Index: /gs2-extensions/video-and-audio/trunk/src/opt/Terrier/AudioDocument.java
===================================================================
--- /gs2-extensions/video-and-audio/trunk/src/opt/Terrier/AudioDocument.java	(revision 29647)
+++ /gs2-extensions/video-and-audio/trunk/src/opt/Terrier/AudioDocument.java	(revision 29647)
@@ -0,0 +1,382 @@
+/**
+ *  Adding support for Audio Files in Terrier
+ *  @author: John Thompson, jmt12, #9826509
+ *
+ *  The contents of this file are subject to the Mozilla Public License
+ *  Version 1.1 (the "License"); you may not use this file except in
+ *  compliance with the License. You may obtain a copy of the License at
+ *  http://www.mozilla.org/MPL/
+ *
+ *  Software distributed under the License is distributed on an "AS IS"
+ *  basis, WITHOUT WARRANTY OF ANY KIND, either express or implied. See
+ *  the License for the specific language governing rights and limitations
+ *  under the License.
+ *
+ *  Copyright (c) 2014 The University of Waikato. All Rights Reserved.
+ */
+package org.terrier.indexing;
+
+import java.io.InputStream;
+import java.io.StringReader;
+import java.io.Reader;
+import java.nio.charset.Charset;
+import java.nio.file.Files;
+import java.nio.file.Path;
+import java.nio.file.Paths;
+import java.security.MessageDigest;
+import java.security.NoSuchAlgorithmException;
+import java.util.Collections;
+import java.util.Arrays;
+import java.util.Map;
+import java.util.Set;
+
+import org.apache.log4j.Logger;
+import org.terrier.indexing.StreamGobbler;
+import org.terrier.indexing.tokenisation.TokenStream;
+import org.terrier.indexing.tokenisation.Tokeniser;
+import org.terrier.utility.ApplicationSetup;
+
+public class AudioDocument
+  implements Document
+{
+  protected boolean debug = false;
+  /** A reference to the logger for messaging */
+  protected static final Logger logger = Logger.getLogger(FileDocument.class);
+  /** The map of properties (fields) for this document. */
+  protected Map<String,String> properties;
+  /** A reader built from a dummy text string. */
+  protected Reader reader;
+  /** A token stream produced by the configured tokeniser when feed the dummy
+   *  reader.
+   */
+  protected TokenStream tokenizer;
+
+  /** The streaming filetype. **/
+  protected final String preview_format = ApplicationSetup.getProperty("AudioDocument.streaming_format", "flv");
+  /** Optional feature extraction **/
+  protected String calculate_fft_features = ApplicationSetup.getProperty("AudioDocument.fft_features", "true");
+  protected String calculate_mir_features = ApplicationSetup.getProperty("AudioDocument.mir_features", "true");
+
+  /** Default constructor. **/
+  protected AudioDocument() {}
+
+  /** Constructs an instance of the AudioDocument from the given input stream.
+   *  @param docStream the input stream that reads the file.
+   *  @param docProperties the initial properties (docno, filename)
+   *  @param tok the tokeniser defined for this collection
+   */
+  public AudioDocument(InputStream istream, Map<String,String> default_properties, Tokeniser tok)
+  {
+    if (this.debug)
+    {
+      logger.info("AudioDocument::AudioDocument()");
+    }
+    // Initialization from arguments
+    this.properties = default_properties;
+
+    // Set properties
+    if (this.debug)
+    {
+      logger.info("AudioDocument - current properties");
+      for (Map.Entry<String, String> entry : this.properties.entrySet())
+      {
+        logger.info(entry.getKey() + "=" + entry.getValue());
+      }
+    }
+
+    if (this.debug)
+    {
+      logger.info("ImageDocument - extracting properties");
+    }
+    // A. Hardcoded properties
+    this.properties.put("parser", "AudioDocument");
+    this.properties.put("abstract", "This is audio so here is some dummy text to prevent indexer failing.");
+    // B. Properties derived from filename
+    // - A simple title for the document
+    String filepath = this.properties.get("filename");
+    String title = filepath.substring(filepath.lastIndexOf(System.getProperty("file.separator")) + 1);
+    this.properties.put("title", title);
+    String ext = filepath.substring(filepath.lastIndexOf(".") + 1);
+    // - The name of the copy of the original document
+    String target_filename = "doc." + ext;
+    this.properties.put("source","doc." + ext);
+    // - A unique associated directory. This gets a little tricky as we need
+    //   to create the directory at the same time if an effort to promote
+    //   synchronous behaviour
+    String unique_id = this.generateHash(filepath);
+    //   - we start with the first 4 characters
+    int offset = 0;
+    String assoc_filename = "D" + unique_id.substring(offset, offset + 4);
+    //   - we add ".dir" as a suffix to the directory that actually contains
+    //     files (so the non-suffixed version contains nested directories)
+    Path assoc_path = Paths.get(ApplicationSetup.TERRIER_SHARE, "images", "assoc", assoc_filename + ".dir");
+    //   - then we continue adding blocks of 4 characters until we get a
+    //     directory that doesn't already exist
+    while (assoc_path.toFile().exists() && offset < unique_id.length())
+    {
+      offset += 4;
+      assoc_filename += System.getProperty("file.separator") + unique_id.substring(offset, offset + 4);
+      assoc_path = Paths.get(ApplicationSetup.TERRIER_SHARE, "images", "assoc", assoc_filename + ".dir");
+    }
+    //   - still not unique? but run out of unique_id... time to complain
+    if (assoc_path.toFile().exists())
+    {
+      logger.error("ImageDoument - can't determine unique assocfilepath");
+      System.exit(0);
+    }
+    //   - create the directories quick... hopefully before someone else does
+    assoc_path.toFile().mkdirs(); // bet there is a nice nio way to do this
+    this.properties.put("assocfile", assoc_filename);
+
+    // Copy (symlink) the file into place in the shared directory
+    Path source_path = Paths.get(properties.get("filename"));
+    Path target_path = assoc_path.resolve(target_filename);
+    if (target_path.toFile().exists())
+    {
+      if (this.debug)
+      {
+        logger.info("AudioDocument - removing existing (old) associated image");
+      }
+      try
+      {
+        Files.delete(target_path);
+      }
+      catch (Exception e)
+      {
+        logger.error("Exception while deleting old image: ", e);
+      }
+    }
+    if (this.debug)
+    {
+      logger.info("AudioDocument - symlinking image into assoc directory");
+    }
+    try
+    {
+      Files.createSymbolicLink(target_path, source_path);
+    }
+    // not supported? We'll try copying below
+    catch (UnsupportedOperationException ex)
+    {
+    }
+    // All other exceptions can be fatal
+    catch (Exception e)
+    {
+      logger.error("Exception while symlinking image: ", e);
+    }
+    // - copy if the file doesn't exist yet
+    if (!target_path.toFile().exists())
+    {
+      if (this.debug)
+      {
+        logger.info("ImageDocument - symlink failed, copying instead");
+      }
+      try
+      {
+        Files.copy(source_path, target_path);
+      }
+      // Fatality!
+      catch (Exception e)
+      {
+        logger.error("Exception while copying image: ", e);
+      }
+    }
+
+    // Generate streaming audio version
+    if (this.debug)
+    {
+      logger.info("AudioDocument - generate streaming version");
+    }
+    try
+    {
+      String streaming_filename = this.generatePreview(source_path, assoc_path);
+      this.properties.put("streaming", streaming_filename);
+    }
+    catch (Exception e)
+    {
+      logger.error("Exception while generating preview image: ", e);
+    }
+
+    // Extracting Fast Fourier Transform features
+    if (this.calculate_fft_features.equals("true"))
+    {
+      if (this.debug)
+      {
+        logger.info("AudioDocument - generate and record FFT features");
+      }
+      try
+      {
+        String chroma_filename = this.calculateFFTFeatures(source_path, assoc_path, "chroma");
+        this.properties.put("fft-chroma", chroma_filename);
+        String powerlog_filename = this.calculateFFTFeatures(source_path, assoc_path, "power-log");
+        this.properties.put("fft-power-log", powerlog_filename);
+      }
+      catch (Exception e)
+      {
+        logger.error("Exception while generating preview image: ", e);
+      }
+    }
+
+    // Extracting Music IR features
+    if (this.calculate_mir_features.equals("true"))
+    {
+      if (this.debug)
+      {
+        logger.info("AudioDocument - generate and record MIR features");
+      }
+      try
+      {
+        String mir_filename = this.calculateMIRFeatures(source_path, assoc_path);
+      }
+      catch (Exception e)
+      {
+        logger.error("Exception while generating preview image: ", e);
+      }
+    }
+
+    // Create a dummy reader around some dummy text and then tokenize it
+    if (this.debug)
+    {
+      logger.info("AudioDocument - feed dummy text as token stream to indexer");
+    }
+    try
+    {
+      this.reader = new StringReader(this.properties.get("abstract"));
+      this.tokenizer = tok.tokenise(this.reader);
+    }
+    catch (Exception e)
+    {
+      logger.error("Exception while creating dummy text stream: ", e);
+    }
+
+    if (this.debug)
+    {
+      logger.info("AudioDocument - Complete!");
+    }
+  }
+  /** ImageDocument(InputStream istream, Map<String,String> default_properties, Tokeniser tok) **/
+
+  /** Returns true when the end of the document has been reached, and there
+   *  are no other terms to be retrieved from it.
+   *  @return boolean true if there are no more terms in the document, otherwise
+   *          it returns false.
+   */
+  public boolean endOfDocument()
+  {
+    return !this.tokenizer.hasNext();
+  }
+  /** endOfDocument() **/
+
+  /** Use ImageMagick to generate a preview image.
+   *  @pre assumes you have ImageMagick installed and available on Path
+   *  @pre uses member variables preview_format and preview_width
+   *  @return the filename of the preview image (within the assoc directory)
+   */
+  private String generatePreview(Path source_path, Path assoc_path)
+    throws Exception
+  {
+    String preview_filename = "preview." + this.preview_format;
+    Path preview_path = assoc_path.resolve(preview_filename);
+    String convert_command[] = {
+      "convert",
+      source_path.toString(),
+      "-resize",
+      this.preview_width + "x",
+      preview_path.toString()
+    };
+    logger.info("ImageDocument - convert command: " + Arrays.toString(convert_command));
+    Process convert_process = Runtime.getRuntime().exec(convert_command);
+    // Gobble up the streams to prevent them hanging the process when buffers
+    // are full
+    StreamGobbler convert_process_error_gobbler = new StreamGobbler(convert_process.getErrorStream());
+    convert_process_error_gobbler.start();
+    StreamGobbler convert_process_input_gobbler = new StreamGobbler(convert_process.getInputStream());
+    convert_process_input_gobbler.start();
+    // Let the conversion finish
+    int convert_status = convert_process.waitFor();
+    if (convert_status != 0 || !preview_path.toFile().exists())
+    {
+      throw new Exception("Convert command failed (exit status: " + convert_status + ")");
+    }
+    return preview_filename;
+  }
+  /** generatePreview(Path, Path) **/
+
+  /** Returns the underlying map of all the properties defined by this Document.
+   *  @since 1.1.0
+   */
+  public Map<String,String> getAllProperties()
+  {
+    return this.properties;
+  }
+  /** getAllProperties() **/
+
+  /** Returns a list of the fields the current term appears in.
+   * @return HashSet a set of the terms that the current term appears in.
+   */
+  public Set<String> getFields()
+  {
+    // Returns null because there is no support for fields with file documents.
+    return Collections.emptySet();
+  }
+  /** getFields() **/
+
+  /** Gets the next term of the document.
+   *  <B>NB:</B>Null string returned from getNextTerm() should
+   *  be ignored. They do not signify the lack of any more terms.
+   *  endOfDocument() should be used to check that.
+   *  @return String the next term of the document. Null returns should be
+   *          ignored.
+   */
+  public String getNextTerm()
+  {
+    return this.tokenizer.next();
+  }
+  /** getNextTerm() **/
+
+  /** Allows access to a named property of the Document. Examples might be URL,
+   *  filename etc.
+   *  @param name Name of the property. It is suggested, but not required that
+   *         this name should not be case insensitive.
+   *  @since 1.1.0
+   */
+  public String getProperty(String name)
+  {
+    return this.properties.get(name.toLowerCase());
+  }
+  /** getProperty(String name) **/
+
+  /** Returns a Reader object so client code can tokenise the document
+   * or deal with the document itself. Examples might be extracting URLs,
+   * language detection. */
+  public Reader getReader()
+  {
+    return this.reader;
+  }
+  /** getReader() **/
+
+  /**
+   */
+  private String generateHash(String string)
+  {
+    StringBuffer sb = new StringBuffer();
+    try
+    {
+      final MessageDigest message_digest = MessageDigest.getInstance("MD5");
+      message_digest.reset();
+      message_digest.update(string.getBytes(Charset.forName("UTF8")));
+      final byte[] result_bytes = message_digest.digest();
+      for (int i = 0; i < result_bytes.length; ++i)
+      {
+        sb.append(Integer.toHexString((result_bytes[i] & 0xFF) | 0x100).substring(1,3));
+      }
+    }
+    catch (NoSuchAlgorithmException e)
+    {
+      System.err.println("Exception: " + e);
+      System.exit(0);
+    }
+    return sb.toString();
+  }
+  /** generateHash(String) **/
+}
+
