Is editing mp3 files in Sound Forge Audio Studio (I use ver. 10) "destructive" - that is if I edit an mp3 file, does every save of an edited file reencode it? Many thanks in advance.
I don't have SFAS but the answer to your question is almost certainly, Yes. Inherently, "editing" of .mp3 files can only be done once the original has been converted to a more "accessible" format, most commonly, .wav. Resaving such a file to .mp3 will certainly include further encoding, and hence, degradation of the quality. The .mp3 format was only ever intended as a "distribution" format, not a "production" one.
I suspected this was the case - otherwise there would be some information about this somewhere. I am quite aware of the limitations and purposes of mp3 files, but I have some old (very old :-) ) home archives in mp3 format and wanted to snip them to organize them a bit better, but without further loss of quality. I will consider whether to convert them to WAV to edit in SFAS or perhaps I will use one of the mp3 tools available on the web.
One thing I omitted to say in my previous reply: the problem with .mp3 files is that they are "compressed" and any editing of them can only take place once they are decompressed. I'm not at all sure that any of those mp3 tools can actually "get around" this fact, although I do know of one, "mp3 DirectCut" which may be suitable for your snipping task because it claims to be able to cut such files without any re-encoding. It's available here.
am not sure about AS, but SF Pro has an non-destructive editing mode option and creates a <.frg> project file, leaving the original media file intact. When editing is complete, the project can be 'Rendered as' to the desired format. If the "Always proxy lossy formats" option is enabled in SF Pro, that creates a PCM 32 bit file for editing, but.. with each lossy file type save, quality is lost. It could be saved as a PCM however, edited and re-saved multiple times with minimal loss.. then re-encoded to MP3 from the PCM master. As Jeff stated, the (lossy) MP3 format is intended for distribution to the end user, not for editing.