andyc@hplsla.HP.COM (Andy Cassino) (07/17/90)
I am new to the world of sound and music on the Atari ST. Dave Bagget's
series of sound programs finally piqued my interest in exploring this
arena. I've managed to lay hands on a number of SND files and have noticed
some curious results. Some SND files play just fine using Dave Baggets
PLAY.PRG and some don't. Of the ones that don't, some will play OK on
PLAYEM.PRG which I got from GEnie, but there's still a few that won't
play. The programs that don't play always sound horrifically garbled and
sometimes even cause the floppy disk drive LED to flicker!
I'm wondering if anyone can explain the differences I've seen, er, heard,
and perhaps comment on the availability of hardware to digitise sound
on the ST.
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%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%cape@npdiss1.StPaul.NCR.COM (Robert Cape) (07/19/90)
In article <13510001@hplsla.HP.COM> andyc@hplsla.HP.COM (Andy Cassino writes: >I am new to the world of sound and music on the Atari ST. Dave Bagget's >series of sound programs finally piqued my interest in exploring this >arena. I've managed to lay hands on a number of SND files and have noticed >some curious results. Some SND files play just fine using Dave Baggets >PLAY.PRG and some don't. Of the ones that don't, some will play OK on >PLAYEM.PRG which I got from GEnie, but there's still a few that won't >play. The programs that don't play always sound horrifically garbled and >sometimes even cause the floppy disk drive LED to flicker! > >I'm wondering if anyone can explain the differences I've seen, er, heard, >and perhaps comment on the availability of hardware to digitise sound >on the ST. > I too have enjoyed Dave Bagget's PLAY.PRG. I know there are a tremendous number of sound files available for the MAC, a number of sound files are becoming available for the Sun SPARC, etc. My question(s): - What is the file format of the .SND files that you use Dave? - What other formats are used on the Atari ST? - What format(s) are used by the MAC? - Has anyone written a utility to take a MAC sound file and convert it to .SND? (Setting aside for now the problems of file transfer.) Something like the "ST Picture Formats" description would be nice to compile. Bob Cape r.cape@stpaul.ncr.com
dmb@wam.umd.edu (David M. Baggett) (07/19/90)
Bob Cape <cape@StPaul.NCR.COM> and Andy Cassino <andyc@hplsla.HP.COM> had questions about .SND files: > Some SND files play just fine using Dave Baggets >PLAY.PRG and some don't. Of the ones that don't, some will play OK on >PLAYEM.PRG which I got from GEnie, but there's still a few that won't >play. The programs that don't play always sound horrifically garbled and >sometimes even cause the floppy disk drive LED to flicker! There are a bunch of ways to encode the sample data. I've encountered three methods so far: 1) Each sample is stored as an absolute value (amplitude). In hardware terms, this is a measure of the voltage from, e.g., 0 to 5 volts. 2) Each sample is a signed value, -128 to +127. The hardware analogy here is voltage ranging from -2.5 to +2.5 (or something like that). 3) Each sample is uLAW encoded. uLAW (read "mu-law") compresses the dynamic range of the sample to achieve (in theory) better sound quality on low-resolution D/A devices. Method 1 is found in the Mac world, and is also the method used by ST-Replay. It's the format expected by all my digitized sound software as well. (Play, Beep, Digital Keyclick, etc.) Method 2 is used by the Hippo/Navarone digitizers. Method 3 is used on SparcStations. To "convert" Mac samples to what I call "ST format" (i.e., the format used by Play), just take the data fork and use it directly. You have to figure out the sample rate because it's not stored in the file. (At least not that I know of.) The bytes should be exactly the same for both "formats", unless there are two different Mac sample formats out there. Many of the samples I distribute with Play, Beep, etc. are in fact Mac samples taken from the info-mac archive at sumex-aim.stanford.edu. I just downloaded them, un-BinHexed and unStuffIted them, and put them on my ST. No "conversion" was necessary. I've cooked up programs to convert from uLaw and Hippo/Navarone format to ST format. The uLAW conversion process is bogus and only works some of the time. (I was too lazy to do it right. :-) The Hippo conversions always come out fine because only an AND operation on each sample is involved. If there's enough interest, I'll post the conversion programs to comp.binaries.atari.st. (email if you're interested.) If you play a sound sampled with method 2 using play.prg it will sound very garbled and noisy but still barely intelligible in most cases. If you play a uLAW encoded sample with play.prg it will generally sound like noise. The floppy drive light syndrome exists in old versions of Play, Beep, and Digital Keyclick, but has been fixed in the more recent versions. The problem here is that TOS constantly checks to see if you've switched disks in the floppy drives. To do this, it accesses the same hardware registers that are used to control the sound chip every vertical blank interrupt. The solution is to prevent the vblank routine from running while doing the critical accesses to the sound chip registers. (Otherwise, the vblank routine will eventually interrupt the sound playing process at exactly the time it's messing with the sound chip registers, and the drive light will get "stuck" on.) If you turn the lights out at night while your ST is on, you'll see the drive light flickering faintly. Same thing's going on here. >I'm wondering if anyone can explain the differences I've seen, er, heard, >and perhaps comment on the availability of hardware to digitise sound >on the ST. Well, I use a Navarone digitizer I got a while back for 60 bucks, and it works pretty well. You have to convert all the samples before you use them with play.prg, but this only takes a few seconds. ST Replay is more expensive, but the hardware is better quality I'm told. >I too have enjoyed Dave Bagget's PLAY.PRG. <grin> If you like Play, you should try the other sample playing utilities too. If anyone has missed Digital Keyclick (posted to comp.binaries.atari.st), get a copy. What other computer lets you have a sea lion bark as your return key sound and a sonar ping when you hit the tab key? You can map any key to any sound you want. [End of advertisement] Also: There is a large sound archive at atari.archive (once called terminator, [address 35.1.33.8]). The players are located in atari/sound/players and the sounds are in atari/sound/sounds. There's also an index (called atari/sound/sounds/index) that describes each of the sounds (or at least the ones I uploaded). And for those of you who can't live with only 25 possible startup sounds, the latest version of Play allows you to specify up to 250 sounds in the play.inf file. I'll post it to comp.binaries.atari.st RSN. ('Til then, if you want a copy, email me.) >Something like the "ST Picture Formats" description would be nice to compile. % cc -O ST-Sound-Formats.c % a.out Segmentation Fault Oh well! Seriously, though, this is a good idea. The thought of explaining uLAW makes my skin crawl, though! I'll see what I can do. Dave Baggett dmb%wam.umd.edu@uunet.uu.net
hkim@cornea.mitre.org (Howard Kim) (08/03/90)
In article <139@npdiss1.StPaul.NCR.COM> cape@StPaul.NCR.COM (Robert M. Cape) writes: >- What other formats are used on the Atari ST? >- Has anyone written a utility to take a MAC sound file and convert it to .SND? > (Setting aside for now the problems of file transfer.) The SPL sound format for the Atari is another popular way of storing digitized sound. It's similar to SND except SND appends a speed byte to play the sound at the proper speed. There is a PD program called Babel that converts Mac, Amiga, and other ST formats into SND or SPL. | *=+--** | "Nuke 'em all." - Anonymous | | +*=+-@-+&-* | "It's over." - C.S.I. | | <=> | Cybermage Sempiternus Inquisitus | | _-*=+-_ | hkim@retina.mitre.org |
baffoni@alcor.usc.edu (Juxtaposer) (08/04/90)
Has anyone made a shell for playing digitised sounds, perhaps one that uses the sound-players that Dave Bagget posted on Terminator. When I say shell I mean something along the lines of Arcshell, only for sounds. If noone has done it yet, are there any takers? -Mike