50 lines
1.9 KiB
Java
50 lines
1.9 KiB
Java
package org.jcodec.scale;
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import org.jcodec.common.model.Picture;
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import org.jcodec.common.tools.MathUtil;
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public class RgbToYuv420p implements Transform {
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public void transform(Picture img, Picture dst) {
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byte[] y = img.getData()[0];
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byte[][] dstData = dst.getData();
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byte[][] out = new byte[4][3];
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int offChr = 0, offLuma = 0, offSrc = 0, strideSrc = img.getWidth() * 3, strideDst = dst.getWidth();
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for (int i = 0; i < img.getHeight() >> 1; i++) {
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for (int j = 0; j < img.getWidth() >> 1; j++) {
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dstData[1][offChr] = 0;
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dstData[2][offChr] = 0;
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rgb2yuv(y[offSrc], y[offSrc + 1], y[offSrc + 2], out[0]);
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dstData[0][offLuma] = out[0][0];
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rgb2yuv(y[offSrc + strideSrc], y[offSrc + strideSrc + 1], y[offSrc + strideSrc + 2], out[1]);
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dstData[0][offLuma + strideDst] = out[1][0];
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offLuma++;
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rgb2yuv(y[offSrc + 3], y[offSrc + 4], y[offSrc + 5], out[2]);
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dstData[0][offLuma] = out[2][0];
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rgb2yuv(y[offSrc + strideSrc + 3], y[offSrc + strideSrc + 4], y[offSrc + strideSrc + 5], out[3]);
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dstData[0][offLuma + strideDst] = out[3][0];
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offLuma++;
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dstData[1][offChr] = (byte)(out[0][1] + out[1][1] + out[2][1] + out[3][1] + 2 >> 2);
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dstData[2][offChr] = (byte)(out[0][2] + out[1][2] + out[2][2] + out[3][2] + 2 >> 2);
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offChr++;
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offSrc += 6;
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}
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offLuma += strideDst;
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offSrc += strideSrc;
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}
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}
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public static final void rgb2yuv(byte r, byte g, byte b, byte[] out) {
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int rS = r + 128;
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int gS = g + 128;
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int bS = b + 128;
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int y = 66 * rS + 129 * gS + 25 * bS;
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int u = -38 * rS - 74 * gS + 112 * bS;
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int v = 112 * rS - 94 * gS - 18 * bS;
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y = y + 128 >> 8;
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u = u + 128 >> 8;
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v = v + 128 >> 8;
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out[0] = (byte)MathUtil.clip(y - 112, -128, 127);
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out[1] = (byte)MathUtil.clip(u, -128, 127);
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out[2] = (byte)MathUtil.clip(v, -128, 127);
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}
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}
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