The goal of REX is to archive your album in perfect quality, and at same time saving as much space as possible on your HD or backup media by using top-of-the-art technics.
The best perfect quality/size ratio you get by using the minimum REX-mpc settings (, i.e. '--quality 7 --xlevel' or even better '--quality 7 --ms 15 --xlevel' as examples.)
MPC-REX at this quality level is not to distinguish from the original CD or the uncompressed waves by listening, even if you apply Digital Sound Processing (DSP) like Logic7 or DPL2 for surround sound via 4-6 speakers,
or if you transcode later on the MPC-REX to another format (like mp3) for compatibility/portability reasons.
This means, regarding the usage of music = listening, MPC-REX is without any loss, so called 'transparent'.
Table & Picture: Comparison of bitrates, estimated averaged sizes:
Wave stereo, 16 bit, 44.1 kHz
Lossless like flac, ape, Wavepack
MPC @ q 8
MPC @ q 7.5
MPC @ q 7
MPC @ q 5
1411 kbit/s = 100 %
500 - 1000 kbit/s = 40 - 70 %
265 kbit/s = 19 %
245 kbit/s = 17 %
220 kbit/s = 15 %
180 kbit/s = 12 %
By above diagram you get a feeling, which sizes you have to expect for different ways of archiving your music. See also the ABBA album example in this table here.
If you archive REX-Losslessly (dark-green colours) by flac, ape or wavepack (Hybrid), Optimfrog (Dualstream), the size varies dependent on the style of music, e.g. loudness. If you archive by REX-MPC (light-green colours), the averaged sizes depend on the q-level & then secondary on style/loudness/complexity of music.
Music in mpc@q5 or even mp3@128 cannot be considered Archive-quality, because there is no room left for e.g. applying DSP (Digital Sound Processing) like Logic7 (by Harman Kardon) or the similar DPL2 (Dolby), or another example, transcoding the REX-Archive to High-Quality mp3@320 for playing in stand-alone HiFi-DVD/MP3 players.
With music archived as REX (green colours), you can do these possibilities without fearing, that there might be introduced annoying artefacts.
* Remark to Logic7, DPL2: Don't think about this technique like you might have experienced / think about old-fashioned DPL (Dolby ProLogic). DPL sounds awful, dull, compared to fresh, dynamic Logic7/DPL2. Reason: DPL was developed, as there was no computing power available compared to today's times (power for decoding on the fly during playing the music). DPL produces only 1 (mono) rear-channel with limited frequencies. Logic7 & DPL2 produce 2 independent rear-channels (result like 5.1 ac3/dts) with full frequency content up to 20 kHz.
But maybe you want to archive a very rare album even theoretically Lossless. So you need to use a lossless encoder like FLAC, Monkey's Ape or WavePack.
WavPack offers an hybrid mode, which gives you song files at same time very well encoded lossy and lossless.
Read more at http://www.wavpack.com , if you have interest in details.
So, if you want to have the rare album archived theoretically losslessly
at home, but you want to have it on your laptop on a small HD, too, together with other albums, you could copy only the WavePack lossy (*.wv) songfiles to your Laptop HD, to save space, there.
So, to make a long story short,
WavePack Hybrid offers you an easy to use bridge between 'still quite big' even theoretically lossless music files for archiving, and at same time smaller (265 kbit/s) lossy music files with still good sound.
FLAC or ape as alternative Lossless codecs, offer you some other advantages, like
* files, songs not totally corrupted, if a single error appears inside a file (maybe due
to aging of backup medium like DVD+-R, CD-R.
* 'Hardware' support (by flac, maybe by WavePack in future, probably not by ape)
So, FLAC is your choice, if Archiving is the main purpose for you going lossless with big files, Wavpack Hybrid offers you something additional, wait for the release of WavePack 4.0, then the REX Guide will be updated with a WavePack / Wavepack Hybrid part of the guide.
