[FFmpeg-devel] rectification filter
Daniel Oberhoff
danieloberhoff at gmail.com
Tue Jul 29 08:04:50 CEST 2014
Updated patch:
From 204a8da14f92fcdefe63dda341261bdd25d6ce87 Mon Sep 17 00:00:00 2001
From: Daniel Oberhoff <daniel at danieloberhoff.de>
Date: Mon, 28 Jul 2014 23:58:12 +0200
Subject: [PATCH] added rectification filter
---
libavfilter/Makefile | 1 +
libavfilter/allfilters.c | 1 +
libavfilter/vf_rectification.c | 205 +++++++++++++++++++++++++++++++++++++++++
3 files changed, 207 insertions(+)
create mode 100644 libavfilter/vf_rectification.c
diff --git a/libavfilter/Makefile b/libavfilter/Makefile
index 0f54381..1488eae 100644
--- a/libavfilter/Makefile
+++ b/libavfilter/Makefile
@@ -199,6 +199,7 @@ OBJS-$(CONFIG_W3FDIF_FILTER) += vf_w3fdif.o
OBJS-$(CONFIG_YADIF_FILTER) += vf_yadif.o
OBJS-$(CONFIG_ZMQ_FILTER) += f_zmq.o
OBJS-$(CONFIG_ZOOMPAN_FILTER) += vf_zoompan.o
+OBJS-$(CONFIG_RECTIFICATION_FILTER) += vf_rectification.o
OBJS-$(CONFIG_CELLAUTO_FILTER) += vsrc_cellauto.o
OBJS-$(CONFIG_COLOR_FILTER) += vsrc_testsrc.o
diff --git a/libavfilter/allfilters.c b/libavfilter/allfilters.c
index 1877557..f6e7bc2 100644
--- a/libavfilter/allfilters.c
+++ b/libavfilter/allfilters.c
@@ -216,6 +216,7 @@ void avfilter_register_all(void)
REGISTER_FILTER(YADIF, yadif, vf);
REGISTER_FILTER(ZMQ, zmq, vf);
REGISTER_FILTER(ZOOMPAN, zoompan, vf);
+ REGISTER_FILTER(RECTIFICATION, rectification, vf);
REGISTER_FILTER(CELLAUTO, cellauto, vsrc);
REGISTER_FILTER(COLOR, color, vsrc);
diff --git a/libavfilter/vf_rectification.c b/libavfilter/vf_rectification.c
new file mode 100644
index 0000000..ba3a1e8
--- /dev/null
+++ b/libavfilter/vf_rectification.c
@@ -0,0 +1,205 @@
+/*
+ * Copyright (c) 2014 Daniel Oberhoff
+ *
+ * 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
+ * rectification filter, algorithm from the frei0r plugin with the same name
+*/
+#include <stdlib.h>
+#include <math.h>
+
+#include "libavutil/opt.h"
+#include "libavutil/intreadwrite.h"
+#include "libavutil/pixdesc.h"
+
+#include "avfilter.h"
+#include "internal.h"
+#include "video.h"
+
+#include <float.h>
+
+typedef struct RectificationCtx
+{
+ AVClass* av_class;
+ unsigned int width;
+ unsigned int height;
+ int hsub, vsub;
+ int nb_planes;
+ double cx, cy, k1, k2;
+} RectificationCtx;
+
+#define FLAGS AV_OPT_FLAG_FILTERING_PARAM|AV_OPT_FLAG_VIDEO_PARAM
+static const AVOption rectification_options[] = {
+ { "cx", "set relative center x", offsetof(RectificationCtx, cx), AV_OPT_TYPE_DOUBLE, {.dbl=0.5}, 0, 1, .flags=FLAGS },
+ { "cy", "set relative center y", offsetof(RectificationCtx, cy), AV_OPT_TYPE_DOUBLE, {.dbl=0.5}, 0, 1, .flags=FLAGS },
+ { "k1", "set quadratic distortion factor", offsetof(RectificationCtx, k1), AV_OPT_TYPE_DOUBLE, {.dbl=0.5}, 0, 1, .flags=FLAGS },
+ { "k2", "set double quadratic distortion factor", offsetof(RectificationCtx, k2), AV_OPT_TYPE_DOUBLE, {.dbl=0.5}, 0, 1, .flags=FLAGS },
+ { NULL }
+};
+
+AVFILTER_DEFINE_CLASS(rectification);
+
+static av_cold int init(AVFilterContext *ctx)
+{
+ return 0;
+}
+
+static av_cold void uninit(AVFilterContext *ctx)
+{
+}
+
+typedef struct ThreadData
+{
+ AVFrame *in, *out;
+ int w, h;
+ int plane;
+ float xcenter, ycenter;
+ float k1, k2;
+}ThreadData;
+
+static int filter_slice(AVFilterContext *ctx, void *arg, int job, int nb_jobs)
+{
+ ThreadData* td = (ThreadData*)arg;
+ AVFrame *in = td->in;
+ AVFrame *out = td->out;
+
+ const int w = td->w, h = td->h;
+ const float xcenter = td->xcenter;
+ const float ycenter = td->ycenter;
+ const float r2inv = 4.0 / (w * w + h * h);
+ const float k1 = td->k1 - 0.5;
+ const float k2 = td->k2 - 0.5;
+ const int start = (h * job ) / nb_jobs;
+ const int end = (h * (job+1)) / nb_jobs;
+ const int plane = td->plane;
+ const int inlinesize = in->linesize[plane];
+ const int outlinesize = out->linesize[plane];
+ const uint8_t* indata = in->data[plane];
+ uint8_t* outrow = out->data[plane] + start * outlinesize;
+ int i;
+ for (i = start; i < end; ++i, outrow += outlinesize) {
+ const float off_y = i - ycenter;
+ const float off_y2 = off_y * off_y;
+ uint8_t* out = outrow;
+ int j;
+ for (j = 0; j < w; ++j, ++out) {
+ const float off_x = j - xcenter;
+ const float r2 = (off_x * off_x + off_y2) * r2inv;
+ const float radius_mult = 1.0f + r2 * k1 + r2 * r2 * k2;
+ const int x = xcenter + radius_mult * off_x + 0.5f;
+ const int y = ycenter + radius_mult * off_y + 0.5f;
+ const char isvalid = (x > 0 && x < w - 1 && y > 0 && y < h - 1);
+ *out = isvalid ? indata[y * inlinesize + x] : 0;
+ }
+ }
+ return 0;
+}
+
+static int query_formats(AVFilterContext *ctx)
+{
+ static enum PixelFormat pix_fmts[] = {
+ AV_PIX_FMT_YUV410P,
+ AV_PIX_FMT_YUV444P, AV_PIX_FMT_YUVJ444P,
+ AV_PIX_FMT_YUV420P, AV_PIX_FMT_YUVJ420P,
+ AV_PIX_FMT_YUVA444P, AV_PIX_FMT_YUVA420P,
+ AV_PIX_FMT_NONE
+ };
+
+ ff_set_common_formats(ctx, ff_make_format_list(pix_fmts));
+ return 0;
+}
+
+static int config_props(AVFilterLink *outlink)
+{
+ AVFilterContext* ctx = outlink->src;
+ RectificationCtx* rect = ctx->priv;
+ AVFilterLink *inlink = ctx->inputs[0];
+ const AVPixFmtDescriptor *pixdesc = av_pix_fmt_desc_get(inlink->format);
+ rect->hsub = pixdesc->log2_chroma_w;
+ rect->vsub = pixdesc->log2_chroma_h;
+ outlink->w = rect->width = inlink->w;
+ outlink->h = rect->height = inlink->h;
+ rect->nb_planes = av_pix_fmt_count_planes(inlink->format);
+ return 0;
+}
+
+static int filter_frame(AVFilterLink *inlink, AVFrame *in)
+{
+ AVFilterContext *ctx = inlink->dst;
+ AVFilterLink *outlink = ctx->outputs[0];
+ RectificationCtx* rect = (RectificationCtx*)ctx->priv;
+ AVFrame* 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);
+ int plane;
+ for (plane = 0; plane < rect->nb_planes; ++plane) {
+ int hsub = plane == 1 || plane == 2 ? rect->hsub : 0;
+ int vsub = plane == 1 || plane == 2 ? rect->vsub : 0;
+ const int w = rect->width >> hsub;
+ const int h = rect->height >> vsub;
+ ThreadData td = { .in = in, .out = out,
+ .w = w,
+ .h = h,
+ .xcenter = rect->cx * w,
+ .ycenter = rect->cy * h,
+ .k1 = rect->k1,
+ .k2 = rect->k2,
+ .plane = plane};
+ ctx->internal->execute(ctx, filter_slice, &td, NULL, FFMIN(h, ctx->graph->nb_threads));
+ }
+
+ av_frame_free(&in);
+ return ff_filter_frame(outlink, out);
+}
+
+static const AVFilterPad rectification_inputs[] = {
+ {
+ .name = "default",
+ .type = AVMEDIA_TYPE_VIDEO,
+ .filter_frame = filter_frame,
+ },
+ { NULL }
+};
+
+static const AVFilterPad rectification_outputs[] = {
+ {
+ .name = "default",
+ .type = AVMEDIA_TYPE_VIDEO,
+ .config_props = config_props,
+ },
+ { NULL }
+};
+
+AVFilter ff_vf_rectification = {
+ .name = "rectification",
+ .description = NULL_IF_CONFIG_SMALL("rectify the image."),
+ .priv_size = sizeof(RectificationCtx),
+ .init = init,
+ .uninit = uninit,
+ .query_formats = query_formats,
+ .process_command = NULL,
+ .inputs = rectification_inputs,
+ .outputs = rectification_outputs,
+ .priv_class = &rectification_class,
+ .flags = AVFILTER_FLAG_SLICE_THREADS,
+};
--
1.8.2
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