From 65fc80f0121dd1514160defb97a8bbcab072c58b Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?Cl=C3=A9ment=20B=C5=93sch?= Date: Mon, 4 Mar 2013 16:06:14 +0100 Subject: [PATCH] lavfi: add curves filter. --- Changelog | 4 + doc/filters.texi | 67 ++++++++ libavfilter/Makefile | 1 + libavfilter/allfilters.c | 1 + libavfilter/version.h | 2 +- libavfilter/vf_curves.c | 363 +++++++++++++++++++++++++++++++++++++++ 6 files changed, 437 insertions(+), 1 deletion(-) create mode 100644 libavfilter/vf_curves.c diff --git a/Changelog b/Changelog index a535864104..bff5a1d6b5 100644 --- a/Changelog +++ b/Changelog @@ -2,6 +2,10 @@ Entries are sorted chronologically from oldest to youngest within each release, releases are sorted from youngest to oldest. version : +- curves filter + + +version 1.2: - VDPAU hardware acceleration through normal hwaccel - SRTP support diff --git a/doc/filters.texi b/doc/filters.texi index 88a52acca2..3febd2e3db 100644 --- a/doc/filters.texi +++ b/doc/filters.texi @@ -2217,6 +2217,73 @@ indicates never reset and return the largest area encountered during playback. @end table +@section curves + +Apply color adjustments using curves. + +This filter is similar to the Adobe Photoshop and GIMP curves tools. Each +component (red, green and blue) has its values defined by @var{N} key points +tied from each other using a smooth curve. The x-axis represents the pixel +values from the input frame, and the y-axis the new pixel values to be set for +the output frame. + +By default, a component curve is defined by the two points @var{(0;0)} and +@var{(1;1)}. This creates a straight line where each original pixel value is +"adjusted" to its own value, which means no change to the image. + +The filter allows you to redefine these two points and add some more. A new +curve (using a natural cubic spline interpolation) will be define to pass +smoothly through all these new coordinates. The new defined points needs to be +strictly increasing over the x-axis, and their @var{x} and @var{y} values must +be in the @var{[0;1]} interval. If the computed curves happened to go outside +the vector spaces, the values will be clipped accordingly. + +If there is no key point defined in @code{x=0}, the filter will automatically +insert a @var{(0;0)} point. In the same way, if there is no key point defined +in @code{x=1}, the filter will automatically insert a @var{(1;1)} point. + +The filter accepts parameters as a list of @var{key}=@var{value} pairs, +separated by ":". + +A description of the accepted parameters follows. + +@table @option +@item red, r +Set the key points for the red component. +@item green, g +Set the key points for the green component. +@item blue, b +Set the key points for the blue component. +@end table + +To avoid some filtergraph syntax conflicts, each key points list need to be +defined using the following syntax: @code{x0/y0 x1/y1 x2/y2 ...}. + +@subsection Examples + +@itemize +@item +Increase slightly the middle level of blue: +@example +curves=blue='0.5/0.58' +@end example + +@item +Vintage effect: +@example +curves=r='0/0.11 .42/.51 1/0.95':g='0.50/0.48':b='0/0.22 .49/.44 1/0.8' +@end example +Here we obtain the following coordinates for each components: +@table @var +@item red +@code{(0;0.11) (0.42;0.51) (1;0.95)} +@item green +@code{(0;0) (0.50;0.48) (1;1)} +@item blue +@code{(0;0.22) (0.49;0.44) (1;0.80)} +@end table +@end itemize + @section decimate Drop frames that do not differ greatly from the previous frame in diff --git a/libavfilter/Makefile b/libavfilter/Makefile index 229ae839c0..a391de8a4e 100644 --- a/libavfilter/Makefile +++ b/libavfilter/Makefile @@ -104,6 +104,7 @@ OBJS-$(CONFIG_COLORMATRIX_FILTER) += vf_colormatrix.o OBJS-$(CONFIG_COPY_FILTER) += vf_copy.o OBJS-$(CONFIG_CROP_FILTER) += vf_crop.o OBJS-$(CONFIG_CROPDETECT_FILTER) += vf_cropdetect.o +OBJS-$(CONFIG_CURVES_FILTER) += vf_curves.o OBJS-$(CONFIG_DECIMATE_FILTER) += vf_decimate.o OBJS-$(CONFIG_DELOGO_FILTER) += vf_delogo.o OBJS-$(CONFIG_DESHAKE_FILTER) += vf_deshake.o diff --git a/libavfilter/allfilters.c b/libavfilter/allfilters.c index 141a9a7aaa..f9e5d50ac7 100644 --- a/libavfilter/allfilters.c +++ b/libavfilter/allfilters.c @@ -100,6 +100,7 @@ void avfilter_register_all(void) REGISTER_FILTER(COPY, copy, vf); REGISTER_FILTER(CROP, crop, vf); REGISTER_FILTER(CROPDETECT, cropdetect, vf); + REGISTER_FILTER(CURVES, curves, vf); REGISTER_FILTER(DECIMATE, decimate, vf); REGISTER_FILTER(DELOGO, delogo, vf); REGISTER_FILTER(DESHAKE, deshake, vf); diff --git a/libavfilter/version.h b/libavfilter/version.h index bc3b405c8d..598397b958 100644 --- a/libavfilter/version.h +++ b/libavfilter/version.h @@ -29,7 +29,7 @@ #include "libavutil/avutil.h" #define LIBAVFILTER_VERSION_MAJOR 3 -#define LIBAVFILTER_VERSION_MINOR 43 +#define LIBAVFILTER_VERSION_MINOR 44 #define LIBAVFILTER_VERSION_MICRO 100 #define LIBAVFILTER_VERSION_INT AV_VERSION_INT(LIBAVFILTER_VERSION_MAJOR, \ diff --git a/libavfilter/vf_curves.c b/libavfilter/vf_curves.c new file mode 100644 index 0000000000..7fee90a233 --- /dev/null +++ b/libavfilter/vf_curves.c @@ -0,0 +1,363 @@ +/* + * Copyright (c) 2013 Clément Bœsch + * + * 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/opt.h" +#include "libavutil/eval.h" +#include "libavutil/avassert.h" +#include "avfilter.h" +#include "formats.h" +#include "internal.h" +#include "video.h" + +struct keypoint { + double x, y; + struct keypoint *next; +}; + +#define NB_COMP 3 + +typedef struct { + const AVClass *class; + char *comp_points_str[NB_COMP]; + uint8_t graph[NB_COMP][256]; +} CurvesContext; + +#define OFFSET(x) offsetof(CurvesContext, x) +#define FLAGS AV_OPT_FLAG_FILTERING_PARAM|AV_OPT_FLAG_VIDEO_PARAM +static const AVOption curves_options[] = { + { "red", "set red points coordinates", OFFSET(comp_points_str[0]), AV_OPT_TYPE_STRING, {.str=NULL}, .flags = FLAGS }, + { "r", "set red points coordinates", OFFSET(comp_points_str[0]), AV_OPT_TYPE_STRING, {.str=NULL}, .flags = FLAGS }, + { "green", "set green points coordinates", OFFSET(comp_points_str[1]), AV_OPT_TYPE_STRING, {.str=NULL}, .flags = FLAGS }, + { "g", "set green points coordinates", OFFSET(comp_points_str[1]), AV_OPT_TYPE_STRING, {.str=NULL}, .flags = FLAGS }, + { "blue", "set blue points coordinates", OFFSET(comp_points_str[2]), AV_OPT_TYPE_STRING, {.str=NULL}, .flags = FLAGS }, + { "b", "set blue points coordinates", OFFSET(comp_points_str[2]), AV_OPT_TYPE_STRING, {.str=NULL}, .flags = FLAGS }, + { NULL } +}; + +AVFILTER_DEFINE_CLASS(curves); + +static struct keypoint *make_point(double x, double y, struct keypoint *next) +{ + struct keypoint *point = av_mallocz(sizeof(*point)); + + if (!point) + return NULL; + point->x = x; + point->y = y; + point->next = next; + return point; +} + +static int parse_points_str(AVFilterContext *ctx, struct keypoint **points, const char *s) +{ + char *p = (char *)s; // strtod won't alter the string + struct keypoint *last = NULL; + + /* construct a linked list based on the key points string */ + while (p && *p) { + struct keypoint *point = make_point(0, 0, NULL); + if (!point) + return AVERROR(ENOMEM); + point->x = av_strtod(p, &p); if (p && *p) p++; + point->y = av_strtod(p, &p); if (p && *p) p++; + if (point->x < 0 || point->x > 1 || point->y < 0 || point->y > 1) { + av_log(ctx, AV_LOG_ERROR, "Invalid key point coordinates (%f;%f), " + "x and y must be in the [0;1] range.\n", point->x, point->y); + return AVERROR(EINVAL); + } + if (!*points) + *points = point; + if (last) { + if ((int)(last->x * 255) >= (int)(point->x * 255)) { + av_log(ctx, AV_LOG_ERROR, "Key point coordinates (%f;%f) " + "and (%f;%f) are too close from each other or not " + "strictly increasing on the x-axis\n", + last->x, last->y, point->x, point->y); + return AVERROR(EINVAL); + } + last->next = point; + } + last = point; + } + + /* auto insert first key point if missing at x=0 */ + if (!*points) { + last = make_point(0, 0, NULL); + if (!last) + return AVERROR(ENOMEM); + last->x = last->y = 0; + *points = last; + } else if ((*points)->x != 0.) { + struct keypoint *newfirst = make_point(0, 0, *points); + if (!newfirst) + return AVERROR(ENOMEM); + *points = newfirst; + } + + av_assert0(last); + + /* auto insert last key point if missing at x=1 */ + if (last->x != 1.) { + struct keypoint *point = make_point(1, 1, NULL); + if (!point) + return AVERROR(ENOMEM); + last->next = point; + } + + return 0; +} + +static int get_nb_points(const struct keypoint *d) +{ + int n = 0; + while (d) { + n++; + d = d->next; + } + return n; +} + +/** + * Natural cubic spline interpolation + * Finding curves using Cubic Splines notes by Steven Rauch and John Stockie. + * @see http://people.math.sfu.ca/~stockie/teaching/macm316/notes/splines.pdf + */ +static int interpolate(AVFilterContext *ctx, uint8_t *y, const struct keypoint *points) +{ + int i, ret = 0; + const struct keypoint *point; + double xprev = 0; + + int n = get_nb_points(points); // number of splines + + double (*matrix)[3] = av_calloc(n, sizeof(*matrix)); + double *h = av_malloc((n - 1) * sizeof(*h)); + double *r = av_calloc(n, sizeof(*r)); + + if (!matrix || !h || !r) { + ret = AVERROR(ENOMEM); + goto end; + } + + /* h(i) = x(i+1) - x(i) */ + i = -1; + for (point = points; point; point = point->next) { + if (i != -1) + h[i] = point->x - xprev; + xprev = point->x; + i++; + } + + /* right-side of the polynomials, will be modified to contains the solution */ + point = points; + for (i = 1; i < n - 1; i++) { + double yp = point->y, + yc = point->next->y, + yn = point->next->next->y; + r[i] = 6 * ((yn-yc)/h[i] - (yc-yp)/h[i-1]); + point = point->next; + } + +#define B 0 /* sub diagonal (below main) */ +#define M 1 /* main diagonal (center) */ +#define A 2 /* sup diagonal (above main) */ + + /* left side of the polynomials into a tridiagonal matrix. */ + matrix[0][M] = matrix[n - 1][M] = 1; + for (i = 1; i < n - 1; i++) { + matrix[i][B] = h[i-1]; + matrix[i][M] = 2 * (h[i-1] + h[i]); + matrix[i][A] = h[i]; + } + + /* tridiagonal solving of the linear system */ + for (i = 1; i < n; i++) { + double den = matrix[i][M] - matrix[i][B] * matrix[i-1][A]; + double k = den ? 1./den : 1.; + matrix[i][A] *= k; + r[i] = (r[i] - matrix[i][B] * r[i - 1]) * k; + } + for (i = n - 2; i >= 0; i--) + r[i] = r[i] - matrix[i][A] * r[i + 1]; + + /* compute the graph with x=[0..255] */ + i = 0; + point = points; + av_assert0(point->next); // always at least 2 key points + while (point->next) { + double yc = point->y; + double yn = point->next->y; + + double a = yc; + double b = (yn-yc)/h[i] - h[i]*r[i]/2. - h[i]*(r[i+1]-r[i])/6.; + double c = r[i] / 2.; + double d = (r[i+1] - r[i]) / (6.*h[i]); + + int x; + int x_start = point->x * 255; + int x_end = point->next->x * 255; + + av_assert0(x_start >= 0 && x_start <= 255 && + x_end >= 0 && x_end <= 255); + + for (x = x_start; x <= x_end; x++) { + double xx = (x - x_start) * 1/255.; + double yy = a + b*xx + c*xx*xx + d*xx*xx*xx; + y[x] = av_clipf(yy, 0, 1) * 255; + av_log(ctx, AV_LOG_DEBUG, "f(%f)=%f -> y[%d]=%d\n", xx, yy, x, y[x]); + } + + point = point->next; + i++; + } + +end: + av_free(matrix); + av_free(h); + av_free(r); + return ret; +} + +static av_cold int init(AVFilterContext *ctx, const char *args) +{ + int i, j, ret; + CurvesContext *curves = ctx->priv; + struct keypoint *comp_points[NB_COMP] = {0}; + + curves->class = &curves_class; + av_opt_set_defaults(curves); + + if ((ret = av_set_options_string(curves, args, "=", ":")) < 0) + return ret; + + for (i = 0; i < NB_COMP; i++) { + ret = parse_points_str(ctx, comp_points + i, curves->comp_points_str[i]); + if (ret < 0) + return ret; + ret = interpolate(ctx, curves->graph[i], comp_points[i]); + if (ret < 0) + return ret; + } + + if (av_log_get_level() >= AV_LOG_VERBOSE) { + for (i = 0; i < NB_COMP; i++) { + struct keypoint *point = comp_points[i]; + av_log(ctx, AV_LOG_VERBOSE, "#%d points:", i); + while (point) { + av_log(ctx, AV_LOG_VERBOSE, " (%f;%f)", point->x, point->y); + point = point->next; + } + av_log(ctx, AV_LOG_VERBOSE, "\n"); + av_log(ctx, AV_LOG_VERBOSE, "#%d values:", i); + for (j = 0; j < 256; j++) + av_log(ctx, AV_LOG_VERBOSE, " %02X", curves->graph[i][j]); + av_log(ctx, AV_LOG_VERBOSE, "\n"); + } + } + + for (i = 0; i < NB_COMP; i++) { + struct keypoint *point = comp_points[i]; + while (point) { + struct keypoint *next = point->next; + av_free(point); + point = next; + } + } + + av_opt_free(curves); + return 0; +} + +static int query_formats(AVFilterContext *ctx) +{ + static const enum AVPixelFormat pix_fmts[] = {AV_PIX_FMT_RGB24, AV_PIX_FMT_NONE}; + ff_set_common_formats(ctx, ff_make_format_list(pix_fmts)); + return 0; +} + +static int filter_frame(AVFilterLink *inlink, AVFrame *in) +{ + int x, y, i, direct = 0; + AVFilterContext *ctx = inlink->dst; + CurvesContext *curves = ctx->priv; + AVFilterLink *outlink = inlink->dst->outputs[0]; + AVFrame *out; + uint8_t *dst; + const uint8_t *src; + + if (av_frame_is_writable(in)) { + direct = 1; + out = in; + } else { + out = ff_get_video_buffer(outlink, outlink->w, outlink->h); + if (!out) { + av_frame_free(&in); + return AVERROR(ENOMEM); + } + av_frame_copy_props(out, in); + } + + dst = out->data[0]; + src = in ->data[0]; + + for (y = 0; y < inlink->h; y++) { + uint8_t *dstp = dst; + const uint8_t *srcp = src; + + for (x = 0; x < inlink->w; x++) + for (i = 0; i < NB_COMP; i++, dstp++, srcp++) + *dstp = curves->graph[i][*srcp]; + dst += out->linesize[0]; + src += in ->linesize[0]; + } + + if (!direct) + av_frame_free(&in); + + return ff_filter_frame(outlink, out); +} + +static const AVFilterPad curves_inputs[] = { + { + .name = "default", + .type = AVMEDIA_TYPE_VIDEO, + .filter_frame = filter_frame, + }, + { NULL } +}; + +static const AVFilterPad curves_outputs[] = { + { + .name = "default", + .type = AVMEDIA_TYPE_VIDEO, + }, + { NULL } +}; + +AVFilter avfilter_vf_curves = { + .name = "curves", + .description = NULL_IF_CONFIG_SMALL("Adjust components curves."), + .priv_size = sizeof(CurvesContext), + .init = init, + .query_formats = query_formats, + .inputs = curves_inputs, + .outputs = curves_outputs, + .priv_class = &curves_class, +};