
 
 srs_bool srs_flv_is_eof(int error_code)
diff --git a/trunk/src/utest/srs_utest_kernel.cpp b/trunk/src/utest/srs_utest_kernel.cpp
index 9609acea4..bfaac2a73 100644
--- a/trunk/src/utest/srs_utest_kernel.cpp
+++ b/trunk/src/utest/srs_utest_kernel.cpp
@@ -131,7 +131,7 @@ void MockSrsFileReader::skip(int64_t _size)
     offset += _size;
 }
 
-int64_t MockSrsFileReader::lseek(int64_t _offset)
+int64_t MockSrsFileReader::seek2(int64_t _offset)
 {
     offset = (int)_offset;
     return offset;
@@ -163,6 +163,12 @@ int MockSrsFileReader::read(void* buf, size_t count, ssize_t* pnread)
     return ret;
 }
 
+int MockSrsFileReader::lseek(off_t _offset, int /*whence*/, off_t* /*seeked*/)
+{
+    offset = (int)_offset;
+    return ERROR_SUCCESS;
+}
+
 void MockSrsFileReader::mock_append_data(const char* _data, int _size)
 {
     int s = srs_min(MAX_MOCK_DATA_SIZE - offset, _size);
@@ -952,10 +958,10 @@ VOID TEST(KernelFlvTest, FlvVSDecoderSeek)
     fs.mock_append_data(tag_header, 11);
     EXPECT_TRUE(11 == fs.offset);
 
-    EXPECT_TRUE(ERROR_SUCCESS == dec.lseek(0));
+    EXPECT_TRUE(ERROR_SUCCESS == dec.seek2(0));
     EXPECT_TRUE(0 == fs.offset);
 
-    EXPECT_TRUE(ERROR_SUCCESS == dec.lseek(5));
+    EXPECT_TRUE(ERROR_SUCCESS == dec.seek2(5));
     EXPECT_TRUE(5 == fs.offset);
 }
 
diff --git a/trunk/src/utest/srs_utest_kernel.hpp b/trunk/src/utest/srs_utest_kernel.hpp
index 85d89186f..9a1870b8d 100644
--- a/trunk/src/utest/srs_utest_kernel.hpp
+++ b/trunk/src/utest/srs_utest_kernel.hpp
@@ -81,10 +81,11 @@ public:
     virtual bool is_open();
     virtual int64_t tellg();
     virtual void skip(int64_t size);
-    virtual int64_t lseek(int64_t offset);
+    virtual int64_t seek2(int64_t offset);
     virtual int64_t filesize();
 public:
     virtual int read(void* buf, size_t count, ssize_t* pnread);
+    virtual int lseek(off_t offset, int whence, off_t* seeked);
 // for mock
 public:
     // append data to current offset, modify the offset and size.