Using Existing Audio
There are two primary ways to bring data into Ardour: recording it
within a session from a live sound source or importing pre-existing
audio files. This section covers the various ways to import audio into a
session.
Importing and Embedding
Importing and embedding are two different methods of using existing
audio files on your computer (or network file system) within a
session. They differ in one key respect:
Importing
An existing audio file is copied to the session's sounds folder,
and is converted into the session's native format (WAVE or
Broadcast WAVE depending on your choice) and sample rate. At
this time, no control over the conversion process is offered. If
sample rate conversion is required, it will be carried out at
the highest quality that Ardour can provide. This means that it
can be rather slow (many minutes to import an audio file lasting
a few minutes).
Embedding
An existing audio file is used as a the source for a region, but
is not copied or modified in any way.
Supported External Audio File Formats
The list of audio file formats that Ardour can import/embed is quite
long. It is based on the functionality offered by libsndfile, an
excellent and widely used software library by Australian programmer
Erik de Castro Lopo. As libsndfile's capabilities expand, so will
Ardour's abilities to import (and export) new formats. Ogg/Vorbis (an
excellent, unpatented and license free audio compression format
similar to MP3) is planned for the near future. Currently, supported
formats include:
Microsoft WAV
SGI/Apple AIFF/AIFC
Sun AU/Snd
Raw (headerless)
Paris Audio File (PAF)
Commodore IFF/SVX
Sphere/NIST WAV
IRCAM SF
Creative VOC
SoundForge W64
GNU Octave MAT4.4
Portable Voice Format
Fasttracker 2 XI
HMM Tool Kit HTK
Sample encodings supported include:
Unsigned and signed 8, 16, 24 and 32 bit PCM
IEEE 32 and 64 floating point
U-LAW
A-LAW
IMA ADPCM
MS ADPCM
GSM 6.10
G721/723 ADPCM
12/16/24 bit DWVW
OK Dialogic ADPCM
8/16 DPCM
Using audio files as tracks or regions?
When you want to use existing audio files in an Ardour session, the
first choice you need to make is whether you want to bring the files
in as tracks or as new regions. Consider the two following scenarios:
you have an 8 track recording of existing material, with 1 audio
file per track
you have a sample library containing 500 small audio files
In the first case, your goal is probably to have 8 tracks (at least),
with each track containing a single audio file. In the second case,
its a lot more likely that you simply want to be able to use any of
the samples easily, but do not want any tracks created as a direct
result of the import/embed. It is very important that you understand
this distinction: many new users think there should be a "simple" way
to import existing audio without understanding that the goal of
importing/embedding is not always the same.
Ardour provides two different options when importing. You can
import/embed audio files as new tracks, or you can import/embed them
into the region list, where they will be available as regions to put
into new or existing tracks. You can also insert import/embed audio
files directly into an existing track.
How to import/embed
There are three pathways for importing/embedding an audio file into a
session. One is initiated from the File menu, one is initiated from
the track context menu, and one is initiated from the region list.
These methods are all equivalent: they open the file import dialog.
Once the dialog is open, you can choose to add new audio as new
tracks, as regions in the region list, or as audio in the selected
track. You can change this behavior once the dialog is opened.
If you want to import a file directly into an existing track, you
must have the track selected in the editor before beginning the
import.
If you use Nautilus as your file manager, you can easily import files
into your project by dragging them onto the desired track, then
releasing the mouse button. The file will then be
embedded into your session.
Working with Tags
A "tag" is bit of information, or metadata, that
is associated with a data file. Specifically, tags are keywords or
terms that you feel have some relevance to a particular soundfile.
Ardour can store these tags in a seachable database so that you can
quickly search for sounds based on the tags that you have assigned to
them. For example you can assign the term "120bpm" to a sound, and
then when you search for this tag, the file will appear in the search
list. Tags are independent of the filename or anything else about the
file. Tags, and the file paths that they are associated with, are
stored in a file called "sfdb" in your Ardour user folder.
Adding tags to a file
Select a file in the import dialog.
Enter the tags in the box to the right labeled "Tags".
Tags are stored when the input box loses focus, there is no reason
to explicitly "save" them.
Searching for files using tags
Select the "Search Tags" tab on the import dialog.
Enter the tag(s) to search for and press "Search".
Files which have been "tagged" with the input terms will appear in
the results window. You can audition these files and apply tags to
them from this window.
Searching Freesound for soundfiles (optional)
Freesound (http://freesound.iua.upf.edu/) is an online database with
thousands of soundfiles which can be freely used in many projects
(visit Freesound for the exact licensing terms). Ardour has an option
to download files directly from freesound directly from the import
dialog. Freesound files are tagged with metadata which you can use to
search for relevant sounds.
To enable the Freesound search engine inside Ardour, you must build
Ardour with the option FREESOUND=yes, and you must have the "curl"
library installed. This is currently optional but may later become a
standard feature of Ardour.
To download files from Freesound, you must first register for a
username and password on the freesound website. Enter this information
into the text entry boxes, enter your tags to search for, and then
click "Start Downloading". Ardour will begin downloading files, and
the "Start Downloading" button will change to say "Cancel". Clicking
the "Cancel" button will wait until the currently downloading file is
finished, then the button will switch back to "Start Downloading". The
button will also say "Start Downloading" once Ardour has downloaded
all of the files that match the given tag. In the future there may be
better indication of the file progress and better filtering on the
filetypes that are downloaded.
If you later search for the same terms, you will see that the files
appear in the list more quickly, because any files in the search set
that are already downloaded won't have to be downloaded again.
Sounds that are downloaded from Freesound will automatically be given
tags in Ardour that match their tags in the Freesound database. This
means that once they are downloaded, Ardour can search for the local
files very quickly using the "Search Tags" tab.