Audacity Forum

bgravato wrote:what could it mean to truncate a float and get an int without float->int conversion?

It's something like:

Multiply the original 32 bit float value by 2^23 then round down to get the signed 24 bit integer.
In 32 bit float notation, 0 dB is +/- 1
In 24 bit integer notation, 0 dB is +/- 2^23

bgravato wrote:I can't properly understand what truncate means in this context...

rounding down.

It was a common "feature" of several old SoundBlaster cards that they would clip the input just short of 0 dB. It's perfectly possible that your sound card could be doing this,

Topic moved to the Audacity 1.3.x > Windows forum.

Does the other part of my previous post help?

From ImportPCM.cpp: // In general, go with the user's preferences. However, if // the file is higher-quality, go with a format which preserves // the quality of the original file. if (mFormat != floatSample && sf_subtype_more_than_16_bits(mInfo.format)) mFormat = floatSample; It looks like ...

Set your CD ripper to rip in WAV format.

You're using: Audacity 1.3.14 beta (Unicode) ? Windows 7 ? Ensure that the mixer is connected and recognised by Windows (or whatever operating system) before you start Audacity. Assuming that you're using a recent version of Audacity 1.3.x, select the USB option as the Recording Input device in the ...

So the top track is straight out of the iPod Touch into the line input of the MacBook Pro?
The lower track is out of the iPod Touch, through the pre-amp and then into the line input of the MacBook Pro?

otey wrote:I just posted to bugzilla a url to a simple patch which adds a preview button.

The preview button is present when building with this patch, but it does not preview the effect it just plays the unprocessed audio (tested on Debian Squeeze).

steve wrote:I've posted a bug report here: http://bugzilla.audacityteam.org/show_bug.cgi?id=482 and attached your patch.
I should be able to check in the next couple of days that it builds OK, but I can only test on a 32 bit Debian machine.

It builds OK on 32-bit Debian with Audacity 2.0 RC8.