[FFmpeg-devel] [PATCH] avfilter: add temporal midway equalizer filter
Paul B Mahol
onemda at gmail.com
Mon Dec 28 12:41:22 EET 2020
Signed-off-by: Paul B Mahol <onemda at gmail.com>
---
doc/filters.texi | 22 ++
libavfilter/Makefile | 1 +
libavfilter/allfilters.c | 1 +
libavfilter/vf_tmidequalizer.c | 440 +++++++++++++++++++++++++++++++++
4 files changed, 464 insertions(+)
create mode 100644 libavfilter/vf_tmidequalizer.c
diff --git a/doc/filters.texi b/doc/filters.texi
index f71d33c602..1a515c2681 100644
--- a/doc/filters.texi
+++ b/doc/filters.texi
@@ -19319,6 +19319,28 @@ minimum values, and @code{1} maximum values.
This filter supports all above options as @ref{commands}, excluding option @code{radius}.
+ at section tmidequalizer
+
+Apply Temporal Midway Video Equalization effect.
+
+Midway Video Equalization adjusts a sequence of video frames to have the same
+histograms, while maintaining their dynamics as much as possible. It's
+useful for e.g. matching exposures from a video frames sequence.
+
+This filter accepts the following option:
+
+ at table @option
+ at item radius
+Set filtering radius. Default is @code{5}. Allowed range is from 1 to 127.
+
+ at item sigma
+Set filtering sigma. Default is @code{0.5}. This controls strength of filtering.
+Setting this option to 0 effectively does nothing.
+
+ at item planes
+Set which planes to process. Default is @code{15}, which is all available planes.
+ at end table
+
@section tmix
Mix successive video frames.
diff --git a/libavfilter/Makefile b/libavfilter/Makefile
index 5b4831781f..526da8d69e 100644
--- a/libavfilter/Makefile
+++ b/libavfilter/Makefile
@@ -433,6 +433,7 @@ OBJS-$(CONFIG_TILE_FILTER) += vf_tile.o
OBJS-$(CONFIG_TINTERLACE_FILTER) += vf_tinterlace.o
OBJS-$(CONFIG_TLUT2_FILTER) += vf_lut2.o framesync.o
OBJS-$(CONFIG_TMEDIAN_FILTER) += vf_xmedian.o framesync.o
+OBJS-$(CONFIG_TMIDEQUALIZER_FILTER) += vf_tmidequalizer.o
OBJS-$(CONFIG_TMIX_FILTER) += vf_mix.o framesync.o
OBJS-$(CONFIG_TONEMAP_FILTER) += vf_tonemap.o colorspace.o
OBJS-$(CONFIG_TONEMAP_OPENCL_FILTER) += vf_tonemap_opencl.o colorspace.o opencl.o \
diff --git a/libavfilter/allfilters.c b/libavfilter/allfilters.c
index 1b77bf1c81..ce317dfa1c 100644
--- a/libavfilter/allfilters.c
+++ b/libavfilter/allfilters.c
@@ -413,6 +413,7 @@ extern AVFilter ff_vf_tile;
extern AVFilter ff_vf_tinterlace;
extern AVFilter ff_vf_tlut2;
extern AVFilter ff_vf_tmedian;
+extern AVFilter ff_vf_tmidequalizer;
extern AVFilter ff_vf_tmix;
extern AVFilter ff_vf_tonemap;
extern AVFilter ff_vf_tonemap_opencl;
diff --git a/libavfilter/vf_tmidequalizer.c b/libavfilter/vf_tmidequalizer.c
new file mode 100644
index 0000000000..6e3f3ccce1
--- /dev/null
+++ b/libavfilter/vf_tmidequalizer.c
@@ -0,0 +1,440 @@
+/*
+ * Copyright (c) 2020 Paul B Mahol
+ *
+ * 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/imgutils.h"
+#include "libavutil/pixdesc.h"
+#include "libavutil/opt.h"
+#include "avfilter.h"
+#include "formats.h"
+#include "internal.h"
+#include "video.h"
+
+typedef struct TMidEqualizerContext {
+ const AVClass *class;
+
+ int planes;
+ int radius;
+ float sigma;
+
+ int plane_width[4], plane_height[4];
+ int nb_frames;
+ int depth;
+ int f_frames;
+ int l_frames;
+ int del_frame;
+ int cur_frame;
+ int nb_planes;
+ int histogram_size;
+ float kernel[127];
+ float *histogram[4][256];
+ float *change[4];
+
+ AVFrame **frames;
+
+ void (*compute_histogram)(const uint8_t *ssrc, ptrdiff_t linesize,
+ int w, int h, float *histogram, size_t hsize);
+ void (*apply_contrast_change)(const uint8_t *src, ptrdiff_t src_linesize,
+ uint8_t *dst, ptrdiff_t dst_linesize,
+ int w, int h, float *change, float *orig);
+} TMidEqualizerContext;
+
+#define OFFSET(x) offsetof(TMidEqualizerContext, x)
+#define FLAGS AV_OPT_FLAG_FILTERING_PARAM|AV_OPT_FLAG_VIDEO_PARAM
+
+static const AVOption tmidequalizer_options[] = {
+ { "radius", "set radius", OFFSET(radius), AV_OPT_TYPE_INT, {.i64=5}, 1, 127, FLAGS },
+ { "sigma", "set sigma", OFFSET(sigma), AV_OPT_TYPE_FLOAT, {.dbl=0.5}, 0, 1, FLAGS },
+ { "planes", "set planes", OFFSET(planes), AV_OPT_TYPE_INT, {.i64=0xF}, 0, 0xF, FLAGS },
+ { NULL }
+};
+
+AVFILTER_DEFINE_CLASS(tmidequalizer);
+
+static int query_formats(AVFilterContext *ctx)
+{
+ static const enum AVPixelFormat pix_fmts[] = {
+ AV_PIX_FMT_YUVA444P, AV_PIX_FMT_YUV444P, AV_PIX_FMT_YUV440P,
+ AV_PIX_FMT_YUVJ444P, AV_PIX_FMT_YUVJ440P,
+ AV_PIX_FMT_YUVA422P, AV_PIX_FMT_YUV422P, AV_PIX_FMT_YUVA420P, AV_PIX_FMT_YUV420P,
+ AV_PIX_FMT_YUVJ422P, AV_PIX_FMT_YUVJ420P,
+ AV_PIX_FMT_YUVJ411P, AV_PIX_FMT_YUV411P, AV_PIX_FMT_YUV410P,
+ AV_PIX_FMT_GBRP, AV_PIX_FMT_GBRAP,
+ AV_PIX_FMT_GRAY8, AV_PIX_FMT_GRAY9, AV_PIX_FMT_GRAY10, AV_PIX_FMT_GRAY12, AV_PIX_FMT_GRAY14,
+ AV_PIX_FMT_YUV420P9, AV_PIX_FMT_YUV422P9, AV_PIX_FMT_YUV444P9,
+ AV_PIX_FMT_YUV420P10, AV_PIX_FMT_YUV422P10, AV_PIX_FMT_YUV444P10,
+ AV_PIX_FMT_YUV420P12, AV_PIX_FMT_YUV422P12, AV_PIX_FMT_YUV444P12,
+ AV_PIX_FMT_YUV420P14, AV_PIX_FMT_YUV422P14, AV_PIX_FMT_YUV444P14,
+ AV_PIX_FMT_GBRP9, AV_PIX_FMT_GBRP10, AV_PIX_FMT_GBRP12, AV_PIX_FMT_GBRP14,
+ AV_PIX_FMT_YUVA420P9, AV_PIX_FMT_YUVA422P9, AV_PIX_FMT_YUVA444P9,
+ AV_PIX_FMT_YUVA420P10, AV_PIX_FMT_YUVA422P10, AV_PIX_FMT_YUVA444P10,
+ AV_PIX_FMT_YUVA422P12, AV_PIX_FMT_YUVA444P12,
+ AV_PIX_FMT_GBRAP10, AV_PIX_FMT_GBRAP12,
+ AV_PIX_FMT_YUV420P16, AV_PIX_FMT_YUV422P16, AV_PIX_FMT_YUV444P16,
+ AV_PIX_FMT_YUVA420P16, AV_PIX_FMT_YUVA422P16, AV_PIX_FMT_YUVA444P16,
+ AV_PIX_FMT_GBRP16, AV_PIX_FMT_GBRAP16,
+ AV_PIX_FMT_GRAY16,
+ AV_PIX_FMT_NONE
+ };
+
+ return ff_set_common_formats(ctx, ff_make_format_list(pix_fmts));
+}
+
+static void compute_contrast_function(const float *const histograms[256],
+ const float *const kernel,
+ int nb_frames, int radius, int hsize,
+ float *f, int idx)
+{
+ const float *const h1 = histograms[idx];
+ int p2[256] = { 0 };
+
+ for (int p1 = 0; p1 < hsize; p1++) {
+ float weight = 1.f;
+ float sum = p1 * weight;
+
+ for (int j = 0; j < radius; j++) {
+ const int nidx = ((idx - radius + j) % nb_frames);
+ const float *const h2 = histograms[nidx < 0 ? nidx + nb_frames: nidx];
+ int k = j;
+
+ for (; p2[k] < hsize && h2[p2[k]] < h1[p1]; p2[k]++);
+ if (p2[k] == hsize)
+ p2[k]--;
+
+ weight += kernel[j];
+ sum += kernel[j] * p2[k];
+ }
+
+ for (int j = radius + 1; j < nb_frames; j++) {
+ const int nidx = (idx - radius + j) % nb_frames;
+ const float *const h2 = histograms[nidx < 0 ? nidx + nb_frames: nidx];
+ int k = j;
+
+ for (; p2[k] < hsize && h2[p2[k]] < h1[p1]; p2[k]++);
+ if (p2[k] == hsize)
+ p2[k]--;
+
+ weight += kernel[j - radius - 1];
+ sum += kernel[j - radius - 1] * p2[k];
+ }
+
+ f[p1] = sum / weight;
+ }
+}
+
+static void apply_contrast_change8(const uint8_t *src, ptrdiff_t src_linesize,
+ uint8_t *dst, ptrdiff_t dst_linesize,
+ int w, int h, float *change, float *orig)
+{
+ for (int y = 0; y < h; y++) {
+ for (int x = 0; x < w; x++)
+ dst[x] = lrintf(change[src[x]]);
+
+ dst += dst_linesize;
+ src += src_linesize;
+ }
+}
+
+static void apply_contrast_change16(const uint8_t *ssrc, ptrdiff_t src_linesize,
+ uint8_t *ddst, ptrdiff_t dst_linesize,
+ int w, int h, float *change, float *orig)
+{
+ const uint16_t *src = (const uint16_t *)ssrc;
+ uint16_t *dst = (uint16_t *)ddst;
+
+ for (int y = 0; y < h; y++) {
+ for (int x = 0; x < w; x++)
+ dst[x] = lrintf(change[src[x]]);
+
+ dst += dst_linesize / 2;
+ src += src_linesize / 2;
+ }
+}
+
+static int filter_frame(AVFilterLink *inlink, AVFrame *in)
+{
+ AVFilterContext *ctx = inlink->dst;
+ TMidEqualizerContext *s = ctx->priv;
+ AVFilterLink *outlink = ctx->outputs[0];
+ AVFrame *out;
+ int eof = 0;
+
+ if (!in) {
+ int idx = s->f_frames < s->nb_frames ? s->radius : s->del_frame ? s->del_frame - 1 : s->nb_frames - 1;
+
+ if (s->f_frames < s->nb_frames) {
+ s->l_frames = s->nb_frames - s->f_frames;
+ } else {
+ s->l_frames++;
+ }
+ in = av_frame_clone(s->frames[idx]);
+ if (!in)
+ return AVERROR(ENOMEM);
+ eof = 1;
+ }
+
+ if (s->f_frames < s->nb_frames) {
+ s->frames[s->f_frames] = in;
+
+ for (int p = 0; p < s->nb_planes; p++) {
+ s->compute_histogram(in->data[p], in->linesize[p],
+ s->plane_width[p], s->plane_height[p],
+ s->histogram[p][s->f_frames],
+ s->histogram_size);
+ }
+
+ s->f_frames++;
+
+ while (s->f_frames <= s->radius) {
+ s->frames[s->f_frames] = av_frame_clone(in);
+ if (!s->frames[s->f_frames])
+ return AVERROR(ENOMEM);
+ for (int p = 0; p < s->nb_planes; p++) {
+ memcpy(s->histogram[p][s->f_frames],
+ s->histogram[p][s->f_frames - 1],
+ s->histogram_size * sizeof(float));
+ }
+ s->f_frames++;
+ }
+
+ if (!eof && s->f_frames < s->nb_frames) {
+ return 0;
+ } else {
+ while (s->f_frames < s->nb_frames) {
+ s->frames[s->f_frames] = av_frame_clone(in);
+ if (!s->frames[s->f_frames])
+ return AVERROR(ENOMEM);
+ for (int p = 0; p < s->nb_planes; p++) {
+ memcpy(s->histogram[p][s->f_frames],
+ s->histogram[p][s->f_frames - 1],
+ s->histogram_size * sizeof(float));
+ }
+ s->f_frames++;
+ }
+ }
+ s->cur_frame = s->radius;
+ s->del_frame = 0;
+ } else {
+ av_frame_free(&s->frames[s->del_frame]);
+ s->frames[s->del_frame] = in;
+
+ for (int p = 0; p < s->nb_planes; p++) {
+ s->compute_histogram(in->data[p], in->linesize[p],
+ s->plane_width[p], s->plane_height[p],
+ s->histogram[p][s->del_frame],
+ s->histogram_size);
+ }
+
+ s->del_frame++;
+ if (s->del_frame >= s->nb_frames)
+ s->del_frame = 0;
+ }
+
+ if (ctx->is_disabled) {
+ const int idx = s->cur_frame;
+
+ out = av_frame_clone(s->frames[idx]);
+ if (!out)
+ return AVERROR(ENOMEM);
+ } else {
+ const int idx = s->cur_frame;
+
+ in = s->frames[idx];
+ out = ff_get_video_buffer(outlink, outlink->w, outlink->h);
+ if (!out)
+ return AVERROR(ENOMEM);
+ av_frame_copy_props(out, in);
+
+ for (int p = 0; p < s->nb_planes; p++) {
+ if (!((1 << p) & s->planes)) {
+ av_image_copy_plane(out->data[p], out->linesize[p], in->data[p], in->linesize[p],
+ s->plane_width[p] * (1 + (s->depth > 8)), s->plane_height[p]);
+ continue;
+ }
+
+ compute_contrast_function((const float *const *)s->histogram[p], s->kernel,
+ s->nb_frames, s->radius, s->histogram_size, s->change[p], idx);
+
+ s->apply_contrast_change(in->data[p], in->linesize[p],
+ out->data[p], out->linesize[p],
+ s->plane_width[p], s->plane_height[p],
+ s->change[p], s->histogram[p][idx]);
+ }
+ }
+
+ s->cur_frame++;
+ if (s->cur_frame >= s->nb_frames)
+ s->cur_frame = 0;
+
+ return ff_filter_frame(outlink, out);
+}
+
+static void compute_histogram8(const uint8_t *src, ptrdiff_t linesize,
+ int w, int h, float *histogram, size_t hsize)
+{
+ memset(histogram, 0, hsize * sizeof(*histogram));
+
+ for (int y = 0; y < h; y++) {
+ for (int x = 0; x < w; x++)
+ histogram[src[x]] += 1;
+ src += linesize;
+ }
+
+ for (int x = 0; x < hsize; x++)
+ histogram[x] /= hsize;
+
+ for (int x = 1; x < hsize; x++)
+ histogram[x] += histogram[x-1];
+}
+
+static void compute_histogram16(const uint8_t *ssrc, ptrdiff_t linesize,
+ int w, int h, float *histogram, size_t hsize)
+{
+ const uint16_t *src = (const uint16_t *)ssrc;
+
+ memset(histogram, 0, hsize * sizeof(*histogram));
+
+ for (int y = 0; y < h; y++) {
+ for (int x = 0; x < w; x++)
+ histogram[src[x]] += 1;
+ src += linesize / 2;
+ }
+
+ for (int x = 0; x < hsize; x++)
+ histogram[x] /= hsize;
+
+ for (int x = 1; x < hsize; x++)
+ histogram[x] += histogram[x-1];
+}
+
+static int config_input(AVFilterLink *inlink)
+{
+ AVFilterContext *ctx = inlink->dst;
+ TMidEqualizerContext *s = ctx->priv;
+ const AVPixFmtDescriptor *desc = av_pix_fmt_desc_get(inlink->format);
+ float sigma = s->radius * s->sigma;
+ int vsub, hsub;
+
+ s->depth = desc->comp[0].depth;
+ s->nb_frames = s->radius * 2 + 1;
+ s->nb_planes = av_pix_fmt_count_planes(inlink->format);
+
+ hsub = desc->log2_chroma_w;
+ vsub = desc->log2_chroma_h;
+
+ s->plane_height[0] = s->plane_height[3] = inlink->h;
+ s->plane_width[0] = s->plane_width[3] = inlink->w;
+ s->plane_height[1] = s->plane_height[2] = AV_CEIL_RSHIFT(inlink->h, vsub);
+ s->plane_width[1] = s->plane_width[2] = AV_CEIL_RSHIFT(inlink->w, hsub);
+
+ s->histogram_size = 1 << s->depth;
+
+ for (int n = 0; n < s->radius; n++)
+ s->kernel[n] = expf(-0.5 * (n + 1) * (n + 1) / (sigma * sigma));
+
+ for (int p = 0; p < s->nb_planes; p++) {
+ for (int n = 0; n < s->nb_frames; n++) {
+ s->histogram[p][n] = av_calloc(s->histogram_size, sizeof(float));
+ if (!s->histogram[p][n])
+ return AVERROR(ENOMEM);
+ }
+
+ s->change[p] = av_calloc(s->histogram_size, sizeof(float));
+ if (!s->change[p])
+ return AVERROR(ENOMEM);
+ }
+
+ if (!s->frames)
+ s->frames = av_calloc(s->nb_frames, sizeof(*s->frames));
+ if (!s->frames)
+ return AVERROR(ENOMEM);
+
+ s->compute_histogram = s->depth <= 8 ? compute_histogram8 : compute_histogram16;
+ s->apply_contrast_change = s->depth <= 8 ? apply_contrast_change8 : apply_contrast_change16;
+
+ return 0;
+}
+
+static int request_frame(AVFilterLink *outlink)
+{
+ AVFilterContext *ctx = outlink->src;
+ TMidEqualizerContext *s = ctx->priv;
+ int ret;
+
+ ret = ff_request_frame(ctx->inputs[0]);
+ if (ret == AVERROR_EOF && s->l_frames < s->radius) {
+ ret = filter_frame(ctx->inputs[0], NULL);
+ }
+
+ return ret;
+}
+
+static void free_histograms(AVFilterContext *ctx, int x, int nb_frames)
+{
+ TMidEqualizerContext *s = ctx->priv;
+
+ for (int n = 0; n < nb_frames; n++)
+ av_freep(&s->histogram[x][n]);
+ av_freep(&s->change[x]);
+}
+
+static av_cold void uninit(AVFilterContext *ctx)
+{
+ TMidEqualizerContext *s = ctx->priv;
+
+ free_histograms(ctx, 0, s->nb_frames);
+ free_histograms(ctx, 1, s->nb_frames);
+ free_histograms(ctx, 2, s->nb_frames);
+ free_histograms(ctx, 3, s->nb_frames);
+
+ for (int i = 0; i < s->nb_frames && s->frames; i++)
+ av_frame_free(&s->frames[i]);
+ av_freep(&s->frames);
+}
+
+static const AVFilterPad tmidequalizer_inputs[] = {
+ {
+ .name = "default",
+ .type = AVMEDIA_TYPE_VIDEO,
+ .config_props = config_input,
+ .filter_frame = filter_frame,
+ },
+ { NULL }
+};
+
+static const AVFilterPad tmidequalizer_outputs[] = {
+ {
+ .name = "default",
+ .type = AVMEDIA_TYPE_VIDEO,
+ .request_frame = request_frame,
+ },
+ { NULL }
+};
+
+AVFilter ff_vf_tmidequalizer = {
+ .name = "tmidequalizer",
+ .description = NULL_IF_CONFIG_SMALL("Apply Temporal Midway Equalization."),
+ .priv_size = sizeof(TMidEqualizerContext),
+ .uninit = uninit,
+ .query_formats = query_formats,
+ .inputs = tmidequalizer_inputs,
+ .outputs = tmidequalizer_outputs,
+ .priv_class = &tmidequalizer_class,
+ .flags = AVFILTER_FLAG_SUPPORT_TIMELINE_INTERNAL,
+};
--
2.17.1
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