I have some OGG files which would benefit from the following
simple corrections:
a) removing left channel (which is empty) and changing right
channel to the mono channel (mono sound stereo-recorded by
mistake)
b) volume change
Of course I can open the files in audacity and do those
corrections but that would require re-encoding. And I am afraid
that it will result in additional loss of the quality.
So I have two questions
1) Is it possible to perform those changes 'in place' - without
decoding and reencoding? From my naive point of view it seems
that those changes should not require reencoding but heavy
googling did not help to find any suggestion how to do this.
2) Is re-encoding to be worried about? In other words: if
B.ogg = ogg-encode( ogg-decode( A.ogg) )
is the quality of B.ogg worse than the quality of A.ogg?
PS I am on Linux.
PS2 As it is my first email to the vorbis mailing list, I would
like to make thanks to all the people involved in creation of
this excellent piece of software.
Daniel Schregenberger
2005-Jan-14 05:58 UTC
[Vorbis] Simple OGG editing without re-encoding?
On Fre, 2005-01-14 at 14:05 +0100, Marcin Kasperski wrote: [...]> a) removing left channel (which is empty) and changing right > channel to the mono channel (mono sound stereo-recorded by > mistake) > > b) volume change[...]> 1) Is it possible to perform those changes 'in place' - without > decoding and reencoding? From my naive point of view it seems > that those changes should not require reencoding but heavy > googling did not help to find any suggestion how to do this.I don't know about the channel thing, I think it depends on the encoding quality setting ie. if it's Joint Stereo or real Stereo. For the volume there's the vorbisgain "standard": http://sjeng.org/vorbisgain.html (there are several other pages, I just googled)> 2) Is re-encoding to be worried about? In other words: if > B.ogg = ogg-encode( ogg-decode( A.ogg) ) > is the quality of B.ogg worse than the quality of A.ogg?Yes. Ogg is lossy. Like mp3, jpeg, mpeg, xvid, ... -- Daniel -- Homepage: http://www.npfdd.ch/ -- Q: How many college football players does it take to screw in a light bulb? A: Only one, but he gets three credits for it.