On date Monday 2024-06-03 11:41:59 +0200, Stefano Sabatini wrote:
> On date Tuesday 2024-05-28 18:58:28 +0200, Stefano Sabatini wrote:
> > On date Monday 2024-05-27 23:37:33 +0200, Stefano Sabatini wrote:
> > > Hi,
> > >
> > > still missing documentation and might be optimized (and maybe extended
> > > to support gray16 - this should be simple), comments are welcome.
> >
> > Updated with documentation.
>
> > From 607459e7a184ab2d111b65f5017fb7f76e3bd58d Mon Sep 17 00:00:00 2001
> > From: Stefano Sabatini <stefa...@gmail.com>
> > Date: Mon, 27 May 2024 11:19:08 +0200
> > Subject: [PATCH] lavfi: add perlin noise generator
>
> Anyone interested with reviewing this?
>
> Otherwise I'll probably push in a week or so, further improvements can
> be done on top of that.
Updated patch with minor doc fixes, will push it in a few days unless
I see comments.
>From 9932cfc19500acbd0685eb2cc8fd88e9af3f5dbd Mon Sep 17 00:00:00 2001
From: Stefano Sabatini <stefa...@gmail.com>
Date: Mon, 27 May 2024 11:19:08 +0200
Subject: [PATCH] lavfi: add Perlin noise generator
---
Changelog | 1 +
doc/filters.texi | 100 +++++++++++++++++
libavfilter/Makefile | 1 +
libavfilter/allfilters.c | 1 +
libavfilter/perlin.c | 224 ++++++++++++++++++++++++++++++++++++++
libavfilter/perlin.h | 101 +++++++++++++++++
libavfilter/vsrc_perlin.c | 169 ++++++++++++++++++++++++++++
7 files changed, 597 insertions(+)
create mode 100644 libavfilter/perlin.c
create mode 100644 libavfilter/perlin.h
create mode 100644 libavfilter/vsrc_perlin.c
diff --git a/Changelog b/Changelog
index 03d6b29ad8..b8dcf452ac 100644
--- a/Changelog
+++ b/Changelog
@@ -12,6 +12,7 @@ version <next>:
- qsv_params option added for QSV encoders
- VVC decoder compatible with DVB test content
- xHE-AAC decoder
+- perlin source
version 7.0:
diff --git a/doc/filters.texi b/doc/filters.texi
index 347103c04f..7af299b2a2 100644
--- a/doc/filters.texi
+++ b/doc/filters.texi
@@ -17290,6 +17290,9 @@ The command accepts the same syntax of the corresponding option.
If the specified expression is not valid, it is kept at its current
value.
+@anchor{lutrgb}
+@anchor{lutyuv}
+@anchor{lut}
@section lut, lutrgb, lutyuv
Compute a look-up table for binding each pixel component input value
@@ -29281,6 +29284,103 @@ ffplay -f lavfi life=s=300x200:mold=10:r=60:ratio=0.1:death_color=#C83232:life_c
@end example
@end itemize
+@section perlin
+Generate Perlin noise.
+
+Perlin noise is a kind of noise with local continuity in space. This
+can be used to generate patterns with continuity in space and time,
+e.g. to simulate smoke, fluids, or terrain.
+
+In case more than one octave is specified through the @option{octaves}
+option, Perlin noise is generated as a sum of components, each one
+with doubled frequency. In this case the @option{persistence} option
+specify the ratio of the amplitude with respect to the previous
+component. More octave components enable to specify more high
+frequency details in the generated noise (e.g. small size variations
+due to bolders in a generated terrain).
+
+@subsection Options
+@table @option
+
+@item size, s
+Specify the size (width and height) of the buffered video frames. For the
+syntax of this option, check the
+@ref{video size syntax,,"Video size" section in the ffmpeg-utils manual,ffmpeg-utils}.
+
+@item rate, r
+Specify the frame rate expected for the video stream, expressed as a
+number of frames per second.
+
+@item octaves
+Specify the total number of components making up the noise, each one
+with doubled frequency.
+
+@item persistence
+Set the ratio used to compute the amplitude of the next octave
+component with respect to the previous component amplitude.
+
+@item xscale
+@item yscale
+Define a scale factor used to multiple the x, y coordinates. This can
+be useful to define an effect with a pattern stretched along the x or
+y axis.
+
+@item tscale
+Define a scale factor used to multiple the time coordinate. This can
+be useful to change the time variation speed.
+
+@item random_mode
+Set random mode used to compute initial pattern.
+
+Supported values are:
+@table @option
+@item random
+Compute and use random seed.
+
+@item ken
+Use the predefined initial pattern defined by Ken Perlin in the
+original article, can be useful to compare the output with other
+sources.
+
+@item seed
+Use the value specified by @option{random_seed} option.
+@end table
+
+@item random_seed, seed
+Use this value to compute the initial pattern, it is only considered
+when @option{random_mode} is set to @var{random_seed}.
+@end table
+
+@subsection Examples
+@itemize
+@item
+Generate single component:
+@example
+perlin
+@end example
+
+@item
+Use Perlin noise with 7 components, each one with a halved contribute
+to total amplitude:
+@example
+perlin=octaves=7:persistence=0.5
+@end example
+
+@item
+Chain Perlin noise with the @ref{lutyuv} to generate a black&white
+effect:
+@example
+perlin:octaves=7:tscale=0.3,lutyuv=y='if(lt(val\,128)\,255\,0)'
+@end example
+
+@item
+Stretch noise along the y axis, and convert gray level to red-only
+signal:
+@example
+perlin=octaves=7:tscale=0.4:yscale=0.3,lutrgb=r=val:b=0:g=0
+@end example
+@end itemize
+
@section qrencodesrc
Generate a QR code using the libqrencode library (see
diff --git a/libavfilter/Makefile b/libavfilter/Makefile
index 5992fd161f..63088e9286 100644
--- a/libavfilter/Makefile
+++ b/libavfilter/Makefile
@@ -603,6 +603,7 @@ OBJS-$(CONFIG_NULLSRC_FILTER) += vsrc_testsrc.o
OBJS-$(CONFIG_OPENCLSRC_FILTER) += vf_program_opencl.o opencl.o
OBJS-$(CONFIG_PAL75BARS_FILTER) += vsrc_testsrc.o
OBJS-$(CONFIG_PAL100BARS_FILTER) += vsrc_testsrc.o
+OBJS-$(CONFIG_PERLIN_FILTER) += vsrc_perlin.o perlin.o
OBJS-$(CONFIG_QRENCODE_FILTER) += qrencode.o textutils.o
OBJS-$(CONFIG_QRENCODESRC_FILTER) += qrencode.o textutils.o
OBJS-$(CONFIG_RGBTESTSRC_FILTER) += vsrc_testsrc.o
diff --git a/libavfilter/allfilters.c b/libavfilter/allfilters.c
index c532682fc2..63600e9b58 100644
--- a/libavfilter/allfilters.c
+++ b/libavfilter/allfilters.c
@@ -569,6 +569,7 @@ extern const AVFilter ff_vsrc_openclsrc;
extern const AVFilter ff_vsrc_qrencodesrc;
extern const AVFilter ff_vsrc_pal75bars;
extern const AVFilter ff_vsrc_pal100bars;
+extern const AVFilter ff_vsrc_perlin;
extern const AVFilter ff_vsrc_rgbtestsrc;
extern const AVFilter ff_vsrc_sierpinski;
extern const AVFilter ff_vsrc_smptebars;
diff --git a/libavfilter/perlin.c b/libavfilter/perlin.c
new file mode 100644
index 0000000000..f09020bf8f
--- /dev/null
+++ b/libavfilter/perlin.c
@@ -0,0 +1,224 @@
+/*
+ * This file is part of FFmpeg.
+ *
+ * FFmpeg is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 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 General Public License for more details.
+ *
+ * You should have received a copy of the GNU 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.
+ */
+
+/**
+ * @file
+ * Perlin Noise generator, based on code from:
+ * https://adrianb.io/2014/08/09/perlinnoise.html
+ *
+ * Original article from Ken Perlin:
+ * http://mrl.nyu.edu/~perlin/paper445.pdf
+ */
+
+#include <math.h>
+
+#include "libavutil/lfg.h"
+#include "libavutil/random_seed.h"
+#include "perlin.h"
+
+static inline int inc(int num, int period)
+{
+ num++;
+ if (period > 0)
+ num %= period;
+ return num;
+}
+
+static inline double grad(int hash, double x, double y, double z)
+{
+ // Take the hashed value and take the first 4 bits of it (15 == 0b1111)
+ int h = hash & 15;
+ // If the most significant bit (MSB) of the hash is 0 then set u = x. Otherwise y.
+ double u = h < 8 /* 0b1000 */ ? x : y;
+ double v;
+
+ // In Ken Perlin's original implementation this was another
+ // conditional operator (?:), then expanded for readability.
+ if (h < 4 /* 0b0100 */)
+ // If the first and second significant bits are 0 set v = y
+ v = y;
+ // If the first and second significant bits are 1 set v = x
+ else if (h == 12 /* 0b1100 */ || h == 14 /* 0b1110*/)
+ v = x;
+ else
+ // If the first and second significant bits are not equal (0/1, 1/0) set v = z
+ v = z;
+
+ // Use the last 2 bits to decide if u and v are positive or negative. Then return their addition.
+ return ((h&1) == 0 ? u : -u)+((h&2) == 0 ? v : -v);
+}
+
+static inline double fade(double t)
+{
+ // Fade function as defined by Ken Perlin. This eases coordinate values
+ // so that they will "ease" towards integral values. This ends up smoothing
+ // the final output.
+ return t * t * t * (t * (t * 6 - 15) + 10); // 6t^5 - 15t^4 + 10t^3
+}
+
+static double lerp(double a, double b, double x)
+{
+ return a + x * (b - a);
+}
+
+// Hash lookup table as defined by Ken Perlin. This is a randomly
+// arranged array of all numbers from 0-255 inclusive.
+static uint8_t ken_permutations[] = {
+ 151, 160, 137, 91, 90, 15, 131, 13, 201, 95, 96, 53, 194, 233, 7, 225,
+ 140, 36, 103, 30, 69, 142, 8, 99, 37, 240, 21, 10, 23, 190, 6, 148,
+ 247, 120, 234, 75, 0, 26, 197, 62, 94, 252, 219, 203, 117, 35, 11, 32,
+ 57, 177, 33, 88, 237, 149, 56, 87, 174, 20, 125, 136, 171, 168, 68, 175,
+ 74, 165, 71, 134, 139, 48, 27, 166, 77, 146, 158, 231, 83, 111, 229, 122,
+ 60, 211, 133, 230, 220, 105, 92, 41, 55, 46, 245, 40, 244, 102, 143, 54,
+ 65, 25, 63, 161, 1, 216, 80, 73, 209, 76, 132, 187, 208, 89, 18, 169,
+ 200, 196, 135, 130, 116, 188, 159, 86, 164, 100, 109, 198, 173, 186, 3, 64,
+ 52, 217, 226, 250, 124, 123, 5, 202, 38, 147, 118, 126, 255, 82, 85, 212,
+ 207, 206, 59, 227, 47, 16, 58, 17, 182, 189, 28, 42, 223, 183, 170, 213,
+ 119, 248, 152, 2, 44, 154, 163, 70, 221, 153, 101, 155, 167, 43, 172, 9,
+ 129, 22, 39, 253, 19, 98, 108, 110, 79, 113, 224, 232, 178, 185, 112, 104,
+ 218, 246, 97, 228, 251, 34, 242, 193, 238, 210, 144, 12, 191, 179, 162, 241,
+ 81, 51, 145, 235, 249, 14, 239, 107, 49, 192, 214, 31, 181, 199, 106, 157,
+ 184, 84, 204, 176, 115, 121, 50, 45, 127, 4, 150, 254, 138, 236, 205, 93,
+ 222, 114, 67, 29, 24, 72, 243, 141, 128, 195, 78, 66, 215, 61, 156, 180
+};
+
+int ff_perlin_init(FFPerlin *perlin, double period, int octaves, double persistence,
+ enum FFPerlinRandomMode random_mode, unsigned int random_seed)
+{
+ int i;
+
+ /* todo: perform validation? */
+ perlin->period = period;
+ perlin->octaves = octaves;
+ perlin->persistence = persistence;
+ perlin->random_mode = random_mode;
+ perlin->random_seed = random_seed;
+
+ if (perlin->random_mode == FF_PERLIN_RANDOM_MODE_KEN) {
+ for (i = 0; i < 512; i++) {
+ perlin->permutations[i] = ken_permutations[i % 256];
+ }
+ } else {
+ AVLFG lfg;
+ uint8_t random_permutations[256];
+
+ if (perlin->random_mode == FF_PERLIN_RANDOM_MODE_RANDOM)
+ perlin->random_seed = av_get_random_seed();
+
+ av_lfg_init(&lfg, perlin->random_seed);
+
+ for (i = 0; i < 256; i++) {
+ random_permutations[i] = i;
+ }
+
+ for (i = 0; i < 256; i++) {
+ unsigned int random_idx = av_lfg_get(&lfg) % (256-i);
+ uint8_t random_val = random_permutations[random_idx];
+ random_permutations[random_idx] = random_permutations[256-i];
+
+ perlin->permutations[i] = perlin->permutations[i+256] = random_val;
+ }
+ }
+
+ return 0;
+}
+
+static double perlin_get(FFPerlin *perlin, double x, double y, double z)
+{
+ int xi, yi, zi;
+ double xf, yf, zf;
+ double u, v, w;
+ const uint8_t *p = perlin->permutations;
+ double period = perlin->period;
+ int aaa, aba, aab, abb, baa, bba, bab, bbb;
+ double x1, x2, y1, y2;
+
+ if (perlin->period > 0) {
+ // If we have any period on, change the coordinates to their "local" repetitions
+ x = fmod(x, perlin->period);
+ y = fmod(y, perlin->period);
+ z = fmod(z, perlin->period);
+ }
+
+ // Calculate the "unit cube" that the point asked will be located in
+ // The left bound is ( |_x_|,|_y_|,|_z_| ) and the right bound is that
+ // plus 1. Next we calculate the location (from 0.0 to 1.0) in that cube.
+ xi = (int)x & 255;
+ yi = (int)y & 255;
+ zi = (int)z & 255;
+
+ xf = x - (int)x;
+ yf = y - (int)y;
+ zf = z - (int)z;
+
+ // We also fade the location to smooth the result.
+ u = fade(xf);
+ v = fade(yf);
+ w = fade(zf);
+
+ aaa = p[p[p[ xi ] + yi ] + zi ];
+ aba = p[p[p[ xi ] + inc(yi, period)] + zi ];
+ aab = p[p[p[ xi ] + yi ] + inc(zi, period)];
+ abb = p[p[p[ xi ] + inc(yi, period)] + inc(zi, period)];
+ baa = p[p[p[inc(xi, period)] + yi ] + zi ];
+ bba = p[p[p[inc(xi, period)] + inc(yi, period)] + zi ];
+ bab = p[p[p[inc(xi, period)] + yi ] + inc(zi, period)];
+ bbb = p[p[p[inc(xi, period)] + inc(yi, period)] + inc(zi, period)];
+
+ // The gradient function calculates the dot product between a pseudorandom
+ // gradient vector and the vector from the input coordinate to the 8
+ // surrounding points in its unit cube.
+ // This is all then lerped together as a sort of weighted average based on the faded (u,v,w)
+ // values we made earlier.
+ x1 = lerp(grad(aaa, xf , yf , zf),
+ grad(baa, xf-1, yf , zf),
+ u);
+ x2 = lerp(grad(aba, xf , yf-1, zf),
+ grad(bba, xf-1, yf-1, zf),
+ u);
+ y1 = lerp(x1, x2, v);
+
+ x1 = lerp(grad(aab, xf , yf , zf-1),
+ grad(bab, xf-1, yf , zf-1),
+ u);
+ x2 = lerp(grad(abb, xf , yf-1, zf-1),
+ grad(bbb, xf-1, yf-1, zf-1),
+ u);
+ y2 = lerp(x1, x2, v);
+
+ // For convenience we bound it to 0 - 1 (theoretical min/max before is -1 - 1)
+ return (lerp(y1, y2, w) + 1) / 2;
+}
+
+double ff_perlin_get(FFPerlin *perlin, double x, double y, double z)
+{
+ double total = 0;
+ double frequency = 1;
+ double amplitude = 1;
+ double max_value = 0; // Used for normalizing result to 0.0 - 1.0
+
+ for (int i = 0; i < perlin->octaves; i++) {
+ total += perlin_get(perlin, x * frequency, y * frequency, z * frequency) * amplitude;
+ max_value += amplitude;
+ amplitude *= perlin->persistence;
+ frequency *= 2;
+ }
+
+ return total / max_value;
+}
+
diff --git a/libavfilter/perlin.h b/libavfilter/perlin.h
new file mode 100644
index 0000000000..1d2922a587
--- /dev/null
+++ b/libavfilter/perlin.h
@@ -0,0 +1,101 @@
+/*
+ * Perlin noise generator
+ *
+ * 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
+ */
+
+/**
+ * @file
+ * Perlin Noise generator
+ */
+
+#ifndef AVFILTER_PERLIN_H
+#define AVFILTER_PERLIN_H
+
+#include <stdint.h>
+
+enum FFPerlinRandomMode {
+ FF_PERLIN_RANDOM_MODE_RANDOM,
+ FF_PERLIN_RANDOM_MODE_KEN,
+ FF_PERLIN_RANDOM_MODE_SEED,
+ FF_PERLIN_RANDOM_MODE_NB
+};
+
+/**
+ * Perlin generator context. This needs to be initialized with the
+ * parameters used to generate the Perlin noise.
+ */
+typedef struct FFPerlin {
+ /**
+ * spatial repeat period, if negative it is ignored
+ */
+ double period;
+
+ /**
+ * total number of components making up the noise, each one with
+ * doubled frequency
+ */
+ int octaves;
+
+ /**
+ * ratio used to compute the amplitude of the next octave
+ * component with respect to the previous component
+ */
+ double persistence;
+
+ /**
+ * permutations array used to compute the Perlin noise hash
+ */
+ uint8_t permutations[512];
+
+ /**
+ * define how to compute the permutations array
+ */
+ enum FFPerlinRandomMode random_mode;
+
+ /**
+ * random seed used to compute the permutations array when random_mode is set to
+ * FF_PERLIN_RANDOM_MODE_RANDOM,
+ */
+ unsigned int random_seed;
+} FFPerlin;
+
+/**
+ * Initialize the Perlin noise generator with parameters.
+ *
+ * @param perlin Perlin noise generator context
+ * @param period spatial repeat period, if negative it is ignored
+ * @param octaves total number of components making up the noise, each one with doubled frequency
+ * @param persistence define how to ratio used to compute the amplitude of the next
+ * octave component with respect to the previous component
+ * @param random_mode define how to compute the permutations array
+ * @param random_seed random seed used to compute the permutations array when random_mode is set to
+ * FF_PERLIN_RANDOM_MODE_RANDOM,
+ * @return a negative AVERROR code in case of error, a non negative value otherwise
+ */
+int ff_perlin_init(FFPerlin *perlin, double period, int octaves, double persistence,
+ enum FFPerlinRandomMode random_mode, unsigned int random_seed);
+
+/**
+ * Compute Perlin noise for the 3D coordinates given the x, y, z coordinates.
+ *
+ * @param perlin Perlin noise generator context
+ * @return normalized value for the perlin noise, in the range [0, 1]
+ */
+double ff_perlin_get(FFPerlin *perlin, double x, double y, double z);
+
+#endif /* AVFILTER_PERLIN_H */
diff --git a/libavfilter/vsrc_perlin.c b/libavfilter/vsrc_perlin.c
new file mode 100644
index 0000000000..27493a1b3b
--- /dev/null
+++ b/libavfilter/vsrc_perlin.c
@@ -0,0 +1,169 @@
+/*
+ * 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
+ */
+
+/**
+ * @file
+ * Perlin noise generator
+ */
+
+#include <float.h>
+
+#include "perlin.h"
+#include "libavutil/lfg.h"
+#include "libavutil/opt.h"
+#include "avfilter.h"
+#include "internal.h"
+#include "formats.h"
+#include "video.h"
+
+typedef struct PerlinContext {
+ const AVClass *class;
+
+ int w, h;
+ AVRational frame_rate;
+
+ FFPerlin perlin;
+ int octaves;
+ double persistence;
+ unsigned int random_seed;
+ enum FFPerlinRandomMode random_mode;
+
+ double xscale, yscale, tscale;
+ uint64_t pts;
+} PerlinContext;
+
+#define OFFSET(x) offsetof(PerlinContext, x)
+#define FLAGS AV_OPT_FLAG_VIDEO_PARAM|AV_OPT_FLAG_FILTERING_PARAM
+
+static const AVOption perlin_options[] = {
+ { "size", "set video size", OFFSET(w), AV_OPT_TYPE_IMAGE_SIZE, {.str = "320x240"}, 0, 0, FLAGS },
+ { "s", "set video size", OFFSET(w), AV_OPT_TYPE_IMAGE_SIZE, {.str = "320x240"}, 0, 0, FLAGS },
+ { "rate", "set video rate", OFFSET(frame_rate), AV_OPT_TYPE_VIDEO_RATE, {.str = "25"}, 0, INT_MAX, FLAGS },
+ { "r", "set video rate", OFFSET(frame_rate), AV_OPT_TYPE_VIDEO_RATE, {.str = "25"}, 0, INT_MAX, FLAGS },
+ { "octaves", "set the number of components to use to generate the noise", OFFSET(octaves), AV_OPT_TYPE_INT, {.i64=1}, 1, INT_MAX, FLAGS },
+ { "persistence", "set the octaves persistence", OFFSET(persistence), AV_OPT_TYPE_DOUBLE, {.dbl=1}, 0.0, DBL_MAX, FLAGS },
+
+ { "xscale", "set x-scale factor", OFFSET(xscale), AV_OPT_TYPE_DOUBLE, {.dbl=1}, 0.0, DBL_MAX, FLAGS },
+ { "yscale", "set y-scale factor", OFFSET(yscale), AV_OPT_TYPE_DOUBLE, {.dbl=1}, 0.0, DBL_MAX, FLAGS },
+ { "tscale", "set t-scale factor", OFFSET(tscale), AV_OPT_TYPE_DOUBLE, {.dbl=1}, 0.0, DBL_MAX, FLAGS },
+
+ { "random_mode", "set random mode used to compute initial pattern", OFFSET(random_mode), AV_OPT_TYPE_INT, {.i64=FF_PERLIN_RANDOM_MODE_RANDOM}, 0, FF_PERLIN_RANDOM_MODE_NB-1, FLAGS, .unit = "random_mode" },
+ { "random", "compute and use random seed", 0, AV_OPT_TYPE_CONST, {.i64=FF_PERLIN_RANDOM_MODE_RANDOM}, 0, 0, FLAGS, .unit = "random_mode" },
+ { "ken", "use the predefined initial pattern defined by Ken Perlin in the original article", 0, AV_OPT_TYPE_CONST, {.i64=FF_PERLIN_RANDOM_MODE_KEN}, 0, 0, FLAGS, .unit = "random_mode" },
+ { "seed", "use the value specified by random_seed", 0, AV_OPT_TYPE_CONST, {.i64=FF_PERLIN_RANDOM_MODE_SEED}, 0, 0, FLAGS, .unit = "random_mode" },
+
+ { "random_seed", "set the seed for filling the initial grid randomly", OFFSET(random_seed), AV_OPT_TYPE_UINT, {.i64=0}, 0, UINT_MAX, FLAGS },
+ { "seed", "set the seed for filling the initial grid randomly", OFFSET(random_seed), AV_OPT_TYPE_UINT, {.i64=0}, 0, UINT_MAX, FLAGS },
+ { NULL }
+};
+
+AVFILTER_DEFINE_CLASS(perlin);
+
+static av_cold int init(AVFilterContext *ctx)
+{
+ PerlinContext *perlin = ctx->priv;
+ int ret;
+
+ if (ret = ff_perlin_init(&perlin->perlin, -1, perlin->octaves, perlin->persistence,
+ perlin->random_mode, perlin->random_seed)) {
+ return ret;
+ }
+
+ av_log(ctx, AV_LOG_VERBOSE,
+ "s:%dx%d r:%d/%d octaves:%d persistence:%f xscale:%f yscale:%f tscale:%f\n",
+ perlin->w, perlin->h, perlin->frame_rate.num, perlin->frame_rate.den,
+ perlin->octaves, perlin->persistence,
+ perlin->xscale, perlin->yscale, perlin->tscale);
+ return 0;
+}
+
+static int config_props(AVFilterLink *outlink)
+{
+ PerlinContext *perlin = outlink->src->priv;
+
+ outlink->w = perlin->w;
+ outlink->h = perlin->h;
+ outlink->time_base = av_inv_q(perlin->frame_rate);
+ outlink->frame_rate = perlin->frame_rate;
+
+ return 0;
+}
+
+static int request_frame(AVFilterLink *outlink)
+{
+ AVFilterContext *ctx = outlink->src;
+ PerlinContext *perlin = ctx->priv;
+ AVFrame *picref = ff_get_video_buffer(outlink, perlin->w, perlin->h);
+ int i, j;
+ uint8_t *data0, *data;
+ double x, y, t;
+
+ if (!picref)
+ return AVERROR(ENOMEM);
+
+ picref->sample_aspect_ratio = (AVRational) {1, 1};
+ picref->pts = perlin->pts++;
+ picref->duration = 1;
+
+ t = perlin->tscale * (perlin->pts * av_q2d(outlink->time_base));
+ data0 = picref->data[0];
+
+ for (i = 0; i < perlin->h; i++) {
+ y = perlin->yscale * (double)i / perlin->h;
+
+ data = data0;
+
+ for (j = 0; j < perlin->w; j++) {
+ double res;
+ x = perlin->xscale * (double)j / perlin->w;
+ res = ff_perlin_get(&perlin->perlin, x, y, t);
+ av_log(ctx, AV_LOG_DEBUG, "x:%f y:%f t:%f => %f\n", x, y, t, res);
+ *data++ = res * 255;
+ }
+ data0 += picref->linesize[0];
+ }
+
+ return ff_filter_frame(outlink, picref);
+}
+
+static int query_formats(AVFilterContext *ctx)
+{
+ enum AVPixelFormat pix_fmts[] = { AV_PIX_FMT_GRAY8, AV_PIX_FMT_NONE };
+
+ return ff_set_common_formats_from_list(ctx, pix_fmts);
+}
+
+static const AVFilterPad perlin_outputs[] = {
+ {
+ .name = "default",
+ .type = AVMEDIA_TYPE_VIDEO,
+ .request_frame = request_frame,
+ .config_props = config_props,
+ },
+};
+
+const AVFilter ff_vsrc_perlin = {
+ .name = "perlin",
+ .description = NULL_IF_CONFIG_SMALL("Generate Perlin noise"),
+ .priv_size = sizeof(PerlinContext),
+ .priv_class = &perlin_class,
+ .init = init,
+ .inputs = NULL,
+ FILTER_OUTPUTS(perlin_outputs),
+ FILTER_QUERY_FUNC(query_formats),
+};
--
2.34.1
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