From 29225f167dfa5c11b2efe22c51e99f424fa66002 Mon Sep 17 00:00:00 2001
From: Recrown <yunyangdeng@gmail.com>
Date: Wed, 16 Aug 2017 01:35:45 -0500
Subject: [PATCH] basic mp3 support added

---
 .../rhythmbullet/audio/Mp3AudioData.java      | 77 ++++++++++++-------
 core/src/zero1hd/wavedecoder/WavDecoder.java  |  4 +-
 2 files changed, 53 insertions(+), 28 deletions(-)

diff --git a/core/src/zero1hd/rhythmbullet/audio/Mp3AudioData.java b/core/src/zero1hd/rhythmbullet/audio/Mp3AudioData.java
index cba4662..5e75862 100755
--- a/core/src/zero1hd/rhythmbullet/audio/Mp3AudioData.java
+++ b/core/src/zero1hd/rhythmbullet/audio/Mp3AudioData.java
@@ -28,11 +28,14 @@ public class Mp3AudioData implements AudioData {
 	private int sampleRate;
 	private long sampleCount;
 	private float durationInSeconds;
-	
+	private byte channels;
 	Bitstream bitstream;
 	MP3Decoder decoder;
 	OutputBuffer sampleBuffer;
-	Mp3.Music test;
+	private byte[] currentByteSet;
+	private byte[] workset;
+	private int indexHead = -1;
+	
 	public Mp3AudioData(FileHandle audioFile) {
 		try {
 			MP3File mp3File = new MP3File(audioFile.file());
@@ -49,9 +52,10 @@ public class Mp3AudioData implements AudioData {
 		try {
 			Header header = bitstream.readFrame();
 			if (header == null) throw new GdxRuntimeException("Empty MP3");
-			int channels = header.mode() == Header.SINGLE_CHANNEL ? 1 : 2;
+			channels = (byte) (header.mode() == Header.SINGLE_CHANNEL ? 1 : 2);
 			sampleBuffer = new OutputBuffer(channels, false);
 			decoder.setOutputBuffer(sampleBuffer);
+			workset = new byte[channels*2];
 		} catch (BitstreamException e) {
 			throw new GdxRuntimeException("error while preloading mp3", e);
 		}
@@ -109,44 +113,65 @@ public class Mp3AudioData implements AudioData {
 
 	@Override
 	public int readSamples(float[] samples) {
-		int totalRead = 0;
-		
+		int framesRead = 0;
 		for (int sid = 0; sid < samples.length; sid++) {
-			try {
-				Header header = bitstream.readFrame();
+			for (int wsid = 0; wsid < workset.length; wsid++) {
+				workset[wsid] = nextByte();
+			}
+			if (currentByteSet != null) {
+				samples[sid] += (workset[1] << 8) + (workset[0] & 0x00ff);
+				if (channels > 1) {
+					samples[sid] += (workset[3] << 8) + (workset[2] & 0x00ff);
+					samples[sid] /= 2;
+				}
+				framesRead ++;
 				
-				if (header == null) break;
+				samples[sid] /= Short.MAX_VALUE+1;
+			}
+		}
+		return framesRead;
+	}
+	
+	public byte nextByte() {
+		indexHead++;
+		if (currentByteSet == null || indexHead >= currentByteSet.length) {
+			loadNextBuffer();
+			if (currentByteSet == null) {
+				return 0;
+			}
+			indexHead = 0;
+		}
+		
+		return currentByteSet[indexHead];
+	}
+	
+	public int loadNextBuffer() {
+		int bytesRead = 0;
+		try {
+			Header header = bitstream.readFrame();
+			if (header != null) {
 				
 				try {
 					decoder.decodeFrame(header, bitstream);
 				} catch (ArrayIndexOutOfBoundsException | DecoderException e) {
 					System.out.println(e);
 				}
+				
 				bitstream.closeFrame();
-				sampleBuffer.reset();
-				byte[] buffer = sampleBuffer.getBuffer();
+				bytesRead = sampleBuffer.reset();
 				
-				samples[sid] += (buffer[1] << 8) + (buffer[0] & 0x00ff);
-				if (sampleBuffer.isStereo()) {
-					samples[sid] += (buffer[3] << 8) + (buffer[2] & 0x00ff);
-					samples[sid] /= 2;
-				}
-				totalRead++;
-				
-				samples[sid] /= Short.MAX_VALUE + 1;
-			} catch (BitstreamException e1) {
-				e1.printStackTrace();
+				currentByteSet = sampleBuffer.getBuffer();
+			} else {
+				currentByteSet = null;
 			}
+		} catch (BitstreamException e1) {
+			e1.printStackTrace();
 		}
-		
-		return totalRead;
+		return bytesRead;
 	}
-
+	
 	@Override
 	public float getSampleRate() {
 		return sampleRate;
 	}
-	
-	
-
 }
diff --git a/core/src/zero1hd/wavedecoder/WavDecoder.java b/core/src/zero1hd/wavedecoder/WavDecoder.java
index 21c5d88..3025d51 100755
--- a/core/src/zero1hd/wavedecoder/WavDecoder.java
+++ b/core/src/zero1hd/wavedecoder/WavDecoder.java
@@ -68,10 +68,10 @@ public class WavDecoder {
 					samples[sampleID] /= 2;
 				}
 				framesRead ++;
+				
+				samples[sampleID] /= Short.MAX_VALUE+1;
 			}
 			
-			
-			samples[sampleID] /= Short.MAX_VALUE+1;
 		}
 		
 		return framesRead;