Verilog笔记——YUV2RGB的模块测试

1 YUV2RGB的模块如下：

module yuv2rgb(
    clk,        //时钟输入
    rstn,       //复位输入，低电平复位
    
    y_in,       //变换前Y分量输出
    cb_in,      //变换前Cb分量输出
    cr_in,        //变换前Cr分量输出
    ena_in,        //待变换数据使能，当它为高时，输入数据有效
        
    R_out,        //变换后R分量输出
    G_out,        //变换后G分量输出
    B_out,        //变换后B分量输出
    ena_out        //变换后数据使能输出
    );

    测试模块功能的方法：

         step1 用MATLAB读入一张RGB图片，将RGB转成YUV数据保存在txt文件中；

         step2 用该模块把YUV数据转换成RGB数据并保存;

         step3 用MATLAB读取模块转换的RGB数据做显示。

    接下来详细说明step1~3的实现过程。

2 step1 用MATLAB读入一张RGB图片，将RGB转成YUV数据保存在txt文件中；

clc;close all;clear 

RGBimg =imread('Penguins_720p.jpg'); %%用画图软件重新调整像素大小得到的720p图片
figure;imshow(RGBimg);
YUVimg = rgb2ycbcr(RGBimg); %%matlab中的转换函数
figure;imshow(YUVimg);

[Hs Vs Dim] = size(YUVimg);
yuvimout = zeros(1,Hs*Vs*Dim);
yuvimout(1:3:Hs*Vs*Dim) = reshape(YUVimg(:,:,1)',1,Hs*Vs); %%Y
yuvimout(2:3:Hs*Vs*Dim) = reshape(YUVimg(:,:,2)',1,Hs*Vs); %%U
yuvimout(3:3:Hs*Vs*Dim) = reshape(YUVimg(:,:,3)',1,Hs*Vs); %%V
fid= fopen('Penguins_720p.txt','w'); %%YUV数据写入到txt
    fprintf(fid,'%02x\n',yuvimout);  %%2位十六进制格式
fclose(fid);

fid= fopen('Penguins_720p.yuv','rb'); %%用“7yuv”专业软件转换得到的yuv数据
    yuvdat = fread(fid,'uint8');
    yuvdat = yuvdat';
fclose(fid);
subAB = yuvdat-yuvimout;   %%比较下matlab转换的yuv数据
figure;stem(find(subAB~=0));

3 step2 用该模块把YUV数据转换成RGB数据并保存;

testbench的代码如下：

`timescale 1ns / 1ps

module tb_yuv2rgb;
    // Inputs
    reg clk;
    reg rstn; //复位输入，低电平复位
    reg [7:0] y_in;
    reg [7:0] cb_in;
    reg [7:0] cr_in;
    reg ena_in;
    // Outputs
    wire [7:0] R_out;
    wire [7:0] G_out;
    wire [7:0] B_out;
    wire ena_out;
    // Instantiate the Unit Under Test (UUT)
    yuv2rgb uut (
        .clk(clk), 
        .rstn(rstn), 
        .y_in(y_in), 
        .cb_in(cb_in), 
        .cr_in(cr_in), 
        .ena_in(ena_in), 
        .R_out(R_out), 
        .G_out(G_out), 
        .B_out(B_out), 
        .ena_out(ena_out)
    );
    
localparam    PIXNUM_1080P =(1920*1080*3);
localparam    PIXNUM_720P  =(1280*720*3);

    //read pixel from .txt file
    reg[7:0] mem_imgpixel[0:2**24];
    reg [31:0]  pixaddr;
    integer fid,i;
    initial begin  //读取图片的YUV数据
        $readmemh("Penguins_720p.txt",mem_imgpixel);
        pixaddr = 0;
        #PIXNUM_1080P begin //等待图片的数据转换完成
            fid =  $fopen("Penguins_720pRGBout.txt","w");    
            for(i=0; i<PIXNUM_720P; i=i+1)
                $fdisplay(fid,"%2x",mem_rgbout[i]);//输出转换的RGB数据
            $fclose(fid);
            $stop;
        end
    end
    //clk的上升沿给输入的yuv数据
    always @(posedge clk or negedge rstn) begin
        if(!rstn) begin
            y_in   <=  8'b0;
            cb_in  <=  8'b0;
            cr_in  <=  8'b0;
            ena_in <=  1'b0;
            pixaddr<=  0;
        end
        else begin
            y_in   <= mem_imgpixel[pixaddr];
            cb_in  <= mem_imgpixel[pixaddr+1];
            cr_in  <= mem_imgpixel[pixaddr+2];
            ena_in <= 1'b1;
            pixaddr<= pixaddr + 3;
        end
    end
    
    reg[31:0] outaddr;
    reg[7:0] mem_rgbout[0:2**24];//clk的下降沿读取转换的rgb数据
    always @(negedge clk or negedge rstn) begin
        if(!rstn) begin
            outaddr <= 0;
        end    
        else begin //存入对应下标
            mem_rgbout[outaddr]   <= R_out;
            mem_rgbout[outaddr+1] <= G_out;
            mem_rgbout[outaddr+2] <= B_out;
            outaddr <= outaddr + 3; //下标增加3
        end
    end
    
    initial begin
        // Initialize Inputs
        clk = 0;
        rstn = 1;
        y_in = 0;
        cb_in = 0;
        cr_in = 0;
        ena_in = 0;
        #2;
        rstn = 0;
        // Wait 100 ns for global reset to finish
        #100;
        rstn = 1;
        // Add stimulus here
    end
    always #2 clk =~clk;
endmodule

4 step3 用MATLAB读取模块转换的RGB数据做显示。

clc;close all;clear 

filename = 'Penguins_720pRGBout.txt';
fid = fopen(filename,'r');
    rgbdat = fscanf(fid,'%x');
    rgbdat = uint8(rgbdat'); %%转换为uint8
fclose(fid);

imglen = 1280; imgwidth = 720;
len = length(rgbdat);
r = rgbdat(1:3:len);
r = reshape(r,imglen,imgwidth);
r = r';

g = rgbdat(2:3:len);
g = reshape(g,imglen,imgwidth);
g = g';

b = rgbdat(3:3:len);
b = reshape(b,imglen,imgwidth);
b = b';

rgbimg = cat(3,r,g,b);
imshow(rgbimg);

step3中rgb数据正确时显示的图片