Is it possible to compress a mp3 to an ogg file?
It is possible to
convert a MPEG Layer-III encoded Wave to an OGG Vorbis encoded Wave with certain utilities, but I wouldn't reccomend it. All said utilities essentially decompress the MP3-encoded file back to the Wave format, and then re-encodes that wave as an OGG Vorbis-encoded file. However, since both MP3 and OGG are lossy formats you lose quality of the wave (1) with the original MP3 and (2) again with the new OGG. While OGGs are smaller than MP3s at comparable bitrates, and have lightly better quality at the same rates, you
will lose sound quality from the original MP3 with this method. That is the nature of lossy compression.
or to compress a mp3 back to a wav file and then to compress it with mo3 ?
First, to clear up the vocabulary a little. Converting an MP3-encoded file back to the Wave format is called
decompressing or
decoding. Secondly, MO3s are not simply compressed Waves. MO3s are music
modules in which the
samples have been encoded using MP3, OGG, or lossless compression. MO3 is not a stream compression, like MP3 and OGG.