protected String startConverting(SharedFile file) {
Logger.d(this.getClass(), "startConverting:" + file.getAliasFile().getAbsolutePath());
ConvertTask task = new ConvertTask(file.getAliasFile().getAbsolutePath(), this.workPath);
taskTagFileMap.put(task.getTaskTag(), file);
ConvertTool.getInstance().addConvertTask(task);
return task.getTaskTag();
}