|
What's a Music Database?
One common question is what is a Library or Database
and why do I need one. After all, all your music is
already on your hard drive, and you can easily play
your files by navigating your directories. A database
can be considered a searchable list of all of your
CD albums and audio tracks. Any album or track that
appears in the database is a record of an album or
track that physically exists, either in a drawer somewhere
(one of your CD albums), on your hard drive (e.g.
MP3 files), or on a network. The benefit of having
your music stored in a database is that you can quickly
search your collection of thousands of files for a
single file, and/or organize the files very quickly.
With MediaMonkey, organizing your music,
entails:
-Adding your music to a database (MediaMonkey automatically
adds your files to the Library)
-Organizing your music by Artist, Album, etc. by simply
dragging and dropping Tracks (MediaMonkey updates
both the file tags and the database when you perform
such operations)
-Automatically moving your files and renaming them
into directory structure / filenames that are consistent
(this isn't strictly necessary, but helps you navigate
your collection when doing so via Windows Explorer)
What's Compressed Audio?
Most media players support several digital audio file
formats natively, and others via plug-ins. Some of
these formats (e.g. a standard Audio CD) are uncompressed,
whereas others (e.g. MP3) are compressed. An uncompressed
Audio CD can take up close to 700 MB on your hard
drive, whereas the same audio in a compressed format
often uses less than 20% of the space. MediaMonkey
is able to 'Rip' audio from an Audio CD and save it
to your hard drive in a compressed format.
Audio compression can be lossless or lossy. Lossless
audio compression compresses the audio without losing
any of the original signal's integrity. Consequently,
an audio Track that is compressed with lossless compression
can be converted back to its original uncompressed
form. Lossy compression on the other hand, takes advantage
of the fact that the human auditory system doesn't
notice certain types of signal degradations, thereby
achieving much higher compression ratios. The tradeoff,
of course, is that depending on the algorithm used
and the compression ratio chosen, lossy compression
can introduce artifacts that may be apparent, especially
as the compression ratio increases.
The act of compressing an Audio CD and
saving it to your hard drive is called 'ripping'.
It is done via a CD Ripper which converts the uncompressed
tracks on an Audio CD to a compressed format on your
hard drive.
What Digital Audio Formats exist?
Which is Best?
What follows is a brief description of some of the
various formats supported natively by MediaMonkey
to help you choose the ideal format for your digital
music collection: CDA: CDA (CD Audio) files are the
uncompressed files that appear on a purchased Audio
CD. They can be played by most players, or ripped
to compressed formats to save disk space.
WAV: WAV files are uncompressed and as such, are
usually only used for audio Tracks that are not longer
than a few seconds. Some users with plenty of hard
drive space will convert Audio CDs Tracks to wav files
because they are almost universally supported, however,
generally, this is not an efficient use of hard drive
space.
MP3: MP3 is the most ubiquitous lossy compression
format, and MP3 files can be played by most portable
digital audio players and many DVD players. MP3s are
often ripped at 128 Kbps, achieving decent quality,
although the discerning audiophile will often notice
artifacts at this bitrate and choose to encode them
at a higher bitrate (160 or 192 Kbps).
WMA: WMA (Windows Media Audio) files use a Microsoft
format, that, like MP3, is usually lossy (there is
a lossless version available, but it is rarely used).
It isn't as ubiquitous as MP3, due in part to the
fact that it is perceived as a proprietary format
and is supported on fewer devices and DVDs than MP3.
On the positive side, though, WMA files have noticably
better quality than MP3 files encoded at equivalent
bitrates.
OGG: OGG is a relatively new format, that like MP3/WMA,
is lossy, but is better in quality compared to MP3
files encoded at similar bitrates. What distinguishes
OGG from MP3 and WMA is that the format is an open
specification and may be distributed freely, meaning
that any company can use it at no cost. Few devices
support OGG, however, this seems to be gradually changing.
For best quality, OGG files are generally encoded
at a setting of quality=5 which results in bitrates
of ~140-150 Kbps (OGG only uses as much bandwidth
as is required).
MPC: MPC is a lossy compressed format that is considered
to be one of the best codecs at moderate to high bitrates.
At lower bandwidths of 128 Kbps, any benefits over
OGG or WMA are less clear. The most significant downside
to MPC is that as of today, no hardware devices or
portable audio players support the format. MediaMonkey
tags and plays MPC files out-of-the-box, but does
not yet support encoding.
Monkey's Audio (APE): APE is perhaps the most popular
lossless compressed format today. It can store a complete
CD in ~1/3 the space of a standard CD without any
loss in audio fidelity. MediaMonkey support playback
and tagging of APE files but does not yet encode them.
FLAC: FLAC is becoming increasingly popular as a
lossless compressed format. It can store a complete
CD in ~1/3 the space of a standard CD without any
loss in audio fidelity. MediaMonkey supports playback
and tagging of FLAC files and encodes them as well.
MediaMonkey can also play other formats via 3rd party
plugins. One good example is:
AAC: AAC is a lossy compressed format popularized
by Apple's iTunes store. Like OGG and WMA, it is an
improvement over MP3, but though it is building in
momentum, it is not generally supported by portable
audio players other than the iPod.
Ultimately, the decision of what format to use for
your audio collection is a personal one, involving
tradeoffs between audio quality, hard disk space,
portability, and future-proofing. For most, MP3 is
more than adequate and its widespread support makes
it a no-brainer.
What is DRM?
Some of the formats described above may be encoded
with digital rights management (DRM) information.
Specifically, WMA tracks that are purchased from online
music stores can be encoded with different versions
of Microsoft's DRM, while tracks purchased from the
iTunes music store are encoded with Apple's Fairplay
DRM.
In general, tracks encoded with DRM should be avoided
because they can restrict your ability to use them
as you see fit--even after you've paid for them. For
instance, you may wish to copy the tracks to your
MP3 player, however, the DRM might prevent you from
doing so. On the other hand, DRM allows some companies
to 'rent' music for far less than the cost of purchasing
it, and such subscriptions may be worthwhile, depending
on your needs.
MediaMonkey supports WMA DRM up to version 9.
For more information see the Electronic
Frontier Foundation DRM Page.
What are Tags?
Most digitally encoded file formats also allow Track
information to be embedded within the file. For instance,
you may have a file 'Bryan Adams - Summer of '69.mp3'
in which the filename tells you the Artist and the
Title, however, if you wanted to also store information
about Album, Track #, Year, Music Genre, Rating, Lyrics,
etc. you'd need to store this information in Tags
that are embedded within the file.
MediaMonkey allows you to store all sorts of information
about a Track within the Library, and to update tags
when changes are made to this information. Although
the information is stored in the MediaMonkey Library,
there are 2 reasons for also updating this information
within the track tags as well:
1) If the Track is shared with an external device
such as an MP3 Player or DVD, the tag allows that
information to be available via the device (assuming
the device supports tags).
2) If you wish to use another player or music manager,
the tags embedded within your songs can often be read
by those applications.
Tags are usually stored in a format that is designed
specifically for the file type. e.g. MP3 files usually
have ID3 tags wherease OGG files have OGG tags. What
follows is a brief discussion of the different tag
formats supported in MediaMonkey:
ID3v1: ID3v1 is the lowest common denominator of
MP3 tag formats. It stores only a very limited amount
of information (e.g. Artist, Title, Album, etc.) however,
it is supported almost universally by portable audio
players and DVD players.
ID3V2: ID3v2 tags are also used for MP3 files. They
support a much greater range of metadata (information
about your music files) than ID3v1, however, some
information encoded in ID3v2 tags may not be readable
by another application or device that also supports
ID3v2. For this reason, it's usually a good idea to
store music data in both ID3v1 and ID3v2 tags.
OGG, FLAC and WMA files have there own standard tag
formats. There's no need for alternatives since the
specification supports as much metadata as would be
needed in a relatively unambiguos manner.
APE and MPC files use APE2 tags, which are designed
to resolve some of the difficulties with ID3v2. Although
they work very well, there is limited support for
them in portable audio players and DVD players.
What is Volume Leveling?
When tracks are digitally encoded from different
sources and using different encoders or encoder settings,
they will invariably play back at different volumes
on different players and devices. Several technologies
have evolved to deal with this problem, and it's useful
to understand them so that you use the approach that
best meets your needs:
1. Replay Gain
This is the most standardized approach to volume leveling,
providing a comprehensive approach for all audio formats
without impacting audio fidelity. Replay Gain implementations
use a two phase approach: first track volumes are
analyzed and the resulting co-efficient is saved to
the track's tag. Then, during playback, this tag is
read and the player adjusts the volume up or down
accordingly. This is an excellent approach for PC-based
players, but is limited because many portable devices
do not support Replay Gain tags, and thus when tracks
are synchronized to a device, the volume will vary.
MediaMonkey supports Replay Gain analysis and playback
(via 'Analyze Volume' and 'Level Playback Volume').
2. Soundcheck
This is Apple's variation on Replay Gain. iTunes generates
Soundcheck co-efficients which are used to level playback
volume. The pros of Soundcheck are that it is recognized
by iPod devices and thus volume is leveled even when
playing on them without any loss in fidelity. The
downside is that it is non-standard, and other Players
may not recognize Soundcheck values.
MediaMonkey supports Soundcheck, reading Soundcheck
values and converting them to Replay Gain (if no Replay
Gain co-efficient exists) as well as converting Replay
Gain to Soundcheck on the fly when Synchronizing to
an iPod.
3. MP3 Gain
This is a variation on Replay Gain, the difference
being that rather than saving the analysis co-efficient
to a tag, the volume of the MP3 file is actually modified
based on the analysis. The benefits of this approach
are that like Replay Gain there is no loss in Audio
Fidelity, and the resulting MP3 files can be played
at level volumes on any MP3 player. The downside is
that the approach is limited to MP3.
MediaMonkey supports MP3 Gain type volume leveling
via the 'Level Volume' command.
4. Conversion
Whenever tracks are converted from one format to another,
the level of the volume can be adjusted. This is useful
when there's a need to convert formats, however, for
anything else, this is not a desirable means of achieving
level volumes since it results in loss of fidelity.
MediaMonkey supports conversion (including CD Ripping
and burning) with volume leveling.
5. Audio Normalization
This is an approach used by some Output or DSP plugins
that adjust sound levels on the fly during playback
to keep them within a defined range. It is generally
not recommended as it can introduce audio artifacts.
For more information see the Replay
Gain Standard (by David Robinson).
|
