fix #169, support default values for transcode. 2.0.180

@@ -344,6 +344,7 @@ Remark:
 
 ### SRS 2.0 history
 
+* v2.0, 2015-07-21, for [#169](https://github.com/simple-rtmp-server/srs/issues/169) support default values for transcode. 2.0.180
 * v2.0, 2015-07-21, fix [#435](https://github.com/simple-rtmp-server/srs/issues/435) add pageUrl for HTTP callback on_play.
 * v2.0, 2015-07-20, refine the hls, ignore packet when no sequence header. 2.0.179
 * v2.0, 2015-07-16, for [#441](https://github.com/simple-rtmp-server/srs/issues/441) use 30s timeout for first msg. 2.0.178

@@ -13,19 +13,12 @@ vhost __defaultVhost__ {
             vfilter {
             }
             vcodec          libx264;
-            vbitrate        500;
-            vfps            25;
-            vwidth          768;
-            vheight         320;
-            vthreads        12;
+            vthreads        4;
             vprofile        main;
             vpreset         medium;
             vparams {
             }
             acodec          libfdk_aac;
-            abitrate        70;
-            asample_rate    44100;
-            achannels       2;
             aparams {
             }
             output          rtmp://127.0.0.1:[port]/[app]?vhost=[vhost]/[stream]_[engine];

@@ -918,14 +918,23 @@ vhost example.transcode.srs.com {
             #       vn: disable video output.
             vcodec          libx264;
             # video bitrate, in kbps
+            # @remark 0 to use source video bitrate.
+            # default: 0
             vbitrate        1500;
             # video framerate.
+            # @remark 0 to use source video fps.
+            # default: 0
             vfps            25;
             # video width, must be even numbers.
+            # @remark 0 to use source video width.
+            # default: 0
             vwidth          768;
             # video height, must be even numbers.
+            # @remark 0 to use source video height.
+            # default: 0
             vheight         320;
             # the max threads for ffmpeg to used.
+            # default: 1
             vthreads        12;
             # x264 profile, @see x264 -help, can be:
             # high,main,baseline
@@ -950,17 +959,24 @@ vhost example.transcode.srs.com {
             #       an: disable audio output.
             acodec          libfdk_aac;
             # audio bitrate, in kbps. [16, 72] for libfdk_aac.
+            # @remark 0 to use source audio bitrate.
+            # default: 0
             abitrate        70;
             # audio sample rate. for flv/rtmp, it must be:
             #       44100,22050,11025,5512
+            # @remark 0 to use source audio sample rate.
+            # default: 0
             asample_rate    44100;
             # audio channel, 1 for mono, 2 for stereo.
+            # @remark 0 to use source audio channels.
+            # default: 0
             achannels       2;
             # other ffmpeg audio params
             aparams {
                 # audio params, @see: http://ffmpeg.org/ffmpeg-codecs.html#Audio-Encoders
                 # @remark SRS supported aac profile for HLS is: aac_low, aac_he, aac_he_v2
                 profile:a   aac_low;
+                bsf:a       aac_adtstoasc;
             }
             # output format, can be:
             #       off, do not specifies the format, ffmpeg will guess it.

@@ -20,9 +20,6 @@ vhost __defaultVhost__ {
             enabled         on;
             vcodec          copy;
             acodec          libfdk_aac;
-            abitrate        45;
-            asample_rate    44100;
-            achannels       2;
             aparams {
             }
             output          rtmp://127.0.0.1:[port]/[app]?vhost=[vhost]/[stream]_[engine];

@@ -2976,13 +2976,15 @@ string SrsConfig::get_engine_vcodec(SrsConfDirective* engine)
 
 int SrsConfig::get_engine_vbitrate(SrsConfDirective* engine)
 {
+    static int DEFAULT = 0;
+    
     if (!engine) {
-        return 0;
+        return DEFAULT;
     }
     
     SrsConfDirective* conf = engine->get("vbitrate");
-    if (!conf) {
-        return 0;
+    if (!conf || conf->arg0().empty()) {
+        return DEFAULT;
     }
     
     return ::atoi(conf->arg0().c_str());
@@ -2990,13 +2992,15 @@ int SrsConfig::get_engine_vbitrate(SrsConfDirective* engine)
 
 double SrsConfig::get_engine_vfps(SrsConfDirective* engine)
 {
+    static double DEFAULT = 0;
+    
     if (!engine) {
-        return 0;
+        return DEFAULT;
     }
     
     SrsConfDirective* conf = engine->get("vfps");
-    if (!conf) {
-        return 0;
+    if (!conf || conf->arg0().empty()) {
+        return DEFAULT;
     }
     
     return ::atof(conf->arg0().c_str());
@@ -3004,13 +3008,15 @@ double SrsConfig::get_engine_vfps(SrsConfDirective* engine)
 
 int SrsConfig::get_engine_vwidth(SrsConfDirective* engine)
 {
+    static int DEFAULT = 0;
+    
     if (!engine) {
-        return 0;
+        return DEFAULT;
     }
     
     SrsConfDirective* conf = engine->get("vwidth");
-    if (!conf) {
-        return 0;
+    if (!conf || conf->arg0().empty()) {
+        return DEFAULT;
     }
     
     return ::atoi(conf->arg0().c_str());
@@ -3018,13 +3024,15 @@ int SrsConfig::get_engine_vwidth(SrsConfDirective* engine)
 
 int SrsConfig::get_engine_vheight(SrsConfDirective* engine)
 {
+    static int DEFAULT = 0;
+    
     if (!engine) {
-        return 0;
+        return DEFAULT;
     }
     
     SrsConfDirective* conf = engine->get("vheight");
-    if (!conf) {
-        return 0;
+    if (!conf || conf->arg0().empty()) {
+        return DEFAULT;
     }
     
     return ::atoi(conf->arg0().c_str());
@@ -3032,13 +3040,15 @@ int SrsConfig::get_engine_vheight(SrsConfDirective* engine)
 
 int SrsConfig::get_engine_vthreads(SrsConfDirective* engine)
 {
+    static int DEFAULT = 1;
+    
     if (!engine) {
-        return 0;
+        return DEFAULT;
     }
     
     SrsConfDirective* conf = engine->get("vthreads");
-    if (!conf) {
-        return 0;
+    if (!conf || conf->arg0().empty()) {
+        return DEFAULT;
     }
     
     return ::atoi(conf->arg0().c_str());
@@ -3116,13 +3126,15 @@ string SrsConfig::get_engine_acodec(SrsConfDirective* engine)
 
 int SrsConfig::get_engine_abitrate(SrsConfDirective* engine)
 {
+    static int DEFAULT = 0;
+    
     if (!engine) {
-        return 0;
+        return DEFAULT;
     }
     
     SrsConfDirective* conf = engine->get("abitrate");
-    if (!conf) {
-        return 0;
+    if (!conf || conf->arg0().empty()) {
+        return DEFAULT;
     }
     
     return ::atoi(conf->arg0().c_str());
@@ -3130,13 +3142,15 @@ int SrsConfig::get_engine_abitrate(SrsConfDirective* engine)
 
 int SrsConfig::get_engine_asample_rate(SrsConfDirective* engine)
 {
+    static int DEFAULT = 0;
+    
     if (!engine) {
-        return 0;
+        return DEFAULT;
     }
     
     SrsConfDirective* conf = engine->get("asample_rate");
-    if (!conf) {
-        return 0;
+    if (!conf || conf->arg0().empty()) {
+        return DEFAULT;
     }
     
     return ::atoi(conf->arg0().c_str());
@@ -3144,13 +3158,15 @@ int SrsConfig::get_engine_asample_rate(SrsConfDirective* engine)
 
 int SrsConfig::get_engine_achannels(SrsConfDirective* engine)
 {
+    static int DEFAULT = 0;
+    
     if (!engine) {
-        return 0;
+        return DEFAULT;
     }
     
     SrsConfDirective* conf = engine->get("achannels");
-    if (!conf) {
-        return 0;
+    if (!conf || conf->arg0().empty()) {
+        return DEFAULT;
     }
     
     return ::atoi(conf->arg0().c_str());

@@ -137,22 +137,22 @@ int SrsFFMPEG::initialize_transcode(SrsConfDirective* engine)
                 SRS_RTMP_ENCODER_VCODEC, vcodec.c_str(), ret);
             return ret;
         }
-        if (vbitrate <= 0) {
+        if (vbitrate < 0) {
             ret = ERROR_ENCODER_VBITRATE;
             srs_error("invalid vbitrate: %d, ret=%d", vbitrate, ret);
             return ret;
         }
-        if (vfps <= 0) {
+        if (vfps < 0) {
             ret = ERROR_ENCODER_VFPS;
             srs_error("invalid vfps: %.2f, ret=%d", vfps, ret);
             return ret;
         }
-        if (vwidth <= 0) {
+        if (vwidth < 0) {
             ret = ERROR_ENCODER_VWIDTH;
             srs_error("invalid vwidth: %d, ret=%d", vwidth, ret);
             return ret;
         }
-        if (vheight <= 0) {
+        if (vheight < 0) {
             ret = ERROR_ENCODER_VHEIGHT;
             srs_error("invalid vheight: %d, ret=%d", vheight, ret);
             return ret;
@@ -176,7 +176,7 @@ int SrsFFMPEG::initialize_transcode(SrsConfDirective* engine)
     
     // @see, https://github.com/simple-rtmp-server/srs/issues/145
     if (acodec == SRS_RTMP_ENCODER_LIBAACPLUS && acodec != SRS_RTMP_ENCODER_LIBFDKAAC) {
-        if (abitrate < 16 || abitrate > 72) {
+        if (abitrate != 0 && (abitrate < 16 || abitrate > 72)) {
             ret = ERROR_ENCODER_ABITRATE;
             srs_error("invalid abitrate for aac: %d, must in [16, 72], ret=%d", abitrate, ret);
             return ret;
@@ -184,17 +184,17 @@ int SrsFFMPEG::initialize_transcode(SrsConfDirective* engine)
     }
     
     if (acodec != SRS_RTMP_ENCODER_COPY && acodec != SRS_RTMP_ENCODER_NO_AUDIO) {
-        if (abitrate <= 0) {
+        if (abitrate < 0) {
             ret = ERROR_ENCODER_ABITRATE;
             srs_error("invalid abitrate: %d, ret=%d", abitrate, ret);
             return ret;
         }
-        if (asample_rate <= 0) {
+        if (asample_rate < 0) {
             ret = ERROR_ENCODER_ASAMPLE_RATE;
             srs_error("invalid sample rate: %d, ret=%d", asample_rate, ret);
             return ret;
         }
-        if (achannels != 1 && achannels != 2) {
+        if (achannels != 0 && achannels != 1 && achannels != 2) {
             ret = ERROR_ENCODER_ACHANNELS;
             srs_error("invalid achannels, must be 1 or 2, actual %d, ret=%d", achannels, ret);
             return ret;
@@ -285,26 +285,36 @@ int SrsFFMPEG::start()
     
     // the codec params is disabled when copy
     if (vcodec != SRS_RTMP_ENCODER_COPY && vcodec != SRS_RTMP_ENCODER_NO_VIDEO) {
-        params.push_back("-b:v");
-        snprintf(tmp, sizeof(tmp), "%d", vbitrate * 1000);
-        params.push_back(tmp);
+        if (vbitrate > 0) {
+            params.push_back("-b:v");
+            snprintf(tmp, sizeof(tmp), "%d", vbitrate * 1000);
+            params.push_back(tmp);
+        }
         
-        params.push_back("-r");
-        snprintf(tmp, sizeof(tmp), "%.2f", vfps);
-        params.push_back(tmp);
+        if (vfps > 0) {
+            params.push_back("-r");
+            snprintf(tmp, sizeof(tmp), "%.2f", vfps);
+            params.push_back(tmp);
+        }
         
-        params.push_back("-s");
-        snprintf(tmp, sizeof(tmp), "%dx%d", vwidth, vheight);
-        params.push_back(tmp);
+        if (vwidth > 0 && vheight > 0) {
+            params.push_back("-s");
+            snprintf(tmp, sizeof(tmp), "%dx%d", vwidth, vheight);
+            params.push_back(tmp);
+        }
         
         // TODO: add aspect if needed.
-        params.push_back("-aspect");
-        snprintf(tmp, sizeof(tmp), "%d:%d", vwidth, vheight);
-        params.push_back(tmp);
+        if (vwidth > 0 && vheight > 0) {
+            params.push_back("-aspect");
+            snprintf(tmp, sizeof(tmp), "%d:%d", vwidth, vheight);
+            params.push_back(tmp);
+        }
         
-        params.push_back("-threads");
-        snprintf(tmp, sizeof(tmp), "%d", vthreads);
-        params.push_back(tmp);
+        if (vthreads > 0) {
+            params.push_back("-threads");
+            snprintf(tmp, sizeof(tmp), "%d", vthreads);
+            params.push_back(tmp);
+        }
         
         params.push_back("-profile:v");
         params.push_back(vprofile);
@@ -335,17 +345,23 @@ int SrsFFMPEG::start()
     // the codec params is disabled when copy
     if (acodec != SRS_RTMP_ENCODER_NO_AUDIO) {
         if (acodec != SRS_RTMP_ENCODER_COPY) {
-            params.push_back("-b:a");
-            snprintf(tmp, sizeof(tmp), "%d", abitrate * 1000);
-            params.push_back(tmp);
+            if (abitrate > 0) {
+                params.push_back("-b:a");
+                snprintf(tmp, sizeof(tmp), "%d", abitrate * 1000);
+                params.push_back(tmp);
+            }
             
-            params.push_back("-ar");
-            snprintf(tmp, sizeof(tmp), "%d", asample_rate);
-            params.push_back(tmp);
+            if (asample_rate > 0) {
+                params.push_back("-ar");
+                snprintf(tmp, sizeof(tmp), "%d", asample_rate);
+                params.push_back(tmp);
+            }
             
-            params.push_back("-ac");
-            snprintf(tmp, sizeof(tmp), "%d", achannels);
-            params.push_back(tmp);
+            if (achannels > 0) {
+                params.push_back("-ac");
+                snprintf(tmp, sizeof(tmp), "%d", achannels);
+                params.push_back(tmp);
+            }
             
             // aparams
             std::vector<std::string>::iterator it;

@@ -31,7 +31,7 @@ CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
 // current release version
 #define VERSION_MAJOR       2
 #define VERSION_MINOR       0
-#define VERSION_REVISION    179
+#define VERSION_REVISION    180
 
 // server info.
 #define RTMP_SIG_SRS_KEY "SRS"