fix #119: use iformat and oformat for ffmpeg transcode.

@@ -649,6 +649,12 @@ vhost all.transcode.srs.com {
             # whether the engine is enabled
             # default: off.
             enabled         on;
+            # input format, can be:
+            # off, do not specifies the format, ffmpeg will guess it.
+            # flv, for flv or RTMP stream.
+            # other format, for example, mp4/aac whatever.
+            # default: flv
+            iformat         flv;
             # ffmpeg filters, follows the main input.
             vfilter {
                 # the logo input file.
@@ -706,6 +712,12 @@ vhost all.transcode.srs.com {
                 # audio params, @see: http://ffmpeg.org/ffmpeg-codecs.html#Audio-Encoders
                 profile:a   aac_low;
             }
+            # output format, can be:
+            # off, do not specifies the format, ffmpeg will guess it.
+            # flv, for flv or RTMP stream.
+            # other format, for example, mp4/aac whatever.
+            # default: flv
+            oformat         flv;
             # output stream. variables:
             # [vhost] the input stream vhost.
             # [port] the intput stream port.

@@ -1965,6 +1965,20 @@ bool SrsConfig::get_engine_enabled(SrsConfDirective* engine)
     return true;
 }
 
+string SrsConfig::get_engine_iformat(SrsConfDirective* engine)
+{
+    if (!engine) {
+        return "flv";
+    }
+    
+    SrsConfDirective* conf = engine->get("iformat");
+    if (!conf) {
+        return "flv";
+    }
+    
+    return conf->arg0();
+}
+
 vector<string> SrsConfig::get_engine_vfilter(SrsConfDirective* engine)
 {
     vector<string> vfilter;
@@ -2211,6 +2225,20 @@ vector<string> SrsConfig::get_engine_aparams(SrsConfDirective* engine)
     return aparams;
 }
 
+string SrsConfig::get_engine_oformat(SrsConfDirective* engine)
+{
+    if (!engine) {
+        return "flv";
+    }
+    
+    SrsConfDirective* conf = engine->get("oformat");
+    if (!conf) {
+        return "flv";
+    }
+    
+    return conf->arg0();
+}
+
 string SrsConfig::get_engine_output(SrsConfDirective* engine)
 {
     if (!engine) {

@@ -605,6 +605,10 @@ public:
     */
     virtual bool                get_engine_enabled(SrsConfDirective* engine);
     /**
+    * get the iformat of engine
+    */
+    virtual std::string         get_engine_iformat(SrsConfDirective* engine);
+    /**
     * get the vfilter of engine,
     * the video filter set before the vcodec of FFMPEG.
     */
@@ -679,6 +683,10 @@ public:
     */
     virtual std::vector<std::string> get_engine_aparams(SrsConfDirective* engine);
     /**
+    * get the oformat of engine
+    */
+    virtual std::string         get_engine_oformat(SrsConfDirective* engine);
+    /**
     * get the output of engine, for example, rtmp://127.0.0.1/live/livestream,
     * @remark, we will use some variable, for instance, [vhost] to substitude with vhost.
     */

@@ -96,6 +96,7 @@ int SrsFFMPEG::initialize_transcode(SrsConfDirective* engine)
 {
     int ret = ERROR_SUCCESS;
     
+    iformat             = _srs_config->get_engine_iformat(engine);
     vfilter             = _srs_config->get_engine_vfilter(engine);
     vcodec              = _srs_config->get_engine_vcodec(engine);
     vbitrate            = _srs_config->get_engine_vbitrate(engine);
@@ -111,6 +112,7 @@ int SrsFFMPEG::initialize_transcode(SrsConfDirective* engine)
     asample_rate        = _srs_config->get_engine_asample_rate(engine);
     achannels           = _srs_config->get_engine_achannels(engine);
     aparams             = _srs_config->get_engine_aparams(engine);
+    oformat             = _srs_config->get_engine_oformat(engine);
     
     // ensure the size is even.
     vwidth -= vwidth % 2;
@@ -241,8 +243,10 @@ int SrsFFMPEG::start()
     }
     
     // input.
-    params.push_back("-f");
-    params.push_back("flv");
+    if (iformat != "off") {
+        params.push_back("-f");
+        params.push_back(iformat);
+    }
     
     params.push_back("-i");
     params.push_back(input);
@@ -342,8 +346,10 @@ int SrsFFMPEG::start()
     }
 
     // output
-    params.push_back("-f");
-    params.push_back("flv");
+    if (oformat != "off") {
+        params.push_back("-f");
+        params.push_back(oformat);
+    }
     
     params.push_back("-y");
     params.push_back(_output);

@@ -51,6 +51,8 @@ private:
 private:
     std::string                 ffmpeg;
     std::string                 _iparams;
+    std::string                 iformat;
+    std::string                 input;
     std::vector<std::string>    vfilter;
     std::string                 vcodec;
     int                         vbitrate;
@@ -66,8 +68,8 @@ private:
     int                         asample_rate;
     int                         achannels;
     std::vector<std::string>    aparams;
+    std::string                 oformat;
     std::string                 _output;
-    std::string                 input;
 public:
     SrsFFMPEG(std::string ffmpeg_bin);
     virtual ~SrsFFMPEG();