update readme

README.md

@@ -3,9 +3,15 @@
 Shaders for Avidemux with OpenGL support
 
 ## gopro_8:7 - Fisheye removal for GoPro 11+, 8:7 ratio, 60fps, HyperSmooth off
+
+![Sample image](https://blog.rozk.net/wp-content/uploads/2025/07/compare.png)
+
 - unfish_gopro_8:7.glsl  
 Shader for fisheye removal
 
+- preset_gopro_8:7_4K_youtube.py  
+Preset for mp4, 4K, high bitrate
+
 - preset_gopro_8:7_4K_2160p.py  
 Preset for mp4, 4K, constant bitrate
 
@@ -22,12 +28,16 @@ Preset for mp4, QHD, constant bitrate
 Script to compute output FOV and frame widening
 
 ### Installation for BSD/GNU-Linux systems:
+
 - Copy the presets to ~/.avidemux6/custom/
 - Copy the shader to /opt/rk/avidemux/ (or edit the preset to set the path)  
 
 Or just run the script install_gopro_8:7.sh
-_For commercial OS's, figure out the paths yourself :)_
+
+_For commercial OS's, figure out the paths yourself, then edit the presets to fix the path to the .glsl file_
+
 ### Usage:
+
 - Load and edit video(s)
 - Select "Custom/preset_gopro_8:7_..." in the menu
 - Add filters

gopro_8:7/compute_gopro_8:7.py

@@ -9,6 +9,7 @@ import math
 
 frame_width = 8
 frame_height = 7
+input_ratio = frame_width / frame_height
 
 input_vertical_fov = 108.0
 input_diagonal_fov = 156.0
@@ -20,14 +21,14 @@ output_horizontal_length = math.sqrt((input_diagonal_length ** 2) / (input_verti
 output_diagonal_length = math.hypot(output_horizontal_length, input_vertical_length)
 output_diagonal_fov = math.degrees(math.atan(output_diagonal_length)) * 2.0
 
-output_ratio = output_horizontal_length / input_vertical_length
+output_ratio = 1.0 / (output_horizontal_length / input_vertical_length)
 
 print("Output FOV   = %f" % output_diagonal_fov)
 print("Output Ratio = %f" % output_ratio)
 print("= Resolutions =====================")
 
 def width_rounded_8(height):
-    width = int(round(height * output_ratio))
+    width = int(round(height * input_ratio))
     return ((width + 4) // 8) * 8
 
 print("QHD            = %i x 540" % width_rounded_8(540))

gopro_8:7/preset_gopro_8:7_4K_2160p.py

@@ -91,13 +91,20 @@ adm.addVideoFilter(
     "shaderFile=/opt/rk/avidemux/unfish_gopro_8:7.glsl")
 adm.addVideoFilter(
     "swscale",
-    "width=3312",
+    "width=2472",
     "height=2160",
     "algo=1",
     "sourceAR=0",
     "targetAR=0",
     "lockAR=False",
     "roundup=2")
+adm.addVideoFilter(
+    "MplayerDenoise3DHQ",
+    "mode=4",
+    "luma_spatial=4.000000",
+    "chroma_spatial=3.000000",
+    "luma_temporal=6.000000",
+    "chroma_temporal=4.500000")
 adm.setContainer(
     "MP4",
     "muxerType=0",

gopro_8:7/preset_gopro_8:7_4K_youtube.py

@@ -0,0 +1,116 @@
+#PY  <- Needed to identify #
+# RozK
+# Custom preset for GoPro, 8:7 ratio, without hypersmooth, output widened scaled to 4K (2160p), high bitrate
+
+adm = Avidemux()
+adm.videoCodec(
+    "x264",
+    "useAdvancedConfiguration=False",
+    "general.params=CBR=65536",
+    "general.threads=0",
+    "general.preset=slow",
+    "general.tuning=film",
+    "general.profile=high",
+    "general.fast_decode=False",
+    "general.zero_latency=False",
+    "general.fast_first_pass=True",
+    "general.blueray_compatibility=False",
+    "general.fake_interlaced=False",
+    "level=-1",
+    "vui.sar_height=1",
+    "vui.sar_width=1",
+    "vui.overscan=0",
+    "vui.vidformat=5",
+    "vui.fullrange=False",
+    "vui.colorprim=2",
+    "vui.transfer=2",
+    "vui.colmatrix=2",
+    "vui.chroma_loc=0",
+    "MaxRefFrames=3",
+    "MinIdr=25",
+    "MaxIdr=250",
+    "i_scenecut_threshold=40",
+    "intra_refresh=False",
+    "MaxBFrame=3",
+    "i_bframe_adaptive=1",
+    "i_bframe_bias=0",
+    "i_bframe_pyramid=2",
+    "b_deblocking_filter=True",
+    "i_deblocking_filter_alphac0=0",
+    "i_deblocking_filter_beta=0",
+    "cabac=True",
+    "interlaced=False",
+    "constrained_intra=False",
+    "tff=True",
+    "fake_interlaced=False",
+    "analyze.b_8x8=True",
+    "analyze.b_i4x4=True",
+    "analyze.b_i8x8=True",
+    "analyze.b_p8x8=True",
+    "analyze.b_p16x16=False",
+    "analyze.b_b16x16=False",
+    "analyze.weighted_pred=2",
+    "analyze.weighted_bipred=True",
+    "analyze.direct_mv_pred=1",
+    "analyze.chroma_offset=0",
+    "analyze.me_method=1",
+    "analyze.me_range=16",
+    "analyze.mv_range=-1",
+    "analyze.mv_range_thread=-1",
+    "analyze.subpel_refine=7",
+    "analyze.chroma_me=True",
+    "analyze.mixed_references=True",
+    "analyze.trellis=1",
+    "analyze.psy_rd=1.000000",
+    "analyze.psy_trellis=0.000000",
+    "analyze.fast_pskip=True",
+    "analyze.dct_decimate=True",
+    "analyze.noise_reduction=0",
+    "analyze.psy=True",
+    "analyze.intra_luma=11",
+    "analyze.inter_luma=21",
+    "ratecontrol.rc_method=0",
+    "ratecontrol.qp_constant=0",
+    "ratecontrol.qp_min=10",
+    "ratecontrol.qp_max=51",
+    "ratecontrol.qp_step=4",
+    "ratecontrol.bitrate=0",
+    "ratecontrol.rate_tolerance=1.000000",
+    "ratecontrol.vbv_max_bitrate=0",
+    "ratecontrol.vbv_buffer_size=0",
+    "ratecontrol.vbv_buffer_init=1",
+    "ratecontrol.ip_factor=1.400000",
+    "ratecontrol.pb_factor=1.300000",
+    "ratecontrol.aq_mode=1",
+    "ratecontrol.aq_strength=1.000000",
+    "ratecontrol.mb_tree=True",
+    "ratecontrol.lookahead=40")
+adm.clearVideoFilters()
+adm.addVideoFilter(
+    "shaderLoader",
+    "shaderFile=/opt/rk/avidemux/unfish_gopro_8:7.glsl")
+adm.addVideoFilter(
+    "swscale",
+    "width=2472",
+    "height=2160",
+    "algo=1",
+    "sourceAR=0",
+    "targetAR=0",
+    "lockAR=False",
+    "roundup=2")
+adm.addVideoFilter(
+    "MplayerDenoise3DHQ",
+    "mode=4",
+    "luma_spatial=4.000000",
+    "chroma_spatial=3.000000",
+    "luma_temporal=6.000000",
+    "chroma_temporal=4.500000")
+adm.setContainer(
+    "MP4",
+    "muxerType=0",
+    "optimize=1",
+    "forceAspectRatio=False",
+    "aspectRatio=1",
+    "displayWidth=1280",
+    "rotation=0",
+    "clockfreq=0")

gopro_8:7/preset_gopro_8:7_FullHD_1080p.py

@@ -91,13 +91,20 @@ adm.addVideoFilter(
     "shaderFile=/opt/rk/avidemux/unfish_gopro_8:7.glsl")
 adm.addVideoFilter(
     "swscale",
-    "width=1656",
+    "width=1232",
     "height=1080",
     "algo=1",
     "sourceAR=0",
     "targetAR=0",
     "lockAR=False",
     "roundup=2")
+adm.addVideoFilter(
+    "MplayerDenoise3DHQ",
+    "mode=4",
+    "luma_spatial=4.000000",
+    "chroma_spatial=3.000000",
+    "luma_temporal=6.000000",
+    "chroma_temporal=4.500000")
 adm.setContainer(
     "MP4",
     "muxerType=0",

gopro_8:7/preset_gopro_8:7_HD_720p.py

@@ -91,13 +91,20 @@ adm.addVideoFilter(
     "shaderFile=/opt/rk/avidemux/unfish_gopro_8:7.glsl")
 adm.addVideoFilter(
     "swscale",
-    "width=1104",
+    "width=824",
     "height=720",
     "algo=1",
     "sourceAR=0",
     "targetAR=0",
     "lockAR=False",
     "roundup=2")
+adm.addVideoFilter(
+    "MplayerDenoise3DHQ",
+    "mode=4",
+    "luma_spatial=4.000000",
+    "chroma_spatial=3.000000",
+    "luma_temporal=6.000000",
+    "chroma_temporal=4.500000")
 adm.setContainer(
     "MP4",
     "muxerType=0",

gopro_8:7/preset_gopro_8:7_QHD_540p.py

@@ -91,13 +91,20 @@ adm.addVideoFilter(
     "shaderFile=/opt/rk/avidemux/unfish_gopro_8:7.glsl")
 adm.addVideoFilter(
     "swscale",
-    "width=832",
+    "width=616",
     "height=540",
     "algo=1",
     "sourceAR=0",
     "targetAR=0",
     "lockAR=False",
     "roundup=2")
+adm.addVideoFilter(
+    "MplayerDenoise3DHQ",
+    "mode=4",
+    "luma_spatial=4.000000",
+    "chroma_spatial=3.000000",
+    "luma_temporal=6.000000",
+    "chroma_temporal=4.500000")
 adm.setContainer(
     "MP4",
     "muxerType=0",

gopro_8:7/unfish_gopro_8:7.glsl

@@ -13,17 +13,19 @@ uniform float pts;
 
 const vec2 half_pixel = vec2(0.5, 0.5);
 
+const vec2 input_scale = vec2(0.652485, 1.0);
 const float input_fov = 156.0;
 const float output_fov = 119.789529;
 
 vec2 unfish(vec2 coord) {
     float diameter = sqrt(dot(myResolution, myResolution));
     vec2 center = myResolution * 0.5;
-    vec2 position = coord - center;
+    vec2 input_position = (coord - center) * input_scale;
-    float input_distance = length(position);
+    float input_distance = length(input_position);
-    float input_foc = diameter / radians(input_fov);
+    float input_len = diameter / radians(input_fov);
-    float output_foc = diameter / (2.0 * tan(radians(output_fov) * 0.5));
+    float output_len = diameter / (2.0 * tan(radians(output_fov) * 0.5));
-    return center + position * (input_foc * atan(input_distance / output_foc) / input_distance);
+    float unfish_ratio = input_len * atan(input_distance / output_len) / input_distance;
+    return center + input_position * unfish_ratio;
 }
 
 void main() {