jwz@lucid.com (Jamie Zawinski) (06/04/91)
Greetings one and all, In my continuing quest to convert my Explorer beeps to something my Sparc can use, I've come across some software that will convert a file of 8-bit 8kHz samples into Sun's "ulaw" format. Sounds made-to-order, right? Well, no. It wants the samples to be in the range -127 to 128, with 0 (the middle) being silence. The Explorer seems thinks of these samples as unsigned 8-bit numbers, with 0 (the bottom) being silence (if I remember correctly, sampling silence on an Explorer gets a low-volume 60hz hum of samples between 0 and 50 or so.) So I tried the obvious conversions: 127-n, n-127, ~n, 127-~n, and so on, and with the order of bits in n reversed, with little luck. The samples (of speech, at least) are just barely legible with 127-n (which sounds a lot like n & 16, meaning, I guess, that about half the samples are incorrect.) So I'm pretty confused. Does anyone know what format the TI D/A chip wants? Does anyone have any suggestions? (LGO, are you out there...?) -- Jamie