path: root/tde-i18n-en_GB/docs/tdebase/tdeioslave/audiocd.docbook

<article lang="&language;" id="audiocd">
<title>audiocd</title>
<articleinfo>
<authorgroup>
<author>&Rik.Hemsley; &Rik.Hemsley.mail; </author>
<othercredit role="translator"><firstname>Malcolm</firstname><surname>Hunter</surname><affiliation><address><email>malcolm.hunter@gmx.co.uk</email></address></affiliation><contrib>Conversion to British English</contrib></othercredit> 
</authorgroup>

<date>2001-07-14</date>
<releaseinfo>2.20.00</releaseinfo>

</articleinfo>

<para>Allows treating audio <acronym>CD</acronym>s like a <quote>real</quote> filesystem, where tracks are represented as files and, when copied from the folder, are digitally extracted from the <acronym>CD</acronym>. This ensures a perfect copy of the audio data.</para>

<para>To see how this slave works, insert an audio <acronym>CD</acronym> in your &CD-ROM; drive and type <userinput>audiocd:/</userinput> into &konqueror;. Within a few seconds you should see a list of tracks and some folders.</para>

<para>Audio <acronym>CD</acronym>s don't really have folders, but the audiocd slave provides them as a convenience. If you look inside these folders you will see that they all contain the same number of tracks. If you are connected to the Internet, some folders will have the actual track titles shown as the filenames.</para>

<para>The reason that these separate folders exist are so that you can choose in which format you would like to listen to (or copy) the tracks on the <acronym>CD</acronym>.</para>

<para>If you drag a track from the <filename class="directory">Ogg Vorbis</filename> folder and drop it on another &konqueror; window open at your home folder, you should see a progress window showing you that the track is being extracted from the <acronym>CD</acronym> and saved to a file. Note that Ogg Vorbis is a compressed format, so the file in your home folder will appear a great deal smaller than it would have been if you had copied the raw data.</para>

<para>The mechanism behind this is quite simple. When the audiocd slave is asked to retrieve a track from the <filename class="directory">Ogg Vorbis</filename> folder, it starts extracting the digital audio data from the <acronym>CD</acronym>. As it sends the data over to the file in your home folder, it simultaneously encodes it in Ogg Vorbis format (<acronym>CD</acronym> audio is in an uncompressed format to start with).</para>

<para>You could also try dragging a file ending in <literal role="extension">.wav</literal> and dropping it on the &kde; Media Player, &noatun;. In this case, the procedure that happens behind the scenes is similar, except that instead of encoding the audio data in Ogg Vorbis format, it is put through a very simple conversion, from raw binary data (which the <literal role="extension">.cda</literal> files in the toplevel folder represent) to <quote>RIFF WAV</quote> format, a non-compressed format that most media players understand.</para>

<para>&noatun; should quite happily play the <literal role="extension">.wav</literal> file, but if it has trouble, you may consider using the <option>paranoia_level</option> option, explained below.</para>

<variablelist>
<title>Options</title>
<varlistentry>
<term><option>device</option></term>
<listitem>
<para>Set the path to the audio <acronym>CD</acronym> device, &eg; <userinput>audiocd:/<option>?device</option>=<parameter>/dev/sdc</parameter></userinput>. Normally, the slave will try to find a <acronym>CD</acronym> drive with an audio <acronym>CD</acronym> inserted, but if it fails or you have more than one <acronym>CD</acronym> drive, you may want to try this option. Note that the configuration dialogue allows you to set a default value for this option.</para>
</listitem>
</varlistentry>

<varlistentry>
<term><option>paranoia_level</option></term>
<listitem>
<para>Set the amount of error detection and correction used when extracting data.</para>

<variablelist>
<varlistentry>
<term>Level 0</term>
<listitem>
<para>No detection or correction. Only useful if you have a perfect <acronym>CD</acronym> drive (unlikely).</para>
</listitem>
</varlistentry>

<varlistentry>
<term>Level 1</term>
<listitem>
<para>Enable basic error checking and correction.</para>
</listitem>
</varlistentry>

<varlistentry>
<term>Level 2</term>
<listitem>
<para>Default. Specifies that only a perfect extraction will be accepted.</para>
</listitem>
</varlistentry>
</variablelist>

<para>Note that there is a disadvantage to level 2. Extraction can be very slow, so real-time digital playback may not work properly. If you have a good quality <acronym>CD</acronym> drive (note that more expensive does not necessarily mean better quality) then you probably won't experience very slow extraction, but a poor drive may take days (!) to extract the audio from one <acronym>CD</acronym>.</para>
</listitem>
</varlistentry>

<varlistentry>
<term><option>use_cddb</option></term>
<listitem>

<para>Specify that track names for the inserted <acronym>CD</acronym> will be looked up on the Internet <acronym>CD</acronym> Database. Audio <acronym>CD</acronym>s don't have track names, but the Internet <acronym>CD</acronym> Database is a clever system which uses a special unique identifier generated from the number and length of tracks on each <acronym>CD</acronym> to cross-reference a track listing. Track listings are contributed by the Internet community and made available to all.</para>

<para>You can submit your own track listings using &kscd;, the &kde; <acronym>CD</acronym> player.</para>

<para>This option is on by default. If your Internet connection is not set up correctly, you may find that your <acronym>CD</acronym> tracks don't appear. In this case, you can try <userinput>audiocd:/?<option>use_cddb</option>=<parameter>0</parameter></userinput> to switch this option off.</para>
</listitem>
</varlistentry>

<varlistentry>
<term><option>cddb_server</option></term>
<listitem>
<para>Set the Internet <acronym>CD</acronym> Database server to contact. By default, this is <systemitem>freedb.freedb.org:888</systemitem>, which means server <systemitem>freedb.freedb.org</systemitem> at port 888.</para>
</listitem>
</varlistentry>
</variablelist>

<variablelist>
<title>Examples</title>
<varlistentry>
<term><userinput>audiocd:/?device=/dev/scd0&amp;paranoia_level=0&amp;use_cddb=0</userinput></term>
<listitem>
<para>Gives a listing of the tracks on the audio <acronym>CD</acronym> inserted in <filename class="devicefile">/dev/scd0</filename>, which on &Linux; specifies the first <acronym>SCSI</acronym> &CD-ROM; device. If you copy tracks from the <acronym>CD</acronym>, digital extraction will be performed without error correction or detection. No Internet <acronym>CD</acronym> Database will be contacted.</para>
</listitem>
</varlistentry>
</variablelist>

<qandaset>
<title>Frequently Asked Question</title>
<qandaentry>
<question>
<para>I get <errorname>The file or folder / does not exist</errorname>. How do I fix that? I have an audio <acronym>CD</acronym> in my drive!</para>
</question>

<answer>
<para>Try running <userinput><command>cdparanoia</command> <option>-vsQ</option></userinput> as yourself (not <systemitem class="username">root</systemitem>). Do you see a track list? If not, make sure you have permission to access the <acronym>CD</acronym> device. If you're using <acronym>SCSI</acronym> emulation (possible if you have an <acronym>IDE</acronym> <acronym>CD</acronym> writer) then make sure you check that you have read and write permissions on the generic <acronym>SCSI</acronym> device, which is probably <filename class="devicefile">/dev/sg0</filename>, <filename class="devicefile">/dev/sg1</filename>, &etc;. If it still doesn't work, try typing <userinput>audiocd:/?device=/dev/sg0</userinput> (or similar) to tell tdeio_audiocd which device your &CD-ROM; is.</para> 
</answer>
</qandaentry>
</qandaset>


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