1 files changed, 98 insertions, 0 deletions
diff --git a/src/main/java/gregtech/client/SeekingOggCodec.java b/src/main/java/gregtech/client/SeekingOggCodec.java
new file mode 100644
index 0000000000..7949578f4f
--- /dev/null
+++ b/src/main/java/gregtech/client/SeekingOggCodec.java
@@ -0,0 +1,98 @@
+package gregtech.client;
+
+import java.net.URL;
+
+import javax.sound.sampled.AudioFormat;
+
+import net.minecraft.util.ResourceLocation;
+
+import org.apache.commons.lang3.StringUtils;
+
+import paulscode.sound.SoundBuffer;
+import paulscode.sound.codecs.CodecJOrbis;
+
+/**
+ * A somewhat hacky codec that allows starting music playback from the middle of a Ogg Vorbis file.
+ * Registers for URLs of the form: {@literal jar:blah/blah.jar!blah/music.ogg?seek_ms=5000&ext=.gt5oggseek}
+ */
+public class SeekingOggCodec extends CodecJOrbis {
+
+    public static final String EXTENSION = "gt5oggseek";
+
+    private volatile boolean fullyInitialized = false;
+    private volatile SoundBuffer nextBuffer = null;
+
+    /**
+     * Encodes the given millisecond seek amount into a URL/resource name suffix that can be appended to the sound path
+     * to start playing from that point onwards.
+     */
+    public static String getEncodedSeekSuffxix(long milliseconds) {
+        return String.format("?seek_ms=%d&ext=." + EXTENSION, milliseconds);
+    }
+
+    /**
+     * @return The given path with the seeking metadata stripped from the URL
+     */
+    public static String stripSeekMetadata(String path) {
+        while (path.endsWith("." + EXTENSION)) {
+            int qMark = path.lastIndexOf('?');
+            if (qMark == -1) {
+                break;
+            }
+            path = path.substring(0, qMark);
+        }
+        return path;
+    }
+
+    /**
+     * Turns the input sound ResourceLocation into one that is seeked forward the given number of milliseconds
+     */
+    public static ResourceLocation seekResource(ResourceLocation loc, long milliseconds) {
+        String original = loc.getResourcePath();
+        original = stripSeekMetadata(original);
+        return new ResourceLocation(loc.getResourceDomain(), original + getEncodedSeekSuffxix(milliseconds));
+    }
+
+    @Override
+    public boolean initialize(URL url) {
+        final String textUrl = url.toString();
+        final String[] queryParts = url.getQuery()
+            .split("&");
+        long seekMs = 0;
+        for (String part : queryParts) {
+            if (!part.startsWith("seek_ms=")) {
+                continue;
+            }
+            part = StringUtils.removeStart(part, "seek_ms=");
+            seekMs = Long.parseLong(part);
+        }
+
+        if (!super.initialize(url)) {
+            return false;
+        }
+
+        final AudioFormat format = this.getAudioFormat();
+        final long samplesPerS = (long) format.getSampleRate();
+        final int bytesPerSample = (format.getChannels() * format.getSampleSizeInBits() / 8);
+
+        long remainingBytes = seekMs * samplesPerS * bytesPerSample / 1000L;
+
+        while (remainingBytes > 0) {
+            final SoundBuffer buf = read();
+            if (buf == null || buf.audioData == null) {
+                return false;
+            }
+            remainingBytes -= buf.audioData.length;
+        }
+
+        synchronized (this) {
+            fullyInitialized = true;
+        }
+        return true;
+    }
+
+    @Override
+    public synchronized boolean initialized() {
+        return fullyInitialized;
+    }
+}