Commit c1fd7be5c0 for ffmpeg

commit c1fd7be5c0ba8342ea790bbcf0c7bd63dfa510e7
Author: Michael Niedermayer <michael@niedermayer.cc>
Date:   Tue Oct 27 00:02:57 2026 +0100

    avfilter/owdenoise: move the undecimated 9/7 wavelet transform into wavelet97.c

    Makes the transform usable by other filters. The analysis filter taps become
    a parameter so the same code can also propagate variances with squared taps.

    Assisted-by: Claude

diff --git a/libavfilter/Makefile b/libavfilter/Makefile
index 6d052562e8..47b5899700 100644
--- a/libavfilter/Makefile
+++ b/libavfilter/Makefile
@@ -432,7 +432,7 @@ OBJS-$(CONFIG_OVERLAY_OPENCL_FILTER)         += vf_overlay_opencl.o opencl.o \
 OBJS-$(CONFIG_OVERLAY_QSV_FILTER)            += vf_overlay_qsv.o framesync.o
 OBJS-$(CONFIG_OVERLAY_VAAPI_FILTER)          += vf_overlay_vaapi.o framesync.o vaapi_vpp.o
 OBJS-$(CONFIG_OVERLAY_VULKAN_FILTER)         += vf_overlay_vulkan.o vulkan.o vulkan_filter.o
-OBJS-$(CONFIG_OWDENOISE_FILTER)              += vf_owdenoise.o
+OBJS-$(CONFIG_OWDENOISE_FILTER)              += vf_owdenoise.o wavelet97.o
 OBJS-$(CONFIG_PAD_FILTER)                    += vf_pad.o
 OBJS-$(CONFIG_PAD_CUDA_FILTER)               += vf_pad_cuda.o vf_pad_cuda.ptx.o cuda/load_helper.o
 OBJS-$(CONFIG_PAD_OPENCL_FILTER)             += vf_pad_opencl.o opencl.o opencl/pad.o
diff --git a/libavfilter/vf_owdenoise.c b/libavfilter/vf_owdenoise.c
index 746c55a6e5..55d6dd0f22 100644
--- a/libavfilter/vf_owdenoise.c
+++ b/libavfilter/vf_owdenoise.c
@@ -41,6 +41,7 @@
 #include "avfilter.h"
 #include "filters.h"
 #include "video.h"
+#include "wavelet97.h"

 typedef struct OWDenoiseContext {
     const AVClass *class;
@@ -77,116 +78,6 @@ DECLARE_ALIGNED(8, static const uint8_t, dither)[8][8] = {
     { 42,  26,  38,  22,  41,  25,  37,  21 },
 };

-static const double coeff[2][5] = {
-    {
-         0.6029490182363579  * M_SQRT2,
-         0.2668641184428723  * M_SQRT2,
-        -0.07822326652898785 * M_SQRT2,
-        -0.01686411844287495 * M_SQRT2,
-         0.02674875741080976 * M_SQRT2,
-    },{
-         1.115087052456994   / M_SQRT2,
-        -0.5912717631142470  / M_SQRT2,
-        -0.05754352622849957 / M_SQRT2,
-         0.09127176311424948 / M_SQRT2,
-    }
-};
-
-static const double icoeff[2][5] = {
-    {
-         1.115087052456994   / M_SQRT2,
-         0.5912717631142470  / M_SQRT2,
-        -0.05754352622849957 / M_SQRT2,
-        -0.09127176311424948 / M_SQRT2,
-    },{
-         0.6029490182363579  * M_SQRT2,
-        -0.2668641184428723  * M_SQRT2,
-        -0.07822326652898785 * M_SQRT2,
-         0.01686411844287495 * M_SQRT2,
-         0.02674875741080976 * M_SQRT2,
-    }
-};
-
-
-static inline void decompose(float *dst_l, float *dst_h, const float *src,
-                             int linesize, int w)
-{
-    int x, i;
-    for (x = 0; x < w; x++) {
-        double sum_l = src[x * linesize] * coeff[0][0];
-        double sum_h = src[x * linesize] * coeff[1][0];
-        for (i = 1; i <= 4; i++) {
-            const double s = src[avpriv_mirror(x - i, w - 1) * linesize]
-                           + src[avpriv_mirror(x + i, w - 1) * linesize];
-
-            sum_l += coeff[0][i] * s;
-            sum_h += coeff[1][i] * s;
-        }
-        dst_l[x * linesize] = sum_l;
-        dst_h[x * linesize] = sum_h;
-    }
-}
-
-static inline void compose(float *dst, const float *src_l, const float *src_h,
-                           int linesize, int w)
-{
-    int x, i;
-    for (x = 0; x < w; x++) {
-        double sum_l = src_l[x * linesize] * icoeff[0][0];
-        double sum_h = src_h[x * linesize] * icoeff[1][0];
-        for (i = 1; i <= 4; i++) {
-            const int x0 = avpriv_mirror(x - i, w - 1) * linesize;
-            const int x1 = avpriv_mirror(x + i, w - 1) * linesize;
-
-            sum_l += icoeff[0][i] * (src_l[x0] + src_l[x1]);
-            sum_h += icoeff[1][i] * (src_h[x0] + src_h[x1]);
-        }
-        dst[x * linesize] = (sum_l + sum_h) * 0.5;
-    }
-}
-
-static inline void decompose2D(float *dst_l, float *dst_h, const float *src,
-                               int xlinesize, int ylinesize,
-                               int step, int w, int h)
-{
-    int y, x;
-    for (y = 0; y < h; y++)
-        for (x = 0; x < step; x++)
-            decompose(dst_l + ylinesize*y + xlinesize*x,
-                      dst_h + ylinesize*y + xlinesize*x,
-                      src   + ylinesize*y + xlinesize*x,
-                      step * xlinesize, (w - x + step - 1) / step);
-}
-
-static inline void compose2D(float *dst, const float *src_l, const float *src_h,
-                             int xlinesize, int ylinesize,
-                             int step, int w, int h)
-{
-    int y, x;
-    for (y = 0; y < h; y++)
-        for (x = 0; x < step; x++)
-            compose(dst   + ylinesize*y + xlinesize*x,
-                    src_l + ylinesize*y + xlinesize*x,
-                    src_h + ylinesize*y + xlinesize*x,
-                    step * xlinesize, (w - x + step - 1) / step);
-}
-
-static void decompose2D2(float *dst[4], float *src, float *temp[2],
-                         int linesize, int step, int w, int h)
-{
-    decompose2D(temp[0], temp[1], src,     1, linesize, step, w, h);
-    decompose2D( dst[0],  dst[1], temp[0], linesize, 1, step, h, w);
-    decompose2D( dst[2],  dst[3], temp[1], linesize, 1, step, h, w);
-}
-
-static void compose2D2(float *dst, float *src[4], float *temp[2],
-                       int linesize, int step, int w, int h)
-{
-    compose2D(temp[0],  src[0],  src[1], linesize, 1, step, h, w);
-    compose2D(temp[1],  src[2],  src[3], linesize, 1, step, h, w);
-    compose2D(dst,     temp[0], temp[1], 1, linesize, step, w, h);
-}
-
 static void filter(OWDenoiseContext *s,
                    uint8_t       *dst, int dst_linesize,
                    const uint8_t *src, int src_linesize,
@@ -211,7 +102,8 @@ static void filter(OWDenoiseContext *s,
     }

     for (i = 0; i < depth; i++)
-        decompose2D2(s->plane[i + 1], s->plane[i][0], s->plane[0] + 1, s->linesize, 1<<i, width, height);
+        ff_wavelet97_decompose(s->plane[i + 1], s->plane[i][0], s->plane[0] + 1,
+                               ff_wavelet97_coeff, s->linesize, 1<<i, width, height);

     for (i = 0; i < depth; i++) {
         for (j = 1; j < 4; j++) {
@@ -227,7 +119,8 @@ static void filter(OWDenoiseContext *s,
         }
     }
     for (i = depth-1; i >= 0; i--)
-        compose2D2(s->plane[i][0], s->plane[i + 1], s->plane[0] + 1, s->linesize, 1<<i, width, height);
+        ff_wavelet97_compose(s->plane[i][0], s->plane[i + 1], s->plane[0] + 1,
+                             s->linesize, 1<<i, width, height);

     if (s->pixel_depth <= 8) {
         for (y = 0; y < height; y++) {
diff --git a/libavfilter/wavelet97.c b/libavfilter/wavelet97.c
new file mode 100644
index 0000000000..3a2a52e417
--- /dev/null
+++ b/libavfilter/wavelet97.c
@@ -0,0 +1,135 @@
+/*
+ * Copyright (c) 2007 Michael Niedermayer <michaelni@gmx.at>
+ * Copyright (c) 2013 Clément Bœsch <u pkh me>
+ *
+ * This file is part of FFmpeg.
+ *
+ * FFmpeg is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation; either
+ * version 2.1 of the License, or (at your option) any later version.
+ *
+ * FFmpeg is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with FFmpeg; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
+ */
+
+#include "libavutil/internal.h"
+#include "libavutil/mathematics.h"
+#include "wavelet97.h"
+
+const double ff_wavelet97_coeff[2][5] = {
+    {
+         0.6029490182363579  * M_SQRT2,
+         0.2668641184428723  * M_SQRT2,
+        -0.07822326652898785 * M_SQRT2,
+        -0.01686411844287495 * M_SQRT2,
+         0.02674875741080976 * M_SQRT2,
+    },{
+         1.115087052456994   / M_SQRT2,
+        -0.5912717631142470  / M_SQRT2,
+        -0.05754352622849957 / M_SQRT2,
+         0.09127176311424948 / M_SQRT2,
+    }
+};
+
+static const double icoeff[2][5] = {
+    {
+         1.115087052456994   / M_SQRT2,
+         0.5912717631142470  / M_SQRT2,
+        -0.05754352622849957 / M_SQRT2,
+        -0.09127176311424948 / M_SQRT2,
+    },{
+         0.6029490182363579  * M_SQRT2,
+        -0.2668641184428723  * M_SQRT2,
+        -0.07822326652898785 * M_SQRT2,
+         0.01686411844287495 * M_SQRT2,
+         0.02674875741080976 * M_SQRT2,
+    }
+};
+
+static inline void decompose(float *dst_l, float *dst_h, const float *src,
+                             const double coeff[2][5], int linesize, int w)
+{
+    int x, i;
+    for (x = 0; x < w; x++) {
+        double sum_l = src[x * linesize] * coeff[0][0];
+        double sum_h = src[x * linesize] * coeff[1][0];
+        for (i = 1; i <= 4; i++) {
+            const double s = src[avpriv_mirror(x - i, w - 1) * linesize]
+                           + src[avpriv_mirror(x + i, w - 1) * linesize];
+
+            sum_l += coeff[0][i] * s;
+            sum_h += coeff[1][i] * s;
+        }
+        dst_l[x * linesize] = sum_l;
+        dst_h[x * linesize] = sum_h;
+    }
+}
+
+static inline void compose(float *dst, const float *src_l, const float *src_h,
+                           int linesize, int w)
+{
+    int x, i;
+    for (x = 0; x < w; x++) {
+        double sum_l = src_l[x * linesize] * icoeff[0][0];
+        double sum_h = src_h[x * linesize] * icoeff[1][0];
+        for (i = 1; i <= 4; i++) {
+            const int x0 = avpriv_mirror(x - i, w - 1) * linesize;
+            const int x1 = avpriv_mirror(x + i, w - 1) * linesize;
+
+            sum_l += icoeff[0][i] * (src_l[x0] + src_l[x1]);
+            sum_h += icoeff[1][i] * (src_h[x0] + src_h[x1]);
+        }
+        dst[x * linesize] = (sum_l + sum_h) * 0.5;
+    }
+}
+
+static inline void decompose2D(float *dst_l, float *dst_h, const float *src,
+                               const double coeff[2][5],
+                               int xlinesize, int ylinesize,
+                               int step, int w, int h)
+{
+    int y, x;
+    for (y = 0; y < h; y++)
+        for (x = 0; x < step; x++)
+            decompose(dst_l + ylinesize*y + xlinesize*x,
+                      dst_h + ylinesize*y + xlinesize*x,
+                      src   + ylinesize*y + xlinesize*x,
+                      coeff, step * xlinesize, (w - x + step - 1) / step);
+}
+
+static inline void compose2D(float *dst, const float *src_l, const float *src_h,
+                             int xlinesize, int ylinesize,
+                             int step, int w, int h)
+{
+    int y, x;
+    for (y = 0; y < h; y++)
+        for (x = 0; x < step; x++)
+            compose(dst   + ylinesize*y + xlinesize*x,
+                    src_l + ylinesize*y + xlinesize*x,
+                    src_h + ylinesize*y + xlinesize*x,
+                    step * xlinesize, (w - x + step - 1) / step);
+}
+
+void ff_wavelet97_decompose(float *dst[4], const float *src, float *temp[2],
+                            const double coeff[2][5],
+                            int linesize, int step, int w, int h)
+{
+    decompose2D(temp[0], temp[1], src,     coeff, 1, linesize, step, w, h);
+    decompose2D( dst[0],  dst[1], temp[0], coeff, linesize, 1, step, h, w);
+    decompose2D( dst[2],  dst[3], temp[1], coeff, linesize, 1, step, h, w);
+}
+
+void ff_wavelet97_compose(float *dst, float *const src[4], float *temp[2],
+                          int linesize, int step, int w, int h)
+{
+    compose2D(temp[0],  src[0],  src[1], linesize, 1, step, h, w);
+    compose2D(temp[1],  src[2],  src[3], linesize, 1, step, h, w);
+    compose2D(dst,     temp[0], temp[1], 1, linesize, step, w, h);
+}
diff --git a/libavfilter/wavelet97.h b/libavfilter/wavelet97.h
new file mode 100644
index 0000000000..956d841fa5
--- /dev/null
+++ b/libavfilter/wavelet97.h
@@ -0,0 +1,55 @@
+/*
+ * Copyright (c) 2007 Michael Niedermayer <michaelni@gmx.at>
+ * Copyright (c) 2013 Clément Bœsch <u pkh me>
+ *
+ * This file is part of FFmpeg.
+ *
+ * FFmpeg is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation; either
+ * version 2.1 of the License, or (at your option) any later version.
+ *
+ * FFmpeg is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with FFmpeg; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
+ */
+
+#ifndef AVFILTER_WAVELET97_H
+#define AVFILTER_WAVELET97_H
+
+/**
+ * Undecimated 9/7 wavelet transform
+ */
+
+/**
+ * Analysis lowpass and highpass filters, both symmetric around tap 0
+ */
+extern const double ff_wavelet97_coeff[2][5];
+
+/**
+ * One level of 2D analysis, filters are mirrored at the plane borders.
+ *
+ * @param dst      output bands LL, LH, HL, HH (horizontal/vertical filter)
+ * @param src      input plane
+ * @param temp     two scratch planes
+ * @param coeff    lowpass and highpass filters, normally ff_wavelet97_coeff
+ * @param linesize distance between lines in floats, same for all planes
+ * @param step     dilation of the filters, 1 << level
+ */
+void ff_wavelet97_decompose(float *dst[4], const float *src, float *temp[2],
+                            const double coeff[2][5],
+                            int linesize, int step, int w, int h);
+
+/**
+ * One level of 2D synthesis, the inverse of ff_wavelet97_decompose() with
+ * ff_wavelet97_coeff.
+ */
+void ff_wavelet97_compose(float *dst, float *const src[4], float *temp[2],
+                          int linesize, int step, int w, int h);
+
+#endif /* AVFILTER_WAVELET97_H */