Linux Video Format (and Other) Conversions

Some time back someone asked how to convert .FLV format into a more useable AVI or MPG. I finally stumbled across a very good way to this with ffmpeg:

ffmpeg -i input-video.flv -ab 56 -ar 22050 -b 500 -s 320x240 output-video.avi

Where:
-b bitrate: set the video bitrate in kbit/s (default = 200 kb/s)
-ab bitrate: set the audio bitrate in kbit/s (default = 64)
-ar sample rate: set the audio samplerate in Hz (default = 44100 Hz)
-s size: set frame size. The format is WxH (default 160x128)

This will convert your input-video.flv into a output-video.avi !

My reference for this is:
http://asuaf.org/~jj/blog/index.php/2006/0...pg-etcin-linux/

I was impressed with the quality, and the fact that audio-video sync did not appear to have degraded.

This is quite useful, especially if one is using a site like keepvid ( http://keepvid.com/lite/ ) to download videos (into flv format) from the web which are otherwise difficult to download.

Edit (27/08/06): Changed the output video from .mpg to .avi, as sometimes there can be problems going directly to .mpg.

On a related subject, I was able to convert a .wmv file to an .avi file, and retain audio-video sync.

Keeping the synchronisation is often very difficult.

The command line I used to create an NTSC avi was:
mencoder -ovc lavc -ofps 25 -oac pcm "input-video.wmv" -o "output-video.avi"

Less related, but useful to SuSE users who have digital cameras, and who take videos rotated 90 degrees.

The video can be rotated back 90 degrees by a simple command line (using mplayer's mencoder):
mencoder original.avi -o target.avi -oac copy -ovc lavc -vf rotate=2

Reference: http://selectparks.net/~julian/index.php?e...ry051118-173909

I decided as well to change the topic of this thread, to make it more generic, and use this thread as a focal point of various Linux command line video conversion methods.

ok, here more "goodies"

to split a avi file:
#>transcode -i movie128.avi -P 1 -b 96 -s 2.0 -o movie96.avi -y raw
This is reasonable fast since video is only passed through and the audio quality is still ok. After you are done, use avisplit to split the file into 2 chunks.


so transcode is a really good swiss army knife for video-processing

[Editorial edit (oldcpu) - coloured text / changed font to match thread]

I find this thread a really good idea, and so useful.
Good work!

Here are some more command line methods. Some of them are functionally similar to the great examples provided by oc2pus:

How to extract audio from mpg video to wav (where audio was originally in an ac3 format):
mplex -f 8 -o final1.mpg temp1.m2v temp1.ac3

Here is a Command Line method to backup one's DVD9 video to a DVD5 (it assumes the DVD is already ripped to one's hard drive):
Reference: http://www.linuxquestions.org/linux/answer...9_to_DVD5_guide

Note the key commands are:

Concatenate:
mplex -f 8 -O 66ms -o final.mpg shrinked.m2v movie.ac3

Once "final.mpg" is created, one an use "dvdauthor" to create the appropriate .vob files and the video_ts directory structure.

perhaps someone could pin this in tips and tricks or something. this is great information.

it's really too bad that someone cannot turn these simple commands into a simple 2-3 button gui. hmmm...

Convert rm to avi
mencoder input.rm -ovc lavc -oac mp3lame -o output.avi</span>

I haven't trialled this all that much, but it does seem to work. And it does seem to keep the audio and video synchronised, which is a failing with some packaged applications.

Reference(s):
http://lists.mplayerhq.hu/pipermail/mplaye...une/053992.html
http://lists.mplayerhq.hu/pipermail/mplaye...une/054000.html

[Edit:
1. This requires further testing.
2. The aspect ratio appears not to be entered into the .avi file with the above, as I note this error "<span style="color:#660000">ODML: Aspect information not (yet?) available or unspecified, not writing vprp header". However the video still converts, and many players (such as mplayer) can assign an aspect ration upon playback]

Convert Quicktime to avi
mencoder -ovc copy -oac pcm -o output.avi input.mov

Reference: http://archives.free.net.ph/message/200608...#mencoder-users

I have not tried this (yet) myself.