huffman.vhd

mp3的VHDL实现

         		                bitpos := conv_std_logic_vector((conv_integer(bitpos) + linbits),13);
         		             end if;
         		          else
         		             temppos:=conv_integer(bitpos);
         		             temphuff:= 8191 - temppos+1;
         		             
         		             y:=y+conv_integer(valuebuffer(temppos to 8191) & valuebuffer(0 to linbits-temphuff-1));
         		             bitpos:=(others=>'0');
         		             tempcount1:='1';
         		             bitpos:=conv_std_logic_vector((linbits-temphuff),13);
         		          end if;
         		       end if;
                       if y > 0 then
                          if conv_integer(valuebuffer(conv_integer(bitpos)))=1 then              
                             y := -y;
                          end if;
                       		
                       		 if conv_integer(bitpos)=8191 then
                       			   bitpos:=(others=>'0');
                             tempcount1:='1';  			      
                       		 else
                       			   bitpos := bitpos + '1';
                       			end if;
                       end if;
                       
		       isg(line) <= x;
                       isg(line+1) <= y;
                             
                       line := line +2;
                       if (line >= bigvalues*2 ) then
          		          temp:=0;
      		          tempvector:=(others=>'0');
			  if gr='0' then
			     start_bit1 := conv_integer(frm.sideinfo.main_data)*8;
		 	     if  tempcount1='0' then
			         count1s:=conv_integer(frm.sideinfo.part2_3_length)-(conv_integer(bitpos)-start_bit1);
			     else
	   	                count1s:=conv_integer(frm.sideinfo.part2_3_length)-(8191-start_bit1+conv_integer(bitpos)+1);
                                tempcount1:='0';
			     end if;
			  else
			     if tempcount1='0' then
			        count1s:=conv_integer(frm.sideinfo.part2_3_length)-(conv_integer(bitpos)-start_bit2);
			     else
			        count1s:=conv_integer(frm.sideinfo.part2_3_length)-(8191-start_bit2+conv_integer(bitpos)+1);
			        tempcount1:='0';
			     end if;
			     
			  end if;
			
      		          ns<= HUFFCOUNT1;
      		       else
      		          ns<= HUFFBIGVALUE;
      		       end if;
      when HUFFCOUNT1 =>
                        if count1s>0 and line< 576 then
      			   start_bit := conv_integer(bitpos);
      			   
                           ns<= TABLELOOKUP2;
                        else
                           ns<=HUFFEND;
			end if;
      when TABLELOOKUP2	=>
                       if conv_integer(frm.sideinfo.count1table_select)=0 then
      		          level1 :=0;
      		          loop
      		              temp := get_value(32,level1,0);
      		              if temp=0 then
      		                 value := get_value(32,level1,1);
      		              end if;
      		              exit when temp=0;
      		              
      		              if conv_integer(valuebuffer(conv_integer(bitpos)))=1 then
      		                 level1 := level1+ get_value(32,level1,1);
      	  		      else
      		                 level1 := level1+ get_value(32,level1,0);
      	  		      end if;
      		              if conv_integer(bitpos)=8191 then
                       			       bitpos:=(others=>'0');
                                 tempcount1:='1';  			      
                       		     else
                       			       bitpos := bitpos + '1';
                       			    end if;
      		          end loop;
      		       else
      		          if 8191-conv_integer(bitpos)+1>= 4 then
      		             value := 15- conv_integer(valuebuffer(conv_integer(bitpos) to conv_integer(bitpos)+3));
      		             if 8191-conv_integer(bitpos)+1= 4 then
      		                bitpos:=(others=>'0');
                                tempcount1:='1';  			      
      		             else
      		                bitpos := bitpos+"100";
      		             end if;
      		          else
      		             temppos:=conv_integer(bitpos);
      		             temphuff:= 8191 - temppos+1;
         		             
         		             value:=15- conv_integer(valuebuffer(temppos to 8191)& valuebuffer(0 to 3-temphuff));
      		             bitpos:=(others=>'0');
         		             tempcount1:='1';
      		             bitpos:=conv_std_logic_vector((4-temphuff),13);
      		          end if;
      		       end if;
      		       tempvector1 := conv_std_logic_vector(value,4);
                       u := conv_integer(tempvector1(3));
                       w := conv_integer(tempvector1(2));
                       x := conv_integer(tempvector1(1));
                       y := conv_integer(tempvector1(0));
                       if u>0 then
                          if conv_integer(valuebuffer(conv_integer(bitpos)))=1 then              
                             u := -u;
                          end if;
                          	if conv_integer(bitpos)=8191 then
                       			       bitpos:=(others=>'0');
                                 tempcount1:='1';  			      
                       		  else
                       			       bitpos := bitpos + '1';
                       			 end if;
                       end if;
                       if w>0 then
                          if conv_integer(valuebuffer(conv_integer(bitpos)))=1 then              
                             w := -w;
                          end if;
                          if conv_integer(bitpos)=8191 then
                       			       bitpos:=(others=>'0');
                                 tempcount1:='1';  			      
                       		 else
                       			       bitpos := bitpos + '1';
                       		 end if;
                       end if;
                       if x>0 then
                          if conv_integer(valuebuffer(conv_integer(bitpos)))=1 then              
                             x := -x;
                          end if;
                          if conv_integer(bitpos)=8191 then
                       			       bitpos:=(others=>'0');
                                 tempcount1:='1';  			      
                       		 else
                       			       bitpos := bitpos + '1';
                       			end if;
                       end if;
                       if y>0 then
                          if conv_integer(valuebuffer(conv_integer(bitpos)))=1 then              
                             y := -y;
                          end if;
                          if conv_integer(bitpos)=8191 then
                       			       bitpos:=(others=>'0');
                                 tempcount1:='1';  			      
                       		 else
                       			       bitpos := bitpos + '1';
                       			end if;
                       end if;
                       if tempcount1='0' then
                          count1s :=count1s-(conv_integer(bitpos)-start_bit);
                       else
                          count1s :=count1s-(8191-start_bit+conv_integer(bitpos)+1);
                          tempcount1:='0';
                       end if;
                                             
                       isg(line) <= u;
                       isg(line+1) <= w;
                       isg(line+2) <= x;
                       isg(line+3) <= y;
                       
                       line :=line+4;
                       ns<= HUFFCOUNT1;
 
      when HUFFEND =>  
                       
                     --  if gr='0' then
                       --   tempbit:=conv_integer(bitpos) - start_bit1 - conv_integer(frm.sideinfo.part2_3_length);
                       --else
                         -- tempbit:=conv_integer(bitpos) - start_bit2 - conv_integer(frm.sideinfo.part2_3_length);
                       --end if;
                       --if (tempbit<0) then
                        --  bitpos:=conv_std_logic_vector((conv_integer(bitpos)-tempbit),13);
                       --end if;
   		       --if tempbit>0 then
   			  --bitpos:=conv_std_logic_vector((conv_integer(bitpos)+tempbit),13);
                       -- end if;   
                       loop
                          isg(line) <=0;
                          line := line+1;
                          exit when line >= 576;
                       end loop;
                       ns<= DATAREADY;  
     
      when DATAREADY =>
                     memc.en <= '1';		-- active high
                     memc.oe <= '0';		-- active high
		                memc.we <= '1';		-- active high
                     
                     memc.addr <= memaddrcount;
                     ns<= READY;		     
      when READY  => 
                     dout <= conv_std_logic_vector(isg(line1),32);
                     line1 :=line1+1;
      		             memaddrcount := memaddrcount+1;
      		             if line1 >=576 then
                        done <= '1';		
                        ns<= IDLE2;
                     else
                        ns<= DATAREADY;
                     end if;
     when others =>  null; 
    end case;
           
    sco <= scout; -- output scale factors
    
  end process;
  
 process(clk,rst)
 begin
    if rst='1' then
       cs<=IDLE1;
    elsif rising_edge(clk) then
       cs<=ns;
    end if;
 end process;
end;