process multi audio files

@@ -339,20 +339,39 @@ int process_files(const char * output_dest_file)
 	get_duration_from_video_file();
 
 	if (filesvideo.size()) {//has video files
+
 		for (int i = 0; i < filesaudio.size(); i++){  //
 			fileinfo audio = filesaudio[i];
-			float audio_start = 0;
+			float audio_start = audio.start_time;
+
+			for (int j = i; j < filesaudio.size(); j++){
+				filesaudio[j].start_time -= audio_start;
+				filesaudio[j].end_time -= audio_start;
+			}
+
+			for (int j = nv; j < filesvideo.size(); j++) {
+				filesvideo[j].start_time -= audio_start;
+				filesvideo[j].end_time -= audio_start;
+			}
+
+			audio = filesaudio[i];
+
+			audio_start = 0;
 
 			for (; nv < filesvideo.size(); nv++) {
 				fileinfo video = filesvideo[nv];
 
 				if (video.start_time - audio_start > 0.100) {
-
 					sprintf(destfile, "%d_%s", nf, audio.name.c_str());
+					if (video.start_time > audio.end_time){
+						split_audio(audio, audio_start, audio.end_time - audio_start, destfile);
+					}
+					else{
 						split_audio(audio, audio_start, video.start_time - audio_start, destfile);
+						audio_start = video.start_time;
+					}
 					tmp_files.push_back(destfile);
 				
-					audio_start = video.start_time;
 
 					sprintf(destfile, "%s.jpg", video.name.c_str());
 					get_video_first_frame_jpeg(video, destfile);
@@ -362,6 +381,10 @@ int process_files(const char * output_dest_file)
 					merge_audio_pic(audio, nf, video, destfile);
 					merged_files.push_back(destfile);
 					nf++;
+
+					if (video.start_time > audio.end_time){//to next audio
+						break;
+					}
 				}
 				if (nv != filesvideo.size() - 1) {// not the last one
 					sprintf(destfile, "%d_%s", nf, audio.name.c_str());