Let's sum up things a bit and bring a little more information.
~1: .APE files
* They are music files encoded with a codec called Monkey's Audio (MAC). It is not related to Apple's Macintosh®.
MAC is a
lossless codec, which means it retains all info a WAV provides, but in more compact form. Such compressors are generally based on a technology called "linear predictive coding" which helps reach even higher compression rates than standard compressors such as RAR or 7-Zip.
Nowadays, most used lossless formats on Internet are APE, FLAC and TTA. Apple's also launched its own format, ALAC.
Most formats were designed to be easily seekable and have various advandtages and drawbacks (CPU usage, etc.).
APE has one of the highest compression ratios (files are smaller) and FLAC is a free codec that has been ported on several platforms and on several hardware players.
Generally, lossless formats are considered for music archiving. On the lossy side, MP3s are considered
perceptually transparent (i.e. difference can rarely be told by human listeners) around VBR 245 Kibps, strongest bitrate being 320 Kibps.
There are also so-called hybrid codecs, such as WavPack and OptimFROG, that can produce a lossy file and a complementary file that turns the whole into a lossless file. Quite neat, but not everyone wants this.
~2: Playback
* APE files may of course be converted back to WAV and be recognized by most players, although it is a bit radical. For this, you can use the tools available at
http://www.monkeysaudio.com/
Recent players yield support for the APE format, either natively or by the means of a plug-in. For instance, there is a
Winamp plug-in and
one for foobar2000.
* A recent tendency is to have albums packaged as a (huge) monolithic APE unit, combined with a cuesheet (.cue).
You may see this as the chaptering feature on video DVDs.
One advantage of this method is the ability to play songs without gaps in-between. Once again, support varies between players. foobar2000 supports cuesheet loading natively, for instance, whereas Winamp 5 requires a
plugin.
~3: Converting to other formats
As said above, you may convert APEs back to WAVs to burn them back to CDs (ideally, with the help of a cuesheet to preserve original gaps).
If you want to convert APE files to another format, I suggest using foobar2000's
diskwriter plug-in alongside with the
internal CLI encoder plug-in, which acts as a front-end for command-line-based encoders such as FLAC or LAME, or simply output waveform files.
Predefined profiles may help a bit in configuring the CLI tools options, but you should always have a look at the manuals and online tutorials for reference.
~X: QnA
# Can mp3 have gapless playback information?
Yes, but it's not standard. LAME can embed this metadata info (delay/padding) in a proprietary block, which must be recognized by the player. The latter then automatically trims silence when playing the file.
See:
http://www.answers.com/topic/gapless-playback (from Wikipedia)
# Pros & Cons of APE or <insert lossless format here>?
I suggest reading this article:
http://wiki.hydrogenaudio.org/index.php?ti...less_comparison
Keep in mind that lossless formats were designed for archiving and demanding audiophiles. They do not play in the same court as lossy formats.
If you do not mind at all, you may re-encode everything as MP3 320 Kibps for widespread playback support.