Basic Concepts

If you're new to digital music management, you may want to take a minute to learn some of the basic concepts used in a Digital Library.

The Library

The Library is a database 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 Track, and/or organize the files very quickly.

To organize your music, you'll want to add it to the Library. Once a song is part of the Library, any operation performed on the file will also update the Library as necessary. For example:

Ripping & Digital Audio Compression Formats

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.

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:

Format Compression Type Compression Efficiency Application Compatibility MediaMonkey Support Portable Device Compatibility DVD Compatibility Comments
MP3 lossy good all playback, tagging, encoding all many -
WMA lossy better many playback, tagging, encoding some (but not iPods) many Microsoft format
OGG lossy best many playback, tagging, encoding some (but not iPods) few Open Standard (no patents)
AAC (M4A/M4P) lossy best many playback, tagging,
encoding (via plugin)		 iPods and some phones none Popularized by iTunes
MPC lossy best (at higher bitrates) few playback, tagging none none -
CD Audio (CDA) none - all playback, burning none many -
WAV none - many playback, tagging, encoding some many Tagging implementations vary
Monkey's Audio (APE) lossless ~55% few playback, tagging none none -
FLAC lossless ~58% some playback, tagging, encoding few none Open standard
WMA lossless lossless ~58% some playback, tagging, encoding - some -
ALAC lossless ~58% some playback, tagging iPods none -

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 perfectly adequate and its widespread support makes it a no-brainer as a lossy encoding format.  For lossless compression, the choice depends largely on the devices you use, and whether you prefer an open format like FLAC.

 

Related Information: 

Adding Audio Tracks

MP3 Encoding Settings

Digital Rights Management

Some of the formats described above may be encoded with digital rights management (DRM) information. Specifically, WMA and M4P 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.

 

Related Information:

Electronic Frontier Foundation DRM Page

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 automatically update tags when changes are made to this information. The rationale for storing the information to both the MediaMonkey Library and to the track tags as well is that:

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 vorbis 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 only supports ID3v1. For this reason, it's often a good idea to store music data in both ID3v1 and ID3v2 tags. There are 2 versions of ID3v2 in use today ID3v2.3 and ID3v2.4.  MediaMonkey takes the approach of storing most information in a manner that allows it to be read by devices/applications that support either ID3v2.3 or ID3v2.4.

OGG, FLAC and WMA files have their 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.

Related Information:

Editing Track Properties

About Track Properties

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 multi-phase approach: first track volumes are analyzed and the resulting coefficient is saved to the track's tag (Track gain).  Then after all tracks on an Album have been analyzed, a single coefficient is saved for all tracks on the album (Album gain). Then, during playback, the Album or Track gain tag is read and the player adjusts the volume up or down accordingly (Album gain is preferable for playing an entire Album and preserving the inter-track volume variances encoded in the original album, while Track gain is preferred for playing a playlist of tracks from various sources).  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 synced to a device, the volume will vary.

    MediaMonkey supports Replay Gain analysis and playback (per Track and per Album 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 do not recognize Soundcheck values. 

    MediaMonkey supports Soundcheck, converting Replay Gain and Soundcheck values on the fly as tracks are synced between a PC and 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, and can even do so on-the-fly when synching to a device.     
  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, and can do so on-the-fly when synching to a device.
  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.


Related Information:

Replay Gain Standard (by David Robinson).