ffmpeg -i "concat:12.mp3|22.mp3" -acodec copy arjun.mp3




ffmpeg -i 11.mp3 -i 22.mp3  -filter_complex "[0:a]aformat=sample_fmts=fltp:sample_rates=44100:channel_layouts=mono,atrim=end=20[aud1];[1:a]aformat=sample_fmts=fltp:sample_rates=44100:channel_layouts=mono,atrim=end=240[bud2];[bud2]adelay=10000[aud2];[aud1][aud2]amix=inputs=2"  amerge -ac 2 -c:a libmp3lame -q:a 4
arjun9.mp3


ffmpeg -i 75.mp3 -itsoffset -700 -i 22.mp3 -vn -filter_complex amix 0055598.mp3




ffmpeg -i 75.mp3 -itsoffset -700 -i 22.mp3 -vn -filter_complex amix 0055598.mp3