readdata.m

对数字信号进行分析

function [mpeg] = readdata(l1,tb)
N2=188*8;
% fs=8e6;
% tb=1/fs;
m2=zeros(1,l1*N2);
fid = fopen('D:\ww.mpg','r');
fseek(fid,0,'bof');%从1开始读
[a3 count]= fread(fid,l1*N2/8,'uint8'); 
a3=a3.';

fclose(fid);
    for j=1:1:l1*N2/8
        str=dec2bin(a3(1,j),8);
       m2(1,(j-1)*8+1:(j-1)*8+8)=str(1,:);
    end
    for j=1:1:l1*N2
        if m2(1,j)==48
                m2(1,j)=0;
            else
                m2(1,j)=1;
        end
    end
mpeg=m2;
runum3=length(mpeg);  
t1=tb:tb:tb*runum3;
figure
stairs(t1,mpeg)
axis([0 tb*runum3 -0.5 1.5])