blob: 699429022708eaf5571dcdd6ca22dd71f37d2931 [file] [log] [blame]
/*
* Copyright 2010, Google Inc.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions are
* met:
*
* * Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* * Redistributions in binary form must reproduce the above
* copyright notice, this list of conditions and the following disclaimer
* in the documentation and/or other materials provided with the
* distribution.
* * Neither the name of Google Inc. nor the names of its
* contributors may be used to endorse or promote products derived from
* this software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
* "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
* A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
* OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
* SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
* LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
* THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
* OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
/*
* This is an optimized version of the YUV to RGB conversion shader. This
* shader assumes the height of U and V planes is odd, which means the height
* of the original image is 2 modulo 4.
*/
uniform sampler2D textureSampler;
uniform sampler2D paritySampler;
varying vec2 lineCounter;
varying vec2 yPlane;
varying vec2 uPlane;
varying vec2 vPlane;
#if defined (USE_UNIFORM_MATRIX)
uniform mat4 conversion;
#endif
void main() {
/*
* If the height of the original image is even, offset_odd is not needed.
*/
vec2 offset_even = vec2(texture2D(paritySampler, lineCounter).x * 0.5, 0.0);
vec2 offset_odd = vec2(0.5 - offset_even.x, 0.0);
float yChannel = texture2D(textureSampler, yPlane).x;
float uChannel = texture2D(textureSampler, uPlane + offset_even).x;
float vChannel = texture2D(textureSampler, vPlane + offset_odd).x;
/*
* This does the colorspace conversion from Y'UV to RGB as a matrix
* multiply. It also does the offset of the U and V channels from
* [0,1] to [-.5,.5] as part of the transform.
*/
vec4 channels = vec4(yChannel, uChannel, vChannel, 1.0);
#if !defined(USE_UNIFORM_MATRIX)
mat4 conversion = mat4( 1.0, 1.0, 1.0, 0.0,
0.0, -0.344, 1.772, 0.0,
1.402, -0.714, 0.0, 0.0,
-0.701, 0.529, -0.886, 1.0);
#endif
gl_FragColor = conversion * channels;
}