no rotate

README.md

@@ -2,12 +2,24 @@
 
 Shaders for Avidemux with OpenGL support
 
-## GoPro fisheye removal
+## GoPro fisheye removal v2.0
 
 ![Sample image](https://blog.rozk.net/wp-content/uploads/2025/07/compare.png)
 
 ### gopro_8:7 - Fisheye removal for GoPro 11+, 8:7 ratio, 4K, HyperSmooth off
 
+#### What's new
+
+- New method based on sensor size and focal length
+- Accurate frame widening
+- Fisheye aware subsampling
+- Rec.709 colorspace conversion _(requires to patch and rebuild Avidemux)_
+
+#### Content
+
+- avidemux.patch  
+A patch to use GL_NEAREST instead of GL_LINEAR for the luminance channel (the shader is implementing bilinear interpolation with colorspace conversion).
+
 - unfish_gopro_8:7.py  
 Script to compute the parameters
 
@@ -15,9 +27,9 @@ Script to compute the parameters
 Shader for fisheye removal
 
 - preset_gopro_8:7.py  
-Preset for mp4, 4K, high quality
+Preset for mp4, 4K, high quality compression
 
-### Installation for BSD/GNU-Linux systems:
+#### Installation for BSD/GNU-Linux systems:
 
 - Copy the preset into ~/.avidemux6/custom or ~/.local/share/avidemux6/custom
 - Copy the shader into /opt/rk/avidemux (or edit the preset to set the path)  
@@ -26,7 +38,7 @@ Or just run the script install_gopro_8:7.sh
 
 _For commercial OS's, figure out the paths yourself, then edit the preset to fix the path to the .glsl file_
 
-### Usage:
+#### Usage:
 
 - Load and edit video(s)
 - Select "Custom/preset_gopro_8:7" in the menu

gopro_8:7/avidemux.patch

@@ -0,0 +1,28 @@
+From 42e283d8b7c5d950ff81cff788398665410bcd6b Mon Sep 17 00:00:00 2001
+Message-Id: <42e283d8b7c5d950ff81cff788398665410bcd6b.1759271917.git.roz@rozk.net>
+From: Roz K <roz@rozk.net>
+Date: Wed, 1 Oct 2025 00:38:19 +0200
+Subject: [PATCH] OpenGL: use nearest interpolation filter for Y texture
+
+---
+ avidemux/qt4/ADM_openGL/src/ADM_openGl.cpp | 4 ++--
+ 1 file changed, 2 insertions(+), 2 deletions(-)
+
+diff --git a/avidemux/qt4/ADM_openGL/src/ADM_openGl.cpp b/avidemux/qt4/ADM_openGL/src/ADM_openGl.cpp
+index ea389a1e6..b97a2034f 100644
+--- a/avidemux/qt4/ADM_openGL/src/ADM_openGl.cpp
++++ b/avidemux/qt4/ADM_openGL/src/ADM_openGl.cpp
+@@ -236,8 +236,8 @@ void ADM_coreQtGl::uploadAllPlanes(ADMImage *image)
+         glBindTexture(GL_TEXTURE_RECTANGLE_NV, texName[xplane]); // Use tex engine "texNum"
+         glTexParameteri(GL_TEXTURE_RECTANGLE_NV, GL_TEXTURE_WRAP_S, GL_CLAMP_TO_EDGE);
+         glTexParameteri(GL_TEXTURE_RECTANGLE_NV, GL_TEXTURE_WRAP_T, GL_CLAMP_TO_EDGE);
+-        glTexParameteri(GL_TEXTURE_RECTANGLE_NV, GL_TEXTURE_MAG_FILTER, GL_LINEAR);
+-        glTexParameteri(GL_TEXTURE_RECTANGLE_NV, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
++        glTexParameteri(GL_TEXTURE_RECTANGLE_NV, GL_TEXTURE_MAG_FILTER, plane == PLANAR_Y ? GL_NEAREST : GL_LINEAR);
++        glTexParameteri(GL_TEXTURE_RECTANGLE_NV, GL_TEXTURE_MIN_FILTER, plane == PLANAR_Y ? GL_NEAREST : GL_LINEAR);
+         glTexEnvi(GL_TEXTURE_ENV, GL_TEXTURE_ENV_MODE, GL_MODULATE);
+ 
+         int pitch = (nbComponents == 1)? image->GetPitch(plane) : ALIGNX(image->GetWidth(plane),16); // ???
+-- 
+2.39.5
+

gopro_8:7/preset_gopro_8:7.py

@@ -101,16 +101,9 @@ adm.videoCodec(
     "ratecontrol.lookahead=40")
 adm.addVideoFilter(
     "shaderLoader", "shaderFile=/opt/rk/avidemux/unfish_gopro_8:7.glsl")
-adm.addVideoFilter(
-    "crop",
-    "top=80",
-    "bottom=0",
-    "left=0",
-    "right=0",
-    "ar_select=0")
 adm.addVideoFilter(
     "swscale",
-    "width=2880",
+    "width=2832",
     "height=2160",
     "algo=2",
     "sourceAR=0",

gopro_8:7/unfish_gopro_8:7.glsl

@@ -20,7 +20,7 @@
 
 #define color_conversion
 #define texture_filtering
-#define rotate_180
+//#define rotate_180
 //#define debug_borders
 
 #undef highp // defined by Qt-OpenGl
@@ -37,9 +37,9 @@ uniform float pts;
 // parameters
 
 const vec2  sensor_size              = vec2(5.949440, 5.205760);
-const vec2  rectilinear_scale        = vec2(1.138819, 1.0);
+const vec2  rectilinear_scale        = vec2(1.147370, 1.0);
-const float equidistant_focal_length = 2.970000;
+const float equidistant_focal_length = 2.920000;
-const float rectilinear_focal_length = 2.167601;
+const float rectilinear_focal_length = 2.102263;
 
 // constants
 
@@ -78,39 +78,30 @@ const float luminance_min   =  16.0 / 255.0;
 const float luminance_max   = 235.0 / 255.0;
 const float luminance_range = luminance_max - luminance_min;
 
-const vec2 chroma_min    = vec2( 16.0 / 255.0);
-const vec2 chroma_max    = vec2(240.0 / 255.0);
-const vec2 chroma_range  = chroma_max - chroma_min;
-const vec2 chroma_center = vec2(0.5, 0.5);
-
-const vec3 yuv_min    = vec3(luminance_min,   chroma_min);
-const vec3 yuv_range  = vec3(luminance_range, chroma_range);
-const vec3 yuv_center = vec3(0.0, chroma_center);
-
 float decode_luminance(const in float x) {
     float y = (x - luminance_min) / luminance_range;
     return (y < 0.081) ? (y / 4.5) : pow((y + 0.099) / 1.099, 1.0 / 0.45);
 }
 
-vec2 decode_chroma(const in vec2 yz) {
+float encode_luminance(const in float l) {
-    return (yz - chroma_min) / chroma_range - chroma_center;
+    float x = (l < 0.018) ? (l * 4.5) : (pow(l, 0.45) * 1.099 - 0.099);
+    return x * luminance_range + luminance_min;
 }
 
-vec3 decode_pixel(const in vec3 pixel) {
+vec3 decode_ycbcr(const in vec3 pixel) {
-    return vec3(decode_luminance(pixel.x), decode_chroma(pixel.yz));
+    return vec3(decode_luminance(pixel.x), pixel.yz);
 }
 
-vec3 encode_color(const in vec3 color) {
+vec3 encode_ycbcr(const in vec3 color) {
-    float y = (color.x < 0.018) ? (color.x * 4.5) : (pow(color.x, 0.45) * 1.099 - 0.099);
+    return vec3(encode_luminance(color.x), color.yz);
-    return (vec3(y, color.yz) + yuv_center) * yuv_range + yuv_min;
 }
 
 #else
 
 #define decode_luminance(_x) (_x)
-#define decode_chroma(_yz)   (_yz)
+#define encode_luminance(_l) (_l)
-#define decode_pixel(_pixel) (_pixel)
+#define decode_ycbcr(_pixel) (_pixel)
-#define encode_color(_color) (_color)
+#define encode_ycbcr(_color) (_color)
 
 #endif
 
@@ -125,46 +116,27 @@ const vec2 corner_b = vec2(1.0, 0.0) + half_pixel;
 const vec2 corner_c = vec2(0.0, 1.0) + half_pixel;
 const vec2 corner_d = vec2(1.0, 1.0) + half_pixel;
 
-vec2 bilinear_params(const in vec2 coord, out vec2 a, out vec2 b, out vec2 c, out vec2 d) {
-    vec2 i, f = modf(coord - half_pixel, i);
-    a = i + corner_a;
-    b = i + corner_b;
-    c = i + corner_c;
-    d = i + corner_d;
-    return f;
-}
-
 vec3 texture_filter(const in vec2 y_coord) {
-    vec2 a, b, c, d, f = bilinear_params(y_coord, a, b, c, d);
+    vec2 i, f = modf(y_coord - half_pixel, i);
     float luminance = mix(
         mix(
-            decode_luminance(texture2DRect(myTextureY, a).x),
+            decode_luminance(texture2DRect(myTextureY, i + corner_a).x),
-            decode_luminance(texture2DRect(myTextureY, b).x),
+            decode_luminance(texture2DRect(myTextureY, i + corner_b).x),
             f.x),
         mix(
-            decode_luminance(texture2DRect(myTextureY, c).x),
+            decode_luminance(texture2DRect(myTextureY, i + corner_c).x),
-            decode_luminance(texture2DRect(myTextureY, d).x),
+            decode_luminance(texture2DRect(myTextureY, i + corner_d).x),
             f.x),
         f.y);
-    f = bilinear_params(y_coord * 0.5, a, b, c, d);
+    vec2 uv_coord = y_coord * 0.5;
-    vec2 chroma = mix(
+    return vec3(luminance, texture2DRect(myTextureU, uv_coord).x, texture2DRect(myTextureV, uv_coord).x);
-        mix(
-            decode_chroma(vec2(texture2DRect(myTextureU, a).x, texture2DRect(myTextureV, a).x)),
-            decode_chroma(vec2(texture2DRect(myTextureU, b).x, texture2DRect(myTextureV, b).x)),
-            f.x),
-        mix(
-            decode_chroma(vec2(texture2DRect(myTextureU, c).x, texture2DRect(myTextureV, c).x)),
-            decode_chroma(vec2(texture2DRect(myTextureU, d).x, texture2DRect(myTextureV, d).x)),
-            f.x),
-        f.y);
-    return vec3(luminance, chroma);
 }
 
 #else
 
 vec3 texture_filter(const in vec2 y_coord) {
     vec2 uv_coord = y_coord * 0.5;
-    return decode_pixel(vec3(
+    return decode_ycbcr(vec3(
         texture2DRect(myTextureY, y_coord).x,
         texture2DRect(myTextureU, uv_coord).x,
         texture2DRect(myTextureV, uv_coord).x));
@@ -196,5 +168,5 @@ void main() {
             color += texture_sample(coord + offset);
         }
     }
-    gl_FragColor = vec4(encode_color(color * subsampling_scale), 1.0);
+    gl_FragColor = vec4(encode_ycbcr(color * subsampling_scale), 1.0);
 }

gopro_8:7/unfish_gopro_8:7.py

@@ -41,7 +41,7 @@ print("gopro  size : horizontal = %7.3f, vertical = %7.3f, diagonal = %7.3f (mm)
 
 # https://thinglabs.io/gopro-focal-length-guide
 
-gopro_focal_length = 2.97 # mm
+gopro_focal_length = 2.92
 
 gopro_radius_horizontal = gopro_size_horizontal * 0.5
 gopro_radius_vertical   = gopro_size_vertical   * 0.5
@@ -92,33 +92,21 @@ output_size_vertical   = gopro_size_vertical
 
 output_scale_horizontal = output_size_horizontal / gopro_size_horizontal
 
-print("""// parameters
+print("""// parameters\n
-const vec2 sensor_size = vec2(%.6f, %.6f);
+const vec2  sensor_size              = vec2(%.6f, %.6f);
+const vec2  rectilinear_scale        = vec2(%.6f, 1.0);
 const float equidistant_focal_length = %.6f;
-const float rectilinear_focal_length = %.6f;
+const float rectilinear_focal_length = %.6f;""" % (
-const vec2 rectilinear_scale = vec2(%.6F, 1.0);""" % (
     gopro_size_horizontal, gopro_size_vertical,
+    output_scale_horizontal,
     gopro_focal_length,
-    rectilinear_focal_length_vertical,
+    rectilinear_focal_length_vertical)
-    output_scale_horizontal)
 )
 
 print("\n--- filters parameters ---\n")
 
-output_ratio_horizontal = 4.0
-output_ratio_vertical   = 3.0
-
-output_crop_ratio      = output_ratio_vertical / (output_ratio_horizontal / output_scale_horizontal)
-
-output_crop_horizontal = gopro_texture_horizontal
-output_crop_vertical   = output_crop_horizontal * output_crop_ratio
-
-print("crop  : width = %d, height = %d" % (
-    output_crop_horizontal,
-    round(output_crop_vertical)))
-
 def print_output_array(array_vertical):
-    array_horizontal = (array_vertical / output_ratio_vertical) * output_ratio_horizontal
+    array_horizontal = (array_vertical / gopro_array_vertical) * gopro_array_horizontal * output_scale_horizontal
     print("resize: width = %d, height = %d" % (
         round(array_horizontal / 4.0) * 4,
         array_vertical))