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From: peterk@cbmger.UUCP (Peter Kittel GERMANY)
Newsgroups: comp.sys.amiga.advocacy
Subject: Re: CDTV vs CD-I again
Message-ID: <1102@cbmger.UUCP>
Date: 11 Apr 91 12:08:39 GMT
References: <1991Apr8.085845.24662@ncsu.edu> <1991Apr8.181613.5507@cunixf.cc.columbia.edu> <1991Apr9.170659.17365@ncsu.edu> <1089@cbmger.UUCP> <1991Apr11.052215.143@ncsu.edu>
Reply-To: peterk@cbmger.UUCP (Peter Kittel GERMANY)
Organization: Commodore Bueromaschinen GmbH, West Germany
Lines: 55

In article <1991Apr11.052215.143@ncsu.edu> kdarling@hobbes.catt.ncsu.edu (Kevin Darling) writes:
>
>CDTV: From what I gather (corrections gladly welcomed), an author creates his
>programs and data on a hard disk, then sends the HD to CBM for CDROM mastering.
>The most control over data placement is the general location of files
>(for nearness).  The end CDROM is more or less an exact copy of the HD.

Sorry, I don't have those papers at hand in the moment. Perhaps someone
can cut in? But as I remember, those guidelines for developers said
that the sector layout had to be optimized by them (only they know what
are the critical parts and in what typical sequence they will be accessed).
I don't remember reading that they must send their HD to CBM, more to the
disc manufacturer (???).

>The video data goes into memory.  The audio tracks are mixed by a separate
>audio processor and can continously play without entering the computer section.
>Or if wished, the audio can be vectored into memory for later play, while
>previously stored audio is played.  In either case, what you have is crucial
>control during mastering on a per-sector basis as to what data is where,
>allowing what you might call a 'flowing multi-I/O capability'.
>
>Now, it has occurred to me that I don't know (does someone?) exactly how
>the CDTV player is set up in this situation.  That is, does it have similar
>capabilities?  Or does it simply play straight audio from disc while
>displaying previously loaded video data, and vice versa?  Or ?

Sorry, don't know details. But CDTV sure can play true CD audio directly
from disc while playing animations from memory. If you want to play longer
music plus anim intermixed which doesn't fit completely in RAM, then
I think there are (several different) digital audio modes where audio is
played with adjustable sampling (and thus data) rate by the Amiga (well,
this is in 8 bit, but sure sufficient for speak). As this
data rate is comparably low, the Amiga part still can load and play anims
in real time simultaneously. (If I said something wrong, *please* someone
step in and correct me!)

>IF CDTV uses the disc _only_ like a large HD, 

No, I don't think so.

>  IF CDTV _does_ have per-sector
>distribution hardware, then the included utilities seem to fall very short.

Do you know at all, what utilities are available?

>In either case, the upshot has been (as I said), that I have already heard
>rumblings from multimedia CDROM specialists that CDTV has not mastered the
>science of interleaving data (if used as a HD, then it will _never_ do so).

Well I think there are ways to accomplish this, perhaps they still have
to study a bit...:-)

-- 
Best regards, Dr. Peter Kittel  // E-Mail to  \\  Only my personal opinions... 
Commodore Frankfurt, Germany  \X/ {uunet|pyramid|rutgers}!cbmvax!cbmger!peterk