Converting YUV_420_888 to JPEG and saving file results distorted image

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故里飘歌
故里飘歌 2020-12-01 15:02

I\'ve used the ImageUtil class provided in https://stackoverflow.com/a/40152147/2949966 within my git repo: https://github.com/ahasbini/cameraview/tree/camera_p

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  •  野趣味
    野趣味 (楼主)
    2020-12-01 15:52

    Solution provided by @volodymyr-kulyk does not take into consideration the row stride of the planes within the image. Below code does the trick (image is of android.media.Image type):

    data = NV21toJPEG(YUV420toNV21(image), image.getWidth(), image.getHeight(), 100);
    

    And the implementations:

    private static byte[] NV21toJPEG(byte[] nv21, int width, int height, int quality) {
        ByteArrayOutputStream out = new ByteArrayOutputStream();
        YuvImage yuv = new YuvImage(nv21, ImageFormat.NV21, width, height, null);
        yuv.compressToJpeg(new Rect(0, 0, width, height), quality, out);
        return out.toByteArray();
    }
    
    private static byte[] YUV420toNV21(Image image) {
        Rect crop = image.getCropRect();
        int format = image.getFormat();
        int width = crop.width();
        int height = crop.height();
        Image.Plane[] planes = image.getPlanes();
        byte[] data = new byte[width * height * ImageFormat.getBitsPerPixel(format) / 8];
        byte[] rowData = new byte[planes[0].getRowStride()];
    
        int channelOffset = 0;
        int outputStride = 1;
        for (int i = 0; i < planes.length; i++) {
            switch (i) {
                case 0:
                    channelOffset = 0;
                    outputStride = 1;
                    break;
                case 1:
                    channelOffset = width * height + 1;
                    outputStride = 2;
                    break;
                case 2:
                    channelOffset = width * height;
                    outputStride = 2;
                    break;
            }
    
            ByteBuffer buffer = planes[i].getBuffer();
            int rowStride = planes[i].getRowStride();
            int pixelStride = planes[i].getPixelStride();
    
            int shift = (i == 0) ? 0 : 1;
            int w = width >> shift;
            int h = height >> shift;
            buffer.position(rowStride * (crop.top >> shift) + pixelStride * (crop.left >> shift));
            for (int row = 0; row < h; row++) {
                int length;
                if (pixelStride == 1 && outputStride == 1) {
                    length = w;
                    buffer.get(data, channelOffset, length);
                    channelOffset += length;
                } else {
                    length = (w - 1) * pixelStride + 1;
                    buffer.get(rowData, 0, length);
                    for (int col = 0; col < w; col++) {
                        data[channelOffset] = rowData[col * pixelStride];
                        channelOffset += outputStride;
                    }
                }
                if (row < h - 1) {
                    buffer.position(buffer.position() + rowStride - length);
                }
            }
        }
        return data;
    }
    

    Method was gotten from the following link.

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