Handle streaming audio as frames (#1244)

src/main/java/io/github/dsheirer/audio/convert/AudioFrames.java

@@ -0,0 +1,133 @@
+/*
+ * *****************************************************************************
+ * Copyright (C) 2014-2022 Dennis Sheirer
+ *
+ * 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 io.github.dsheirer.audio.convert;
+
+import java.util.List;
+import org.apache.commons.math3.util.FastMath;
+
+public abstract class AudioFrames
+{
+    protected final int audioDuration;
+    protected final List<byte[]> audioFrames;
+    protected int mCurrentFrame = -1;
+
+    /**
+     * Create new AudioFrame
+     * @param audioDuration total duration in milliseconds
+     * @param audioFrames series of audio frames, split on frame boundaries
+     */
+    public AudioFrames(int audioDuration, List<byte[]> audioFrames)
+    {
+        this.audioDuration = audioDuration;
+        this.audioFrames = audioFrames;
+    }
+
+    /**
+     * Get total duration of frames
+     * @return total duration in milliseconds
+     */
+    public int getDuration()
+    {
+        return audioDuration;
+    }
+
+    /**
+     * Get all frames
+     * @return list of byte arrays, with each element representing a single frame of audio
+     */
+    public List<byte[]> getFrames()
+    {
+        return audioFrames;
+    }
+
+    /**
+     * Get current frame
+     * @return byte array with the current frame of audio
+     */
+    public byte[] getCurrentFrame()
+    {
+        return audioFrames.get(mCurrentFrame);
+    }
+
+    /**
+     * Get current frame duration
+     * @return frame duration in milliseconds
+     */
+    public abstract int getCurrentFrameDuration();
+
+    /**
+     * Indicates if there is a frame before the current one
+     * @return true if the frame exists, otherwise false
+     */
+    public boolean hasPrevFrame()
+    {
+        int prevFrame = mCurrentFrame - 1;
+        return prevFrame >= 0 && prevFrame < audioFrames.size();
+    }
+
+    /**
+     * Indicates if there is a frame after the current one
+     * @return true if the frame exists, otherwise false
+     */
+    public boolean hasNextFrame()
+    {
+        int nextFrame = mCurrentFrame + 1;
+        return nextFrame >= 0 && nextFrame < audioFrames.size();
+    }
+
+    /**
+     * Seek to the previous frame
+     */
+    public void prevFrame()
+    {
+        mCurrentFrame -= 1;
+    }
+
+    /**
+     * Seek to the next frame
+     */
+    public void nextFrame()
+    {
+        mCurrentFrame += 1;
+    }
+
+    /**
+     * Restart from beginning
+     * Must call nextFrame() to get first frame
+     */
+    public void restart()
+    {
+        mCurrentFrame = -1;
+    }
+
+    /**
+     * Seek by the specified time
+     * @param duration_ms time in milliseconds, positive or negative
+     */
+    public void seek(int duration_ms)
+    {
+        int step = duration_ms < 0 ? -1 : 1;
+        int actual_ms = 0;
+        while(FastMath.abs(actual_ms) < FastMath.abs(duration_ms))
+        {
+            mCurrentFrame += step;
+            actual_ms += getCurrentFrameDuration();
+        }
+    }
+}