Re: [SoX-users] Adding silence to lossy files without additional loss/distortion

[Fmiser <fm...@gm...>]

> > Ulrich Klauer wrote, about the 'pad' effect:
> >
> > (NB. If you are using a lossy file format, such as MP3, the
> > audio data will be decoded, then re-encoded in the process,
> > possibly leading to a sound degradation.)
> >

> Ron Leach wrote:

> Taking MP3 as an example, assuming that any re-encoding may
> introduce distortion - which I can understand - does padding
> at the end still rely on a file decode and re-encode process?

Not really distortion.  Loss.  Bits and pieces of the music
are thrown away based on the calculations applied to the
source audio.

> And, does a similar 'file decode and re-encode process' take
> place if, instead of 'pad', a 'concatenate' or 'sequence'
> command/effect is employed, eg to prepend or append a short
> 'silence' file (of equivalent bit and sample rate, as
> described in the Sox documentation)?

As I understand, SoX _always_ decodes, processes, encodes.
There are other tools for handling MP3 files losslessly.

--   Philip