[Cin] thdmerge

So, I slightly modified Windows version of thdmerge. in theory it should prepare thd (trueHD) file for blu-ray muxing. make file.thd and file.ac3 with ffmpeg $ ffmpeg -i ~/vid_20210526.mp4 -vn -c:a ac3 b.ac3 $ ffmpeg -i ~/vid_20210526.mp4 -vn -c:a truehd -strict -2 a.thd compile gcc -o thdmerge thdmerge.cpp run ./thdmerge a.thd b.ac3 full.thd+ac3 try to mux this resulting file with tsmuxer