UCI137@URIACC.BITNET (Andy Kress) (04/13/90)
I know...this has been talked about for days but wouldn't you know
it, I deleted all my old notes. What are the bytes that have to be
changed in a MAC sound to $00 on a GS? I wouldnt have to ask this if I kept
the old notes. The reason I want it is so I can have a friend write me
a C program on the Mac to change the bytes back and forth. Thanks much all.
Andy
UCI137 at URIACCcyliao@eng.umd.edu (Chun-Yao Liao) (04/13/90)
In article <9004121755.AA26040@apple.com> UCI137@URIACC.BITNET (Andy Kress) writes: > > I know...this has been talked about for days but wouldn't you know > it, I deleted all my old notes. What are the bytes that have to be > changed in a MAC sound to $00 on a GS? I wouldnt have to ask this if I kept > the old notes. The reason I want it is so I can have a friend write me > a C program on the Mac to change the bytes back and forth. Thanks much all. I checked in my file, the value is $80. Might someone else confirm this value for the entire net? Thanx. -- cyliao@wam.umd.edu o NeXT : I put main frame power on two chips. @epsl.umd.edu o people: We put main flame power on two guys. @bagend.eng.umd.edu o :::::::::::::::::::::::::::::::::::::::::::: xxxxx@xxxxx.xxx.xxx (reserved) o RC + Apple // + Classic Music + NeXT = cyliao
toddpw@tybalt.caltech.edu (Todd P. Whitesel) (04/13/90)
UCI137@URIACC.BITNET (Andy Kress) writes: > I know...this has been talked about for days but wouldn't you know > it, I deleted all my old notes. What are the bytes that have to be > changed in a MAC sound to $00 on a GS? I wouldnt have to ask this if I kept > the old notes. The reason I want it is so I can have a friend write me > a C program on the Mac to change the bytes back and forth. Thanks much all. The whole brouhaha about this stems from the fact that the GS sound chip uses a $00 byte to indicate END OF SAMPLE so that you don't need to tell the DOC exactly how long the sound is, you just hand it a buffer and it plays the C string (heh) it finds there. Mac and GS sounds both use (for the raw format, at least) unsigned byte values for each sample, which get sent straight to a DAC (there is volume processing but the effect is the same). The only difference is that one end of the scale ($00) is used as a stop byte by the GS sound chip, so all you have to do is take the Mac sound file and change every $00 to $01. The change is not audible as far as sound quality goes. Why bother with a C program on the Mac? You can write a BASIC/ML hack on the GS to do this MUCH faster. Assuming you don't mind entering a few filenames, that is. If you'd like such a program (or how about one that goes from AIFF sound to GS binary?) let me know, and I will write one. I have been meaning to anyway, I have gobs of AIFF files I never bothered to convert them over, as I had a cheap hacked routine to play them out the 8 bit DAC of my Apple Cat. Todd Whitesel toddpw @ tybalt.caltech.edu