PHP script to merge 2 FLV files of same characteristics

Hello, I need (if possible) a php script that can merge together 2 flv videos files. FLVs will have the same height, width, frame rate... and be encoded the same way with ffmpeg, I attached a exemple. The goal is not to use any converter but to do that with just open/read/write functions. My idea is to read the first flv, print the content, read the second one, remove the header, write the rest... but maybe it's not possible ? This is to get a live stream = infinite flv by adding the flv as them come. Thanks