From 5fe6faf15ad95dfc515726bbde2cc667dd154849 Mon Sep 17 00:00:00 2001
From: itsmattkc <34096995+itsmattkc@users.noreply.github.com>
Date: Sat, 29 Oct 2022 09:59:45 -0700
Subject: [PATCH] ffmpeg: slightly improve performance of yuv2rgb

---
 app/codec/ffmpeg/ffmpegdecoder.cpp |  8 ++++----
 app/shaders/yuv2rgb.frag           | 19 +++++++------------
 2 files changed, 11 insertions(+), 16 deletions(-)

diff --git a/app/codec/ffmpeg/ffmpegdecoder.cpp b/app/codec/ffmpeg/ffmpegdecoder.cpp
index edb37d273..377fb5912 100644
--- a/app/codec/ffmpeg/ffmpegdecoder.cpp
+++ b/app/codec/ffmpeg/ffmpegdecoder.cpp
@@ -235,10 +235,10 @@ TexturePtr FFmpegDecoder::RetrieveVideoInternal(const RetrieveVideoParams &p)
           job.Insert(QStringLiteral("full_range"), NodeValue(NodeValue::kBoolean, hw_in->color_range == AVCOL_RANGE_JPEG));
 
           const int *yuv_coeffs = sws_getCoefficients(FFmpegUtils::GetSwsColorspaceFromAVColorSpace(hw_in->colorspace));
-          job.Insert(QStringLiteral("yuv_crv"), NodeValue(NodeValue::kInt, yuv_coeffs[0]));
-          job.Insert(QStringLiteral("yuv_cgu"), NodeValue(NodeValue::kInt, yuv_coeffs[2]));
-          job.Insert(QStringLiteral("yuv_cgv"), NodeValue(NodeValue::kInt, yuv_coeffs[3]));
-          job.Insert(QStringLiteral("yuv_cbu"), NodeValue(NodeValue::kInt, yuv_coeffs[1]));
+          job.Insert(QStringLiteral("yuv_crv"), NodeValue(NodeValue::kFloat, yuv_coeffs[0]/65536.0));
+          job.Insert(QStringLiteral("yuv_cgu"), NodeValue(NodeValue::kFloat, yuv_coeffs[2]/65536.0));
+          job.Insert(QStringLiteral("yuv_cgv"), NodeValue(NodeValue::kFloat, yuv_coeffs[3]/65536.0));
+          job.Insert(QStringLiteral("yuv_cbu"), NodeValue(NodeValue::kFloat, yuv_coeffs[1]/65536.0));
 
           int interlacing = 0;
           if (p.src_interlacing != VideoParams::kInterlaceNone) {
diff --git a/app/shaders/yuv2rgb.frag b/app/shaders/yuv2rgb.frag
index 8c40b5918..623badc4f 100644
--- a/app/shaders/yuv2rgb.frag
+++ b/app/shaders/yuv2rgb.frag
@@ -5,10 +5,10 @@ uniform sampler2D v_channel;
 uniform int bits_per_pixel;
 uniform bool full_range;
 
-uniform int yuv_crv;
-uniform int yuv_cgu;
-uniform int yuv_cgv;
-uniform int yuv_cbu;
+uniform float yuv_crv;
+uniform float yuv_cgu;
+uniform float yuv_cgv;
+uniform float yuv_cbu;
 
 uniform int interlacing;
 uniform int pixel_height;
@@ -51,15 +51,10 @@ void main()
   yuv.b = yuv.b - 0.5;
 
   // Use coefficients to weigh YUV into RGB
-  float crv = float(yuv_crv) / 65536.0;
-  float cgu = float(yuv_cgu) / 65536.0;
-  float cgv = float(yuv_cgv) / 65536.0;
-  float cbu = float(yuv_cbu) / 65536.0;
-
   vec4 rgba;
-  rgba.r = yuv.r + crv * yuv.b;
-  rgba.g = yuv.r - cgu * yuv.g - cgv * yuv.b;
-  rgba.b = yuv.r + cbu * yuv.g;
+  rgba.r = yuv.r + yuv_crv * yuv.b;
+  rgba.g = yuv.r - yuv_cgu * yuv.g - yuv_cgv * yuv.b;
+  rgba.b = yuv.r + yuv_cbu * yuv.g;
 
   // If the expected value is full range, transform to full range here
   if (full_range) {