From d58b6b908ea130e9422b08b5b3b460b48da7d337 Mon Sep 17 00:00:00 2001 From: Tomasz Olszak Date: Tue, 13 Jun 2017 11:24:47 +0200 Subject: Improve quality of YUVY and UYVY rendering Idea is to upload YUYV/UYVY data as 2 textures and use GL_LINEAR like in biplanar formats. Having proper interpolation of only one texture (using e.g. mix function) resulted in vertical and horizontal 1 pixel stripes depending on scale. The reason was float precision and unexpected value of fract function. Additionally branching in shader is expensive so this solution should be more performant. Task-number: QTBUG-62155 Change-Id: I7ceeb09b4a54eecd16640a626b499d638b52c127 Reviewed-by: Christian Stromme --- src/qtmultimediaquicktools/shaders/uyvyvideo.frag | 18 ++++-------------- 1 file changed, 4 insertions(+), 14 deletions(-) (limited to 'src/qtmultimediaquicktools/shaders/uyvyvideo.frag') diff --git a/src/qtmultimediaquicktools/shaders/uyvyvideo.frag b/src/qtmultimediaquicktools/shaders/uyvyvideo.frag index 905035703..5c62441c2 100644 --- a/src/qtmultimediaquicktools/shaders/uyvyvideo.frag +++ b/src/qtmultimediaquicktools/shaders/uyvyvideo.frag @@ -1,22 +1,12 @@ -uniform sampler2D yuvTexture; // UYVY macropixel texture passed as RGBA format -uniform mediump float imageWidth; // The UYVY texture appears to the shader with 1/2 the image width since we use the RGBA format to pass UYVY +uniform sampler2D yTexture; // Y component passed as GL_LUMINANCE_ALPHA, in uyvy Y = a +uniform sampler2D uvTexture; // UV component passed as RGBA macropixel, in uyvy U = r, V = b uniform mediump mat4 colorMatrix; uniform lowp float opacity; - varying highp vec2 qt_TexCoord; void main() { - // For U0 Y0 V0 Y1 macropixel, lookup Y0 or Y1 based on whether - // the original texture x coord is even or odd. - mediump float Y; - if (fract(floor(qt_TexCoord.x * imageWidth + 0.5) / 2.0) > 0.0) - Y = texture2D(yuvTexture, qt_TexCoord).a; // odd so choose Y1 - else - Y = texture2D(yuvTexture, qt_TexCoord).g; // even so choose Y0 - mediump float Cb = texture2D(yuvTexture, qt_TexCoord).r; - mediump float Cr = texture2D(yuvTexture, qt_TexCoord).b; + mediump vec3 YUV = vec3(texture2D(yTexture, qt_TexCoord).a, texture2D(uvTexture, qt_TexCoord).rb); - mediump vec4 color = vec4(Y, Cb, Cr, 1.0); - gl_FragColor = colorMatrix * color * opacity; + gl_FragColor = colorMatrix * vec4(YUV, 1.0) * opacity; } -- cgit v1.2.1