[LAD] How do I write meta data into a wave file? (Command line tools?)

Hello list, libsndfile-info shows various useful information like the one at the end of this mail. I have Sonatina Symphonic Orchestra waves here (violins 1) and a one note wave includes "Midi Note", "Loop Count" and "Cue Start : 92078 End : 223977", which is the actual loop start/end Is this custom data or does it follow a standard? And no matter what, how do I write that into my own wave files? I would prefer command line tools. But programming interfaces are fine as well. Greetings, Nils $ sndfile-info test.wav Version : libsndfile-1.0.25 ======================================== File : test.wav Length : 896548 RIFF : 896540 WAVE fmt : 16 Format : 0x1 => WAVE_FORMAT_PCM Channels : 2 Sample Rate : 44100 Block Align : 4 Bit Width : 16 Bytes/sec : 176400 data : 895916 *** SAUR : 512 (unknown marker) smpl : 60 Manufacturer : 0 Product : 0 Period : 22675 nsec Midi Note : 76 Pitch Fract. : 0 SMPTE Format : 0 SMPTE Offset : 00:00:00 00 Loop Count : 1 Cue ID : 0 Type : 0 Start : 92078 End : 223977 Fraction : 0 Count : 0 Sampler Data : 0 End ---------------------------------------- Sample Rate : 44100 Frames : 223979 Channels : 2 Format : 0x00010002 Sections : 1 Seekable : TRUE Duration : 00:00:05.079 Signal Max : 31468 (-0.35 dB)