donot mix the read and write for librtmp

@@ -121,14 +121,14 @@ int process(const char* in_flv_file, const char* out_flv_file, srs_flv_t* pic, s
     srs_amf0_t amf0_data = NULL;
     srs_amf0_t filepositions = NULL;
     
-    if ((ic = srs_flv_open(in_flv_file)) == NULL) {
+    if ((ic = srs_flv_open_read(in_flv_file)) == NULL) {
         ret = 2;
         trace("open input flv file failed. ret=%d", ret);
         return ret;
     }
     *pic = ic;
     
-    if ((oc = srs_flv_open(out_flv_file)) == NULL) {
+    if ((oc = srs_flv_open_write(out_flv_file)) == NULL) {
         ret = 2;
         trace("open output flv file failed. ret=%d", ret);
         return ret;

@@ -64,7 +64,7 @@ int main(int argc, char** argv)
     trace("version: %d.%d.%d", srs_version_major(), srs_version_minor(), srs_version_revision());
     trace("input:  %s", in_flv_file);
 
-    if ((flv = srs_flv_open(in_flv_file)) == NULL) {
+    if ((flv = srs_flv_open_read(in_flv_file)) == NULL) {
         ret = 2;
         trace("open flv file failed. ret=%d", ret);
         return ret;

@@ -93,7 +93,7 @@ int main(int argc, char** argv)
     trace("input:  %s", in_flv_file);
     trace("output: %s", out_rtmp_url);
 
-    if ((flv = srs_flv_open(in_flv_file)) == NULL) {
+    if ((flv = srs_flv_open_read(in_flv_file)) == NULL) {
         ret = 2;
         trace("open flv file failed. ret=%d", ret);
         return ret;

@@ -120,6 +120,7 @@ CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
 #define ERROR_SYSTEM_CREATE_PIPE            430
 #define ERROR_SYSTEM_FILE_SEEK              431
 #define ERROR_SYSTEM_FLV_HEADER             432
+#define ERROR_SYSTEM_IO_INVALID             433
 
 // see librtmp.
 // failed when open ssl create the dh

@@ -165,6 +165,11 @@ void SrsFileReader::close()
     return;
 }
 
+bool SrsFileReader::is_open()
+{
+    return fd > 0;
+}
+
 int64_t SrsFileReader::tellg()
 {
     return (int64_t)::lseek(fd, 0, SEEK_CUR);

@@ -69,6 +69,7 @@ public:
     virtual int open(std::string file);
     virtual void close();
 public:
+    virtual bool is_open();
     virtual int64_t tellg();
     virtual void skip(int64_t size);
     virtual int64_t lseek(int64_t offset);

@@ -467,28 +467,37 @@ struct FlvContext
     SrsFlvDecoder dec;
 };
 
-srs_flv_t srs_flv_open(const char* file)
+srs_flv_t srs_flv_open_read(const char* file)
 {
     int ret = ERROR_SUCCESS;
     
     FlvContext* flv = new FlvContext();
     
-    if ((ret = flv->writer.open(file)) != ERROR_SUCCESS) {
+    if ((ret = flv->reader.open(file)) != ERROR_SUCCESS) {
         srs_freep(flv);
         return NULL;
     }
     
-    if ((ret = flv->enc.initialize(&flv->writer)) != ERROR_SUCCESS) {
+    if ((ret = flv->dec.initialize(&flv->reader)) != ERROR_SUCCESS) {
         srs_freep(flv);
         return NULL;
     }
     
-    if ((ret = flv->reader.open(file)) != ERROR_SUCCESS) {
+    return flv;
+}
+
+srs_flv_t srs_flv_open_write(const char* file)
+{
+    int ret = ERROR_SUCCESS;
+    
+    FlvContext* flv = new FlvContext();
+    
+    if ((ret = flv->writer.open(file)) != ERROR_SUCCESS) {
         srs_freep(flv);
         return NULL;
     }
     
-    if ((ret = flv->dec.initialize(&flv->reader)) != ERROR_SUCCESS) {
+    if ((ret = flv->enc.initialize(&flv->writer)) != ERROR_SUCCESS) {
         srs_freep(flv);
         return NULL;
     }
@@ -507,6 +516,11 @@ int srs_flv_read_header(srs_flv_t flv, char header[9])
     int ret = ERROR_SUCCESS;
     
     FlvContext* context = (FlvContext*)flv;
+
+    if (!context->reader.is_open()) {
+        return ERROR_SYSTEM_IO_INVALID;
+    }
+    
     if ((ret = context->dec.read_header(header)) != ERROR_SUCCESS) {
         return ret;
     }
@@ -524,6 +538,11 @@ int srs_flv_read_tag_header(srs_flv_t flv, char* ptype, int32_t* pdata_size, u_i
     int ret = ERROR_SUCCESS;
     
     FlvContext* context = (FlvContext*)flv;
+
+    if (!context->reader.is_open()) {
+        return ERROR_SYSTEM_IO_INVALID;
+    }
+    
     if ((ret = context->dec.read_tag_header(ptype, pdata_size, ptime)) != ERROR_SUCCESS) {
         return ret;
     }
@@ -536,6 +555,11 @@ int srs_flv_read_tag_data(srs_flv_t flv, char* data, int32_t size)
     int ret = ERROR_SUCCESS;
     
     FlvContext* context = (FlvContext*)flv;
+
+    if (!context->reader.is_open()) {
+        return ERROR_SYSTEM_IO_INVALID;
+    }
+    
     if ((ret = context->dec.read_tag_data(data, size)) != ERROR_SUCCESS) {
         return ret;
     }
@@ -553,6 +577,11 @@ int srs_flv_write_header(srs_flv_t flv, char header[9])
     int ret = ERROR_SUCCESS;
     
     FlvContext* context = (FlvContext*)flv;
+
+    if (!context->writer.is_open()) {
+        return ERROR_SYSTEM_IO_INVALID;
+    }
+    
     if ((ret = context->enc.write_header(header)) != ERROR_SUCCESS) {
         return ret;
     }
@@ -565,6 +594,11 @@ int srs_flv_write_tag(srs_flv_t flv, char type, int32_t time, char* data, int si
     int ret = ERROR_SUCCESS;
     
     FlvContext* context = (FlvContext*)flv;
+
+    if (!context->writer.is_open()) {
+        return ERROR_SYSTEM_IO_INVALID;
+    }
+    
     if (type == SRS_RTMP_TYPE_AUDIO) {
         return context->enc.write_audio(time, data, size);
     } else if (type == SRS_RTMP_TYPE_VIDEO) {

@@ -166,7 +166,8 @@ int64_t srs_get_nrecv_bytes(srs_rtmp_t rtmp);
 typedef void* srs_flv_t;
 typedef int flv_bool;
 /* open flv file for both read/write. */
-srs_flv_t srs_flv_open(const char* file);
+srs_flv_t srs_flv_open_read(const char* file);
+srs_flv_t srs_flv_open_write(const char* file);
 void srs_flv_close(srs_flv_t flv);
 /* read the flv header. 9bytes header. drop the 4bytes zero previous tag size */
 int srs_flv_read_header(srs_flv_t flv, char header[9]);