modify the pip layout,if both teacher and student has video ,teacher at lop,and student at bottom

@@ -105,13 +105,16 @@ void get_config_path(){
 const char * default_vcodec_param = "-vcodec libx264 -level 3.1 -preset veryfast -g 100 -r 20 -bf 0 -vsync cfr";
 const char * default_acodec_param = "-acodec copy";
 const char * default_av_codec_param = "-acodec aac -vcodec libx264 -level 3.1 -preset veryfast -g 100 -r 20 -bf 0 -vsync cfr";
-const char * default_pip_param = "-filter_complex \"[1:v]scale=w=96:h=72:force_original_aspect_ratio=decrease[b];[0:v][b]overlay=x=0:y=0\" -filter_complex amix=inputs=2:duration=first:dropout_transition=2,volume=1";
+//const char * default_pip_param = "-filter_complex \"[1:v]scale=w=96:h=72:force_original_aspect_ratio=decrease[b];[0:v][b]overlay=x=0:y=0\" -filter_complex amix=inputs=2:duration=first:dropout_transition=2,volume=1";
+const char * default_pip_param = "-filter_complex \"[1:v]scale=w=320:h=240:force_original_aspect_ratio=decrease[b];[0:v]scale=w=320:h=240,pad=320:480:0:0:#165a82[c],[c][b]overlay=x=0:y=240\" -filter_complex amix=inputs=2:duration=first:dropout_transition=2,volume=1";
+const char * default_pip1_param = " -filter_complex \"scale=w=320:h=240,pad=320:480:0:0:#165a82\" -vcodec libx264 -level 3.1 -preset veryfast -g 100 -r 20 -bf 0 -vsync cfr -acodec copy";
 
 
 char av_codec_param[1024];
 char vcodec_param[1024];
 char acodec_param[1024];
 char pip_param[1024];
+char pip1_param[1024];
 
 bool first_time_set = false;
 float start_time = 0.0f;
@@ -199,6 +202,20 @@ void split_av(const char * mediafile, float start, float duration, char * destfi
 	run_shell_cmd(buf);
 }
 
+void split_av_for_1pip(const char * mediafile, float start, float duration, char * destfile)
+{
+	char buf[2048];
+	sprintf(buf, "ffmpeg -y -i %s -ss %.3f -t %.3f %s %s", mediafile, start, duration, pip1_param, destfile);
+	run_shell_cmd(buf);
+}
+
+void transcode_to_1pip(const char * mediafile, char * destfile)
+{
+	char buf[2048];
+	sprintf(buf, "ffmpeg -y -i %s %s %s", mediafile, pip1_param, destfile);
+	run_shell_cmd(buf);
+}
+
 void get_video_first_frame_jpeg(const char * video, const char * destfile)
 {
 	char buf[2048];
@@ -766,11 +783,13 @@ int transcode_file(vector<media_info> files)
 	
 	if (video.type_time - video.start_time > 0.10 || video_end.end_time - video_end.type_time > 0.10) {
 		sprintf(video_file, "%d_%s", nf, video.name.c_str());
-		split_av(video.name.c_str(), video.type_time - video.start_time, video_end.type_time - video.type_time, video_file);
+		split_av_for_1pip(video.name.c_str(), video.type_time - video.start_time, video_end.type_time - video.type_time, video_file);
 		tmp_files.push_back(video_file);
 	}
 	else{
-		strcpy(video_file, video.name.c_str());
+		sprintf(video_file, "%d_%s", nf, video.name.c_str());
+		transcode_to_1pip(video.name.c_str(), video_file);
+		tmp_files.push_back(video_file);
 	}
 	
 	merged_files.push_back(video_file);
@@ -1429,6 +1448,7 @@ void load_codec_param()
 	strcpy(vcodec_param, default_vcodec_param);
 	strcpy(av_codec_param, default_av_codec_param);
 	strcpy(pip_param, default_pip_param);
+	strcpy(pip1_param, default_pip1_param);
 
 	char cfgfile[1024];
 
@@ -1462,9 +1482,15 @@ void load_codec_param()
 	str[0] = 0;
 	if (fin.getline(str, LINE_LENGTH))
 	{
-		printf("load av codec from %s: %s\n", cfgfile, str);
+		printf("load pip codec from %s: %s\n", cfgfile, str);
 		strcpy(pip_param, str);
 	}
+	str[0] = 0;
+	if (fin.getline(str, LINE_LENGTH))
+	{
+		printf("load pip1 codec from %s: %s\n", cfgfile, str);
+		strcpy(pip1_param, str);
+	}
 }
 
 void get_outinfo_file_name(char * input1 , char * input2)