OpenCores
URL https://opencores.org/ocsvn/video_systems/video_systems/trunk

Subversion Repositories video_systems

[/] [video_systems/] [trunk/] [common/] [color_space converters/] [ycrcb2rgb/] [rtl/] [verilog/] [ycrcb2rgb.v] - Blame information for rev 2

Go to most recent revision | Details | Compare with Previous | View Log

Line No. Rev Author Line
1 2 rherveille 
/////////////////////////////////////////////////////////////////////
2 
////                                                             ////
3 
////  YCrCb to RGB Color Space converter                         ////
4 
////                                                             ////
5 
////  Converts YCrCb (YUV) values to RGB values                  ////
6 
////  R = Y + 1.403Cr                                            ////
7 
////  G = Y - 0.344Cb - 0.714Cr                                  ////
8 
////  B = Y + 1.770Cb                                            ////
9 
////                                                             ////
10 
////  Author: Richard Herveille                                  ////
11 
////          richard@asics.ws                                   ////
12 
////          www.asics.ws                                       ////
13 
////                                                             ////
14 
////                                                             ////
15 
/////////////////////////////////////////////////////////////////////
16 
////                                                             ////
17 
//// Copyright (C) 2001 Richard Herveille                        ////
18 
////                    richard@asics.ws                         ////
19 
////                                                             ////
20 
//// This source file may be used and distributed without        ////
21 
//// restriction provided that this copyright statement is not   ////
22 
//// removed from the file and that any derivative work contains ////
23 
//// the original copyright notice and the associated disclaimer.////
24 
////                                                             ////
25 
////     THIS SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY     ////
26 
//// EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED   ////
27 
//// TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS   ////
28 
//// FOR A PARTICULAR PURPOSE. IN NO EVENT SHALL THE AUTHOR      ////
29 
//// OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,         ////
30 
//// INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES    ////
31 
//// (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE   ////
32 
//// GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR        ////
33 
//// BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF  ////
34 
//// LIABILITY, WHETHER IN  CONTRACT, STRICT LIABILITY, OR TORT  ////
35 
//// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT  ////
36 
//// OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE         ////
37 
//// POSSIBILITY OF SUCH DAMAGE.                                 ////
38 
////                                                             ////
39 
/////////////////////////////////////////////////////////////////////
40 
 
41 
//  CVS Log
42 
//
43 
//  $Id: ycrcb2rgb.v,v 1.1.1.1 2002-03-26 07:25:09 rherveille Exp $
44 
//
45 
//  $Date: 2002-03-26 07:25:09 $
46 
//  $Revision: 1.1.1.1 $
47 
//  $Author: rherveille $
48 
//  $Locker:  $
49 
//  $State: Exp $
50 
//
51 
// Change History:
52 
//               $Log: not supported by cvs2svn $
53 
 
54 
 
55 
`timescale 1ns/10ps
56 
 
57 
module ycrcb2rgb(clk, ena, y, cr, cb, r, g, b);
58 
        //
59 
        // inputs & outputs
60 
        //
61 
        input        clk;
62 
        input        ena;
63 
        input  [9:0] y, cr, cb;
64 
 
65 
        output [9:0] r, g, b;
66 
        reg [9:0] r, g, b;
67 
 
68 
 
69 
        reg [9:0] dy, dcr, dcb;
70 
 
71 
        //
72 
        // variables
73 
        //
74 
        reg [22:0] ir, ig, ib;
75 
 
76 
        //
77 
        // module body
78 
        //
79 
 
80 
 
81 
        // step 1: Calculate R, G, B
82 
        //
83 
        // Use N.M format for multiplication:
84 
        // R = Y + 1.403Cr = Y + Cr + 0.403Cr
85 
        // R = Y + Cr + 0x19C*Cr
86 
        //
87 
        // G = Y - 0.344Cb - 0.714Cr
88 
        // G = Y - 0x160*Cb - 0x2DB*Cr
89 
        //
90 
        // B = Y + 1.770Cb = Y + Cb + 0.770Cb
91 
        // B = Y + Cb + 0x314*Cb
92 
 
93 
 
94 
        // delay y, cr and cb
95 
        always@(posedge clk)
96 
                if (ena)
97 
                begin
98 
                        dy  <= #1 y;
99 
                        dcr <= #1 cr;
100 
                        dcb <= #1 cb;
101 
                end
102 
 
103 
        // calculate R
104 
        reg [19:0] rm;
105 
 
106 
        always@(posedge clk)
107 
                if (ena)
108 
                begin
109 
                        rm <= #1 10'h19C * cr;
110 
 
111 
                        ir <= #1 ( (dy + dcr) << 10) + rm;
112 
                end
113 
 
114 
        // calculate G
115 
        reg [19:0] gm1, gm2;
116 
 
117 
        always@(posedge clk)
118 
                if (ena)
119 
                begin
120 
                        gm1 <= #1 10'h160 * cb;
121 
                        gm2 <= #1 10'h2DB * cr;
122 
 
123 
                        ig  <= #1 (dy << 10) - (gm1 + gm2);
124 
                end
125 
 
126 
        // calculate B
127 
        reg [19:0] bm;
128 
 
129 
        always@(posedge clk)
130 
                if (ena)
131 
                begin
132 
                        bm <= #1 10'h314 * cb;
133 
 
134 
                        ib <= #1 ( (dy + dcb) << 10) + bm;
135 
                end
136 
 
137 
        //
138 
        // step2: check boundaries
139 
        //
140 
        always@(posedge clk)
141 
                if (ena)
142 
                begin
143 
                        // check R
144 
                        r <= #1 (ir[19:10] & {10{!ir[22]}}) | {10{(!ir[22] && (ir[21] || ir[20]))}};
145 
 
146 
                        // check G
147 
                        g <= #1 (ig[19:10] & {10{!ig[22]}}) | {10{(!ig[22] && (ig[21] || ig[20]))}};
148 
 
149 
                        // check B
150 
                        b <= #1 (ib[19:10] & {10{!ib[22]}}) | {10{(!ib[22] && (ib[21] || ib[20]))}};
151 
                end
152 
endmodule
153 
 
154 
 
155 
 
156 
 

powered by: WebSVN 2.1.0

© copyright 1999-2024 OpenCores.org, equivalent to Oliscience, all rights reserved. OpenCores®, registered trademark.