Presenting a fully automated DVD authoring rakefile

As promised, here is the script I use to change a set of AVI files
into a DVD disc image. It uses Rake and rmovie along with a whole
bunch of Linux utilities, and doesn't require any aditional input from
the user beyond having the AVI files in the same directory as the
rakefile.

It goes through the following steps:

For each AVI file in the current directory:
   - Use transcode to convert it into a M2V video file and an AC3 audio track.
   - Use mplex to join these two files into a MPG file.

- Use dvdauthor to convert the MPGs to a DVD file structure.
- Use mkisofs to change the DVD file structure into a ISO image file,
ready for burning.
- Clean up by deleting everything except the AVI files, the ISO image
and the MPG files (which take the longest time to create, and are
useful if something goes wrong and I have to start over :)).

It's probably too specific to be worth posting to Rubyforge or one of
its equivalents, so I'm sending it here in case someone else finds it
useful. There's probably a lot I can improve here, so I'd be thankful
to hear any suggestions or criticisms.

···

=====================================================

require 'rubygems'
require 'rake'
require 'rake/clean'
require 'rmovie'

OUTPUT_RATIO = 1.6

SOURCE_FILES = FileList['*.avi']
DESTINATION_FILES = SOURCE_FILES.gsub('avi','mpg')
CLEAN.include('*.xml','*.cfg','DVD')

def adjust_clip(x, y)

  clip_size = -1* (((x.to_i / OUTPUT_RATIO) - y.to_i) / 2).abs
  int_clip = clip_size.to_i
  return int_clip if int_clip % 2 == 0

  return int_clip - 1

end

def transcode(filename)
    nome, extensao = filename.split('.')
    movie = RMovie::Movie.new(filename)

    clip_size = adjust_clip(movie.frame_width, movie.frame_height)

    bit_rate = ( movie.bit_rate / 1000 ).ceil

    ratio = movie.frame_width.to_f / movie.frame_height.to_f

    if ratio == ( 4.0 / 3.0 )
        aspect = 2
    elsif ratio == ( 16.0 / 9.0 )
        aspect = 3
    end

    sh <<-FIM
    transcode -i "#{filename}" -y ffmpeg --export_prof dvd-ntsc
--export_asr #{aspect} --pre_clip=#{clip_size},#{clip_size} -w
#{bit_rate} -o #{nome} -D0 -b224 -N 0x2000 -s2 -m #{nome}.ac3 -J
modfps=clonetype=3 --export_fps 29.97
    FIM
end

def mplex(basename)
    nome = basename.split('.')[0]
    sh "mplex -f 8 -o #{nome}.mpg #{nome}.m2v #{nome}.ac3"
end

def write_xml_header(xml)
    xml.write <<-HEADER
<dvdauthor dest="DVD">
    <vmgm />
    <titleset>
        <titles>
            <pgc>
    HEADER

end

def write_xml_footer(xml)
        xml.write <<-FOOTER
            </pgc>
        </titles>
    </titleset>
</dvdauthor>
        FOOTER
end

rule '.mpg' => ['.avi'] do |t|
    nome = t.name.split('.')[0]
    transcode(t.prerequisites[0])
    mplex( nome )
    rm "#{nome}.m2v"
    rm "#{nome}.ac3"
end

rule '.mpg' => ['.m2v', 'ac3'] do |t|
    nome = t.name.split('.')[0]
    mplex( nome )
    rm "#{nome}.m2v"
    rm "#{nome}.ac3"
end

file 'ffmpeg.cfg' do |t|
    File.open(t.name, 'w') do |cfg|
          cfg.write <<-FIM
        [mpeg2video]
         vrc_minrate=0
         vrc_maxrate = 5000
         vrc_buf_size = 1792
          FIM
    end
    puts 'ffmpeg.cfg escrito'
end

file 'dvdauthor.xml' => DESTINATION_FILES do |t|
    File.open(t.name, 'w') do |xml|
        write_xml_header(xml)
        DESTINATION_FILES.sort.each do |file|
            xml.write <<-LINHA
                <vob file="#{file}" />
            LINHA
        end
        write_xml_footer(xml)
    end
end

file 'DVD' => ['dvdauthor.xml'] do |t|
    sh "dvdauthor -o #{t.name} -x #{t.prerequisites[0]}"
end

task 'dvd.iso' => ['DVD'] do |t|
    sh "mkisofs -o #{t.name} -dvd-video #{t.prerequisites[0]}"
end

task :default =>['ffmpeg.cfg','dvd.iso', :clean]

=======================================================

--
Bira


http://sinfoniaferida.blogspot.com

Might be worth posting to http://www.doom9.org

···

On 10/13/06, Bira <u.alberton@gmail.com> wrote:

As promised, here is the script I use to change a set of AVI files
into a DVD disc image. It uses Rake and rmovie along with a whole
bunch of Linux utilities, and doesn't require any aditional input from
the user beyond having the AVI files in the same directory as the
rakefile.