Re: [linux-audio-user] Linux music editor, less than 16-bit ?

Hallo,
carmen hat gesagt: // carmen wrote:

>
> i'm thinking of picking up the new korg pocket DSD recorder. and im wondering - does anything support editing of 1-bit audio recordings in the OSS world? i know theress 3 dozen wave editors, but theyre all pretty mediocre and can usually not even connect to jack and play a flac without crashing. i guess this is what happens when wave editor developers have NIH syndrome?

Hey, that's actually the first time I read about 1-bit recording and
at first I thought you were joking or had a typo. But you weren't and
hadn't.

Nevertheless I found some interesting papers linked from the Wikipedia
SACD page. One is this:

  Audio Engineering Society Convention Paper 5395: Why 1-Bit Sigma-Delta
  Conversion is Unsuitable for High-Quality Applications
  http://sjeng.org/ftp/SACD.pdf

and it states:

  Single-stage, 1-bit sigma-delta converters are in principle
  imperfectible. We prove this fact. The reason, simply stated, is that,
  when properly dithered, they are in constant overload. Prevention of
  overload allows only partial dithering to be performed. The
  consequence is that distortion, limit cycles, instability, and noise
  modulation can never be totally avoided. We demonstrate these effects,
  and using coherent averaging techniques, are able to display the
  consequent profusion of nonlinear artefacts which are usually hidden
  in the noise floor. Recording, editing, storage, or conversion systems
  using single-stage, 1-bit sigma-delta modulators, are thus inimical to
  audio of the highest quality. In contrast, multi-bit sigma-delta
  converters, which output linear PCM code, are in principle infinitely
  perfectible. (Here, multi-bit refers to at least two bits in the
  converter.) They can be properly dithered so as to guarantee the
  absence of all distortion, limit cycles, and noise modulation. The
  audio industry is misguided if it adopts 1-bit sigma-delta conversion
  as the basis for any high-quality processing, archiving, or
  distribution format to replace multi-bit, linear PCM.

The other is this by famous James A. Moorer et al.:
  
  Audio Engineering Society Convention Paper 4719 on the 1st DSD
  commercial editor
  http://www.sonicstudio.com/pdf/papers/DSDStereoEdit.pdf

which abstracts to:

  The editing in native form of 2.8224 Mhz 1-bit audio (Direct-Stream
  Digital) is problematic since the required computation rate to
  achieve level control, pan, and crossfade in real time is beyond the
  capabilities of general-purpose digital signal processing chips. A
  system has been developed which incorporates a special- purpose chip
  designed specifically for computations on 1-bit audio. This is
  embedded into the framework of a general-purpose audio editing and
  premastering system. It behaves, looks and feels exactly like a
  stereo, PCM editing system with full flexibility of sample-accurate
  cross-fades, level control, metering, and non- linear random-access
  editing, except that internally it is operating directly on the 1-
  bit signal. This paper describes the data flow and architecture of
  the system.

Now I'm wiser than before.

Ciao

-- 
 Frank Barknecht                 _ ______footils.org_ __goto10.org__