Mythencode.pl
From MythTV Official Wiki
Note: The correct title of this article is mythencode.pl. It appears incorrectly here due to technical restrictions.
mythencode.pl is a perl script to automate some of the encoding tasks associated with getting MythTV files into a nice DivX .AVI file.
Contents
Overview
mythencode.pl is a perl script which takes as input a MythTV filename and then runs a patched mencoder on the filename to convert it to a .avi file usable by programs outside the Myth world. mythencode.pl has quite a few options, including one to call mythname.pl to automatically name the output file with a human readable name i.e. 'The Daily Show.avi'. Run mythencode.pl with no options to see the command-line options.
Customizing
mythencode.pl has a couple of items that will probably need editing at the top of the file: the name/path/command-line options to mythname.pl and name/path to mencoder. You should set these before running the script since they aren't configurable by the command line. You should really only need to edit the settings once.
Using With cron
One thing I have found useful is using these scripts inside a cron job to automatically convert files which are still around after 3 days to a transferable format. I use something like this:
0 4 * * * mythtransfer.sh
Where mythtransfer.sh is:
#!/bin/sh
for i in `find /mnt/store -mtime +3`; do
mythencode.pl -hours 4 -cdsize 700 -getname $i
done
This will take all my files that are over 36 hours old in /mnt/store and convert them to fit 4 hours per CD and rename them to the original show name.
Usage
usage: mythencode.pl [options] /path/to/store/1001_20030401190000_20030401200000.nuv
Where [options] is:
--hours [3.0] - Hours per 700MB CD. Can be a float
(i.e. --hours 2.25 for 2:15) (default: 3 hours)
--nice [10] - Nice level to run mencoder at (default: 10)
--cdsize [700] - Size of CD to create for
(185, 650, 700 are obvious choices) (default: 700)
--ratio [0.8] - Ratio of Video to total bitrate (default: 0.8)
(lower to add more audio and less video)
--1 - 1 pass (default: 2 pass)
--test - Show values that would be used and exit
--getname - Get name with mythname.pl script (default: no)
--namehost - db where mythname.pl should look
--scale [320:240] - Set output scale by hand (default: 320:240)
--autoscale - Set to autopick scale/fps based on bitrate
--fps [30] - Set output fps (default: 30)
--debug - Dump some debugging output
mythencode.pl
#!/usr/bin/perl
##
## Script to automate some of the encoding tasks associated with
## Getting MythTV files into a nice DIVX .AVI file.
##
## Hack and Slash done by Rob Snow (rsnow a dympna d com)
##
## 15 Apr 03 1.0 Hacked
## 16 Apr 03 1.0.1 Remove .log file when we start (may not be needed)
## 16 Apr 03 1.1 Added nice support and autoscale/fps support
## 18 Jun 03 1.1.1 Added patch by Andrew Albinger to fix ' in strings
## 24 Jun 03 1.2 Large patch by Mike Nugent to make things right
## Now runs under strict and added debug option
## Also allows a hostname to be passed to mythname
## 2003-07-16 1.3 Added quality options to one pass
##
## TODO:
## 1) Fine tune the --autoscale function
##
## use at your own risk, i am not responsible for anything this program may
## or may not do.
use strict;
use Getopt::Long;
use File::Basename;
#
# Constant
# These should be changed to point to your values
#
use constant mythname => '/usr/local/bin/mythname.pl -s -rep=. ';
use constant mencoder => '/usr/local/bin/mencoder';
#
# get command line args and printout some usage if no args
#
my $argc=@ARGV;
if ($argc == 0) {
print qq{usage: mythencode.pl [options] /path/to/store/1001_20030401190000_20030401200000.nuv
Where [options] is:
--hours [3.0]\t\t- Hours per 700MB CD. Can be a float
\t\t\t(i.e. --hours 2.25 for 2:15) (default: 3 hours)
--nice [10]\t\t- Nice level to run mencoder at (default: 10)
--cdsize [700]\t\t- Size of CD to create for
\t\t\t(185, 650, 700 are obvious choices) (default: 700)
--ratio [0.8]\t\t- Ratio of Video to total bitrate (default: 0.8)
\t\t\t(lower to add more audio and less video)
--1\t\t\t- 1 pass (default: 2 pass)
--test\t\t\t- Show values that would be used and exit
--getname\t\t- Get name with mythname.pl script (default: no)
--namehost\t\t- db where mythname.pl should look
--scale [320:240]\t- Set output scale by hand (default: 320:240)
--autoscale\t\t- Set to autopick scale/fps based on bitrate
--fps [30]\t\t- Set output fps (default: 30)
--debug\t\t\t- Dump some debugging output
};
exit(0);
}
my ($hours, $nice, $cdsize, $ratio, $passes, $test, $getname, $namehost);
my ($scale, $auto, $fps, $debug);
GetOptions('hours=f' =>\$hours,
'nice:i' =>\$nice,
'cdsize=f' =>\$cdsize,
'ratio=f' =>\$ratio,
'1+' =>\$passes,
'test+' =>\$test,
'getname+' =>\$getname,
'namehost=s' =>\$namehost,
'scale=s' =>\$scale,
'autoscale+' =>\$auto,
'fps=s' =>\$fps,
'debug' =>\$debug,
);
#
# Set some default values if not set via commandline
#
if ($nice==0) { $nice=10; }
if (!$cdsize) { $cdsize=700.0; }
if (!$ratio) { $ratio=0.8; }
if (!$passes) { $passes=2; }
if (!$hours) { $hours=3; }
if (!$scale) { $scale="320:240"; }
if (!$fps) { $fps=30; }
#
#Remove the divx2pass.log file, probably doesn't need to be done.
#
unlink "divx2pass.log";
#
# Parse out the filename
#
my ($show, $path, $suffix) = fileparse(@ARGV[0],"\.nuv");
#
# Do some computations and print out the debugging output
# This is messy
#
my $max_bits=$cdsize*2.285;
my $total_br=($max_bits/$hours);
my $vid_br=int($total_br*$ratio);
my $aud_br=int($total_br-$vid_br);
if ($debug) {
warn "cdsize:\t$cdsize\n";
warn "hours:\t$hours\n";
warn "nice:\t$nice\n";
warn "max_br:\t$max_bits\n";
warn "total_br:\t$total_br\n";
warn "video_br:\t$vid_br\n";
warn "audio_br:\t$aud_br\n";
warn "passes:\t$passes\n";
warn "file:\t$show\n";
warn "path:\t$path\n";
warn "suffix:\t$suffix";
}
#
# Set the output filename to the input filename first, then modify it
# if we are using the external call to the mythname.pl script.
#
my $outname=$show;
if ($getname) {
my $mythname = mythname;
if ($namehost) {
$mythname .= ' -h ' . $namehost;
}
my $getnamestr= $mythname . ' ' . $path . $show . $suffix;
if ($debug) {
warn "string to execute:\t$getnamestr\n";
}
$outname=`$getnamestr`;
$outname = quotemeta($outname);
chomp $outname;
}
if ($debug) {
warn "outname:\t$outname\n";
}
#
# Setup the nice string so we can put it into the rest of the command line
# without having to add additional cases
#
my $nicestr;
if ($nice) {
$nicestr="/bin/nice -$nice ";
}
else {
$nicestr="/bin/nice";
}
#
# Set a scale if autoscale has been chosen
#
if ($auto) {
if ($vid_br > 600) { $scale="400:300"; }
elsif ($vid_br > 400) { $scale="320:240"; }
elsif ($vid_br > 250) { $scale="256:192"; }
elsif ($vid_br > 175) { $scale="192:144"; }
elsif ($vid_br > 150) { $scale="192:144"; $fps=20; }
elsif ($vid_br > 100) { $scale="160:120"; $fps=20; }
else { $scale="160:120"; $fps=15; }
if ($debug) {
warn "scale:\t$scale\n";
}
}
#
# Print out some bppixel info
#
my @res=split(/:/, $scale);
my $pps=($res[0]*$res[1])*$fps;
my $bps=($vid_br*1024);
my $bpp=$bps/$pps;
if ($debug) {
warn "xs:\t$res[0] ys:\t$res[1]\n";
warn "pixels/sec:\t$pps\n";
warn "bits/sec:\t$bps\n";
warn "bitsec/pixel:\t$bpp\n";
}
#
# A case based on number of passes
#
if ($passes==1) {
print "Doing a one pass encode.\n";
my $pass1="$nicestr " . mencoder . " -idx $path$show.nuv -fps $fps " .
"-oac mp3lame -lameopts vbr=3:br=$aud_br -ovc lavc " .
"-lavcopts vcodec=mpeg4:vbitrate=$vid_br:vhq:v4mv:vpass=1 " .
"-vop lavcdeint,scale=$scale -aspect 4:3 -o $outname.avi";
print "\tPASS ONE=$pass1\n";
if(!$test) {
system $pass1;
}
}
else {
print "Doing a two pass encode.\n";
my $pass1="$nicestr " . mencoder . " -idx $path$show.nuv -fps $fps " .
"-oac mp3lame -lameopts vbr=3:br=$aud_br -ovc lavc -lavcopts " .
"vcodec=mpeg4:vbitrate=$vid_br:vpass=1 -vop lavcdeint,scale=$scale " .
"-aspect 4:3 -o $outname.avi";
my $pass2="$nicestr " . mencoder . " -idx $path$show.nuv -fps $fps " .
"-oac mp3lame -lameopts vbr=3:br=$aud_br -ovc lavc -lavcopts " .
"vcodec=mpeg4:vbitrate=$vid_br:vhq:v4mv:vpass=2 -vop lavcdeint," .
"scale=$scale -aspect 4:3 -o $outname.avi";
print "\tPASS ONE=$pass1\n";
print "\tPASS TWO=$pass2\n";
if(!$test) {
exec $pass1;
exec $pass2;
}
}
exit(0);
