Editing 192/24 files

[cpaqf1]

Hey,

I'm about to join different songs (in 192/24) together in one file. Thing is I don't want any dither or quality loss, I'm not doing ANY changes, just joining them. When I import them then it says 32 float . Will that add any processing ? or should I change it to 24bits (set sample format) ?

thanks

[kozikowski]

Let's see if I remember this. Yes, set Audacity Project to the exact standard you wish to use. Then turn dithering off in:
Audacity > Edit > Preferences > Quality.

Audacity will still try to convert to 32-floating internally, but the conversion error both directions should be zero, particularly if you do no effects. I think that's one way to get bit-accurate transfers (someone will correct me).

Note this does not work with any compressed format like MP3.

Koz

[Gale Andrews]

Dithering will not occur (even if enabled at "High-quality conversion" in Quality Preferences) when pasting, even if the Default Sample Format in Quality Preferences is 16-bit or 24-bit.

Dithering will occur (unless disabled) when processing audio, unless Default Sample Format is 32-bit float. This is because Audacity has to return the audio to the track after processing it in 32-bit float. Processing means using an effect.

So to be sure there is no dithering in the project when dithering is enabled, you must use 32-bit float resolution, not the same resolution that the file happens to be.

Dithering is still preferred when exporting from a 32-bit float project to a lower resolution audio format.

http://wiki.audacityteam.org/wiki/Dither

PS You cannot actually import 24-bit files in 24-bit resolution - even if your quality preferences are 24-bit, the 24-bit file will import at 32-bit. That's what the code says:

Code: Select all

if (mFormat != floatSample &&
       sf_subtype_more_than_16_bits(mInfo.format))
      mFormat = floatSample;

but I'm not sure why that decision was made rather than "don't import at a lower resolution than the file has".

Gale