mf@uunet.UU.NET (mf) (10/27/88)
In article <898@accelerator> Michael S. Czeiszperger writes: > (Ok, so the input sound quality is so terrible >at 8 bits that you'd have to buy an A/D converter anyway, but >nothings perfect This may be a conscious choice of NeXT due to the fact that writing to the disk is probably *much* slower than reading from it. Hence, sustaining 44.1Khz of stereo (say) is much more feasible as output (disk reads) than on input. If this is indeed the case, the limit is inherent to the disk(s) and buying a good A/D might not help at all.
czei@accelerator (Michael S. Czeiszperger) (10/28/88)
In article <34059@uunet.UU.NET> ..!uunet!ircam!mf writes: >In article <898@accelerator> Michael S. Czeiszperger writes: >> (Ok, so the input sound quality is so terrible >>at 8 bits that you'd have to buy an A/D converter anyway, but >>nothings perfect > >This may be a conscious choice of NeXT due to the fact that writing to the disk >is probably *much* slower than reading from it. Hence, >sustaining 44.1Khz of stereo (say) is much more feasible as >output (disk reads) than on input. If this is indeed the case, the limit >is inherent to the disk(s) and buying a good A/D might not help at all. I'd be suprised if they could play 44.1Khz stereo audio directly from the optical disk. More than likely they just load up several megs of audio directly into memory and play from there. I don't have the specs on the particular optical drive that comes with NeXT, but using the typical specs given in the MIX Magazine article on optical drives, you can forget about recording or playing directly to optical disk, at least for the next year or two. -- Michael S. Czeiszperger | "milihelen: The amount of beauty required to sail Systems Analyst | Snail: 2015 Neil Avenue (614) a single ship" The Ohio State University | Columbus, OH 43210 292- ARPA:czei@accelerator.eng.ohio-state.edu PAN:CZEI 0161
bob@allosaur.cis.ohio-state.edu (Bob Sutterfield) (10/28/88)
In article <907@accelerator> czei@accelerator.eng.ohio-state.edu (Michael S. Czeiszperger) writes: >I'd be suprised if they could play 44.1Khz stereo audio directly from >the optical disk. More than likely they just load up several megs of >audio directly into memory and play from there. Neither. It synthesizes in real time from notation, which has a much lower storage bandwidth and size requirement than the sound itself. -=- Zippy sez, --Bob This ASEXUAL PIG really BOILS my BLOOD... He's so..so.....URGENT!!
czei@neutron.eng.ohio-state.edu (Michael S. Czeiszperger) (10/28/88)
In article <25890@tut.cis.ohio-state.edu> bob@allosaur.cis.ohio-state.edu (Bob Sutterfield) writes: >In article <907@accelerator> czei@accelerator.eng.ohio-state.edu (Michael S. Czeiszperger) writes: >>I'd be suprised if they could play 44.1Khz stereo audio directly from >>the optical disk. More than likely they just load up several megs of >>audio directly into memory and play from there. > >Neither. It synthesizes in real time from notation, which has a much >lower storage bandwidth and size requirement than the sound itself. >-=- My answer was in response to a previous statement that the audio input was only 8 bits, because it is probably impossible to record stereo 44.1Khz audio directly to the optical disk. While the DSP chip on the NeXT has been highly touted as an audio wonder, it is certainly not the only way to make sound with a computer. It is a definate requirement that a computer music workstation be capable of recording or playing directly from disk. -=- Michael S. Czeiszperger | "milihelen: The amount of beauty required to sail Systems Analyst | Snail: 2015 Neil Avenue (614) a single ship" The Ohio State University | Columbus, OH 43210 292- ARPA:czei@accelerator.eng.ohio-state.edu PAN:CZEI 0161
jtn@potomac.ads.com (John T. Nelson) (10/28/88)
> In article <34059@uunet.UU.NET>, mf@uunet.UU.NET (mf) writes: > >In article <898@accelerator> Michael S. Czeiszperger writes: > >at 8 bits that you'd have to buy an A/D converter anyway, but > >nothings perfect > > This may be a conscious choice of NeXT due to the fact that writing to > the disk is probably *much* slower than reading from it. Hence, > sustaining 44.1Khz of stereo (say) is much more feasible as output > (disk reads) than on input. If this is indeed the case, the limit is > inherent to the disk(s) and buying a good A/D might not help at all. SCSI magenetic disks are available for NeXT that would eliminate this bottleneck. I'm not sure what the rational for such low input resolution is. Surely an A/D DSP board will be developed to make up for this anyway (e.g. Digitech and Sound Design boards for the Mac II). Jobs says that they have a sound library which already contains some sounds (samples?) and that they will expand the library. I'm sure that samples will be available from various sources over time if not created by the NeXT machine itself. As for the debate on NeXT's mistake in not including a floppy, can't you just connect a SCSI-controlled floppy to the SCSI port (if such a thing exists)? -- John T. Nelson UUCP: sun!sundc!potomac!jtn Advanced Decision Systems Internet: jtn@potomac.ads.com 1500 Wilson Blvd #512; Arlington, VA 22209-2401 (703) 243-1611 Shar and Enjoy!
dorn@fabscal.UUCP (Alan Dorn Hetzel) (10/31/88)
Don't be ridiculous, of course they can play 44.1 KHz Audio directly from the optical read/write disk. Do you *know* how slow a compact disk *really* is? Well, I do... 44.1 KHz * 2 channels * 2 bytes per sample = 176.4 KBytes per second, or around 1.45 Megabits. The disk won't have any trouble at all keeping up. Now, it will run out of data in 30 minutes or so. By the way, someone earlier seemed to think that the capacity of a standard compact disk was around 50 minutes. Nope, 74 minutes is the standard, and if you are very carefull in pressing to get good tracks all the way out to the edge, you can squeeze 80 or 81 minutes. (Compact disks play from inside out, and 74 minutes is a limit to allow for pressing flaws around the outer edge) Dorn
zimerman@phoenix.Princeton.EDU (Jacob Ben-david Zimmerman) (11/08/88)
In article <8711@spl1.UUCP> ..!uunet!ircam!mf writes: >In article <898@accelerator> Michael S. Czeiszperger writes: >> (Ok, so the input sound quality is so terrible >>at 8 bits that you'd have to buy an A/D converter anyway, but >>nothings perfect > >This may be a conscious choice of NeXT due to the fact that writing to the disk >is probably *much* slower than reading from it. Hence, >sustaining 44.1Khz of stereo (say) is much more feasible as >output (disk reads) than on input. If this is indeed the case, the limit >is inherent to the disk(s) and buying a good A/D might not help at all. ...okay, ignorant question here...I read earlier on that during writes, the optidrive does TWO passes, one to zero the fields, and one to write in the 'one' state bits. Now, since it has to do two passes and needs to therefore know how big the files is gonna be, can it handle real-time contintuous 16-bit input? Or will its having to go back twice choke it up? Could a rountine be written that used the main RAM as a buffer while it was doing its double write? Would it be fast enough to get everything written to disc AND 'catch up' before the RAM was consumed? -curious -JBZimmerman! DISCLAIMER:The opinions of Princeton University in no way reflect my own. Any resemblance is purely coincidental. -- ___________ | "A flute with no holes is not a flute. A donut || | with no holes is a danish." || ||acob Zimmerman!+> <zimerman@phoenix.Princeton.EDU> INTERNET === | <zimerman@PUCC> BITnet