I have two AV tasks I need to perform, which are otherwise unrelated...
1. I have some video for which the sound is out of sync. The video files use an XviD codec (not sure what sound codec). I'm looking for a tool to allow me to correct them. Ideally I want something I can just use left/right arrow keys to jog the sound a small amount ahead or behind the video until it's correct, then hit save to create a new file. It all ought to be pretty quick (no recompression needed, just re-synchronising). Any suggestions?
2. I want to take some audio files and slow them down (quite a lot) without changing their pitch. I'm trying to learn to play the guitar and I can't play fast enough to play alongside anything yet unless I can slow it right down!
My desktop is Ubuntu 9.04 if that's relevant.
On 08-Jun-09 15:04:26, Mark Rogers wrote:
I have two AV tasks I need to perform, which are otherwise unrelated...
- I have some video for which the sound is out of sync. The video
files use an XviD codec (not sure what sound codec). I'm looking for a tool to allow me to correct them. Ideally I want something I can just use left/right arrow keys to jog the sound a small amount ahead or behind the video until it's correct, then hit save to create a new file. It all ought to be pretty quick (no recompression needed, just re-synchronising). Any suggestions?
- I want to take some audio files and slow them down (quite a lot)
without changing their pitch. I'm trying to learn to play the guitar and I can't play fast enough to play alongside anything yet unless I can slow it right down!
My desktop is Ubuntu 9.04 if that's relevant.
Dunno about #1 (others will, though).
For #2, have a look at 'sox', especially option "stretch".
Ted.
-------------------------------------------------------------------- E-Mail: (Ted Harding) Ted.Harding@manchester.ac.uk Fax-to-email: +44 (0)870 094 0861 Date: 08-Jun-09 Time: 16:23:29 ------------------------------ XFMail ------------------------------
(Ted Harding) wrote:
For #2, have a look at 'sox', especially option "stretch".
Perfect, thanks!
(Actually, the docs said to use tempo instead of stretch, but sox infile.flac outfile.ogg tempo 0.75 50 30 .. gave me the results I wanted)
On 09-Jun-09 08:53:20, Mark Rogers wrote:
(Ted Harding) wrote:
For #2, have a look at 'sox', especially option "stretch".
Perfect, thanks!
Glad it worked!
(Actually, the docs said to use tempo instead of stretch, but sox infile.flac outfile.ogg tempo 0.75 50 30 .. gave me the results I wanted)
Interesting! When I look at 'man sox', the word "tempo" does not occur, and the option to slow down/speed up without changing pitch is "stretch". This is sox version 12.17.7 ('sox -h') on a Debian Etch installed late 2007, and the man-page has the date "December 11, 2001" at the end.
Have things changed recently? Ted.
-------------------------------------------------------------------- E-Mail: (Ted Harding) Ted.Harding@manchester.ac.uk Fax-to-email: +44 (0)870 094 0861 Date: 09-Jun-09 Time: 11:20:51 ------------------------------ XFMail ------------------------------
(Ted Harding) wrote:
Interesting! When I look at 'man sox', the word "tempo" does not occur, and the option to slow down/speed up without changing pitch is "stretch". This is sox version 12.17.7 ('sox -h') on a Debian Etch installed late 2007, and the man-page has the date "December 11, 2001" at the end.
$ sox --version sox: SoX v14.2.0
That's on Ubuntu 9.04. I assume it is derived from the latest Debian version, though.
Have things changed recently?
Well there's quite a big version jump, but I don't know the history.
Man page for stretch now says: stretch factor [window fade shift fading] Change the audio duration (but not its pitch). This effect is broadly equivalent to the tempo effect with (factor inverted and) search set to zero, so in general, its results are comparatively poor; it is retained as it can sometimes out-perform tempo for small factors.
[...]
See also the tempo effect.
On 09-Jun-09 10:32:19, Mark Rogers wrote:
(Ted Harding) wrote:
Interesting! When I look at 'man sox', the word "tempo" does not occur, and the option to slow down/speed up without changing pitch is "stretch". This is sox version 12.17.7 ('sox -h') on a Debian Etch installed late 2007, and the man-page has the date "December 11, 2001" at the end.
$ sox --version sox: SoX v14.2.0
That's on Ubuntu 9.04. I assume it is derived from the latest Debian version, though.
Have things changed recently?
Well there's quite a big version jump, but I don't know the history.
Man page for stretch now says: stretch factor [window fade shift fading] Change the audio duration (but not its pitch). This effect is broadly equivalent to the tempo effect with (factor inverted and) search set to zero, so in general, its results are comparatively poor; it is retained as it can sometimes out-perform tempo for small factors. [...] See also the tempo effect. --
Well, well, well!! I've just checked back into what's in the repositories for Debian Etch, and it's still sox 12.17.7, so no update there ("Latest available version"). However, on the sox homepage at sourceforge:
http://sox.sourceforge.net/ SoX 14.3.0 is coming soon! SoX 14.2.0 was released on November 9, 2008.
and, clicking through to the project page:
http://sourceforge.net/projects/sox SoX 14.2.0 released 2008-11-09 SoX 14.0.1 Released 2008-01-30 SoX 13.0.0 Released 2007-02-12
so it looks as though Debian never bothered with updating it for Etch (My Etch installed 2007-09-22, so 13.0.0 had already been around for several months).
For the earlier history (available under "View all news"):
SoX 12.18.2 Released 2006-09-04 SoX 12.18.1 Released 2006-05-07 SoX 12.17.9 Released 2005-12-06 SoX 12.17.8 Released 2005-08-22 SoX 12.17.7 Released 2004-12-21
So my version 12.17.7 was already 2 years out of date (12.7.8 had been released) when I installed Etch, is now nearly 4 years out of date, and has never been updated on the Debian Etch repositories!
However, when I go to another machine, on which I experimentally installed the latest Debian (Lenny) a couple of months ago, though sox is not installed the available version (via 'synaptic') is now 14.0.1!
Interesting indeed! Ted.
-------------------------------------------------------------------- E-Mail: (Ted Harding) Ted.Harding@manchester.ac.uk Fax-to-email: +44 (0)870 094 0861 Date: 09-Jun-09 Time: 12:26:04 ------------------------------ XFMail ------------------------------
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Mark Rogers -
Ted.Harding＠manchester.ac.uk