- added simplified MKV/audio only policy

SLUB_mediaconch_policy_retrodigitized_audio.xml

+<?xml version="1.0"?>
+<policy type="or" name="SLUB Policy for MKV/linear PCM, retrodigitized audio" license="CC-BY-SA-4.0+">
+  <description>SLUB related policy to test that the audio file is suitable for archiving purposes.
+    This checks if a MKV/linear PCM fulfills the needs for Audio retrodigitization:
+    - Container format is Matroska with error detection (CRC)
+    - Audio format is PCM (unfortunately it can not contain error detection) or FLAC (it has CRC by design)
+    This policy is based on:
+    - Example MKV FFV1 digitization policy.xml
+    - Video file is MKV + FFV1-Intra + PCM or FLAC with CRC32 everywhere.xml
+    If there are any policy violations or suggestions, please send an email to langzeitarchiv@slub-dresden.de
+  </description>
+  <policy type="and" name="MKV, FFV1 Intra, PCM/FLAC, error detection">
+    <policy type="and" name="Container">
+      <rule name="General/FileExtension is mkv" value="FileExtension" tracktype="General" occurrence="*" operator="=">mkv</rule>
+      <rule name="Container is MKV" value="Format" tracktype="General" occurrence="*" operator="=">Matroska</rule>
+      <rule name="Unique ID is present" value="UniqueID" tracktype="General" occurrence="*"/>
+      <rule name="Container uses error detection" value="extra/ErrorDetectionType" tracktype="General" occurrence="*" operator="=">Per level 1</rule>
+      <rule name="General/Format_Version is 4" value="Format_Version" tracktype="General" occurrence="*" operator="=">4</rule>
+      
+    </policy>
+
+    <policy type="or" name="Audio">
+      <rule name="General/AudioCount is 1" value="AudioCount" tracktype="General" occurrence="*" operator="=">1</rule>
+      <policy type="or" name="Audio is PCM or FLAC">
+        <rule name="Audio is PCM" value="Format" tracktype="Audio" occurrence="*" operator="=">PCM</rule>
+        <rule name="Audio is FLAC" value="Format" tracktype="Audio" occurrence="*" operator="=">FLAC</rule>
+      </policy>
+      <rule name="Audio is 48000 Hz" value="SamplingRate" tracktype="Audio" occurrence="*" operator="=">48000</rule>
+      <policy type="or" name="Audio is Stereo or Mono">
+        <rule name="Audio is mono" value="Channels" tracktype="Audio" occurrence="*" operator="=">1</rule>
+        <rule name="Audio is stereo" value="Channels" tracktype="Audio" occurrence="*" operator="=">2</rule>
+      </policy>
+      <policy type="or" name="Audio Bit Depth is 16 or 24">
+        <rule name="Bit Depth is 16" value="BitDepth" tracktype="Audio" occurrence="*" operator="=">16</rule>
+        <rule name="Bit Depth is 24" value="BitDepth" tracktype="Audio" occurrence="*" operator="=">24</rule>
+      </policy>
+    </policy>
+  </policy>
+</policy>