YUV420 转 RGB 转 BMP图片

/* 在WindowsMobile和WinForm上都可以，我测过了
 * 这个不是我写的，我找了好几天才找到的,我只是改了几句话而已，不过效率不是很高，供大家参考吧
 * 在这里谢谢 Galactica , 也希望大家有比这更好的方法给小弟共享一下...
 * 文件下载地址：http://trace.eas.asu.edu/yuv/tempete.zip
 * */

using System;
using System.Linq;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Text;
using System.Windows.Forms;
using System.IO;

namespace deCodeYUV
{
    public partial class MainForm : Form
    {


        static double[,] YUV2RGB_CONVERT_MATRIX = 
            new double[3, 3] { { 1, 0, 1.4022 }, { 1, -0.3456, -0.7145 }, { 1, 1.771, 0 } };


        public MainForm()
        {
            InitializeComponent();
            GetByteData();
        }

        public void GetByteData()
        {

            int width = 352; 
            int height = 288; 
            int imgSize = width * height;
            int frameSize = imgSize + (imgSize >> 1);
            byte[] yuv = new byte[frameSize];
            byte[] rgb = new byte[3 * imgSize];
            
            //这里需要注意，这个是本地文件夹，是模拟器共享的文件夹或手机设备的文件夹
            using (FileStream fs = File.OpenRead(@"\Storage Card\tempete.cif"))
             {                
                 int frame = (int)fs.Length / frameSize;                            
                using (BinaryReader br = new BinaryReader(fs))
                 {      
                     int index = 0;
                     while (br.PeekChar() != -1)                                           
                     {        
                             // 循环读取每一桢 
                             br.Read(yuv, 0, frameSize); 
   
                             //转换为 RGB 
                             ConvertYUV2RGB(yuv, rgb, width, height); 

                             // 写 BMP 文件。   
                             WriteBMP(rgb, width, height);

                             index++;
                     }                
                 }            
             }

        }

        /// <summary>
        /// 将转换后的 RGB 图像数据按照 BMP 格式写入文件。
        /// </summary>
        /// <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>
        /// <param name="bmpFile"> BMP 文件名。</param>
         void WriteBMP(byte[] rgbFrame, int width, int height)        
        {          
            // 写 BMP 图像文件。
            int yu = width * 3 % 4;
            int bytePerLine = 0;
            yu = yu != 0 ? 4 - yu : yu;  
            bytePerLine = width * 3 + yu;

            int length = rgbFrame.GetLength(0);

             //将文件头以及数据写到内存流里面
            using (MemoryStream stream = new MemoryStream(length + 54))
            {
                using (BinaryWriter bw = new BinaryWriter(stream, Encoding.Default))
                {
                    bw.Write('B');
                    bw.Write('M');
                    bw.Write(bytePerLine * height + 54);
                    bw.Write(0);
                    bw.Write(54);
                    bw.Write(40);
                    bw.Write(width);
                    bw.Write(height);
                    bw.Write((ushort)1);
                    bw.Write((ushort)24);
                    bw.Write(0);
                    bw.Write(bytePerLine * height);
                    bw.Write(0);
                    bw.Write(0);
                    bw.Write(0);
                    bw.Write(0);

                    byte[] data = new byte[bytePerLine * height];
                    int gIndex = width * height;
                    int bIndex = gIndex * 2;
                    for (int y = height - 1, j = 0; y >= 0; y--, j++)
                    {
                        for (int x = 0, i = 0; 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, 0, data.Length);
                    Bitmap image = new Bitmap(stream);
                    this.pictureBox1.Image = image;
                    stream.Flush();
                    stream.Close();
                    bw.Flush();
                    bw.Close();

                }
            }
        }

        /// <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>
           void ConvertYUV2RGB(byte[] yuvFrame, byte[] rgbFrame, int width, int height)    
          {          
              int uIndex = width * height;      
              int vIndex = uIndex + ((width * height) >> 2);    
              int gIndex = width * height;      
              int bIndex = gIndex * 2;         
              int temp = 0;        
              for (int y = 0; y < height; y++)      
              {               
                  for (int x = 0; x < width; x++)      
                  {                 
                      // R分量        
                      temp = (int)(yuvFrame[y * width + x] + (yuvFrame[vIndex + (y / 2) * (width / 2) + x / 2] - 128) * YUV2RGB_CONVERT_MATRIX[0, 2]);          
                      rgbFrame[y * width + x] = (byte)(temp < 0 ? 0 : (temp > 255 ? 255 : temp));        
                      // G分量       
                      temp = (int)(yuvFrame[y * width + x] + (yuvFrame[uIndex + (y / 2) * (width / 2) + x / 2] - 128) * YUV2RGB_CONVERT_MATRIX[1, 1] + (yuvFrame[vIndex + (y / 2) * (width / 2) + x / 2] - 128) * YUV2RGB_CONVERT_MATRIX[1, 2]);     
                      rgbFrame[gIndex + y * width + x] = (byte)(temp < 0 ? 0 : (temp > 255 ? 255 : temp));        
                      // B分量             
                      temp = (int)(yuvFrame[y * width + x] + (yuvFrame[uIndex + (y / 2) * (width / 2) + x / 2] - 128) * YUV2RGB_CONVERT_MATRIX[2, 1]);               
                      rgbFrame[bIndex + y * width + x] = (byte)(temp < 0 ? 0 : (temp > 255 ? 255 : temp));          
                  }           
              }     
          }

    }
}