Add streaming audio source.

diff --git a/src/main/java/net/pterodactylus/sonitus/data/source/StreamSource.java b/src/main/java/net/pterodactylus/sonitus/data/source/StreamSource.java
new file mode 100644 (file)
index 0000000..d9df054
--- /dev/null
+++ b/src/main/java/net/pterodactylus/sonitus/data/source/StreamSource.java
@@ -0,0 +1,145 @@
+/*
+ * Sonitus - StreamSource.java - Copyright © 2013 David Roden
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+package net.pterodactylus.sonitus.data.source;
+
+import java.io.BufferedInputStream;
+import java.io.IOException;
+import java.net.HttpURLConnection;
+import java.net.URL;
+import java.net.URLConnection;
+import java.util.Map;
+
+import net.pterodactylus.sonitus.data.ContentMetadata;
+import net.pterodactylus.sonitus.data.FormatMetadata;
+import net.pterodactylus.sonitus.data.Metadata;
+import net.pterodactylus.sonitus.data.Source;
+import net.pterodactylus.sonitus.io.MetadataStream;
+
+import com.google.common.base.Optional;
+import com.google.common.collect.Maps;
+import com.google.common.primitives.Ints;
+
+/**
+ * {@link Source} implementation that can download an audio stream from a
+ * streaming server.
+ * <p/>
+ * Currently only “audio/mpeg” (aka MP3) streams are supported.
+ *
+ * @author <a href="mailto:bombe@pterodactylus.net">David ‘Bombe’ Roden</a>
+ */
+public class StreamSource implements Source {
+
+       /** The URL of the stream. */
+       private final String streamUrl;
+
+       /** The metadata stream. */
+       private final MetadataStream metadataStream;
+
+       /** The current metadata. */
+       private Metadata metadata;
+
+       /**
+        * Creates a new stream source. This will also connect to the server and parse
+        * the response header for vital information (sampling frequency, number of
+        * channels, etc.).
+        *
+        * @param streamUrl
+        *              The URL of the stream
+        * @throws IOException
+        *              if an I/O error occurs
+        */
+       public StreamSource(String streamUrl) throws IOException {
+               this.streamUrl = streamUrl;
+               URL url = new URL(streamUrl);
+
+               /* set up connection. */
+               URLConnection urlConnection = url.openConnection();
+               if (!(urlConnection instanceof HttpURLConnection)) {
+                       throw new IllegalArgumentException("Not an HTTP URL!");
+               }
+               HttpURLConnection httpUrlConnection = (HttpURLConnection) urlConnection;
+               httpUrlConnection.setRequestProperty("ICY-Metadata", "1");
+
+               /* connect. */
+               httpUrlConnection.connect();
+
+               /* check content type. */
+               String contentType = httpUrlConnection.getContentType();
+               if (!contentType.startsWith("audio/mpeg")) {
+                       throw new IllegalArgumentException("Not an MP3 stream!");
+               }
+
+               /* get ice-audio-info header. */
+               String iceAudioInfo = httpUrlConnection.getHeaderField("ICE-Audio-Info");
+               if (iceAudioInfo == null) {
+                       throw new IllegalArgumentException("No ICE Audio Info!");
+               }
+
+               /* parse ice-audio-info header. */
+               String[] audioInfos = iceAudioInfo.split(";");
+               Map<String, Integer> audioParameters = Maps.newHashMap();
+               for (String audioInfo : audioInfos) {
+                       String key = audioInfo.substring(0, audioInfo.indexOf('=')).toLowerCase();
+                       int value = Ints.tryParse(audioInfo.substring(audioInfo.indexOf('=') + 1));
+                       audioParameters.put(key, value);
+               }
+
+               /* check metadata interval. */
+               String metadataIntervalHeader = httpUrlConnection.getHeaderField("ICY-MetaInt");
+               if (metadataIntervalHeader == null) {
+                       throw new IllegalArgumentException("No Metadata Interval header!");
+               }
+               Integer metadataInterval = Ints.tryParse(metadataIntervalHeader);
+               if (metadataInterval == null) {
+                       throw new IllegalArgumentException(String.format("Invalid Metadata Interval header: %s", metadataIntervalHeader));
+               }
+
+               metadata = new Metadata(new FormatMetadata(audioParameters.get("ice-channels"), audioParameters.get("ice-samplerate"), "MP3"), new ContentMetadata());
+               metadataStream = new MetadataStream(new BufferedInputStream(httpUrlConnection.getInputStream()), metadataInterval);
+       }
+
+       //
+       // SOURCE METHODS
+       //
+
+       @Override
+       public Metadata metadata() {
+               Optional<ContentMetadata> streamMetadata = metadataStream.getContentMetadata();
+               if (!streamMetadata.isPresent()) {
+                       return metadata;
+               }
+               return metadata = metadata.title(streamMetadata.get().title());
+       }
+
+       @Override
+       public byte[] get(int bufferSize) throws IOException {
+               byte[] buffer = new byte[bufferSize];
+               metadataStream.read(buffer);
+               return buffer;
+       }
+
+       //
+       // OBJECT METHODS
+       //
+
+       @Override
+       public String toString() {
+               return String.format("StreamSource(%s,%s)", streamUrl, metadata);
+       }
+
+}