Android Renderscript-在Renderscript中旋转YUV数据 [英] Android Renderscript - Rotate YUV data in Renderscript

问题描述

基于我在 Camera2 api上进行的讨论Imageformat.yuv_420_888关于旋转图像的结果，我想知道如何调整通过rsGetElementAt_uchar方法完成的查找，以使YUV数据旋转90度.我还有一个项目，例如Google提供的 HdrViewfinder .问题在于输出是横向的，因为用作目标表面的输出表面已连接到yuv分配，而yuv分配并不关心设备是横向还是纵向模式.但我想调整代码，使其处于纵向模式.因此，我采用了自定义的YUVToRGBA渲染脚本，但不知道要更改哪些内容以旋转输出.有人可以帮我将以下自定义YUVtoRGBA脚本调整90度，因为我想在纵向模式下使用输出:

Based on the discussion I had at Camera2 api Imageformat.yuv_420_888 results on rotated image, I wanted to know how to adjust the lookup done via rsGetElementAt_uchar methods so that the YUV data is rotated by 90 degree. I also have a project like the HdrViewfinder provided by Google. The problem is that the output is in landscape because the output surface used as target surface is connected to the yuv allocation which does not care if the device is in landscape or portrait mode. But I want to adjust the code so that it is in portrait mode. Therefore, I took a custom YUVToRGBA renderscript but I do not know what to change to rotate the output. Can somebody help me to adjust the following custom YUVtoRGBA script by 90 degree because I want to use the output in portrait mode:

// Needed directive for RS to work
#pragma version(1)

// The java_package_name directive needs to use your Activity's package path
#pragma rs java_package_name(net.hydex11.cameracaptureexample)

rs_allocation inputAllocation;

int wIn, hIn;
int numTotalPixels;

// Function to invoke before applying conversion
void setInputImageSize(int _w, int _h)
{
    wIn = _w;
    hIn = _h;
    numTotalPixels = wIn * hIn;
}

// Kernel that converts a YUV element to a RGBA one
uchar4 __attribute__((kernel)) convert(uint32_t x, uint32_t y)
{

    // YUV 4:2:0 planar image, with 8 bit Y samples, followed by
    // interleaved V/U plane with 8bit 2x2 subsampled chroma samples
    int baseIdx = x + y * wIn;
    int baseUYIndex = numTotalPixels + (y >> 1) * wIn + (x & 0xfffffe);

    uchar _y = rsGetElementAt_uchar(inputAllocation, baseIdx);
    uchar _u = rsGetElementAt_uchar(inputAllocation, baseUYIndex);
    uchar _v = rsGetElementAt_uchar(inputAllocation, baseUYIndex + 1);
    _y = _y < 16 ? 16 : _y;

    short Y = ((short)_y) - 16;
    short U = ((short)_u) - 128;
    short V = ((short)_v) - 128;

    uchar4 out;
    out.r = (uchar) clamp((float)(
        (Y * 298 + V * 409 + 128) >> 8), 0.f, 255.f);   
    out.g = (uchar) clamp((float)(
        (Y * 298 - U * 100 - V * 208 + 128) >> 8), 0.f, 255.f); 
    out.b = (uchar) clamp((float)(
        (Y * 298 + U * 516 + 128) >> 8), 0.f, 255.f); // 
    out.a = 255;

    return out;
}

我在 这里有人放置了Java代码来旋转YUV数据.但是我想用Renderscript来做，因为那样更快.

Here someone has put the Java code to rotate YUV data. But I want to do it in Renderscript since that is faster.

任何帮助都会很棒.

最诚挚的问候，

推荐答案

我假设您希望输出像在转换脚本中那样以RGBA格式显示.您应该能够使用此答案中使用的方法；也就是说，只需简单地将x和y坐标修改为转换内核的第一步即可:

I'm assuming you want the output to be in RGBA, as in your conversion script. You should be able to use an approach like that used in this answer; that is, simply modify the x and y coordinates as the first step in the convert kernel:

//Rotate 90 deg clockwise during the conversion
uchar4 __attribute__((kernel)) convert(uint32_t inX, uint32_t inY)
{
    uint32_t x = wIn - 1 - inY;
    uint32_t y = inX;

    //...rest of the function

请注意对参数名称的更改.

Note the changes to the parameter names.

这假定您已正确设置输出尺寸(请参阅链接的答案).可以类似的方式完成270度旋转.

This presumes you have set up the output dimensions correctly (see linked answer). A 270 degree rotation can be accomplished in a similar way.

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