Преобразование синусоидальных значений в аудио в Android - PullRequest
0 голосов
/ 13 февраля 2019

Я графически представляю аудио по осям x и y.Из этих точек по оси Y я хочу снова сгенерировать аудио.

Далее https://github.com/billthefarmer/scope, чтобы получить точки по оси Y.У меня есть все значения точек оси Y.Эти точки могут использоваться для графического представления волны.

import android.content.Context;
import android.graphics.Bitmap;
import android.graphics.Canvas;
import android.graphics.Color;
import android.graphics.Paint;
import android.graphics.Path;
import android.util.AttributeSet;
import android.util.Log;
import android.view.MotionEvent;
import android.view.View;

import java.io.IOException;
import java.io.OutputStreamWriter;
import java.util.Locale;

// Scope
public class Scope extends View {
private int width;
private int height;

private Path path;
private Canvas cb;
private Paint paint;
private Bitmap bitmap;
private Bitmap graticule;

protected boolean storage;
protected boolean clear;

protected float step;
protected float scale;
protected float start;
protected float index;

protected float yscale;

protected boolean points;
protected MainActivity.Audio audio;

// Scope
public Scope(Context context, AttributeSet attrs) {
    super(context, attrs);

    // Create path and paint
    path = new Path();
    paint = new Paint();
}

// On size changed
@Override
protected void onSizeChanged(int w, int h, int oldw, int oldh) {
    super.onSizeChanged(w, h, oldw, oldh);

    // Get dimensions
    width = w;
    height = h;

    // Create a bitmap for trace storage
    bitmap = Bitmap.createBitmap(width, height, Bitmap.Config.ARGB_8888);
    cb = new Canvas(bitmap);

    // Create a bitmap for the graticule
    graticule = Bitmap.createBitmap(width, height,
            Bitmap.Config.ARGB_8888);
    Canvas canvas = new Canvas(graticule);

    // Black background
    canvas.drawColor(Color.BLACK);

    // Set up paint
    paint.setStrokeWidth(2);
    paint.setStyle(Paint.Style.STROKE);
    paint.setColor(Color.argb(255, 0, 63, 0));

    // Draw graticule
    for (int i = 0; i < width; i += MainActivity.SIZE)
        canvas.drawLine(i, 0, i, height, paint);

    canvas.translate(0, height / 2);
    for (int i = 0; i < height / 2; i += MainActivity.SIZE) {
        canvas.drawLine(0, i, width, i, paint);
        canvas.drawLine(0, -i, width, -i, paint);
    }

    // Draw the graticule on the bitmap
    cb.drawBitmap(graticule, 0, 0, null);

    cb.translate(0, height / 2);
}

private int max;

// On draw
@Override
protected void onDraw(Canvas canvas) {
    // Check for data
    if ((audio == null) || (audio.data == null)) {
        canvas.drawBitmap(graticule, 0, 0, null);
        return;
    }

    // Draw the graticule on the bitmap
    if (!storage || clear) {
        cb.drawBitmap(graticule, 0, -height / 2, null);
        clear = false;
    }

    // Calculate x scale etc
    float xscale = (float) (2.0 / ((audio.sample / 100000.0) * scale));
    int xstart = Math.round(start);
    int xstep = Math.round((float) 1.0 / xscale);
    int xstop = Math.round(xstart + ((float) width / xscale));

    if (xstop > audio.length)
        xstop = (int) audio.length;

    // Calculate y scale

    if (max < 4096)
        max = 4096;

    yscale = (float) (max / (height / 2.0));

    max = 0;

    // Draw the trace
    path.rewind();
    path.moveTo(0, 0);

    if (xscale < 1.0) {
        for (int i = 0; i < xstop - xstart; i += xstep) {
            if (max < Math.abs(audio.data[i + xstart]))
                max = Math.abs(audio.data[i + xstart]);

            float x = (float) i * xscale;
            float y = -(float) audio.data[i + xstart] / yscale;
            path.lineTo(x, y);
            Log.d("y values", "y = " + String.valueOf(y)); // KING
            writeToFile("y = " + String.valueOf(y), getContext());
        }
    } else {
        for (int i = 0; i < xstop - xstart; i++) {
            if (max < Math.abs(audio.data[i + xstart]))
                max = Math.abs(audio.data[i + xstart]);

            float x = (float) i * xscale;
            float y = -(float) audio.data[i + xstart] / yscale;
            path.lineTo(x, y);
            Log.d("y values", "y = " + String.valueOf(y)); // KING
            writeToFile("y = " + String.valueOf(y), getContext());
            // Draw points at max resolution
            if (points) {
                path.addRect(x - 2, y - 2, x + 2, y + 2, Path.Direction.CW);
                path.moveTo(x, y);
                Log.d("y values", "y = " + String.valueOf(y)); // KING
                writeToFile("y = " + String.valueOf(y), getContext());
            }
        }
    }

    // Green trace
    paint.setColor(Color.GREEN);
    paint.setAntiAlias(true);
    cb.drawPath(path, paint);

    // Draw index
    if (index > 0 && index < width) {
        // Yellow index
        paint.setColor(Color.YELLOW);

        paint.setAntiAlias(false);
        cb.drawLine(index, -height / 2, index, height / 2, paint);

        paint.setAntiAlias(true);
        paint.setTextSize(height / 48);
        paint.setTextAlign(Paint.Align.LEFT);

        // Get value
        int i = Math.round(index / xscale);
        if (i + xstart < audio.length) {
            float y = -audio.data[i + xstart] / yscale;


            // Draw value

            String s = String.format(Locale.getDefault(), "%3.2f",
                    audio.data[i + xstart] / 32768.0);
            cb.drawText(s, index, y, paint);
        }

        paint.setTextAlign(Paint.Align.CENTER);

        // Draw time value
        if (scale < 100.0) {
            String s = String.format(Locale.getDefault(),
                    (scale < 1.0) ? "%3.3f" :
                            (scale < 10.0) ? "%3.2f" : "%3.1f",
                    (start + (index * scale)) /
                            MainActivity.SMALL_SCALE);
            cb.drawText(s, index, height / 2, paint);
// Log.d("y values", "y = " + String.valueOf(y));
        } else {
            String s = String.format(Locale.getDefault(), "%3.3f",
                    (start + (index * scale)) /
                            MainActivity.LARGE_SCALE);
            cb.drawText(s, index, height / 2, paint);
        }
    }
    canvas.drawBitmap(bitmap, 0, 0, null);
}

private void writeToFile(String data, Context context) {
    try {
        OutputStreamWriter outputStreamWriter = new OutputStreamWriter(context.openFileOutput("Sinusoids.txt", Context.MODE_PRIVATE));
        outputStreamWriter.write(data);
        outputStreamWriter.close();
    } catch (IOException e) {
        Log.e("Exception", "File write failed: " + e.toString());
    }
}

// On touch event
@Override
public boolean onTouchEvent(MotionEvent event) {
    float x = event.getX();
    float y = event.getY();

    // Set the index from the touch dimension
    switch (event.getAction()) {
        case MotionEvent.ACTION_DOWN:
            index = x;
            break;

        case MotionEvent.ACTION_MOVE:
            index = x;
            break;

        case MotionEvent.ACTION_UP:
            index = x;
            break;
    }

    return true;
}
}

Создание байтового массива из точек оси y.Затем массив можно преобразовать в звук.

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