compressor.vhd

vhdl source for jpeg beginner

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--
-- Title       : JPEG Hardware Compressor
-- Design      : jpeg
-- Author      : Victor Lopez Lorenzo
-- E-mail      : [e-mail]
--
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--
--
--    Copyright (C) 2004  Victor Lopez Lorenzo
--
--    This library is free software; you can redistribute it and/or
--    modify it under the terms of the GNU Lesser General Public
--    License as published by the Free Software Foundation; either
--    version 2.1 of the License, or (at your option) any later version.
--
--    This library is distributed in the hope that it will be useful,
--    but WITHOUT ANY WARRANTY; without even the implied warranty of
--    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
--    Lesser General Public License for more details.
--
--    You should have received a copy of the GNU Lesser General Public
--    License along with this library; if not, write to the Free Software
--    Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
--                                                                                                 
--
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--
--	Contributors :
--		Peter Eisemann   -  Fixed GetCategory, writes and file declarations in order to
--						simulate code under ModelSim
--                                                                                                 
--
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--
--    
--    IMPORTANT NOTES :
--
--    This source code features a compliant JPEG compressor Baseline DCT with
--    Huffman enconding and 2x2 1x1 1x1 subsampling. The header is the widely
--    employed JFIF.
--
--    Baseline DCT JPEG with JFIF header is one of the most used image formats.
--
--    The maximum number of columns is limited, in this source code, to 352, but
--    it can be very easily changed to as many as wanted just by recustomizing
--    the BlockRAMs used for buffer_comp and buffer_comp_chrom as indicated in the
--    project's documentation, plus changing their associated signals in this
--    file and updating two functions: Mult_Columns and Mult_Half_Columns.
--    For the BlockRAMs, mainly:
--       - buffer_comp must have a depth of (number_of_columns x 16) positions
--       - buffer_comp_chrom must have a depth of (number_of_columns x 4) positions
--    width is 12 bits for both
--
--    There is another easily overridable limitation, buffer_img, the core of BlockRAM
--    memory used to save the final compressed image. I generated one of 51200 bytes,
--    if it is not enough for your application (remember that final compressed images
--    vary in size even with similar resolution input images as some compress better
--    than others), largening it may be as simple as recustomizing the core and
--    changing two signals (addri and addribk) and one constant (MaxImageSize),
--    apart from copying the new buffer_img declaration.
--    
--    The only real limitation is that the input image must have width and height
--    multiple of 16 (that is, an image 32x32 will produce a strictly compliant
--    JPEG image file, but not a 32x24 or a 24x32 input image, although the resulting
--    image will more likely still be viewable), this is due to the subsampling
--    method employed. This limitation could be overriden with some extra logic
--    (for padding as indicated in the JPEG standard).
--
--    I apologize if you find this code somewhat messy. When I programmed it I imposed
--    myself very strict deadlines and making it opensource was not in my mind, mainly
--    because, if I were to do it again, I would do it in other way to get much
--    more performance. The main problem faced with this implementation was a very
--	scarce availability of BlockRAM in the target FPGA, so some areas that could
--	perfectly run in parallel, speeding a lot the whole process, had to be made
--	sequential in order to save up BlockRAMs. Anyways, this code works
--	(it functioned as a webcam, attached to a CMOS sensor) and, though not
--	as fast as it could be, it has a good performance.
--    
--    As a part of this project there is a quite useful Testbench that takes as input
--    any BMP (24 bit color) image and compresses it with this code, outputting a JPG
--    file that you can view in your computer.
--
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library IEEE;
use IEEE.STD_LOGIC_1164.all;
use IEEE.numeric_std.all;
use IEEE.std_logic_unsigned.all; --for arithmetic ops
--pragma translate_off
library STD;
use STD.textio.all;
use IEEE.std_logic_textio.all;
library XilinxCoreLib;
--pragma translate_on
library UNISIM; 
use UNISIM.all; 

entity Compressor is port (
 	      clk : in STD_LOGIC;
	      reset : in STD_LOGIC;
         --Control/Status Interface
         CompressImage : in std_logic; --must be active high for just one cycle
         Compression : in std_logic_vector(1 downto 0); --Quality: 00 = low, 01 = medium, 10 = high
         Mono : in std_logic; --active high for grey-scale input image (Red=Green=Blue)
         ImgColumns : in std_logic_vector(9 downto 0); --columns in each line of the image to compress
         ImgLines : in std_logic_vector(8 downto 0); --lines of the image to compress
         Compressing : out std_logic;
         
         --Data Interface
         ProcessRGB : in std_logic;
         ProcessingRGB : out std_logic;
         Red : in std_logic_vector(7 downto 0);
         Green : in std_logic_vector(7 downto 0);
         Blue : in std_logic_vector(7 downto 0);
         
         --JPEG Image BlockRAM (Output) Interface
         addr: out std_logic_VECTOR(15 downto 0);
         din: out std_logic_VECTOR(7 downto 0);
         we: out std_logic);
end Compressor;

architecture JPG of Compressor is

--pragma translate_off

file Debug:   TEXT open WRITE_MODE is "Debug.txt";
file DebugY:  TEXT open WRITE_MODE is "DebugY.txt";
file DebugCb: TEXT open WRITE_MODE is "DebugCb.txt";
file DebugCr: TEXT open WRITE_MODE is "DebugCr.txt";

--   file Debug:TEXT is out "Debug.txt";
--   file DebugY:TEXT is out "DebugY.txt";
--	file DebugCb:TEXT is out "DebugCb.txt";
--   file DebugCr:TEXT is out "DebugCr.txt";
	constant espacio:string:=" ";
   constant espacios:string:="  ";
   constant puntoycoma:string:=";";
	constant strElemento:string:=" Element: ";
   constant strColumna:string:=" Column: ";
   constant strLinea:string:=" Line: ";
--pragma translate_on


   component dct2d port (
   	ND: IN std_logic;
   	RDY: OUT std_logic;
   	RFD: OUT std_logic;
   	CLK: IN std_logic;
   	DIN: IN std_logic_VECTOR(7 downto 0);
   	DOUT: OUT std_logic_VECTOR(18 downto 0));
   end component;

   component buffer_comp port (
   	addr: IN std_logic_VECTOR(12 downto 0);
   	clk: IN std_logic;
   	din: IN std_logic_VECTOR(11 downto 0);
   	dout: OUT std_logic_VECTOR(11 downto 0);
   	we: IN std_logic);
   end component;
   
   component buffer_comp_chrom port (
   	addr: IN std_logic_VECTOR(10 downto 0);
   	clk: IN std_logic;
   	din: IN std_logic_VECTOR(11 downto 0);
   	dout: OUT std_logic_VECTOR(11 downto 0);
   	we: IN std_logic);
   end component;
   
   component q_rom port (
   	addr: IN std_logic_VECTOR(8 downto 0);
   	clk: IN std_logic;
   	dout: OUT std_logic_VECTOR(12 downto 0));
   end component;
   
   component huff_rom port (
	   addr: IN std_logic_VECTOR(8 downto 0);
	   clk: IN std_logic;
	   dout: OUT std_logic_VECTOR(19 downto 0));
   end component;

   component tabla_q
   	port (
   	addr: IN std_logic_VECTOR(8 downto 0);
   	clk: IN std_logic;
   	dout: OUT std_logic_VECTOR(7 downto 0));
   end component;   

   --signals for tabla_q
   signal addrTablaQ: std_logic_VECTOR(8 downto 0);
  	signal doutTablaQ: std_logic_VECTOR(7 downto 0);

   
   --signal for huff_rom
   signal addrH : std_logic_vector(8 downto 0);
   signal doutH : std_logic_vector(19 downto 0);
   
   --signals for DCT block
	signal ND: std_logic;
	signal RDY: std_logic;
	signal RFD: std_logic;
	signal DIND: std_logic_VECTOR(7 downto 0);
	signal DOUTD: std_logic_VECTOR(18 downto 0);
   
   --signals for compression buffer
   signal addrY: std_logic_VECTOR(12 downto 0);
	signal dinY: std_logic_VECTOR(11 downto 0);
	signal doutY: std_logic_VECTOR(11 downto 0);
	signal weY: std_logic;
   signal addrCb: std_logic_VECTOR(10 downto 0);
	signal dinCb: std_logic_VECTOR(11 downto 0);
	signal doutCb: std_logic_VECTOR(11 downto 0);
	signal weCb: std_logic;
   signal addrCr: std_logic_VECTOR(10 downto 0);
	signal dinCr: std_logic_VECTOR(11 downto 0);
	signal doutCr: std_logic_VECTOR(11 downto 0);
	signal weCr: std_logic;                      
   
   signal addrY1: std_logic_VECTOR(12 downto 0);
   signal addrCb1: std_logic_VECTOR(10 downto 0);   
   signal addrCr1: std_logic_VECTOR(10 downto 0);   
   signal addrY2: std_logic_VECTOR(12 downto 0);   
   signal addrCb2: std_logic_VECTOR(10 downto 0);   
   signal addrCr2: std_logic_VECTOR(10 downto 0);   

	signal dinY1: std_logic_VECTOR(11 downto 0);
   signal dinY2: std_logic_VECTOR(11 downto 0);
   signal dinCb1: std_logic_VECTOR(11 downto 0);
   signal dinCb2: std_logic_VECTOR(11 downto 0);
   signal dinCr1: std_logic_VECTOR(11 downto 0);
   signal dinCr2: std_logic_VECTOR(11 downto 0);

   signal weY1: std_logic;
   signal weY2: std_logic;
	signal weCb1: std_logic;
   signal weCb2: std_logic;
	signal weCr1: std_logic;
   signal weCr2: std_logic;
   
   --signals for the quantization coefficients ROM
   signal addrQ : std_logic_vector(8 downto 0);
   signal doutQ : std_logic_vector(12 downto 0);

   
   
   --this is, (obviously along with the buffer_img blockram core itself) the limiting factor of final compressed image size
   signal addri : std_logic_vector(15 downto 0); --to write directly to the port (headers and JPEG size) and read from it
   signal addribk : std_logic_vector(15 downto 0); --exclusive when signal Save='1', it holds the current pixel
   constant MaxImageSize : std_logic_vector(15 downto 0) :="1100011111111100"; --51196 bytes
   --for bigger images, enlarge buffer_img and change these signals' lengths
   
   
   
   signal ColumnToCompress : std_logic_vector(9 downto 0);
   signal LineToCompress : std_logic_vector(3 downto 0); --goes from 0 to 15, the 16 that may occupy the luminance buffer
   signal LineAbsToCompress: std_logic_vector(8 downto 0);

   signal MakeDCT : std_logic;
   signal CompressingInt : std_logic;
   
   signal Done : std_logic; --the Huffman encoding part rises it for one cycle when finishes

   signal StepV : integer range 0 to 5;
   signal Save : std_logic;
   signal NDe : std_logic;                   
   signal WriteAdditionalBits : std_logic;

   
   signal WriteTables : std_logic;