Recording - Audacity vs. Total Recorder

[David-G]

In another thread "Shostakovich" on 25-08-11, johnb wrote:

Originally Posted by austin "Also, as a long time user of Total Recorder, I have just been made aware that the new Beta version of Audacity will also record, and it's free! "

What will Audacity record though?

There is quite a difference between Total Recorder capturing the digital output of the software (as it can do with Windows XP, using the "Total Recorder" driver) or from the digital output of Windows Mixer (as it does with Windows 7) and capturing the analogue output of the soundboard and then re-converting it to digital (as Audacity might well do).

(Sorry for repeating myself.)

PS The bad effects of Windows Mixer can be minimised in Windows 7 by setting the "Default Format" to the same as the original format (44.1/16 for iPlayer) so that it doesn't resample, turning off Windows Sounds, setting Communications to "Do nothing" and setting "Allow application to take exclusive control of this device" (though not all applications will take advantage of that).

PPS When using Total Recorder or any other similar software with iPlayer - set the iPlayer volume to maximum.

I have been using Audacity successfully for recording, but on reading johnb's post, I wonder if I am missing something important. Does Audacity really capture the analogue output of the soundcard, and reconvert it to digital? This must imply a loss of quality, and quality is important for me. Can anyone confirm that this is what Audacity does?

If this is correct, and if Total Recorder records the input digital stream directly with no digital-analogue-digital conversion, it would seem that this is a much better option.

I have been puzzled that one has to set the input level when recording with Audacity, in order to avoid clipping. I could not understand why this should be necessary when recording a digital stream. If Audacity is really recording an analogue signal, all becomes clear.

If anyone who understands this could confirm that my conclusion is correct, I would be most grateful.

[french frank]

Hello, David_G, and welcome!

I'm sure johnb, Bryn or someone will be able to answer your query ... (sorry, I can't!).

[johnb]

On the Audacity Wiki page for "Recording audio playing on the computer" it states:

Generally, it is better to extract or import audio from CDs, DVDs or existing video or audio files than record them as they play. Recording from an analog sound card is relatively inexact and lossy because the digital source is converted to analog to play it, then back to digital to record it. The resulting quality will depend (amongst other things) on the quality of your sound card's digital to analog and analog to digital converters.

[David-G]

Thanks, John. As I understand it, we are concluding that Audacity is "bad" because it is recording from an analogue sound card; and that Total Recorder is "good" because it is importing audio directly. Is that the correct conclusion?

[johnb]

David,

I am assuming that Audacity records from the sound card because that is what many of these software packages do and also because of the implication of the statement that I quoted from the Audacity Wiki.

As for "good" or "bad", I'm not sure those are necessarily appropriate terms - they both do a job but do it in different ways. However, IMO Total Recorder is likely to give better results, all other things being equal. Whether someone will be able to distinguish between the two is another matter!

By the way, (as I wrote in the post that you quoted) if you are using Windows 7 it is a good idea to set the sound properties of the device you are using (headphones, speakers, etc) so as to minimise the effect of the Windows Mixer.

Start/Control Panel/Hardware and Sound/Sound

Highlight the active device (shown with a green tick) and click on Properties

In the Enhancements: Disable all sound effects
In the Advanced: Set the default format to the same as the source. For iPlayer this is '2 channel, 16 bit, 44100 Hz (CD Quality)'.
and ..................Allow applications to take exclusive control, which is useful for ASIO software.
(I'm not sure whether you can do this is Vista. you certainly can't in XP.)

[MrGongGong]

I'm not 100% sure that Audacity records the analogue out and then re-digitieses it ?
I only tend to use it for teaching BUT if i route stuff on a mac (using Soundflower or Jack) then its a totally digital internal connection.

Though I would get rid of ALL sound effects and such nonsense !

[johnb]

To expand my reply a little:

I'm by no stretch of the imagination an expert on this and I am only relaying what I have picked up but, when recording sound, IMO the order of preference would be:

a) The original 'native' digital data (in the case of iPlayer this is the data that is streamed over the internet in aac format)
.... it is possible to capture this with the appropriate software, though editing and converting it to playable formats is fiddly.

b) The digital output of the software that is playing the audio (e.g. the output of iPlayer, etc, etc)
.... This can be captured using Total Recorder with the Total Recorder driver but only in Windows XP.

c) The digital output of Windows Mixer
.... This is the best option for Total Recorder in Windows 7 (using the Kernal-mode driver)

d) The analogue output of the Soundcard
.... What many software packages capture

[David-G]

To expand my reply a little:

I'm by no stretch of the imagination an expert on this and I am only relaying what I have picked up but, when recording sound, IMO the order of preference would be:

a) The original 'native' digital data (in the case of iPlayer this is the data that is streamed over the internet in aac format)
.... it is possible to capture this with the appropriate software, though editing and converting it to playable formats is fiddly.

b) The digital output of the software that is playing the audio (e.g. the output of iPlayer, etc, etc)
.... This can be captured using Total Recorder with the Total Recorder driver but only in Windows XP.

c) The digital output of Windows Mixer
.... This is the best option for Total Recorder in Windows 7 (using the Kernal-mode driver)

d) The analogue output of the Soundcard
.... What many software packages capture

That is a very helpful way of summing it up.

Would it be fair to say that (b) is essentially the same as (a), though probably in a different format?

In other words, do you think that the software playing the audio is "doing anything" to the content of the digital stream, other than perhaps reformatting it in some way? Or is some "quality" being lost between (a) and (b), do you think?

Thanks,
David.

[johnb]

Would it be fair to say that (b) is essentially the same as (a), though probably in a different format?

In other words, do you think that the software playing the audio is "doing anything" to the content of the digital stream, other than perhaps reformatting it in some way? Or is some "quality" being lost between (a) and (b), do you think?

I suppose that depends on the software (though I realise that is patently obvious), e.g. to use as an example something we are all familiar with, the iPlayer, if the volume control isn't set to the maximum the iPlayer software attenuates the audio. (In using the iPlayer as an example I am not suggesting that anyone attempts to capture audio from it - I suspect that the BBC would frown upon any such activity.)

Option (b) is probably OK and it can definitely save an awful lot of fiddling around with other software, though I would still prefer (a). With (b), to avoid any unnecessary resampling, make sure that Total Recorder saves any file either using the same sampling rate as the source data or without any conversion (though that would result in a PCM file which then you would have to convert to FLAC or mp3).

[Bryn]

To expand my reply a little:

...

a) The original 'native' digital data (in the case of iPlayer this is the data that is streamed over the internet in aac format)
.... it is possible to capture this with the appropriate software, though editing and converting it to playable formats is fiddly.

It's a multi-stage process: editing/extracting the aac file/converting to WAV, m4a, whatever, but "fiddly"? Not once you get the hang of it. A bit like riding a bike in that respect. Neither the software concerned in the capture nor that used in the editing is of the most intuitive, however. Anyone know of such software which runs on a Mac? PM me if you do. I am Apple averse myself, but other are not, and I sometimes get asked how it's done with Mac, and I simply do not know.