Difference between revisions of "Sending your work to others"

From Audacity Wiki
Jump to: navigation, search
(Sending an exported audio file: some typos ; explain use File > Export Selection As... to send each track of a project)
Line 74: Line 74:

Revision as of 20:49, 14 September 2008

You may be working with other users and want to send your multi-track Project to them so they can contribute to it. Or perhaps you created a five minute message with some music and want to send it to a relative by email. Or what if you want to open your Project on another of your own computers running a different operating system?

Are any of these possible?

Sending Projects to others

It's quite possible to send an Audacity Project to another person or open it on another computer of your own, so that the Project can be opened in another copy of Audacity with all the tracks, label and envelope information in situ. However when opening the .aup Project file you need to have its associated _data folder with the same name as the .aup file present in the same folder. For example, if you were sending a Project to someone else you could include these in the contents of an attached .zip folder compressed with 7-Zip  for Windows, Stuffit  for OS X or similar program. Then have your recipient extract both the .aup file and _data folder to the same directory and open the .aup file from inside that folder.

In practice, the problem with sending such a folder to someone else is the size of the _data folder. At Audacity's default 32 bit float sample format and 44 100 Hz sample rate, stereo Projects take up 20 MB of space per minute, and more as soon as you start editing them. This rules out most email transfers. You can transfer larger files over the internet with a service like yousendit.com  but for very large files this is unlikely to be free. For example, the yousendit.com free service permits sending files up to 100 MB in size, with a charge for larger files. However you can always combine your .aup Project file and _data folder in a .zip folder, burn this to a data CD and send it by snail mail.

There are other restrictions on opening an Audacity Project on another computer:

1) If the Project contains audio data that was imported into Audacity from a WAV or AIFF file, you must have previously set Audacity to make a copy of that original audio when you imported it, so that it's included in the _data folder. You set this option on the File Formats tab of Preferences: ("when importing uncompressed audio....make a copy of the file before editing"). This is not an issue when importing compressed audio like MP3 or .OGG as Audacity always copies the audio into the _data folder.

2) If the person you are sending the Project to has a 1.2.x version of Audacity you will need to save the Project in a 1.2.x version of Audacity, because 1.2.x versions of Audacity cannot open Projects created in 1.3.x versions. If the person you are sending the Project to has Audacity 1.3.2, the other person should be able to open it even if you created it in 1.2.x, but ask them to back up the .aup file and _data folder first to be sure.

3) If the person you are sending the Project to uses Audacity 1.0.0 (users on Mac OS 9 are limited to this version of Audacity), you must create the Project in 1.0.0, because 1.0.0 cannot open Projects created in 1.1.0 or later. If that person sends you a Project created in 1.0.0, you should generally be able to open it in 1.1.0 to 1.2.6, but Audacity's conversion of a 1.0.0 Project to the new format used by 1.1.0 or later does not always work. You should not open Projects created in 1.0.0 in the Beta 1.3.x versions of Audacity.

4) If the person you are sending the Project to is on a different operating platform (e.g. you are on Windows and the other user is on a Mac), you must create the Project using Audacity 1.2.2 or later, and the other user must be using 1.2.2 or later. Prior to 1.2.2, .aup Project files are not portable between different operating platforms.

Sending an exported audio file

You can always send an exported audio file (such as an MP3) from your Project to the other user. To export your Project as audio file(s), use the File > Export As... command.

Exporting as a WAV or AIFF file creates a file with no loss of audio quality, but this takes 10 MB of disc space per minute for CD quality (44100 Hz, 16 bit stereo). Exporting as an MP3 greatly reduces the size of the exported file, at the expense of some quality loss. Audacity's default MP3 export bit rate of 128 kbps gives very reasonable sound quality for about 1 MB of space per minute. To compress the MP3 to a still smaller file (at the cost of further quality loss), go in Audacity 1.2.x to the File Formats tab of Preferences and reduce the MP3 Export bit rate at MP3 Export Setup. Simply click the downward pointing arrow in the Bit Rate dropdown as shown below, choose a lower bit rate from the list, and click OK:


For example, a 64 kbps MP3 would take up 0.5 MB (500 kb) per minute, because 64 kbps is half the bit rate of 128 kbps. In Audacity 1.3.3 and later, choose the required MP3 bit rate in the "Options" button after clicking File > Export and choosing MP3 as the export format.

To export MP3s you must add the LAME encoder to your computer. Instructions for doing this are at Lame Installation.

If your Project only contains one stereo or mono track, only Project–specific information such as label and envelope data will be lost by doing this. But if you have multiple tracks in your Project, Audacity 1.2.x will always mix these down to a single mono or stereo track when exporting to an audio file. To get round this you can:

  1. Send each track separately to the other person. To do this, select the first track, choose File > Export Selection As... then repeat in turn for the other tracks. The recipient can then shift-select and multiple import each file into separate tracks of an empty Audacity Project.
  2. Use Audacity 1.3.2 Beta or later which can export the individual tracks in a Project as one multichannel audio file. So if you had a Project with six mono or left/right tracks, it could be exported as a one six-channel audio file, and any 1.2.x user of Audacity can open that file and see the channels displayed as individual tracks. To use multichannel export you must go to the File Formats tab of Preferences (Audio Files tab in 1.3.4) and turn on "Advanced Mixing Options" in the "When exporting tracks" panel.

Note that you should always attach your audio file to the email message. Some email clients can embed the audio inside HTML email messages so that the recipient hears the audio on opening the email without having to open an attachment. However whether the recipient will hear the audio depends on the recipient having an HTML email client (or having HTML enabled without any security restrictions in place). Many email users disable HTML email due to the perceived security risk of HTML email.

Note also that sending files greater than 5 MB by email is usually out of the question due to server bandwidth and storage restrictions. Some webmail services such as GMail do allow files up to 10 MB to be transferred. The solution is to use a web-based transfer service like yousendit.com  or burn the exported audio file on to an audio CD and send it by postal mail. If you want to burn to an audio CD you need to export 44 100 Hz, 16 bit stereo WAV or AIFF files, and tell your burning software to burn an "audio" or "music" CD. For instructions on how to do this, see How to burn CDs.

Audio CDs will retain the full quality of the original track in Audacity, can contain 74 – 80 minutes of music and can be played in computers and on any standalone CD player (and some standalone DVD players).

Reducing File Size

The following can be used to reduce total file size:

  • Zipping
    • produces one file from many, thus reducing slack space wastage on storage media.
    • provides lossless compression, but typically only produces a small reduction in file size. Current versions of Winzip  are able to reduce the size of WAV files by up to one-third, but this is untypical of most compression utilities.
  • Exporting from Audacity as FLAC
    • provides lossless compression and reliably reduces file size by about 40% compared to WAV or AIFF
  • Exporting as a lossy compressed format such as MP3 or OGG
    • provides compression to about one-tenth the size of WAV at Audacity's standard 128 kbps export bit rate (at the cost of some quality loss).
  • Reducing recording or export sample rate
    • no quality effect on some files especially speech
    • affects high frequency response of full bandwidth audio
    • can reduce file size to one-half or even one-quarter
  • Reducing recording or export bit depth
    • no effect on quality in some cases especially speech
    • does affect quality of edited files in some cases