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#if(XBMC_texture_rectangle)
# extension GL_ARB_texture_rectangle : enable
# define texture2D texture2DRect
# define sampler2D sampler2DRect
#endif
uniform sampler2D m_sampY;
uniform sampler2D m_sampU;
uniform sampler2D m_sampV;
varying vec2 m_cordY;
varying vec2 m_cordU;
varying vec2 m_cordV;
uniform mat4 m_yuvmat;
uniform float m_stretch;
#if (XBMC_STRETCH)
#define POSITION(pos) stretch(pos)
vec2 stretch(vec2 pos)
{
// our transform should map [0..1] to itself, with f(0) = 0, f(1) = 1, f(0.5) = 0.5, and f'(0.5) = b.
// a simple curve to do this is g(x) = b(x-0.5) + (1-b)2^(n-1)(x-0.5)^n + 0.5
// where the power preserves sign. n = 2 is the simplest non-linear case (required when b != 1)
float x = pos.x - 0.5;
return vec2(mix(2.0 * x * abs(x), x, m_stretch) + 0.5, pos.y);
}
#else
#define POSITION(pos) (pos)
#endif
void main()
{
vec4 yuv, rgb;
yuv.rgba = vec4( texture2D(m_sampY, POSITION(m_cordY)).r
, texture2D(m_sampU, POSITION(m_cordU)).r
, texture2D(m_sampV, POSITION(m_cordV)).a
, 1.0 );
rgb = m_yuvmat * yuv;
rgb.a = gl_Color.a;
gl_FragColor = rgb;
}
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