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 DEBIAN

oggz

oggz(1) 						      General Commands Manual							   oggz(1)

NAME

       oggz -- inspect and manipulate Ogg multimedia files

SYNOPSIS

       oggzhelp command command args

Description
       oggz  is  a  suite  of  tools for manipulating Ogg multimedia files.  It supports multiplexed files conformant with RFC3533. Oggz can parse
       headers for CELT, CMML, Dirac, FLAC, Kate, PCM, Speex, Theora and Vorbis, and can read and write Ogg Skeleton logical bitstreams.

Commands
	  o  helpDisplay help for a specific subcommand (eg. "oggz help chop")

   Reporting
	  o  diffHexdump the packets of two Ogg files and output differences.

	  o  dumpHexdump packets of an Ogg file, or revert an Ogg file from such a hexdump.

	  o  infoDisplay information about one or more Ogg files and their bitstreams.

	  o  scanScan an Ogg file and output characteristic landmarks.

	  o  validateValidate the Ogg framing of one or more files.

   Extraction
	  o  ripExtract one or more logical bitstreams from an Ogg file.

   Editing
	  o  chopExtract the part of an Ogg file between given start and/or end times.

	  o  commentList or edit comments in an Ogg file.  mergeMerge Ogg files together, interleaving pages in order of  presentation	time.sort-
	     Sort the pages of an Ogg file in order of presentation time.

Options
       oggz accepts the following options:

   Miscellaneous options
       -h, --help
		 Display usage information and exit.

       -v, --version
		 Output version information and exit.

AUTHOR

       Conrad Parker	    July  9, 2008;

COPYRIGHT

       Copyright (C) 2008 Annodex Association

SEE ALSO

       ogginfo(1)	hogg(1)

																	   oggz(1)