redmond+@cs.cmu.edu (Redmond English) (05/02/91)
How can I play digitised sound samples from a program ? I've
downloaded a number of *.SND samples, and a program that plays them,
but I'd like to load them into my program and play them myself.
I can handle background tasks using interrupts, so I don't need
details of that, but what do I actually *do* with all those numbers ?
Thanks in advance,
Red/.ZVD007@DMSWWU1C.BITNET (Ulrich Kuehn) (05/02/91)
In article <1991May2.012642.26008@cs.cmu.edu>, redmond+@cs.cmu.edu (Redmond English) says: > >How can I play digitised sound samples from a program ? I've >downloaded a number of *.SND samples, and a program that plays them, >but I'd like to load them into my program and play them myself. > >I can handle background tasks using interrupts, so I don't need >details of that, but what do I actually *do* with all those numbers ? > These soundfiles contain 8-bit-sampled sounds with 0 as the lowest an 255 as th e highest value. To play such a sound, you "only" have to use the internal soundship as a D/A-converter. To do so, set all the delay-values in the registe rs 0 to 5 of the soundship to 0 (the highest frequency it can play) an then turn it off (it has really to be off, otherwise there are interferences in the sound). Install then an interrupt-routine that gets every time it's called a byte from the soundfile (which hab been read somewhere into memory), then converts it with a table, because the soundship has only 4 levelcontrolbits per voice and it's not linear. You can get this table by analysing one off those soundplayers while playing a sound, they often use the timer-a-interrupt. There you can also see a playing routine. After converting, all you have to do, is put the 3 values for the 3 voices into the right registers ( I think it's 8 to 11) When using the DMA-sound of the STE, remember that these sounds range from -128 to 127 (signed), so you have to convert them before playing. U. Kuehn <zvd007@dmswwu1c.bitnet>
friedric@r2d2.fmi.uni-passau.de (Carsten Friedrich) (05/03/91)
In article <91122.134051ZVD007@DMSWWU1C.BITNET> ZVD007@DMSWWU1C.BITNET (Ulrich Kuehn) writes: >In article <1991May2.012642.26008@cs.cmu.edu>, redmond+@cs.cmu.edu (Redmond >English) says: >> >>How can I play digitised sound samples from a program ? I've >>downloaded a number of *.SND samples, and a program that plays them, >>but I'd like to load them into my program and play them myself. . . . >is put the 3 values for the 3 voices into the right registers ( I think it's >8 to 11) > if this doesn't help you, you can also have the source-code of a program doing this. Just mail me if you want it and I'll send it to you. >When using the DMA-sound of the STE, remember that these sounds range from >-128 to 127 (signed), so you have to convert them before playing. > >U. Kuehn <zvd007@dmswwu1c.bitnet> I tried to produce DMA-sound on a STE, but failed. Can anyone give me some hints how to do this ? Carsten Friedrich, e-mail: friedric@unipas.fmi.uni-passau.de
ZVD007@DMSWWU1C.BITNET (Ulrich Kuehn) (05/06/91)
In article <1991May3.122558.5911@forwiss.uni-passau.de>, friedric@r2d2.fmi.uni-passau.de (Carsten Friedrich) says: >I tried to produce DMA-sound on a STE, but failed. Can anyone give me some s >hint >how to do this ? > I think the problem is, that you dont have set the micro-wire-register to enable the output of the analog signals, so the soundchip did its work, but you didnt hear it. Unfortunately, I dont have a STe myself, so I cant tell you more exactly about that. Ulrich Kuehn