A little help understanding FIFOs?

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11-01-2005

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A little help understanding FIFOs?

This isn't strictly a Linux question, but... I've been working on a project to archive some streaming media for time shifting using 'mplayer' and have been using FIFOs to archive in Ogg Vorbis format:

Code:

mkfifo program_name.wav

(mplayer -ao pcm -aofile program_name.wav &)
MPLAYER_PID="`/sbin/pidof mplayer`"

(oggenc program_name.wav &)
OGGENC_PID="`/sbin/pidof oggenc`"

sleep 30m && kill -9 "$MPLAYER_PID" "$OGGENC_PID"
rm program_name.wav

That works OK. But some of the streams I archive are long (3-4 hours) and are difficult to "fast forward" through on my car player. So I'd like to break the recordings up into 5 minute segments WHILE I am encoding the stream. The problem is that when oggenc stops reading from the program_name.wav FIFO, mplayer stops streaming and won't start up again. Any ideas how I would do this without just grabbing the whole show in WAV format and then splitting it after the fact?

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LEARN ABOUT SUNOS

libvorbis

libvorbis(3)							   User Commands						      libvorbis(3)

NAME

       libvorbis - Xiph.org compression format library

DESCRIPTION

       libvorbis  is  an  implementation of the Vorbis specification by the Xiph.org foundation. libvorbis provides an API to work with the Vorbis
       multimedia compression format.

       Vorbis is an audio compression scheme that is designed to be contained in the Ogg container. Note that other formats are capable  of  being
       embedded in an Ogg container, such as FLAC and Speex.

       To access the API documentation, you must install the developer version of the package.

FILES

       The following files are used by this application:

       /usr/share/gtk-doc/html Location of developer documentation

ATTRIBUTES

       See attributes(5) for descriptions of the following attributes:

       +-----------------------------+-----------------------------+
       |      ATTRIBUTE TYPE	     |	    ATTRIBUTE VALUE	   |
       +-----------------------------+-----------------------------+
       |Availability		     |SUNWogg-vorbis		   |
       +-----------------------------+-----------------------------+
       |Interface stability	     |External			   |
       +-----------------------------+-----------------------------+

SEE ALSO

       libogg(3)

NOTES

       Written by Brian Cameron, Sun Microsystems Inc., 2004.

SunOS 5.10							    7 Sep 2004							      libvorbis(3)