Re: Dithering??
Re: Dithering??
- Subject: Re: Dithering??
- From: Brian Willoughby <email@hidden>
- Date: Tue, 16 Sep 2008 13:28:06 -0700
I understand your complaints. There does not seem to be a one-stop
solution for either developers or end-users with regard to batch-
converting many audio files for burning to CD.
However, if you are interested in developing CD burning software
which does a better job than Sound Grinder or Toast or even
WaveBurner, then we can help you here with the CoreAudio part. You
can also look to the DiscRecording mailing list for help with the
burning aspects of the software development. Using that API, you
should be able to create a custom object that would read your hi-res
24/88.2 files, leverage the AudioConverter to change them to 16/44.1,
and the follow up with some custom or licensed dithering code before
passing off the data to the burning API. The ultimate version would
use Leopard's 'bats' SRC and some expensive dithering code.
P.S. WaveBurner (part of Logic Studio) would allow you to create a
project using hi-res 24/88.2 tracks, and it would convert them on the
fly as the CD is burned. However, this convenience would not be
using the highest quality SRC that is available in CoreAudio - at
least not the most recent version I used.
Brian Willoughby
Sound Consulting
On Sep 16, 2008, at 13:18, Ryan Gilligan wrote:
I'm fully aware of what dithering is and when it should be applied.
I'm just looking for an easy way to burn a redbook cd from these hi
res files. Ideally, they would be converted to 44.1 and dithered down
to 16 bit before they get burned. Toast can't handle 88.2 without a
ton of terrible distortion over the whole track. Of course none of
this would be an issue if the damn Tascam DV-RA1000 HD would burn
redbooks by itself.
Thanks all.
On Sep 16, 2008, at 3:55 PM, Brian Willoughby wrote:
I have two comments.
Dithering should only be done once, and only as the last step, and
that is why the CoreAudio SRC does not apply dithering. There's
just no way for the AudioConverter to know whether dithering would
be appropriate in each individual case.
Unfortunately, CoreAudio does not provide everything you might need
as an audio developer, and dithering is one of the things you will
have to develop or license yourself. MusicDSP.org might be a good
place to start for a variety of basic dithering algorithms. More
advanced dither such as POW-r are available as part of commercial
software, so you might need to look into automated DAW software
with scripting if you don't want to write or license code.
For QuickTime questions, there is a QT mailing list. My guess is
that it's doubtful they're applying dither in QuickTime.
Brian Willoughby
Sound Consulting
On Sep 16, 2008, at 12:42, Ryan Gilligan wrote:
I just got a demo of a new audio conversion program called Sound
Grinder, which apparently uses the built in Core Audio SRC to
convert sample rates. I will be converting 88.2 24 bit wav files
down to 44.1 16 bit to burn redbook cd's. The developer of Sound
Grinder believes that the current Core Audio SRC would not do any
dithering to accomplish this. Is this true? Does the Core Audio API
simply not include any dithering?
Also, I'm not sure if this is beyond the realm of this particular
mailing list, but does the Quicktime SRC use dithering? Its pretty
much a necessity for what I need to do, which is batch converting
lots of these files, with no artifacts in the 16 bit files.
I hope someone can help! Thank you!
Ryan Gilligan
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