From: David ‘Bombe’ Roden <bombe@pterodactylus.net>
Date: Fri, 24 May 2013 21:46:03 +0000 (+0200)
Subject: Add streaming audio source.
X-Git-Url: https://git.pterodactylus.net/?a=commitdiff_plain;h=333be3ce0c4f49a8b5ce447b80bb4491f0f7001d;p=sonitus.git

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
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);
+	}
+
+}