CoolEdit and MP3

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When I edit an MP3 file in Cool Edit 2000, is it edited AS an MP3 file
or is it internally converted to a wave and then compressed BACK into an
MP3? If it is compressed a second time, that's not good.

 

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"mcp6453" wrote ...
> When I edit an MP3 file in Cool Edit 2000, is it edited
> AS an MP3 file or is it internally converted to a wave
> and then compressed BACK into an MP3?

The answer is as close as the help menu...
"As an .mp3 file is opend, it's decompressed into Cool
Edit Pro's uncompressed internal format..."

This internal format is most likely identical to ".wav",
perhaps at 24-bit resolution (speculation).

> If it is compressed a second time, that's not good.

Which is why CoolEdit posts a warning about saving in MP3.

Many of us consider MP3 to be a play-only format. No further
editing (at least not high quality editing) is possible.

 

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Richard Crowley wrote:
>
> "mcp6453" wrote ...
> > When I edit an MP3 file in Cool Edit 2000, is it edited
> > AS an MP3 file or is it internally converted to a wave
> > and then compressed BACK into an MP3?
>
> The answer is as close as the help menu...
> "As an .mp3 file is opend, it's decompressed into Cool
> Edit Pro's uncompressed internal format..."
>
> This internal format is most likely identical to ".wav",
> perhaps at 24-bit resolution (speculation).
>
> > If it is compressed a second time, that's not good.
>
> Which is why CoolEdit posts a warning about saving in MP3.
>
> Many of us consider MP3 to be a play-only format. No further
> editing (at least not high quality editing) is possible.


Thanks, Richard. Yes, I often check Help menus, but so many software
developers skimp on their Help files that it is not an automatic habit.

Bonus question, not in the help file. Flash audio files are saved as
SWFs. If I open them in CoolEdit, they play fine, and CE says they are
really MP3 files. However, if I edit the file and save it, unlike a
normal MP3 file, the audio has glitches. Is there an SWF file editor
(even though it decompresses and recompresses)?

 

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"mcp6453" wrote ...
> Bonus question, not in the help file. Flash audio files are saved as
> SWFs. If I open them in CoolEdit, they play fine, and CE says they are
> really MP3 files. However, if I edit the file and save it, unlike a
> normal MP3 file, the audio has glitches. Is there an SWF file editor
> (even though it decompresses and recompresses)?

I'm not familiar with "Flash audio files" or SWF format.
Is this something unique to a particular device? Wouldn't
hurt to provide additional context like the make/model of
the device.

 

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"Richard Crowley" <rcrowley7@xprt.net> writes:

> "mcp6453" wrote ...
>> When I edit an MP3 file in Cool Edit 2000, is it edited
>> AS an MP3 file or is it internally converted to a wave
>> and then compressed BACK into an MP3?
>
> The answer is as close as the help menu...
> "As an .mp3 file is opend, it's decompressed into Cool
> Edit Pro's uncompressed internal format..."
>
> This internal format is most likely identical to ".wav",
> perhaps at 24-bit resolution (speculation).

I could be wrong, but I thought the internal format was
floating-point.
--
% Randy Yates % "And all that I can do
%% Fuquay-Varina, NC % is say I'm sorry,
%%% 919-577-9882 % that's the way it goes..."
%%%% <yates@ieee.org> % Getting To The Point', *Balance of Power*, ELO
http/home.earthlink.net/~yatescr

 

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Archived from groups: rec.audio.tech (More info?)

On Sun, 16 May 2004 01:30:44 GMT, Randy Yates <yates@ieee.org> wrote:

>I could be wrong, but I thought the internal format was
>floating-point.

Yep, it's 32-bit floating point.

 

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Archived from groups: rec.audio.tech (More info?)

> Randy Yates wrote:
> >I could be wrong, but I thought the internal format was
> >floating-point.

"François Yves Le Gal" wrote ...
> Yep, it's 32-bit floating point.

According to their help file...
"32-bit 16.8 float (type 1 - 32-bit)"
"This is Cool Edit Pro's internal format. Floating point
values are in the range of +/- 32768.0, but larger and
smaller values are valid and not clipped since the floating
point exponent is saved as well. The .wav BitsPerSample
fileld is set to 32 and BlockAlign is set to 4 bites per
channel."

Note that +/- 32768 is 16-bit signed integer. Same as
standard 16-bit fixed-point wav files. So they appear
to accomodate "floating point" input and output protocol
while processing only the actual 16-bits of data.

 

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Archived from groups: rec.audio.tech (More info?)

RC [Sat, 15 May 2004 22:40:12 -0700]:
>Note that +/- 32768 is 16-bit signed integer.

Not quite right. 0x8000 is -32768, but 0x7FFF is 32767,
in a 16-bit short integer. It will sound VERY bad if
you saturate at -32768 and 32768. Go ahead, try it.
Close only counts in hand-grenades, and maybe horseshoes.

--
40th Floor - Software @ http/40th.com/
iPlay : the ultimate audio player for iPAQs
mp3, ogg, mp4, m4a, aac, wav, and then some

 

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On Sat, 15 May 2004 22:40:12 -0700, "Richard Crowley" <rcrowley7@xprt.net>
wrote:

>Note that +/- 32768 is 16-bit signed integer. Same as
>standard 16-bit fixed-point wav files. So they appear
>to accomodate "floating point" input and output protocol
>while processing only the actual 16-bits of data.

Here's a cut'n paste of the "20- to 32-bit File Formats" section of the help
file:

"32-bit int (type 1 - 32-bit)
This format saves 32-bit audio as 32-bit integers.

32-bit 24.0 float (type 1 - 24-bit)

Full 32-bit floats are actually saved (and in the range of +/-8million), but
the .wav BitsPerSample field is set to 24 while BlockAlign is still set to 4
bytes per channel.

32-bit 16.8 float (type 1 - 32-bit)
Cool Edit Pro’s internal format (floating point values in the range of
+/-32768.0 but larger and smaller values are valid and not clipped since the
floating point exponent is saved as well). The .wav BitsPerSample field is
set to 32 and BlockAlign to 4 bytes per channel.

32-bit 0.24 normalized float (type 3 - 32-bit)
Standard floating point format for type 3 .wav files. Values are normalized
to the range +/-1.0 and although values above and below this range are
saved, some programs may clip when reading them back in.

24-bit packed int (type 1 - 24-bit)
Straight 24-bit integers are saved (so any data beyond the bounds are
clipped). The .wav BitsPerSample field is set to 24 and BlockAlign to 3
bytes per channel.

24-bit packed int (type 1 - 20-bit)
Straight 24-bit integers are saved (so any data beyond the bounds are
clipped). The .wav BitsPerSample field is set to 20 and BlockAlign to 3
bytes per channel. The extra 4 bits that are saved are actually the
remaining valid bits when saving, and are used when reading (thus giving
24-bit accuracy still if those bits were actually when writing).
Applications should either fill those last 4 bits with zeros, or with actual
data, but generally A/D converters that generate 20 bits of valid data
automatically set the remaining 4 bits to zero. Any type 1 format with
BlockAlign set to 3 bytes per channel is assumed to be packed integers, and
a BitsPerSample field between 17 and 24 inclusively will read in all 24 bits
fine and assume the remaining bits are either accurate or set to zero."