What is audio transcoding? It is the process of converting an audio file from one format to another. There are two types of audio codecs - lossless and lossy. Let's talk about how transcoding affects sound quality. This will allow you to choose the best format for recording and storing your home collection.
1 Lossy to Lossy
Each time, when using the lossy encoder, the sound quality is reduced. There is not way can you recover the original quality, even if you encode from 128 kbps to 320 kbps. For this reason, transcoding between lossy formats is not recommended. The quality of the resulting file will be worse than that of the source file.
The only reason for such a process can be lowering the bit rate or converting to another format for use with portable players, for which quality is not very important.
2 Lossless to Lossless
Unlike the above lossy transcoding, in this case the quality is not lost. Thus, you can perform conversion from one lossless format to another as many times as you need (for example, to increase the compression ratio or to ensure compatibility with certain programs / devices).
3 Lossy to Lossless
Quite often people think that they can improve the sound quality by transcoding lossy into lossless (for example, MP3 to FLAC). In fact, the lossy transformation into lossless is meaningless, because once the sound has passed lossy coding, the losses have already occurred and they are irreversible. Converting from lossy to lossless makes sense only if the original file uses an outdated or rare codec that is not supported by your devices.
4 Lossless to Lossy
Archiving music to lossless gives you the possibility of further transcoding music to any lossy format (for example, in case of new versions of encoders). If you encode into lossy from a lossless source, it is strongly recommended that you save the original lossless file. In this case, if the encoding results are unsatisfactory, you can re-encode your audio collection again.