Subversion Repositories motion_estimation_processor

----------------------------------------------------------------------------

--  This file is a part of the LM VHDL IP LIBRARY

--  Copyright (C) 2009 Jose Nunez-Yanez

--

--  This program is free software; you can redistribute it and/or modify

--  it under the terms of the GNU General Public License as published by

--  the Free Software Foundation; either version 2 of the License, or

--  (at your option) any later version.

--

--  See the file COPYING for the full details of the license.

--

--  The license allows free and unlimited use of the library and tools for research and education purposes. 

--  The full LM core supports many more advanced motion estimation features and it is available under a 

--  low-cost commercial license. See the readme file to learn more or contact us at 

--  eejlny@byacom.co.uk or www.byacom.co.uk

-----------------------------------------------------------------------------

-- Entity:      range_checker

-- File:        range_checker.vhd

-- Author:      Jose Luis Nunez 

-- Description: range checker to be able to process frame edges

------------------------------------------------------------------------------

library IEEE;

use IEEE.std_logic_1164.all;

use work.config.all;

use IEEE.std_logic_signed."+";

use IEEE.std_logic_signed."<";

use IEEE.std_logic_signed.">";

use work.config.all;

entity range_checker is --make sure that MVs are not out of range

port (

clk : in std_logic;

clear : in std_logic;

reset : in std_logic;

candidate_mvx : in std_logic_vector(7 downto 0);

candidate_mvy : in std_logic_vector(7 downto 0);

frame_dimension_x : in std_logic_vector(7 downto 0); --in mb  

frame_dimension_y : in std_logic_vector(7 downto 0);

mbx_coordinate : in std_logic_vector(7 downto 0); --in mb

mby_coordinate : in std_logic_vector(7 downto 0);

range_ok : out std_logic

);

end;

architecture behav of range_checker is

signal mbx_coordinate_pixels : std_logic_vector(11 downto 0);

signal mby_coordinate_pixels : std_logic_vector(11 downto 0);

signal frame_dimension_x_pixels,candidate_mvx_long,candidate_mvy_long : std_logic_vector(11 downto 0);

signal frame_dimension_y_pixels : std_logic_vector(11 downto 0);

signal range_x_low,range_x_high,range_y_low,range_y_high : std_logic;

begin

mbx_coordinate_pixels <= mbx_coordinate & "0000";

mby_coordinate_pixels <= mby_coordinate & "0000";

frame_dimension_x_pixels <= frame_dimension_x & "0000";

frame_dimension_y_pixels <= frame_dimension_y & "0000";

candidate_mvx_long <= "0000" & candidate_mvx when candidate_mvx(7)='0' else "1111" & candidate_mvx; --sign extension

candidate_mvy_long <= "0000" & candidate_mvy when candidate_mvy(7)='0' else "1111" & candidate_mvy;

range_process_x_low : process(candidate_mvx_long,mbx_coordinate_pixels)

begin

if ((candidate_mvx_long + mbx_coordinate_pixels) < 0) then

        range_x_low <= '0';

else

        range_x_low <= '1';

end if;

end process;

range_process_x_high : process(candidate_mvx_long,mbx_coordinate_pixels,frame_dimension_x_pixels)

begin

if ((candidate_mvx_long + 16 + mbx_coordinate_pixels) > frame_dimension_x_pixels) then

        range_x_high <= '0';

else

        range_x_high <= '1';

end if;

end process;

range_process_y_low : process(candidate_mvy_long,mby_coordinate_pixels)

begin

if ((candidate_mvy_long + mby_coordinate_pixels) < 0) then

        range_y_low <= '0';

else

        range_y_low <= '1';

end if;

end process;

range_process_y_high : process(candidate_mvy_long,mby_coordinate_pixels,frame_dimension_y_pixels)

begin

if ((candidate_mvy_long + 16 + mby_coordinate_pixels) > frame_dimension_y_pixels) then

        range_y_high <= '0';

else

        range_y_high <= '1';

end if;

end process;

--rangec1 : if CFG_PIPELINE_COUNT_QP = 1 generate

--      range_ok <= range_x_low and range_x_high and range_y_low and range_y_high; -- if all ranges ok then ok

--end generate;

--rangec0 : if CFG_PIPELINE_COUNT_QP = 1 generate

        range_ok <= '1';  -- Hardwired to one since the codec can pad the reference memory with pixels. 

--end generate;

end behav;