yuv420转rgb 及 rgb转bmp保存

 /// <summary>
        /// 将一桢 YUV 格式的图像转换为一桢 RGB 格式图像。
        /// </summary>
        /// <param name="yuvFrame">YUV 格式图像数据。</param>
        /// <param name="rgbFrame">RGB 格式图像数据。</param>
        /// <param name="width">图像宽（单位：像素）。</param>
        /// <param name="height">图像高（单位：像素）。</param>
        static void ConvertYUV2RGB(byte[] yuvFrame, byte[] rgbFrame, int width, int height)
        {
            int uIndex = width * height;
            int vIndex = uIndex + ((width * height) >> );
            int gIndex = width * height;
            int bIndex = gIndex * ;

            int temp = ;

            for (int y = ; y < height; y++)
            {
                for (int x = ; x < width; x++)
                {
                    // R分量
                    temp = (int)(yuvFrame[y * width + x] + (yuvFrame[vIndex + (y / ) * (width / ) + x / ] - ) * YUV2RGB_CONVERT_MATRIX[, ]);
                    rgbFrame[y * width + x] = (byte)(temp <  ?  : (temp >  ?  : temp));

                    // G分量
                    temp = (int)(yuvFrame[y * width + x] + (yuvFrame[uIndex + (y / ) * (width / ) + x / ] - ) * YUV2RGB_CONVERT_MATRIX[, ] + (yuvFrame[vIndex + (y / ) * (width / ) + x / ] - ) * YUV2RGB_CONVERT_MATRIX[, ]);
                    rgbFrame[gIndex + y * width + x] = (byte)(temp <  ?  : (temp >  ?  : temp));

                    // B分量
                    temp = (int)(yuvFrame[y * width + x] + (yuvFrame[uIndex + (y / ) * (width / ) + x / ] - ) * YUV2RGB_CONVERT_MATRIX[, ]);
                    rgbFrame[bIndex + y * width + x] = (byte)(temp <  ?  : (temp >  ?  : temp));
                }
            }
        }

        void WriteBMP(byte[] rgbFrame, int width, int height)
        {
            // 写 BMP 图像文件。
            int yu = width *  % ;
            int bytePerLine = ;
            yu = yu !=  ?  - yu : yu;
            bytePerLine = width *  + yu;

            int length = rgbFrame.GetLength();

            //将文件头以及数据写到内存流里面
            using (MemoryStream stream = new MemoryStream(length + ))
            {
                using (BinaryWriter bw = new BinaryWriter(stream, Encoding.Default))
                {
                    bw.Write('B');
                    bw.Write('M');
                    bw.Write(bytePerLine * height + );
                    bw.Write();
                    bw.Write();
                    bw.Write();
                    bw.Write(width);
                    bw.Write(height);
                    bw.Write((ushort));
                    bw.Write((ushort));
                    bw.Write();
                    bw.Write(bytePerLine * height);
                    bw.Write();
                    bw.Write();
                    bw.Write();
                    bw.Write();

                    byte[] data = new byte[bytePerLine * height];
                    int gIndex = width * height;
                    int bIndex = gIndex * ;
                    for (int y = height - , j = ; y >= ; y--, j++)
                    {
                        for (int x = , i = ; x < width; x++)
                        {
                            data[y * bytePerLine + i++] = rgbFrame[bIndex + j * width + x];
                            // B
                            data[y * bytePerLine + i++] = rgbFrame[gIndex + j * width + x];
                            // G
                            data[y * bytePerLine + i++] = rgbFrame[j * width + x];
                            // R
                        }
                    }

                    bw.Write(data, , data.Length);
                    Bitmap image = new Bitmap(stream);
                    this.pictureBox2.Image = image;
                    stream.Flush();
                    stream.Close();
                    bw.Flush();
                    bw.Close();

                }
            }
        }