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1 <html> | |
2 <head> | |
3 <meta charset="utf-8"> | |
4 <script type="application/x-javascript" src="../util.js"></script> | |
5 <script> | |
6 var processor = { | |
7 lastTime : new Date, | |
8 timerCallback: function() { | |
9 if (this.video.paused || this.video.ended) { | |
10 return; | |
11 } | |
12 this.computeFrame(); | |
13 var t = new Date; | |
14 var elapsed = t - this.lastTime; | |
15 this.lastTime = t; | |
16 var self = this; | |
17 setTimeout(function () { | |
18 self.timerCallback(); | |
19 }, Math.max(0, 33-elapsed)); | |
20 }, | |
21 | |
22 init: function() { | |
23 if (this.initDone) return; | |
24 this.c2 = document.getElementById("c2"); | |
25 this.ctx2 = this.c2.getContext(GL_CONTEXT_ID); | |
26 this.greenScreen = new Filter(this.ctx2, 'identity-flip-vert', 'greenScreen'
); | |
27 this.ctx2.activeTexture(this.ctx2.TEXTURE0); | |
28 this.tex = loadTexture(this.ctx2, this.c1, false); | |
29 this.ctx2.activeTexture(this.ctx2.TEXTURE1); | |
30 this.tex2 = loadTexture(this.ctx2, document.getElementById('i'), false); | |
31 this.ctx2.activeTexture(this.ctx2.TEXTURE0); | |
32 this.initDone = true; | |
33 }, | |
34 | |
35 doLoad: function() { | |
36 this.video = document.getElementById("video"); | |
37 this.c1 = document.getElementById("c1"); | |
38 this.ctx1 = this.c1.getContext("2d"); | |
39 this.ctx1.globalCompositeOperation = 'copy'; | |
40 this.ctx1.fillRect(0,0,this.c1.width, this.c1.height); | |
41 var self = this; | |
42 this.video.addEventListener("play", function() { | |
43 self.init(); | |
44 self.width = self.video.videoWidth; | |
45 self.height = self.video.videoHeight; | |
46 self.lastTime = new Date; | |
47 self.timerCallback(); | |
48 }, false); | |
49 }, | |
50 | |
51 computeFrame: function() { | |
52 // this.ctx1.drawImage(this.video, 0, 0, this.width, this.height); | |
53 this.ctx2.texImage2D(this.ctx2.TEXTURE_2D, 0, gl.RGBA, gl.RGBA, gl.UNSIGNED_
BYTE, this.video); | |
54 this.greenScreen.apply(function(s) { | |
55 s.uniform1i('Texture', 0); | |
56 s.uniform1i('Texture2', 1); | |
57 }); | |
58 | |
59 return; | |
60 } | |
61 }; | |
62 | |
63 </script> | |
64 <script id="identity-flip-vert" type="x-shader/x-vertex"> | |
65 attribute vec3 Vertex; | |
66 attribute vec2 Tex; | |
67 | |
68 varying vec4 texCoord0; | |
69 void main() | |
70 { | |
71 texCoord0 = vec4(Tex.s,1.0-Tex.t,0.0,0.0); | |
72 gl_Position = vec4(Vertex, 1.0); | |
73 } | |
74 </script> | |
75 <script id="greenScreen" type="x-shader/x-fragment"> | |
76 precision mediump float; | |
77 | |
78 uniform sampler2D Texture; | |
79 uniform sampler2D Texture2; | |
80 | |
81 varying vec4 texCoord0; | |
82 void main() | |
83 { | |
84 vec4 c = texture2D(Texture, texCoord0.st); | |
85 float r = c.r * 0.5; | |
86 float a = c.g * 6.28; | |
87 float x = cos(a) * r; | |
88 float y = sin(a) * r; | |
89 vec4 c2 = texture2D(Texture2, vec2(0.7+x, 0.5+y)); | |
90 // Shaders with branches are not allowed when dealing with non-SOP conte
nt | |
91 // so instead of "if (b) c2.a = 0;", we use mix() | |
92 bool b = (c.g > 120.0/255.0 && c.r > 120.0/255.0 && c.b < 50.0/255.0); | |
93 c2.a = mix(c2.a, 0.0, float(b)); | |
94 gl_FragColor = c2; | |
95 } | |
96 </script> | |
97 <style> | |
98 body { | |
99 background: black; | |
100 color:#CCCCCC; | |
101 } | |
102 a { | |
103 color: white; | |
104 } | |
105 #c2 { | |
106 background-image: url(http://www.mozbox.org/pub/green/foo.png); | |
107 background-repeat: repeat; | |
108 } | |
109 div { | |
110 float: left; | |
111 border :1px solid #444444; | |
112 padding:10px; | |
113 margin: 10px; | |
114 background:#3B3B3B; | |
115 } | |
116 img { display: none; } | |
117 </style> | |
118 </head> | |
119 <body onload="processor.doLoad()"> | |
120 <div> | |
121 This is a port of Paul Rouget's <a href="http://blog.mozbox.org/post/200
9/02/25/video-canvas%3A-special-effects">Canvas+Video green screen demo</a>, plu
s a texture lookup from the Firefox logo based on the values of the green and re
d color channels. | |
122 </div> | |
123 <div> | |
124 <video id="video" controls="true"> | |
125 <source src="http://www.mozbox.org/pub/green/video.ogv"></source> | |
126 <source src="http://cs.helsinki.fi/u/ilmarihe/c3d/demos/video.mp4"></sou
rce> | |
127 </video> | |
128 <canvas id="c1" width="320" height="192"></canvas> | |
129 </div> | |
130 <div> | |
131 <canvas id="c2" width="640" height="384"></canvas> | |
132 </div> | |
133 <img id="i" src="http://www.mozbox.org/pub/green/foo.png"> | |
134 </body> | |
135 </html> | |
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