Michael Murtaugh: /* audio */

2009-07-16T14:27:22Z

audio

← Older revision		Revision as of 16:27, 16 July 2009
Line 74:		Line 74:
	=== audio ===		=== audio ===

	* ["sox"]		* [[sox]]

	== Other useful (GUI) apps ==		== Other useful (GUI) apps ==

Michael Murtaugh: /* video */

2009-07-16T14:27:13Z

video

← Older revision		Revision as of 16:27, 16 July 2009
Line 68:		Line 68:
	=== video ===		=== video ===

	* ["mplayer/mencoder"]		* [[mplayer/mencoder]]
	* ["ffmpeg"]		* [[ffmpeg]]
	* ["dvgrab"]		* [[dvgrab]]

	=== audio ===		=== audio ===

Michael Murtaugh at 10:00, 21 May 2008

2008-05-21T10:00:47Z

New page

core concepts:
bitmap, PCM, frame rate, sampling rate, frame size, data rate, compression, lossless vs. lossy compression, codecs, spatial compression, temporal compression, keyframes, VBR, 2-pass encoding

http://en.wikipedia.org/wiki/Pulse-code_modulation
http://en.wikipedia.org/wiki/Video_compression

== Examples ==

Examples of appending images in bash, including a simply "flow" layout algorithm... [[BashAppendingImages]]

=== Encoding Videos (including flash flv's) to DIVX/AVI with mencoder ===
Basically to encode any format that mplayer understands to a divx file (which is a version of mpeg4, and typically stored in an "avi" format file), you use something along the lines of:

<pre>
mencoder -oac mp3lame -ovc lavc -lavcopts vcodec=mpeg4:vbitrate=600 -o newmovie.avi sourcemovie.flv
</pre>

This specifies the "libavcodec" (lavc) to do the video compression, and options to that (separate) library are given as "lavcopts". To, for instance, specify an output frame frame (ofps) of 15fps *and* to limit the maximum number of frames between keyframes to one second (15 frame thus), you could use:

<pre>
mencoder -oac mp3lame -ofps 15 -ovc lavc -lavcopts vcodec=mpeg4:vbitrate=600:keyint=15 -o newmovie.avi sourcemovie.flv
</pre>

=== Images to movie ===
==== with ffmpeg ====
<pre>
ffmpeg -y -r 3 -b 1800 -sameq -i frames/%06d.png foo.mp4
</pre>
source: http://electron.mit.edu/~gsteele/ffmpeg/

==== with mencoder ====
<pre>
mencoder "mf://*.jpg" -o movie.avi -ovc lavc -lavcopts vcodec=mjpeg
</pre>
source: http://www.gfd.geophys.ethz.ch/~pjt/makingMovies.html
also: http://www.mplayerhq.hu/DOCS/HTML/en/menc-feat-enc-images.html

=== Movie to images ===

==== with ffmpeg ====

<pre>
ffmpeg -i movie.avi -f image2 -y -r .01 -an frame %06d.jpg
</pre>

<pre>
ffmpeg -i FILE0007.MOV -f image2 -y -an frame%06d.png
</pre>

<pre>
ffmpeg -i source.mov -an -y -t 0:0:0.001 -f image2 poster.png
</pre>

<pre>
ffmpeg -i source.mov -an -y -ss 0:01:30 -t 0:0:0.001 -f image2 frame.png
</pre>

==== mplayer ====
<pre>
mplayer -vo png rearwindow.avi

</pre>

== Important command line tools ==

=== video ===

* ["mplayer/mencoder"]
* ["ffmpeg"]
* ["dvgrab"]

=== audio ===

* ["sox"]

== Other useful (GUI) apps ==

Audacity, Kino

== Resources ==
* Linux Video Production: the State of the Art, by Dan Sawyer, http://www.linuxjournal.com/article/8589

== older page ==
[[MoreMediaBashing]]

MediaBashing - Revision history

Michael Murtaugh: /* audio */

Michael Murtaugh: /* video */

Michael Murtaugh at 10:00, 21 May 2008