Formats Traded
CD Audio
A standard CD, whether official or homemade, contains .wav files, masked by .cda 'handler' files which merely direct the playback of the .wav files themselves. Hence, trading in CD Audio format provides discs playable on any CD player, whether in a computer, home stereo system or in a car. The files are not compressed, so are at the maximum resolution and playback quality achieved by the original recorder.
A significant problem of trading in CD Audio format is that inexperienced or careless traders can unnecessarily introduce flaws into recordings during the copying process. It is important to note that this is a problem of incompetent users, not an inherent flaw of the CD Audio format.
.shn
Some traders prefer to trade in a compressed format, most commonly Shorten (.shn). This compresses the original audio (.wav) files into far smaller files, meaning that more can be fitted onto each CD-R; fewer discs need to be exchanged by post, and large collections can be stored on fewer discs.
Compression is less than that achieved by such formats as .mp3, but the key difference is that .mp3 is lossy - it reduces file sizes by permanently discarding parts of the original recording. In contrast .shn is lossless, compressing by optimising storage of the original music, without discarding anything. The .shn file can be uncompressed back to an identical clone of the source recording.
A second benefit of .shn is that the smaller file sizes mean additional data can be fitted onto the traded disc. These are typically a text file containing the tracklist and additional information, graphics files of cover artwork and, most importantly, a validation file, which can be used to verify that the disc of .shn files is an exact copy of the original disc.
This verification is the major advantage of .shn format over CD Audio, but the 'flawless' copying aspect can be over-emphasised.
It must be remembered that the .shn copy is only as good as the source recording - a flawless copy of a flawed original is still flawed, and .shn doesn't perform miracles! More accurately, the .shn copy is only as good as the .shn files originally encoded from the .wav source - any errors introduced at the outset will be reproduced exactly on subsequent copies.
However, it is fair to say that whilst .shn needs a competent person to produce the original files, subsequent copying is relatively foolproof, whereas with trading in CD Audio format, all participants need to be competent.
A disadvantage of trading in compressed formats is that the .shn files cannot be played in a standard CD player. This limits playback to specialist software on computers, or requires the recipient to uncompress the .shn files and reburn the recording to fresh blank discs in .wav format, exactly as if the trade had been in CD Audio format from the start, and potentially introducing the very flaws that the .shn trade was supposed to avoid. Furthermore, rather than reducing the number of discs used, the reverse is the case, with an uncompressed copy needing to be kept for listening and another, in .shn format, for trading.
At the Ministry, we take the view that the disadvantages outweigh the advantages, for those competent in CD Audio copying. The foolproof reproduction of .shn discs is not an adequate substitute for copying CD Audio discs properly (never mind foolproof; just avoid fools), and we don't feel the use of additional discs is justified.
Hence we do not offer or accept compressed formats at all. Instead, we ensure the CD Audio discs sent and received are flawless; if we accidentally do send a flawed copy, we will replace it at our own expense, and expect the same from others.
Though this has been made available as a 'service to the trading community', please remember it is copyrighted, not in the public domain nor freely usable by other publications without express permission.
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