1 /* 2 * Copyright 2010, Google Inc. 3 * All rights reserved. 4 * 5 * Redistribution and use in source and binary forms, with or without 6 * modification, are permitted provided that the following conditions are 7 * met: 8 * 9 * * Redistributions of source code must retain the above copyright 10 * notice, this list of conditions and the following disclaimer. 11 * * Redistributions in binary form must reproduce the above 12 * copyright notice, this list of conditions and the following disclaimer 13 * in the documentation and/or other materials provided with the 14 * distribution. 15 * * Neither the name of Google Inc. nor the names of its 16 * contributors may be used to endorse or promote products derived from 17 * this software without specific prior written permission. 18 * 19 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS 20 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT 21 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR 22 * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT 23 * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, 24 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT 25 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 26 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 27 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 28 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE 29 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 30 */ 31 32 /* 33 * This is an optimized version of the YUV to RGB conversion shader. This 34 * shader assumes the height of U and V planes is odd, which means the height 35 * of the original image is 2 modulo 4. 36 */ 37 38 uniform sampler2D textureSampler; 39 uniform sampler2D paritySampler; 40 41 varying vec2 lineCounter; 42 varying vec2 yPlane; 43 varying vec2 uPlane; 44 varying vec2 vPlane; 45 46 #if defined (USE_UNIFORM_MATRIX) 47 uniform mat4 conversion; 48 #endif 49 50 void main() { 51 /* 52 * If the height of the original image is even, offset_odd is not needed. 53 */ 54 vec2 offset_even = vec2(texture2D(paritySampler, lineCounter).x * 0.5, 0.0); 55 vec2 offset_odd = vec2(0.5 - offset_even.x, 0.0); 56 57 float yChannel = texture2D(textureSampler, yPlane).x; 58 float uChannel = texture2D(textureSampler, uPlane + offset_even).x; 59 float vChannel = texture2D(textureSampler, vPlane + offset_odd).x; 60 61 /* 62 * This does the colorspace conversion from Y'UV to RGB as a matrix 63 * multiply. It also does the offset of the U and V channels from 64 * [0,1] to [-.5,.5] as part of the transform. 65 */ 66 vec4 channels = vec4(yChannel, uChannel, vChannel, 1.0); 67 #if !defined(USE_UNIFORM_MATRIX) 68 mat4 conversion = mat4( 1.0, 1.0, 1.0, 0.0, 69 0.0, -0.344, 1.772, 0.0, 70 1.402, -0.714, 0.0, 0.0, 71 -0.701, 0.529, -0.886, 1.0); 72 #endif 73 74 gl_FragColor = conversion * channels; 75 } 76
