lav2wav - Extract the audio out of MJPEG container files to stdout


   lav2wav  [-s num] [-c num] [-v num] [-I] [-R] [-r samplerate, bitesize,
   channels] lavfile1 [lavfile2 ... lavfileN]


   lav2wav can be used to extract the audio to stdout.  This  output  goes
   to  stdout  and  can  be  saved as a wav file or piped to another sound
   processing tool that is able to handle the wav  format.   This  can  be
   mp2enc and toolame for mpeg layer 2 audio, or for example lame for mpeg
   layer 3 audio.

   The input files may be any combination of AVI (.avi),  Quicktime  (.qt)
   or  editlist  files  so  long  as they are all lavtools- readable (e.g.
   MJPEG-encoded AVI/Quicktime or DV type 2 AVI).


   lav2wav accepts the following options:

   -s num
        Start extracting at video frame (num)

   -c num
        Extract (num) frames of audio

   -v num
        Verbosity level (0, 1 or 2)

   -I   Ignore unsupported bitrates/bits per sample

   -R   If the file does  not  contain  any  sound.  lav2wav  will  create
        silence  with  44100kHz  Sampelrate,  16  Bit  audio bitsize and 2

   -r sr,bs,ch
        If the file does not  contain  any  sound  lav2wav  will  generate
        silence  with  the  values  you supply the samplerate (sr), audio-
        bitsize (bs) and channel (ch).


   The "WAV" file format (technically: RIFF) is really very much less than
   ideal  for  a tool intended to be used in pipelines as lav2wav is.  The
   problem is that the header includes a field specifying  the  length  of
   the  file.   This  can't  be  filled  in  except by seeking back to the
   begining and over-writing.  If the output  is  unseekable  (e.g.  pipe)
   lav2wav  simply  writes a large length into the header and leaves it at
   that.  Most tools like sox(1) or mp2enc(1)  either  ignore  the  length
   field anyway or only give a warning.
   The  audio  length  is  inacurate  calculated  when  lav2wav  generates
   silence.  This happens only if you have  NTSC  framerate  and  than  it
   creates for every hour of video 1.1498sec too less of silence.


   This man page was written by Bernhard Praschinger.
   If  you  have  questions, remarks, problems or you just want to contact
   the developers, the main mailing list for the MJPEG-tools is:

   For more info, see our website at


   mjpegtools(1), mp2enc(1), sox(1)


Personal Opportunity - Free software gives you access to billions of dollars of software at no cost. Use this software for your business, personal use or to develop a profitable skill. Access to source code provides access to a level of capabilities/information that companies protect though copyrights. Open source is a core component of the Internet and it is available to you. Leverage the billions of dollars in resources and capabilities to build a career, establish a business or change the world. The potential is endless for those who understand the opportunity.

Business Opportunity - Goldman Sachs, IBM and countless large corporations are leveraging open source to reduce costs, develop products and increase their bottom lines. Learn what these companies know about open source and how open source can give you the advantage.

Free Software

Free Software provides computer programs and capabilities at no cost but more importantly, it provides the freedom to run, edit, contribute to, and share the software. The importance of free software is a matter of access, not price. Software at no cost is a benefit but ownership rights to the software and source code is far more significant.

Free Office Software - The Libre Office suite provides top desktop productivity tools for free. This includes, a word processor, spreadsheet, presentation engine, drawing and flowcharting, database and math applications. Libre Office is available for Linux or Windows.

Free Books

The Free Books Library is a collection of thousands of the most popular public domain books in an online readable format. The collection includes great classical literature and more recent works where the U.S. copyright has expired. These books are yours to read and use without restrictions.

Source Code - Want to change a program or know how it works? Open Source provides the source code for its programs so that anyone can use, modify or learn how to write those programs themselves. Visit the GNU source code repositories to download the source.


Study at Harvard, Stanford or MIT - Open edX provides free online courses from Harvard, MIT, Columbia, UC Berkeley and other top Universities. Hundreds of courses for almost all major subjects and course levels. Open edx also offers some paid courses and selected certifications.

Linux Manual Pages - A man or manual page is a form of software documentation found on Linux/Unix operating systems. Topics covered include computer programs (including library and system calls), formal standards and conventions, and even abstract concepts.