Noise Shaping for high rez files and streams
 

I've continued to think about ways to reduce the excess 'sea of noise bits'
that tend to occuply the least significant bits per sample of 'high rez'
streams and files. These tend to bloat FLACing, etc, so waste space, money,
time, etc. Occurred to me that Noise Shaping down the sample size whilst
keeping the high sample rate might help. So I did some simple experiments.

If anyone is interested you can see the results at

http://www.audiomisc.co.uk/MQA/intos...ngHighRez.html

All being well, I'll put up a tidied version of the demo program as well in
case any computer programmers want to have a play with it.

Jim

--
Please use the address on the audiomisc page if you wish to email me.
Electronics http://www.st-and.ac.uk/~www_pa/Scot...o/electron.htm
Armstrong Audio http://www.audiomisc.co.uk/Armstrong/armstrong.html
Audio Misc http://www.audiomisc.co.uk/index.html

Noise Shaping for high rez files and streams
 

In the very start of digital some recordings looked fantastic on specs but
sounded crap, seeming like they had some kind of noise gate on them. then
came dither, which made recordings sound right again. I'll just leave this
hanging there....
Brian

--
From the Sofa of Brian Gaff Reply address is active
Remember, if you don't like where I post
or what I say, you don't have to
read my posts! :-)
"Jim Lesurf" wrote in message
...
I've continued to think about ways to reduce the excess 'sea of noise
bits'
that tend to occuply the least significant bits per sample of 'high rez'
streams and files. These tend to bloat FLACing, etc, so waste space,
money,
time, etc. Occurred to me that Noise Shaping down the sample size whilst
keeping the high sample rate might help. So I did some simple experiments.

If anyone is interested you can see the results at

http://www.audiomisc.co.uk/MQA/intos...ngHighRez.html

All being well, I'll put up a tidied version of the demo program as well
in
case any computer programmers want to have a play with it.

Jim

--
Please use the address on the audiomisc page if you wish to email me.
Electronics
http://www.st-and.ac.uk/~www_pa/Scot...o/electron.htm
Armstrong Audio http://www.audiomisc.co.uk/Armstrong/armstrong.html
Audio Misc http://www.audiomisc.co.uk/index.html

Noise Shaping for high rez files and streams
 

Brian-Gaff wrote:

In the very start of digital some recordings looked fantastic on specs but
sounded crap, seeming like they had some kind of noise gate on them. then
came dither, which made recordings sound right again. I'll just leave this
hanging there....




** One of the first CDs I bought was of solo classical piano on the Erato label. At the end of each track, as the final note faded down it turned into a fizzing sound. This was noticeable at other quiet times too.

Reminded of crossover distortion in an amplifier.

So I returned the CD to the store because of the defect and was offered another copy by the sales person - who must have thought is was a bad pressing.

I knew better and asked for a credit instead.

I got a very funny reaction to doing that.


..... Phil

Noise Shaping for high rez files and streams
 

"Brian-Gaff" wrote in message
...
In the very start of digital some recordings looked fantastic on specs but
sounded crap, seeming like they had some kind of noise gate on them. then
came dither, which made recordings sound right again. I'll just leave this
hanging there....
Brian

Yes. Dither is required when converting from
32, 24 or 20 bits to16bits. It is done in the mastering
process, (not mixdown) and without it, mastering
software truncates all signals to which
wordlength reduction is applied.

My first experiences of digital recording
were back in the mid/late 1970's when
I heard some recordings made on the
Denon DN34. The machine's predecessor
had apparently been demonstrated as early
as 1972. I was very impressed!

Shortly after that, Decca,the record
company where I worked in the UK,
designed and built their own digital
recording/editing system for in-house use.

http://www.kolumbus.fi/iain.churches...alRecorder.jpg

Details from a Decca promo leaflet:

** The top rack housed an 18 bit D/A converter
for SPDIF, AES. The second rack housed a
20 bit A/D which converted the studio line level
signal to digital data stream in the Decca format.
SR 48kHz A signal processing unit (euro card frame)
that takes the digital data stream and converts it into a
signal that a modified video transport can record
(such as adding the various video sync pulses).
It also generates timecode and error correction data.
Working simultaneously in record and playback it also
displays off-tape record level via a peak hold PPM. It
reads the off-tape timecode and monitors the overall
quality of the recording (by counting lost samples).
It also has a limited amount of system
self-diagnostics.**

Iain

Noise Shaping for high rez files and streams
 

In article , Iain Churches
wrote:

http://www.kolumbus.fi/iain.churches...alRecorder.jpg

Details from a Decca promo leaflet:

** The top rack housed an 18 bit D/A converter for SPDIF, AES. The
second rack housed a 20 bit A/D which converted the studio line level
signal to digital data stream in the Decca format. SR 48kHz A signal
processing unit (euro card frame) that takes the digital data stream and
converts it into a signal that a modified video transport can record
(such as adding the various video sync pulses). It also generates
timecode and error correction data. Working simultaneously in record and
playback it also displays off-tape record level via a peak hold PPM. It
reads the off-tape timecode and monitors the overall quality of the
recording (by counting lost samples). It also has a limited amount of
system self-diagnostics.**

UKHHSoc would be interested in good scans of that leaflet. Would you be
willing to provide them or loan the leaflet?

BTW given the title of this thread people may find

http://jcgl.orpheusweb.co.uk/temp/shaped.png

of interest. It stems from a simple demo program I've written so that
people can experiment with DIY shaping 'high rez' files from 24 bit
down to 16bit in order to deal with the over-specifed 'noise' that
bloats FLACed versions

Jim

--
Please use the address on the audiomisc page if you wish to email me.
Electronics http://www.st-and.ac.uk/~www_pa/Scot...o/electron.htm
Armstrong Audio http://www.audiomisc.co.uk/Armstrong/armstrong.html
Audio Misc http://www.audiomisc.co.uk/index.html

Noise Shaping for high rez files and streams
 

"Phil Allison" wrote in message
...
Brian-Gaff wrote:

In the very start of digital some recordings looked fantastic on specs
but
sounded crap, seeming like they had some kind of noise gate on them. then
came dither, which made recordings sound right again. I'll just leave
this
hanging there....




** One of the first CDs I bought was of solo classical piano on the Erato
label. At the end of each track, as the final note faded down it turned
into a fizzing sound. This was noticeable at other quiet times too.

Reminded of crossover distortion in an amplifier.

So I returned the CD to the store because of the defect and was offered
another copy by the sales person - who must have thought is was a bad
pressing.

I knew better and asked for a credit instead.

I got a very funny reaction to doing that.

A bad pressing? I like that :-))
The sales person could have checked the bad pressing as
below. Pic taken 2010 by Keith G )

http://www.kolumbus.fi/iain.churches...rafidelity.jpg


Iain

Noise Shaping for high rez files and streams
 

In article ,
Phil Allison wrote:
Brian-Gaff wrote:

In the very start of digital some recordings looked fantastic on specs
but sounded crap, seeming like they had some kind of noise gate on
them. then came dither, which made recordings sound right again. I'll
just leave this hanging there....




** One of the first CDs I bought was of solo classical piano on the
Erato label. At the end of each track, as the final note faded down it
turned into a fizzing sound. This was noticeable at other quiet times
too.

It was also common practice on early CDs made from older analogue tapes to
have a steeper fade out at the end of a track than on the original vinyl
so you got silence between tracks. Never did see the point of that.

Reminded of crossover distortion in an amplifier.

So I returned the CD to the store because of the defect and was offered
another copy by the sales person - who must have thought is was a bad
pressing.

I knew better and asked for a credit instead.

I got a very funny reaction to doing that.


Of course there was plenty vinyl sold too with faults. That couldn't be
fixed by a new copy.

--
*It's o.k. to laugh during sexŒ.Œ.just don't point!

Dave Plowman London SW
To e-mail, change noise into sound.

Noise Shaping for high rez files and streams
 

On 17/02/2017 09:42, Iain Churches wrote:
A bad pressing? I like that :-))

I did have one once. It so happened we had a CD tester at work, and it
showed multiple errors scattered all over the surface. I contacted the
manufacturer, and they sent me a new disc. Pressed somewhere else... I
don't know if they did anything with the tester report I sent them.

Andy

Noise Shaping for high rez files and streams
 

In article , Vir
Campestris wrote:
On 17/02/2017 09:42, Iain Churches wrote:
A bad pressing? I like that :-))

I did have one once. It so happened we had a CD tester at work, and it
showed multiple errors scattered all over the surface. I contacted the
manufacturer, and they sent me a new disc. Pressed somewhere else... I
don't know if they did anything with the tester report I sent them.

I still have a CD which shows visible fingerprints in the information
layer. It does play OK.

Jim

--
Please use the address on the audiomisc page if you wish to email me.
Electronics http://www.st-and.ac.uk/~www_pa/Scot...o/electron.htm
Armstrong Audio http://www.audiomisc.co.uk/Armstrong/armstrong.html
Audio Misc http://www.audiomisc.co.uk/index.html

Noise Shaping for high rez files and streams
 

"Jim Lesurf" wrote in message
...
In article , Vir
Campestris wrote:
On 17/02/2017 09:42, Iain Churches wrote:
A bad pressing? I like that :-))

I did have one once. It so happened we had a CD tester at work, and it
showed multiple errors scattered all over the surface. I contacted the
manufacturer, and they sent me a new disc. Pressed somewhere else... I
don't know if they did anything with the tester report I sent them.

I still have a CD which shows visible fingerprints in the information
layer. It does play OK.

There was a subscriber on the valve/tube audio group RAT
who bought a Chinese KT88 that had a cigarette butt inside.

One wag asked "Was it still alight?"
Another replied "Alight? In a vacuum?"

:-))

Iain