将yuv转bitmap后，是黑白的并且有大面积的绿色和紫色

[leestars]

int width = mpeg.get(FFMpeg.KEY_WIDTH);
int height = mpeg.get(FFMpeg.KEY_HEIGHT);
data = new byte[widthheight3/2];
mpeg.output(data);
ByteArrayOutputStream out = new ByteArrayOutputStream();
YuvImage yuv = new YuvImage(data, ImageFormat.NV21, width, height, null);
yuv.compressToJpeg(new Rect(0, 0, width, height), 50, out);
byte[] bytes = out.toByteArray();
Bitmap bitmap= BitmapFactory.decodeByteArray(bytes, 0, bytes.length);
mImageView.setImageBitmap(bitmap);

调用output方法所得到的数据是不是就是yuv数据？
@doggycoder

[doggycoder]

@leestars 确定导出的YUV数据到底是NV21的，还是NV12的。output导出的数据是YUV的，但是YUV也有YUV420\YUV422\YUV420SP等等格式，建议先看下这些基础性的东西。

[leestars]

我查了资料，确实有很多种格式，我调用output方法,看打印出来的log是yuv420p，我用了下面这种方法将yuv转rgb,转出来的效果是一样的。

private int[] yuv420pToRgb(byte[] yuv420p,int width,int height) {
int frameSize = width * height;
int[] rgb = new int[frameSize];
int i = 0, j = 0,yp = 0;
int uvp = 0, u = 0, v = 0;
for (j = 0, yp = 0; j < height; j++) {
uvp = frameSize + (j >> 1) * width;
u = 0;
v = 0;
for (i = 0; i < width; i++, yp++)
{
int y = (0xff & ((int) yuv420p[yp])) - 16;
if (y < 0)
y = 0;
if ((i & 1) == 0)
{
v = (0xff & yuv420p[uvp++]) - 128;
u = (0xff & yuv420p[uvp++]) - 128;
}

            int y1192 = 1192 * y;
            int r = (y1192 + 1634 * v);
            int g = (y1192 - 833 * v - 400 * u);
            int b = (y1192 + 2066 * u);

            if (r < 0) r = 0; else if (r > 262143) r = 262143;
            if (g < 0) g = 0; else if (g > 262143) g = 262143;
            if (b < 0) b = 0; else if (b > 262143) b = 262143;

            rgb[yp] = 0xff000000 | ((r << 6) & 0xff0000) | ((g >> 2) & 0xff00) | ((b >> 10) & 0xff);
        }
    }
    return rgb;
}

有黑白图像,但是有绿色的紫色在上面,这种情况是不是y转对了,但是u和v没有转对?
@doggycoder

[Xiqiao-Zhao]

我查了资料，确实有很多种格式，我调用output方法,看打印出来的log是yuv420p，我用了下面这种方法将yuv转rgb,转出来的效果是一样的。

private int[] yuv420pToRgb(byte[] yuv420p,int width,int height) {
int frameSize = width * height;
int[] rgb = new int[frameSize];
int i = 0, j = 0,yp = 0;
int uvp = 0, u = 0, v = 0;
for (j = 0, yp = 0; j < height; j++) {
uvp = frameSize + (j >> 1) * width;
u = 0;
v = 0;
for (i = 0; i < width; i++, yp++)
{
int y = (0xff & ((int) yuv420p[yp])) - 16;
if (y < 0)
y = 0;
if ((i & 1) == 0)
{
v = (0xff & yuv420p[uvp++]) - 128;
u = (0xff & yuv420p[uvp++]) - 128;
}

            int y1192 = 1192 * y;
            int r = (y1192 + 1634 * v);
            int g = (y1192 - 833 * v - 400 * u);
            int b = (y1192 + 2066 * u);

            if (r < 0) r = 0; else if (r > 262143) r = 262143;
            if (g < 0) g = 0; else if (g > 262143) g = 262143;
            if (b < 0) b = 0; else if (b > 262143) b = 262143;

            rgb[yp] = 0xff000000 | ((r << 6) & 0xff0000) | ((g >> 2) & 0xff00) | ((b >> 10) & 0xff);
        }
    }
    return rgb;
}

有黑白图像,但是有绿色的紫色在上面,这种情况是不是y转对了,但是u和v没有转对?
@doggycoder
是不是UV的通道读错了，比如误将V通道读入了U通道数据