Batch Processing

[klausk]

A few comments and feedback on your product. Which sofar I love, but there are some issues and ONE MAJOR request.

1-It apparently will not let you "import" from a Windows 7 library. It says all files must be in the same folder. So you must choose the folder in the library with explorer. A Silly WIn7 issue.

2-Here is my request, and yes, it is possible you already allow this, just there is so much in this program that it is hard to understand it all. You alsomt need to go to a class!
Over the years I have accumulated a lot of music, from live, tape, records, FM, CD, etc. Trouble is when I listen to them on my Ipod, some are barely audible others so loud they are distorted.
I want to "import" my entire library (multiple directories with numerous songs each) and have you output each item to a NORMALIZED standard so that all songs sound like they came from a high quality CD at the same volume level.
Possible? How? Yes I know it may take days.

Thanks for listening
Klaus

[steve]

A Silly WIn7 issue.

Sounds like it.
Media player libraries will generally list titles from a database - these are not the actual files, just an "index" of the files. Consequently trying to access files from the library will often cause unpredictable results in other applications. I don't think this is something that Audacity can fix as it's most likely just the way that Win 7 works.

I have accumulated a lot of music, from live, tape, records, FM, CD, etc. Trouble is when I listen to them on my Ipod, some are barely audible others so loud they are distorted.
I want to "import" my entire library (multiple directories with numerous songs each) and have you output each item to a NORMALIZED standard so that all songs sound like they came from a high quality CD at the same volume level.
Possible? How? Yes I know it may take days.

Yes possible, but there's probably a better, and much quicker way of accomplishing the task.
iTunes has a feature called "Replay Gain" that can automatically set the play volume of tracks. The feature is also supported by iPods, so when you sync your iPod to the computer the Replay Gain settings can be transferred to the iPod.

Apart from the time taken to do the task, another major benefit is that this method does not require decoding and re-encoding the music files, so there will be no loss in sound quality.

[waxcylinder]

As Steve says - and in iTunes you get it by using Edit > Preferences > Playback and check the box that says Soundcheck

WC

[Edgar]

I agree with Steve, the best way is to have your player do the job and not change the file. However, if you really want to perform this kind of surgery with Audacity (and I expect there may be a better tool out there) you can do so if you either change the source code and compile your own version of Audacity or grab a pre-compiled version from my website. I do this exact same process via a command line batch file process--I process hundreds of files at a time (usually overnight). Look at this forum post:
http://forum.audacityteam.org/viewtopic.php?f=21&t=38341
for the details.

[Shaky]

+1 Vote for having a batch processing feature. Is it worth registering this in the separate features request thread?

In any case it seems like this was the intention of adding Amplify as a Chain option, but the command does not appear to take any parameters, although that may be down to my inexperience. Is there any way to achieve this effect with Chains?

Apart from the time taken to do the task, another major benefit is that this method does not require decoding and re-encoding the music files, so there will be no loss in sound quality.

Could you please elaborate on this?

If I have a .wav file then run it through Audacity’s amplify effect and produce another .wav file will the sound quality on this degrade?

[steve]

+1 Vote for having a batch processing feature

Audacity 1.3.13 has a batch processing feature - "Chains", however there are several limitations as to what it can do. Among the limitations: it can only use built in effects and cannot use Nyquist effects.

it seems like this was the intention of adding Amplify as a Chain option, but the command does not appear to take any parameters,

Click on the "Edit Parameters" button.

Apart from the time taken to do the task, another major benefit is that this method does not require decoding and re-encoding the music files, so there will be no loss in sound quality.

klausk was asking about his music collection on his computer, which I guess will contain mostly audio files that are compressed as MP3, WMA or other lossy format. Re-compressing a lossy format will introduce further sound quality losses. ReplayGain and Soundcheck do not actually change the audio data at all - they simply tell the player how loud to play the file, so there is no sound quality loss.

[Shaky]

it seems like this was the intention of adding Amplify as a Chain option, but the command does not appear to take any parameters,

Click on the "Edit Parameters" button.

Steve, I believe it would be helpful if you could please make the assumption I am a complete idiot.

What I would like to do is create a chain that sets the peak amplitude to say -0.2 dB (and then exports the file in - for example - a .wav format). But I can find no reference to the method name and syntax to achieve this.

After clicking on Edit Parameters, what should I enter?

[steve]

What I would like to do is create a chain that sets the peak amplitude to say -0.2 dB

In that case you need to use "Normalize" rather than "Amplify".

When used in Chains, the "Amplify" effect will amplify the audio by a specified amount.
For example you can set it to amplify each file by 6dB.

When used in Chains, the "Normalize" effect will amplify the audio to a specified level.
For example you can set it to amplify each file to a peak level of -0.2 dB.

One side effect of the Normalize effect (that may be beneficial, or may be a problem) is that for stereo tracks it amplifies left and right channels independently.This means that if, say, the left channel has a higher peak level than the right channel, the Normalize will amplify the right channel more. After Normalizing, both left and right channels will have the same peak level.

[Shaky]

Steve, I now understand the nuance I was previously missing regarding Amplify vs normalise and will put in a feature request.

Told you the best course was to assume I am an idiot -- Thanks!