Batch converting video files

rudlavibizon · 11-28-2006, 02:45 PM

I would like to convert multiple video files using mencoder but i don't know which command to use. Is there an universal unix command that i can use to execute a program on multiple files?
I'm a newbie to linux and just started to learn the basic shell commands.

fordeck · 11-28-2006, 03:53 PM

You could use a for loop. Example:

Code:

$ ls -l
total 16
-rw-rw-r--  1 userbob userbob 0 Nov 28 14:43 file1
-rw-rw-r--  1 userbob userbob 0 Nov 28 14:43 file2
-rw-rw-r--  1 userbob userbob 0 Nov 28 14:43 file3
-rw-rw-r--  1 userbob userbob 0 Nov 28 14:43 file4
$
$
$ for i in file[1-4]; do mv $i "${i}.txt"; done
$
$
$ ls -l
total 16
-rw-rw-r--  1 userbob userbob  0 Nov 28 14:43 file1.txt
-rw-rw-r--  1 userbob userbob  0 Nov 28 14:43 file2.txt
-rw-rw-r--  1 userbob userbob  0 Nov 28 14:43 file3.txt
-rw-rw-r--  1 userbob userbob  0 Nov 28 14:43 file4.txt
$

Of course you would have to edit this to apply your conversion command.

Hope this helps.
Fordeck

rudlavibizon · 11-29-2006, 04:32 AM

Thanks for replying. I'll have to get more deeply into the matter. I've found some tutorials about shell scripting on the web . The problem i encountered is that mencoder asks for -o output option and that complicates the whole thing. I've not done any programming since high school (we were thought BASIC) and it will take me some time. Oh well...

fordeck · 11-29-2006, 07:22 AM

Actually you wouldn't have to script this, in the above example it was entered on the command line as shown.

I've not used mencoder, however if you post the syntax you're using to do single file I'll try to send you a small script that will do the job.

rudlavibizon · 11-30-2006, 10:16 AM

here is an example:

Code:

mencoder [input-file] -ovc copy -oac pcm -o [output-file]

fordeck · 11-30-2006, 10:39 AM

Ok, I don't have any files to test this on. But this one liner is meant to be entered in a terminal at the prompt. It assumes that you are converting <filename>.wmv files in the current directory to <filename>.pcm files, again in the current directory. If that was your intention you could simply cut the following line and paste it at the command prompt.

Code:

for i in *wmv; do mencoder $i -ovc copy -oac pcm -o "${i}.pcm"; done

Let me know if this is what you're after?

Regards,

Fordeck

rudlavibizon · 12-01-2006, 04:25 AM

Not exactly but i get the picture. Actually i was converting audio to pcm and just copying video (-ovc and -oac are options for video and audio codec) because mjpeg avi files from my camera have noisy audio playback in linux. So I did this:

Code:

for i in *AVI; do mencoder $i -ovc copy -oac pcm -o "pcm_${i}"; done

It was a success.

Many thanks

R.B.