diff --git a/trunk/conf/srs.conf b/trunk/conf/srs.conf
index 8230d7e00..5aa39bdab 100755
--- a/trunk/conf/srs.conf
+++ b/trunk/conf/srs.conf
@@ -15,7 +15,129 @@ vhost __defaultVhost__ {
     hls_path        ./objs/nginx/html;
     hls_fragment    5;
     hls_window      30;
-    forward         127.0.0.1:1936;
+    #forward         127.0.0.1:1936;
+    transcode {
+        ffmpeg ./objs/ffmpeg/bin/ffmpeg;
+        engine fd{
+            vcodec          libx264;
+            vbitrate        300;
+            vfps            20;
+            vwidth          480;
+            vheight         320;
+            vthreads        2;
+            vprofile        baseline;
+            vpreset         superfast;
+            vparams {}
+            acodec          libaacplus;
+            abitrate        30;
+            asample_rate    22050;
+            achannels       2;
+            aparams {}
+            output rtmp://[vhost]:[port]/[app]/[stream]_fast;
+        }
+    }
+}
+# transcode all app and stream of vhost
+vhost all.transcode.vhost.com {
+    transcode {
+        # the ffmpeg 
+        ffmpeg ./objs/ffmpeg/bin/ffmpeg;
+        # all matched stream will transcoded to the following stream.
+        # the transcode set name(ie. hd) is optional and not used.
+        engine super{
+            # video encoder name
+            vcodec          libx264;
+            # video bitrate, in kbps
+            vbitrate        1500;
+            # video framerate.
+            vfps            25;
+            # video width, must be even numbers.
+            vwidth          1280;
+            # video height, must be even numbers.
+            vheight         720;
+            # the max threads for ffmpeg to used.
+            vthreads        12;
+            # x264 profile, @see x264 -help, can be:
+            # high,main,baseline
+            vprofile        main;
+            # x264 preset, @see x264 -help, can be: 
+            # ultrafast,superfast,veryfast,faster,fast
+            # medium,slow,slower,veryslow,placebo
+            vpreset         medium;
+            # other x264 or ffmpeg video params
+            vparams {
+            }
+            # audio encoder name
+            acodec          libaacplus;
+            # audio bitrate, in kbps. [16, 72] for libaacplus.
+            abitrate        70;
+            # audio sample rate. for flv/rtmp, it must be:
+            # 44100,22050,11025,5512
+            asample_rate    44100;
+            # audio channel, 1 for mono, 2 for stereo.
+            achannels       2;
+            # other ffmpeg audio params
+            aparams {
+            }
+            # output stream. variables:
+            # [vhost] the input stream vhost.
+            # [port] the intput stream port.
+            # [app] the input stream app.
+            # [stream] the input stream name.
+            output rtmp://[vhost]:[port]/[app]/[stream]_super;
+        }
+        engine hd{
+            vcodec          libx264;
+            vbitrate        1200;
+            vfps            25;
+            vwidth          1024;
+            vheight         576;
+            vthreads        6;
+            vprofile        main;
+            vpreset         medium;
+            vparams {}
+            acodec          libaacplus;
+            abitrate        70;
+            asample_rate    44100;
+            achannels       2;
+            aparams {}
+            output rtmp://[vhost]:[port]/[app]/[stream]_hd;
+        }
+        engine sd{
+            vcodec          libx264;
+            vbitrate        800;
+            vfps            25;
+            vwidth          720;
+            vheight         480;
+            vthreads        4;
+            vprofile        main;
+            vpreset         fast;
+            vparams {}
+            acodec          libaacplus;
+            abitrate        60;
+            asample_rate    44100;
+            achannels       2;
+            aparams {}
+            output rtmp://[vhost]:[port]/[app]/[stream]_sd;
+        }
+        engine fast{
+            vcodec          libx264;
+            vbitrate        300;
+            vfps            20;
+            vwidth          480;
+            vheight         320;
+            vthreads        2;
+            vprofile        baseline;
+            vpreset         superfast;
+            vparams {}
+            acodec          libaacplus;
+            abitrate        30;
+            asample_rate    22050;
+            achannels       2;
+            aparams {}
+            output rtmp://[vhost]:[port]/[app]/[stream]_fast;
+        }
+    }
 }
 # the vhost which forward publish streams.
 vhost forward.vhost.com {
@@ -109,3 +231,4 @@ pithy_print {
     forwarder       3000;
 }
 
+
diff --git a/trunk/src/core/srs_core_config.cpp b/trunk/src/core/srs_core_config.cpp
index df188c233..812bf0172 100644
--- a/trunk/src/core/srs_core_config.cpp
+++ b/trunk/src/core/srs_core_config.cpp
@@ -58,7 +58,7 @@ bool is_common_space(char ch)
 	return (ch == ' ' || ch == '\t' || ch == CR || ch == LF);
 }
 
-#define CONF_BUFFER_SIZE 4096
+#define CONF_BUFFER_SIZE 1024 * 1024
 
 SrsFileBuffer::SrsFileBuffer()
 {
@@ -369,6 +369,12 @@ int SrsConfDirective::refill_buffer(SrsFileBuffer* buffer, bool d_quoted, bool s
 	}
 	
 	int size = FILE_SIZE(buffer->fd) - FILE_OFFSET(buffer->fd);
+	if (size > CONF_BUFFER_SIZE) {
+		ret = ERROR_SYSTEM_CONFIG_TOO_LARGE;
+		srs_error("config file too large, max=%d, actual=%d, ret=%d",
+			CONF_BUFFER_SIZE, size, ret);
+		return ret;
+	}
 	
 	if (size <= 0) {
 		return ERROR_SYSTEM_CONFIG_EOF;
diff --git a/trunk/src/core/srs_core_error.hpp b/trunk/src/core/srs_core_error.hpp
index 24a5292c1..738e7f26e 100644
--- a/trunk/src/core/srs_core_error.hpp
+++ b/trunk/src/core/srs_core_error.hpp
@@ -84,6 +84,7 @@ CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
 #define ERROR_SYSTEM_CONFIG_EOF			409
 #define ERROR_SYSTEM_STREAM_BUSY		410
 #define ERROR_SYSTEM_IP_INVALID			411
+#define ERROR_SYSTEM_CONFIG_TOO_LARGE	412
 
 // see librtmp.
 // failed when open ssl create the dh