diff options
| -rw-r--r-- | Changelog | 1 | ||||
| -rw-r--r-- | MAINTAINERS | 1 | ||||
| -rw-r--r-- | doc/filters.texi | 46 | ||||
| -rw-r--r-- | libavfilter/Makefile | 1 | ||||
| -rw-r--r-- | libavfilter/allfilters.c | 1 | ||||
| -rw-r--r-- | libavfilter/vf_lenscorrection.c | 198 |
6 files changed, 248 insertions, 0 deletions
@@ -3,6 +3,7 @@ releases are sorted from youngest to oldest. version <next>: - Icecast protocol +- ported lenscorrection filter from frei0r filter version 2.3: diff --git a/MAINTAINERS b/MAINTAINERS index c383d3f45c..6948e22a99 100644 --- a/MAINTAINERS +++ b/MAINTAINERS @@ -354,6 +354,7 @@ Filters: vf_histogram.c Paul B Mahol vf_hqx.c Clément Bœsch vf_il.c Paul B Mahol + vf_lenscorrection.c Daniel Oberhoff vf_mergeplanes.c Paul B Mahol vf_psnr.c Paul B Mahol vf_scale.c Michael Niedermayer diff --git a/doc/filters.texi b/doc/filters.texi index e0759fccfd..54b4451da1 100644 --- a/doc/filters.texi +++ b/doc/filters.texi @@ -5546,6 +5546,51 @@ kerndeint=map=1 @end example @end itemize +@section lenscorrection + +Correct radial lens distortion + +This filter can be used to correct for radial distortion as can result from the use +of wide angle lenses, and thereby re-rectify the image. To find the right parameters +one can use tools available for example as part of opencv or simply trial-and-error. +To use opencv use the calibration sample (under samples/cpp) from the opencv sources +and extract the k1 and k2 coefficients from the resulting matrix. + +Note that effectively the same filter is available in the open-source tools Krita and +Digikam from the KDE project. + +In contrast to the @ref{vignette} filter, which can also be used to compensate lens errors, +this filter corrects the distortion of the image, whereas @ref{vignette} corrects the +brightness distribution, so you may want to use both filters together in certain +cases, though you will have to take care of ordering, i.e. whether vignetting should +be applied before or after lens correction. + +@subsection Options + +The filter accepts the following options: + +@table @option +@item cx +Relative x-coordinate of the focal point of the image, and thereby the center of the +distrortion. This value has a range [0,1] and is expressed as fractions of the image +width. +@item cy +Relative y-coordinate of the focal point of the image, and thereby the center of the +distrortion. This value has a range [0,1] and is expressed as fractions of the image +height. +@item k1 +Coefficient of the quadratic correction term. 0.5 means no correction. +@item k2 +Coefficient of the double quadratic correction term. 0.5 means no correction. +@end table + +The formula that generates the correction is: + +@var{r_src} = @var{r_tgt} * (1 + @var{k1} * (@var{r_tgt} / @var{r_0})^2 + @var{k2} * (@var{r_tgt} / @var{r_0})^4) + +where @var{r_0} is halve of the image diagonal and @var{r_src} and @var{r_tgt} are the +distances from the focal point in the source and target images, respectively. + @anchor{lut3d} @section lut3d @@ -8758,6 +8803,7 @@ For example, to vertically flip a video with @command{ffmpeg}: ffmpeg -i in.avi -vf "vflip" out.avi @end example +@anchor{vignette} @section vignette Make or reverse a natural vignetting effect. diff --git a/libavfilter/Makefile b/libavfilter/Makefile index 0f54381ae2..e9c8456313 100644 --- a/libavfilter/Makefile +++ b/libavfilter/Makefile @@ -138,6 +138,7 @@ OBJS-$(CONFIG_IL_FILTER) += vf_il.o OBJS-$(CONFIG_INTERLACE_FILTER) += vf_interlace.o OBJS-$(CONFIG_INTERLEAVE_FILTER) += f_interleave.o OBJS-$(CONFIG_KERNDEINT_FILTER) += vf_kerndeint.o +OBJS-$(CONFIG_LENSCORRECTION_FILTER) += vf_lenscorrection.o OBJS-$(CONFIG_LUT3D_FILTER) += vf_lut3d.o OBJS-$(CONFIG_LUT_FILTER) += vf_lut.o OBJS-$(CONFIG_LUTRGB_FILTER) += vf_lut.o diff --git a/libavfilter/allfilters.c b/libavfilter/allfilters.c index 18775572ed..b1d6ff5b11 100644 --- a/libavfilter/allfilters.c +++ b/libavfilter/allfilters.c @@ -156,6 +156,7 @@ void avfilter_register_all(void) REGISTER_FILTER(INTERLACE, interlace, vf); REGISTER_FILTER(INTERLEAVE, interleave, vf); REGISTER_FILTER(KERNDEINT, kerndeint, vf); + REGISTER_FILTER(LENSCORRECTION, lenscorrection, vf); REGISTER_FILTER(LUT3D, lut3d, vf); REGISTER_FILTER(LUT, lut, vf); REGISTER_FILTER(LUTRGB, lutrgb, vf); diff --git a/libavfilter/vf_lenscorrection.c b/libavfilter/vf_lenscorrection.c new file mode 100644 index 0000000000..f4b167671c --- /dev/null +++ b/libavfilter/vf_lenscorrection.c @@ -0,0 +1,198 @@ +/* + * Copyright (C) 2007 Richard Spindler (author of frei0r plugin from which this was derived) + * 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 + * Lenscorrection 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" + +typedef struct LenscorrectionCtx { + const AVClass *av_class; + unsigned int width; + unsigned int height; + int hsub, vsub; + int nb_planes; + double cx, cy, k1, k2; +} LenscorrectionCtx; + +#define FLAGS AV_OPT_FLAG_FILTERING_PARAM|AV_OPT_FLAG_VIDEO_PARAM +static const AVOption lenscorrection_options[] = { + { "cx", "set relative center x", offsetof(LenscorrectionCtx, cx), AV_OPT_TYPE_DOUBLE, {.dbl=0.5}, 0, 1, .flags=FLAGS }, + { "cy", "set relative center y", offsetof(LenscorrectionCtx, cy), AV_OPT_TYPE_DOUBLE, {.dbl=0.5}, 0, 1, .flags=FLAGS }, + { "k1", "set quadratic distortion factor", offsetof(LenscorrectionCtx, k1), AV_OPT_TYPE_DOUBLE, {.dbl=0.0}, -1, 1, .flags=FLAGS }, + { "k2", "set double quadratic distortion factor", offsetof(LenscorrectionCtx, k2), AV_OPT_TYPE_DOUBLE, {.dbl=0.0}, -1, 1, .flags=FLAGS }, + { NULL } +}; + +AVFILTER_DEFINE_CLASS(lenscorrection); + +typedef struct ThreadData { + AVFrame *in, *out; + float 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 float 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; + const float k2 = td->k2; + 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++) { + 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 AVPixelFormat 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_YUV422P, + 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; + LenscorrectionCtx *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]; + LenscorrectionCtx *rect = (LenscorrectionCtx*)ctx->priv; + AVFrame *out = ff_get_video_buffer(outlink, outlink->w, outlink->h); + int plane; + + if (!out) { + av_frame_free(&in); + return AVERROR(ENOMEM); + } + + av_frame_copy_props(out, in); + + 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; + float hdiv = 1 << hsub; + float vdiv = 1 << vsub; + float w = rect->width / hdiv; + float h = rect->height / vdiv; + 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 lenscorrection_inputs[] = { + { + .name = "default", + .type = AVMEDIA_TYPE_VIDEO, + .filter_frame = filter_frame, + }, + { NULL } +}; + +static const AVFilterPad lenscorrection_outputs[] = { + { + .name = "default", + .type = AVMEDIA_TYPE_VIDEO, + .config_props = config_props, + }, + { NULL } +}; + +AVFilter ff_vf_lenscorrection = { + .name = "lenscorrection", + .description = NULL_IF_CONFIG_SMALL("Rectify the image by correcting for lens distortion."), + .priv_size = sizeof(LenscorrectionCtx), + .query_formats = query_formats, + .inputs = lenscorrection_inputs, + .outputs = lenscorrection_outputs, + .priv_class = &lenscorrection_class, + .flags = AVFILTER_FLAG_SLICE_THREADS, +}; |