A suggestion :was: From Hawkwind

Paul Mather paul at GROMIT.DLIB.VT.EDU
Sat Dec 13 17:01:53 EST 2003


On Fri, Dec 12, 2003 at 06:01:05AM +0000, chris at HAWKLORD.UKLINUX.NET wrote:

=> It was meant to be just that. But I maintain anyone (with ok hearing not
=> special hearing) can tell the difference between 44.1 and 48k its a lot.

Have you confirmed this with blind listening tests?

=> >The great thing about DVD standards is that there are so many from
=> >which to choose! :-)  That would be one strike against Hawkwind using
=> >it.  At least with audio CD they know they're selling something that
=> >will play on everyone's little-silver-platter players.  (Recall the
=> >confusing "will this play on my player?" thread that attended the Huw
=> >PAL DVD release.)
=>
=> No!  That's just not the case.  There is exactly one official dvd
=> standard.  A 'standard' like DAD must conform to DVD standard first!  So
=> saying a disk is DAD means it will play on your dvd player.
=> Its not like the kareoke cd standard which requires special firmware to
=> read sub channels.

With regards to application formats, there are at least two standards:
DVD-Video and DVD-Audio.  (DVD-Audio came later, to cater to
audiophiles.)  It is possible to create DVD-Audio discs that will not
play in DVD-Video players.  (E.g., a disc consisting only of PCM audio
at a sample rate of 192 KHz.  The maximum sample rate supported by the
DVD-Video standard is 96 KHz.)

As for physical formats, pressed discs adhere to the DVD-ROM standard,
and, as Colin said these would be pressed discs, that would eliminate
*that* potential incompatibility.  (But pressed DVDs would likely
increase the price compared to pressed CDs, which require lower
quality control standards.)  But, if you step into the recordable
physical formats, then you do get a hodge-podge of potential
incompatibilities as you wade through the morass of acronyms that
includes DVD-R, DVD-RAM, DVD-RW, DVD+RW, and DVD+R.  (I know for a
fact that a friend's laptop CD-RW/DVD-ROM combo drive will not read
DVD+R or DVD+RW discs.)  This is an issue of physical incompatibility
(mostly due to reflectivity problems), and is not a matter of which OS
you run or what firmware your drive has.

As for the encoding within application formats, the confusing "will
this play on my player?" thread that attended the Huw PAL DVD release
I mentioned was a real concern, and a source of head-scratching at the
time.  Here is what the DVD FAQ (http://www.dvddemystified.com/dvdfaq.html)
has to say on the topic of "Is DVD-Video a worldwide standard? Does it
work with NTSC, PAL, and SECAM?":

>>>>>
The MPEG video on a DVD is stored in digital format, but it's
formatted for one of two mutually incompatible television systems:
525/60 (NTSC) or 625/50 (PAL/SECAM). Therefore, there are two kinds of
DVDs: "NTSC DVDs" and "PAL DVDs." Some players only play NTSC discs,
others play PAL and NTSC discs.

[[...]]

Almost all DVD players sold in PAL countries play both kinds of
discs. These multi-standard players partially convert NTSC to a 60-Hz
PAL (4.43 NTSC) signal.

[[..]]

Most NTSC players can't play PAL discs. A very small number of NTSC
players (such as Apex and SMC) can convert PAL to NTSC.

[[..]]

Many standards-converting players can't convert anamorphic widescreen
video for 4:3 displays.

[[..]]

Bottom line: NTSC discs (with Dolby Digital audio) play on over 95% of
DVD systems worldwide. PAL discs play on very few players outside of
PAL countries.
<<<<<

So, I would say that for those with consumer DVD players, this
compatibility issue is somewhat real.  (BTW, NTSC is used in the USA;
PAL in the UK.)

=> What I was actually suggesting was not a 'standard' just dump 48k audio
=> on a cd filesystem leave it to us to convert to a cd if we wish or we
=> can play the higher quality audio on whatever we got. Its not difficult.

It's perhaps not difficult (in your opinion), but hardly
user-friendly---at least compared to a conventional CD, which
requires no additional steps to play.

Your suggestion is just one step removed from simply making the tracks
available for download in FLAC format.

=> There is no dvd standard nonsense (ok try to burn your own video dvd
=> with motion menus, mulitiple camera angles, multiple ac3 and mp2 audio
=> tracks - I've no idea if you can on Microsoft OS, on linux 'we' can and
=> if 'we' find a dvd that won't work in a particular dvd player 'we' fix
=> the software till it does. Stuff I've seen to create dvd on windows does
=> not seem to allow you to do much - unless you pay over £2,000) The only
=> 'dvd standard hassle' is really for DVD-R and DVD-RW. Both dvd+ and dvd-
=> are equal with respect to what you can do with DVDR.  Both standards
=> meet the current official dvd standard.  There is a slight difference
=> regarding how you can use RW media, but not enougth to care about.

I suggest you check your facts.  There are incompatibilities in the
various recordable DVD standards.  It has been claimed that this is
partly intentional, at least in the case of the DVD+ variants, to
avoid having to split format royalties amongst so many companies.
Greed is a big motivator.

This is from the DVD FAQ (http://www.dvddemystified.com/dvdfaq.html):

>>>>>
[4.3.1] Is it true there are compatibility problems with recordable
DVD formats?

Yes. None of the writable formats are fully compatible with each other
or even with existing drives and players. In other words, a DVD+R/RW
drive can't write a DVD-R or DVD-RW disc, and vice versa (unless it's
a combo drive that writes both formats). As time goes by the different
formats are becoming more compatible and more intermixed. A player
with the DVD Forum's DVD Multi is guaranteed to read DVD-R, DVD-RW,
and DVD-RAM discs, and a DVD Multi recorder can record using all three
formats. Some new "super combo" drives can record in both plus and
dash format, and a few "super multi" drives can record all 5 disc
types (DVD-R, DVD-RW, DVD+R, DVD+RW, and DVD-RAM).

In addition, not all players and drives can read recorded discs. The
basic problem is that recordable discs have different reflectivity
than pressed discs (the pre-recorded kind you buy in a store -- see
5), and not all players have been correctly designed to read
them. There are compatibility lists at CustomFlix, DVDMadeEasy,
DVDRHelp, YesVideo.com, HomeMovie.com, and Apple that indicate player
compatibility with DVD-R and DVD-RW discs. DVDplusRW.org maintains a
list of  DVD+RW compatible players and drives. (Note: test results
vary depending on media quality, handling, writing conditions, player
tolerances, and so on. The indications of compatibility in these lists
are often anecdotal in nature and are only general guidelines.) Very
roughly, DVD-R and DVD+R discs work in about 85% of existing drives
and players, while DVD-RW and DVD+RW discs work in around 70%. The
situation is steadily improving. In another few years compatibility
problems will mostly be behind us, just as with CD-R (did you know
that early CD-Rs had all kinds of compatibility problems?).

[[...]]
<<<<<

Again, this is not an OS issue, and "you" cannot change "your"
software until it is fixed, no matter how hard you wish you could.

=> Existing proposal is a winner

It is from your point of view.  But then again, you are speaking from
a PC-user perspective.  I would argue that most people's home audio or
home theatre system does *not* revolve around a PC.  It probably uses
standalone consumer DVD and audio devices.

=> Thats my assumption but I have no idea really what is a soundboard or
=> what you can do with one.

And you feel qualified to chime in on the best way to do audio, why? :-)

=> You sould never alter sample rate upwards - unless you must because you
=> want to make a cd.  Doing so _will_ result in distortion.  But down
=> sampling also results in distortion, though its fairly easy to treat;-)

You have that exactly backwards.  (What you say is also incorrect in
parts: are you saying that I _will_ get distortion if I, say, double
the sample rate??)  There are much more serious problems with sample
rate reduction than with increasing the sample rate.  (See Nyquist's
Theorem for details.:)

Quick quiz: Which will sound more different: a) an 8 KHz source
upsampled to 32 KHz, or, b) a 32 KHz source downsampled to 8 KHz?

=> Cheapo 5.1 low-fi makes reasonable job of stereo cd in 5.1 mode.  I'm

"low-fi" does not sound very hi-fi to me.  This was all about
improving sound quality, wasn't it?

=> >This can be true, but it is not necessarily true.  This is
=> >*especially* pertinent for consumer-grade mass market equipment, which
=> >may not use, shall we say, the finest quality components.  (Have you
=> >ever considered what is the *real* resolution of a DAC?)
=>
=> Yup!!!  I got a socket A motherboard that has via82c833 chip.

Sadly, you obviously did not understand the question.

=> That is
=> certainly not the best chip but it performs as well as my 'proper' card.
=> But I prefer a Audigy2 cause its more usefull and has much better midi,
=> the DAC is worth the price.  If I need to I can use both cards to
=> record, and I'll get the channels to synch OK:-)   If I were in any way
=> 'proffessional' I'd want a card capable of recording at 128k but at
=> moment they are >= £1,000 or they were last time I looked.

If I were in any way "professional," I'd be more interested in the
signal to noise ratio of my sound card more than how high went its
sample rate.  I'd also be worried if its digital inputs did
unnecessary resampling (as do many consumer PC sound cards), or
whether it suffered excessive jitter.

Those sound cards you mention are good for gaming.  (For example, I
believe the Audigy2 card does unneccesary resampling, making it a poor
choice for bit-accurate transfers from digital sources.)

=> >If you are worried about the sound quality of your audio, you should
=> >actually be more worried about the quality of the analogue components
=> >of your system (and that includes the analogue stages in your DVD
=> >player).  A cheap DVD player is likely to be just that: a great
=> >potential with a lousy realisation.  A good CD player will beat it
=> >hands down *every time*.
=>
=> I think you miss the point.  (Ok I don't actually have a tv as such so I
=> have no dedicated dvd-payer) A pc dvd player costs less than £50 the
=> only 'analoge' stage is the ad converter to mantain compatibility with
=> pc analogue audio cd input.  Most pc dvdplayer has also a digital audio
=> out now, and good cheep soundcards like soundblaster live really are
=> fine hi-fi devices, hell ancient cards like Ensonique and GUS sound
=> great.  So computer is very much the center of my hi-fi, its how I
=> control 2 cheep 5.1 sound systems and an old 80's Hi-fi.  The result is
=> supprisingly cool.

I think you are confusing, misusing and abusing the term "hi-fi."
None of the sound cards you mention meet my definition of hi-fi (which
I take to mean "of audiophile quality").

I would not use my computer as my audio listening device, anyway.  For
one, it is not physically set up very well for that: speaker placement
is an issue, immediately.  Then there's the high-frequency whine from
my monitor.  Plus there's the ambient noise from multiple case and
disk drive enclosure fans---not to mention the noise from the drives
themselves.  And that's just the ambient noise.  The electromagnetic
noise *inside* the computer is worse.  The inside of a modern computer
case is *hell* for analogue signals.  Sure, the FCC regulates how much
interference is allowed to leak *outside* the case, but what goes on
inside is its own business.

As motherboards become smaller and cheaper, and CPUs faster, the
problem of electromagnetic noise and interference grows larger.  Good
shielding costs in terms of component quality and PCB real estate.
Once your samples leave your DAC and become analogue, they're battered
and bruised by various noise sources in the components through which
they then pass on their way ultimately to your speakers.  This is one
reason why outboard DAC and ADC units are popular in audiophile
editing and recording setups.

Computers may be great at digital signal processing (DSP), but DSP is
but one aspect of digital audio.  Digital audio is not just about the
digital domain.  I don't think you fully realise that.

=> Why do you feel need to spend money to get quality?  Pick your kit with
=> care, technology is very cheep now.   Sometimes you'll get better
=> results from a second hand £10 Hauppauge card than you will from a new
=> one costing £150 - depends on what you are doing or more importantly
=> _how_ you want to do it.

I don't think I ever said you had to spend a lot to get good audio
quality.  I just said you had to use good quality components.

Now I will admit there seems to be a positive correlation between
having to spend more and getting good quality components, but, like
you said, if you choose wisely, you can buck the trend and get lucky
for less money.

Although value for money is increasing in the computer industry, the
physical quality of hardware is tending to go down, especially for
mass-market commodity hardware as used in x86-based systems.  (I hear
complaints of this all the time from sysadmin who find buying reliable
hardware more difficult these days.)  This is understandable, as
vendors seek to preserve margins in an industry beset by falling
prices and increasing expectations.

Like anything, electronic components (capacitors, resistors, diodes,
etc.) have different operating characteristics depending upon the
materials they use and how they were manufactured.  Operating
characteristics can vary under ambient conditions (heat, humidity,
etc.) or different loads.  It's all a trade-off.  But, it is usually a
sad fact that the highest quality components usually require purer
materials, and so ultimately cost more.

If you believe a capacitor is a capacitor is a capacitor, then you
probably also believe boomboxes and all-in-one midi systems sound just
as good as hi-fi separates and wonder what all the fuss is about.  If
that is the case, there's no point in discussing audio quality.  We
have to agree to disagree. :-)

=> software is free.  Not simple to use but even old versions of dvdauthor
=> are capable of any DVD audio standards I'm aware of.

Care to provide an existence proof?  I looked at the WWW page of
dvdauthor and there was no mention of it supporting DVD-Audio.

=> The only audio standard I have problem with is SACD like pink floyd
=> dsotm.  You need special player that might or might not also be a dvd.

I heard that some SACD discs are released in dual-layer format.  One
of these layers is readable and playable on ordinary CD players.  (I
think the Rolling Stones remasters [or some incarnation of them]
recently came out in this format.)  So, in some ways, SACD discs are
more compatible with legacy players than DVD. :-)

In the end, when I think of compatibility with "DVD players" I'm
thinking of people with consumer DVD players, not DVD drives in a PC.
That's because I believe most people's home entertainment solution
right now is not centred around their PC, but is invested in some kind
of "home theatre" or hi-fi setup that has its own DVD player.  (This
is particularly true of people fond of those big-screen TVs.:)

To target people using DVD devices in a PC would unduly limit the
potential reach of the releases to no real useful gain.

Cheers,

Paul.

e-mail: paul at gromit.dlib.vt.edu

"Without music to decorate it, time is just a bunch of boring production
 deadlines or dates by which bills must be paid."
        --- Frank Vincent Zappa



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