fix pixel scale

4x4 subsampling
remove 4:3
2025-09-12 03:00:28 +02:00 · 2025-09-10 13:56:31 +02:00 · 2025-09-06 03:32:57 +02:00 · 2025-09-06 03:32:42 +02:00 · 2025-09-06 03:16:59 +02:00 · 2025-09-06 03:11:44 +02:00
9 changed files with 533 additions and 44 deletions
--- a/README.md
+++ b/README.md
@ -2,20 +2,42 @@

 Shaders for Avidemux with OpenGL support

-## gopro_8:7 - Fisheye removal for GoPro 11+, 8:7 ratio
+## GoPro fisheye removal
+
+![Sample image](https://blog.rozk.net/wp-content/uploads/2025/07/compare.png)
+
+### gopro_8:7 - Fisheye removal for GoPro 11+, 8:7 ratio, 60fps, HyperSmooth off
+
 - unfish_gopro_8:7.glsl  
 Shader for fisheye removal

- preset_gopro_8:7_1080.py  
-Preset for mp4, 1656x1080, constant bitrate
+- 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
+
+- preset_gopro_8:7_FullHD_1080p.py  
+Preset for mp4, FullHD, constant bitrate
+
+- preset_gopro_8:7_HD_720p.py  
+Preset for mp4, HD, constant bitrate

 - compute_gopro_8:7.py  
 Script to compute output FOV and frame widening

 ### Installation for BSD/GNU-Linux systems:
- Copy the preset to ~/.avidemux6/custom/
+
+- Copy the presets to ~/.avidemux6/custom/ or ~/.local/share/avidemux6/custom/
 - Copy the shader to /opt/rk/avidemux/ (or edit the preset to set the path)  

-_For commercial OS's, figure out the paths yourself :)_
+Or just run the script install_gopro_8:7.sh
+
+_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_1080" in the menu and save the video.
+
+- Load and edit video(s)
+- Select "Custom/preset_gopro..." in the menu
+- Add filters
+- Save the video
--- a/gopro_8:7/compute_gopro_8:7.py
+++ b/gopro_8:7/compute_gopro_8:7.py
@ -2,12 +2,14 @@
 # Computes fisheye removal parameters for GoPro 11+, 8:7 ratio, without hypersmooth,
 # keeping the vertical FOV and widening the frame to preserve the diagonal FOV

+# https://www.bobatkins.com/photography/technical/field_of_view.html
 # https://community.gopro.com/s/article/HERO11-Black-Mini-Digital-Lenses-FOV-Information?language=fr

 import math

 frame_width = 8
 frame_height = 7
+input_ratio = frame_width / frame_height

 input_vertical_fov = 108.0
 input_diagonal_fov = 156.0
@ -19,14 +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("HD             = %i x 720" % width_rounded_8(720))
--- a/gopro_8:7/preset_gopro_8:7_1080.py
+++ b/gopro_8:7/preset_gopro_8:7_1080.py
@ -1,18 +0,0 @@
-#PY  <- Needed to identify #
-
-# Custom preset for GoPro, 8:7 ratio, without hypersmooth, output widened scaled to Full HD (1080p)
-
-adm = Avidemux()
-adm.videoCodec("x264", "useAdvancedConfiguration=False", "general.params=CBR=16384", "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.addVideoFilter("shaderLoader", "shaderFile=/opt/rk/avidemux/unfish_gopro_8:7.glsl")
-adm.addVideoFilter("swscale", "width=1656", "height=1080", "algo=1", "sourceAR=0", "targetAR=0", "lockAR=False", "roundup=2")
-adm.setContainer("MP4", "muxerType=0", "optimize=1", "forceAspectRatio=False", "aspectRatio=1", "displayWidth=1280", "rotation=0", "clockfreq=0")
--- a/gopro_8:7/preset_gopro_8:7_4K_2160p.py
+++ b/gopro_8:7/preset_gopro_8:7_4K_2160p.py
@ -0,0 +1,109 @@
+#PY  <- Needed to identify #
+# RozK
+# Custom preset for GoPro, 8:7 ratio, without hypersmooth, output widened scaled to 4K (2160p)
+
+adm = Avidemux()
+adm.videoCodec(
+    "x264",
+    "useAdvancedConfiguration=False",
+    "general.params=CBR=32768",
+    "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=2",
+    "sourceAR=0",
+    "targetAR=0",
+    "lockAR=False",
+    "roundup=2")
+adm.setContainer(
+    "MP4",
+    "muxerType=0",
+    "optimize=1",
+    "forceAspectRatio=False",
+    "aspectRatio=1",
+    "displayWidth=1280",
+    "rotation=0",
+    "clockfreq=0")
--- a/gopro_8:7/preset_gopro_8:7_4K_youtube.py
+++ b/gopro_8:7/preset_gopro_8:7_4K_youtube.py
@ -0,0 +1,109 @@
+#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=2",
+    "sourceAR=0",
+    "targetAR=0",
+    "lockAR=False",
+    "roundup=2")
+adm.setContainer(
+    "MP4",
+    "muxerType=0",
+    "optimize=1",
+    "forceAspectRatio=False",
+    "aspectRatio=1",
+    "displayWidth=1280",
+    "rotation=0",
+    "clockfreq=0")
--- a/gopro_8:7/preset_gopro_8:7_FullHD_1080p.py
+++ b/gopro_8:7/preset_gopro_8:7_FullHD_1080p.py
@ -0,0 +1,109 @@
+#PY  <- Needed to identify #
+# RozK
+# Custom preset for GoPro, 8:7 ratio, without hypersmooth, output widened scaled to Full HD (1080p)
+
+adm = Avidemux()
+adm.videoCodec(
+    "x264",
+    "useAdvancedConfiguration=False",
+    "general.params=CBR=16384",
+    "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=1232",
+    "height=1080",
+    "algo=2",
+    "sourceAR=0",
+    "targetAR=0",
+    "lockAR=False",
+    "roundup=2")
+adm.setContainer(
+    "MP4",
+    "muxerType=0",
+    "optimize=1",
+    "forceAspectRatio=False",
+    "aspectRatio=1",
+    "displayWidth=1280",
+    "rotation=0",
+    "clockfreq=0")
--- a/gopro_8:7/preset_gopro_8:7_HD_720p.py
+++ b/gopro_8:7/preset_gopro_8:7_HD_720p.py
@ -0,0 +1,109 @@
+#PY  <- Needed to identify #
+# RozK
+# Custom preset for GoPro, 8:7 ratio, without hypersmooth, output widened scaled to HD (720p)
+
+adm = Avidemux()
+adm.videoCodec(
+    "x264",
+    "useAdvancedConfiguration=False",
+    "general.params=CBR=12288",
+    "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=824",
+    "height=720",
+    "algo=2",
+    "sourceAR=0",
+    "targetAR=0",
+    "lockAR=False",
+    "roundup=2")
+adm.setContainer(
+    "MP4",
+    "muxerType=0",
+    "optimize=1",
+    "forceAspectRatio=False",
+    "aspectRatio=1",
+    "displayWidth=1280",
+    "rotation=0",
+    "clockfreq=0")
--- a/gopro_8:7/unfish_gopro_8:7.glsl
+++ b/gopro_8:7/unfish_gopro_8:7.glsl
@ -5,32 +5,61 @@

 #extension GL_ARB_texture_rectangle: enable

+// TODO: investigate
+// precision highp float;
+
+// uniforms
 uniform sampler2DRect myTextureY;
 uniform sampler2DRect myTextureU;
 uniform sampler2DRect myTextureV;
 uniform vec2 myResolution;
 uniform float pts;

-const vec2 half_pixel = vec2(0.5, 0.5);
-
+// parameters
 const float input_fov = 156.0;
-const float output_fov = 119.789529;
+const float output_fov = 124.45;
+const vec2 pixel_scale = vec2(0.652485, 1.0);
+const int subsampling = 4;

-vec2 unfish(vec2 coord) {
-    float diameter = sqrt(dot(myResolution, myResolution));
-    vec2 center = myResolution * 0.5;
-    vec2 position = coord - center;
-    float input_distance = length(position);
-    float input_foc = diameter / radians(input_fov);
-    float output_foc = diameter / (2.0 * tan(radians(output_fov) * 0.5));
-    return center + position * (input_foc * atan(input_distance / output_foc) / input_distance);
+// subsampling constants
+const float substep = 1.0 / float(subsampling);
+const float substart = substep * 0.5 - 0.5;
+const float subscale = 1.0 / float(subsampling * subsampling);
+
+// variables
+vec2 center;
+float diameter;
+float input_len;
+float inv_output_len;
+
+vec4 unfish(const in vec2 coord) {
+    float len = max(0.001, length(coord));
+    vec2 y_coord = center + coord * ((input_len / len) * atan(len * inv_output_len));
+    vec2 uv_coord = y_coord * 0.5;
+    return vec4(
+        texture2DRect(myTextureY, y_coord).r,
+        texture2DRect(myTextureU, uv_coord).r,
+        texture2DRect(myTextureV, uv_coord).r,
+        1.0
+    );
 }

 void main() {
-    vec2 y_coord = unfish(gl_TexCoord[0].xy + half_pixel);
-    vec2 uv_coord = y_coord * 0.5;
-    vec4 y = texture2DRect(myTextureY, y_coord);
-    vec4 u = texture2DRect(myTextureU, uv_coord);
-    vec4 v = texture2DRect(myTextureV, uv_coord);
-    gl_FragColor = vec4(y.r, u.r, v.r, 1.0);
+    center = myResolution * 0.5;
+    diameter = length(myResolution);
+    input_len = diameter / radians(input_fov);
+    inv_output_len = (2.0 * tan(radians(output_fov * 0.5))) / diameter;
+
+    vec2 coord = gl_TexCoord[0].xy - center;
+    vec4 pixel = vec4(0.0, 0.0, 0.0, 0.0);
+
+    float x, y = substart;
+    for (int column = 0; column < subsampling; column++, y += substep) {
+        x = substart;
+        for (int row = 0; row < subsampling; row++, x += substep) {
+            pixel += unfish((coord + vec2(x, y)) * pixel_scale);
+        }
+    }
+
+    gl_FragColor = pixel * subscale;
 }
--- a/install_gopro_8:7.sh
+++ b/install_gopro_8:7.sh
@ -0,0 +1,18 @@
+#!/bin/sh
+# RozK
+
+if [ -d ~/.local/share/avidemux6 ]; then
+  mkdir -p ~/.local/share/avidemux6/custom
+  rm -f ~/.local/share/avidemux6/custom/preset_gopro*
+  cp gopro_8:7/preset_gopro* ~/.local/share/avidemux6/custom/
+fi
+
+if [ -d ~/.avidemux6 ]; then
+  mkdir -p ~/.avidemux6/custom
+  rm -f ~/.avidemux6/custom/preset_gopro*
+  cp gopro_8:7/preset_gopro* ~/.avidemux6/custom/
+fi
+
+sudo mkdir -p /opt/rk/avidemux
+sudo rm -f /opt/rk/avidemux/*
+sudo cp gopro_8:7/unfish_gopro_8:7.glsl /opt/rk/avidemux
Author	SHA1	Message	Date
Roz K	1bbe6653d2	fix pixel scale	2025-09-12 03:00:28 +02:00
Roz K	d32778977c	4x4 subsampling	2025-09-10 13:56:31 +02:00
Roz K	daa353e3ac	remove 4:3	2025-09-06 03:32:57 +02:00
Roz K	cf6ae78cd4	fix installation script	2025-09-06 03:32:42 +02:00
Roz K	4b581de6c3	lanczos downscaling 8:7	2025-09-06 03:16:59 +02:00
Roz K	48c1b43531	remove 8:7 denoiser	2025-09-06 03:11:44 +02:00
Roz K	de4e7266a0	resize 4:3 to 8:7	2025-08-01 05:06:00 +02:00
Roz K	00343ce52d	fisheye removel for 4:3 max superview	2025-07-31 04:43:45 +02:00
Roz K	142cf30662	remove QHD preset	2025-07-31 04:04:23 +02:00
Roz K	0b96dbf448	update readme	2025-07-29 05:18:05 +02:00
Roz K	24eb92378d	add a preset for youtube 4k with high bitrate	2025-07-29 05:10:00 +02:00
Roz K	39702c78ab	keep original format and scale pixels instead	2025-07-29 05:09:28 +02:00
Roz K	179ebc96d9	add a denoiser filter	2025-07-29 03:47:58 +02:00
Roz K	bea1eaea17	fix installation script	2025-07-29 03:45:48 +02:00
Roz K	e810812f93	update usage instructions	2025-06-20 05:38:42 +02:00
Roz K	c08226952b	update readme	2025-06-20 05:15:51 +02:00
Roz K	b2af23bd2e	add install script	2025-06-20 05:15:40 +02:00
Roz K	4a9852dc4e	add support for QHD, HD and 4K	2025-06-20 05:15:15 +02:00