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lavfi: port perspective filter from libmpcodecs

Signed-off-by: Paul B Mahol <onemda@gmail.com>
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1 parent ab5f581 commit 80c644593223ac74bba915c698926ffcc8a90d68 @richardpl richardpl committed Jul 12, 2013
Showing with 452 additions and 2 deletions.
  1. +1 −0 Changelog
  2. +1 −0 LICENSE
  3. +1 −0 configure
  4. +38 −0 doc/filters.texi
  5. +1 −0 libavfilter/Makefile
  6. +1 −0 libavfilter/allfilters.c
  7. +2 −2 libavfilter/version.h
  8. +407 −0 libavfilter/vf_perspective.c
View
1 Changelog
@@ -4,6 +4,7 @@ releases are sorted from youngest to oldest.
version <next>
- aecho filter
+- perspective filter ported from libmpcodecs
version 2.0:
View
1 LICENSE
@@ -39,6 +39,7 @@ Specifically, the GPL parts of FFmpeg are
- vf_mp.c
- vf_noise.c
- vf_owdenoise.c
+ - vf_perspective.c
- vf_pp.c
- vf_sab.c
- vf_smartblur.c
View
1 configure
@@ -2175,6 +2175,7 @@ mpdecimate_filter_deps="gpl avcodec"
mptestsrc_filter_deps="gpl"
negate_filter_deps="lut_filter"
noise_filter_deps="gpl"
+perspective_filter_deps="gpl"
resample_filter_deps="avresample"
ocv_filter_deps="libopencv"
owdenoise_filter_deps="gpl"
View
38 doc/filters.texi
@@ -5722,6 +5722,44 @@ pad="2*iw:2*ih:ow-iw:oh-ih"
@end example
@end itemize
+@section perspective
+
+Correct perspective of video not recorded perpendicular to the screen.
+
+A description of the accepted parameters follows.
+
+@table @option
+@item x0
+@item y0
+@item x1
+@item y1
+@item x2
+@item y2
+@item x3
+@item y3
+Set coordinates expression for top left, top right, bottom left and bottom right corners.
+Default values are @code{0:0:W:0:0:H:W:H} with which perspective will remain unchanged.
+
+The expressions can use the following variables:
+
+@table @option
+@item W
+@item H
+the width and height of video frame.
+@end table
+
+@item interpolation
+Set interpolation for perspective correction.
+
+It accepts the following values:
+@table @samp
+@item linear
+@item cubic
+@end table
+
+Default value is @samp{linear}.
+@end table
+
@section pixdesctest
Pixel format descriptor test filter, mainly useful for internal
View
1 libavfilter/Makefile
@@ -166,6 +166,7 @@ OBJS-$(CONFIG_OVERLAY_FILTER) += vf_overlay.o dualinput.o
OBJS-$(CONFIG_OWDENOISE_FILTER) += vf_owdenoise.o
OBJS-$(CONFIG_PAD_FILTER) += vf_pad.o
OBJS-$(CONFIG_PERMS_FILTER) += f_perms.o
+OBJS-$(CONFIG_PERSPECTIVE_FILTER) += vf_perspective.o
OBJS-$(CONFIG_PIXDESCTEST_FILTER) += vf_pixdesctest.o
OBJS-$(CONFIG_PP_FILTER) += vf_pp.o
OBJS-$(CONFIG_PSNR_FILTER) += vf_psnr.o dualinput.o
View
1 libavfilter/allfilters.c
@@ -161,6 +161,7 @@ void avfilter_register_all(void)
REGISTER_FILTER(OWDENOISE, owdenoise, vf);
REGISTER_FILTER(PAD, pad, vf);
REGISTER_FILTER(PERMS, perms, vf);
+ REGISTER_FILTER(PERSPECTIVE, perspective, vf);
REGISTER_FILTER(PIXDESCTEST, pixdesctest, vf);
REGISTER_FILTER(PP, pp, vf);
REGISTER_FILTER(PSNR, psnr, vf);
View
4 libavfilter/version.h
@@ -30,8 +30,8 @@
#include "libavutil/avutil.h"
#define LIBAVFILTER_VERSION_MAJOR 3
-#define LIBAVFILTER_VERSION_MINOR 80
-#define LIBAVFILTER_VERSION_MICRO 101
+#define LIBAVFILTER_VERSION_MINOR 81
+#define LIBAVFILTER_VERSION_MICRO 100
#define LIBAVFILTER_VERSION_INT AV_VERSION_INT(LIBAVFILTER_VERSION_MAJOR, \
LIBAVFILTER_VERSION_MINOR, \
View
407 libavfilter/vf_perspective.c
@@ -0,0 +1,407 @@
+/*
+ * Copyright (c) 2002 Michael Niedermayer <michaelni@gmx.at>
+ * Copyright (c) 2013 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 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
+ */
+
+#include "libavutil/eval.h"
+#include "libavutil/imgutils.h"
+#include "libavutil/pixdesc.h"
+#include "libavutil/opt.h"
+#include "avfilter.h"
+#include "formats.h"
+#include "internal.h"
+#include "video.h"
+
+#define SUB_PIXEL_BITS 8
+#define SUB_PIXELS (1 << SUB_PIXEL_BITS)
+#define COEFF_BITS 11
+
+#define LINEAR 0
+#define CUBIC 1
+
+typedef struct PerspectiveContext {
+ const AVClass *class;
+ char *expr_str[4][2];
+ double ref[4][2];
+ int32_t (*pv)[2];
+ int32_t coeff[SUB_PIXELS][4];
+ int interpolation;
+ int linesize[4];
+ int height[4];
+ int hsub, vsub;
+ int nb_planes;
+
+ void (*perspective)(struct PerspectiveContext *s,
+ uint8_t *dst, int dst_linesize,
+ uint8_t *src, int src_linesize,
+ int w, int h, int hsub, int vsub);
+} PerspectiveContext;
+
+#define OFFSET(x) offsetof(PerspectiveContext, x)
+#define FLAGS AV_OPT_FLAG_FILTERING_PARAM|AV_OPT_FLAG_VIDEO_PARAM
+
+static const AVOption perspective_options[] = {
+ { "x0", "set top left x coordinate", OFFSET(expr_str[0][0]), AV_OPT_TYPE_STRING, {.str="0"}, 0, 0, FLAGS },
+ { "y0", "set top left y coordinate", OFFSET(expr_str[0][1]), AV_OPT_TYPE_STRING, {.str="0"}, 0, 0, FLAGS },
+ { "x1", "set top right x coordinate", OFFSET(expr_str[1][0]), AV_OPT_TYPE_STRING, {.str="W"}, 0, 0, FLAGS },
+ { "y1", "set top right y coordinate", OFFSET(expr_str[1][1]), AV_OPT_TYPE_STRING, {.str="0"}, 0, 0, FLAGS },
+ { "x2", "set bottom left x coordinate", OFFSET(expr_str[2][0]), AV_OPT_TYPE_STRING, {.str="0"}, 0, 0, FLAGS },
+ { "y2", "set bottom left y coordinate", OFFSET(expr_str[2][1]), AV_OPT_TYPE_STRING, {.str="H"}, 0, 0, FLAGS },
+ { "x3", "set bottom right x coordinate", OFFSET(expr_str[3][0]), AV_OPT_TYPE_STRING, {.str="W"}, 0, 0, FLAGS },
+ { "y3", "set bottom right y coordinate", OFFSET(expr_str[3][1]), AV_OPT_TYPE_STRING, {.str="H"}, 0, 0, FLAGS },
+ { "interpolation", "set interpolation", OFFSET(interpolation), AV_OPT_TYPE_INT, {.i64=LINEAR}, 0, 1, FLAGS, "interpolation" },
+ { "linear", "", 0, AV_OPT_TYPE_CONST, {.i64=LINEAR}, 0, 0, FLAGS, "interpolation" },
+ { "cubic", "", 0, AV_OPT_TYPE_CONST, {.i64=CUBIC}, 0, 0, FLAGS, "interpolation" },
+ { NULL }
+};
+
+AVFILTER_DEFINE_CLASS(perspective);
+
+static int query_formats(AVFilterContext *ctx)
+{
+ static const enum AVPixelFormat pix_fmts[] = {
+ AV_PIX_FMT_YUVA444P, AV_PIX_FMT_YUVA422P, AV_PIX_FMT_YUVA420P,
+ AV_PIX_FMT_YUVJ444P, AV_PIX_FMT_YUVJ440P, AV_PIX_FMT_YUVJ422P,AV_PIX_FMT_YUVJ420P, AV_PIX_FMT_YUVJ411P,
+ AV_PIX_FMT_YUV444P, AV_PIX_FMT_YUV440P, AV_PIX_FMT_YUV422P, AV_PIX_FMT_YUV420P, AV_PIX_FMT_YUV411P, AV_PIX_FMT_YUV410P,
+ AV_PIX_FMT_GBRP, AV_PIX_FMT_GBRAP, AV_PIX_FMT_GRAY8, AV_PIX_FMT_NONE
+ };
+
+ ff_set_common_formats(ctx, ff_make_format_list(pix_fmts));
+ return 0;
+}
+
+static inline double get_coeff(double d)
+{
+ double coeff, A = -0.60;
+
+ d = fabs(d);
+
+ if (d < 1.0)
+ coeff = (1.0 - (A + 3.0) * d * d + (A + 2.0) * d * d * d);
+ else if (d < 2.0)
+ coeff = (-4.0 * A + 8.0 * A * d - 5.0 * A * d * d + A * d * d * d);
+ else
+ coeff = 0.0;
+
+ return coeff;
+}
+
+static const char *const var_names[] = { "W", "H", NULL };
+enum { VAR_W, VAR_H, VAR_VARS_NB };
+
+static int config_input(AVFilterLink *inlink)
+{
+ double x0, x1, x2, x3, x4, x5, x6, x7, q;
+ AVFilterContext *ctx = inlink->dst;
+ PerspectiveContext *s = ctx->priv;
+ double (*ref)[2] = s->ref;
+ const AVPixFmtDescriptor *desc = av_pix_fmt_desc_get(inlink->format);
+ double values[VAR_VARS_NB] = { [VAR_W] = inlink->w, [VAR_H] = inlink->h };
+ int h = inlink->h;
+ int w = inlink->w;
+ int x, y, i, j, ret;
+
+ for (i = 0; i < 4; i++) {
+ for (j = 0; j < 2; j++) {
+ if (!s->expr_str[i][j])
+ return AVERROR(EINVAL);
+ ret = av_expr_parse_and_eval(&s->ref[i][j], s->expr_str[i][j],
+ var_names, &values[0],
+ NULL, NULL, NULL, NULL,
+ 0, 0, ctx);
+ if (ret < 0)
+ return ret;
+ }
+ }
+
+ s->hsub = desc->log2_chroma_w;
+ s->vsub = desc->log2_chroma_h;
+ s->nb_planes = av_pix_fmt_count_planes(inlink->format);
+ if ((ret = av_image_fill_linesizes(s->linesize, inlink->format, inlink->w)) < 0)
+ return ret;
+
+ s->height[1] = s->height[2] = FF_CEIL_RSHIFT(inlink->h, desc->log2_chroma_h);
+ s->height[0] = s->height[3] = inlink->h;
+
+ s->pv = av_realloc_f(s->pv, w * h, 2 * sizeof(*s->pv));
+ if (!s->pv)
+ return AVERROR(ENOMEM);
+
+ x6 = ((ref[0][0] - ref[1][0] - ref[2][0] + ref[3][0]) *
+ (ref[2][1] - ref[3][1]) -
+ ( ref[0][1] - ref[1][1] - ref[2][1] + ref[3][1]) *
+ (ref[2][0] - ref[3][0])) * h;
+ x7 = ((ref[0][1] - ref[1][1] - ref[2][1] + ref[3][1]) *
+ (ref[1][0] - ref[3][0]) -
+ ( ref[0][0] - ref[1][0] - ref[2][0] + ref[3][0]) *
+ (ref[1][1] - ref[3][1])) * w;
+ q = ( ref[1][0] - ref[3][0]) * (ref[2][1] - ref[3][1]) -
+ ( ref[2][0] - ref[3][0]) * (ref[1][1] - ref[3][1]);
+
+ x0 = q * (ref[1][0] - ref[0][0]) * h + x6 * ref[1][0];
+ x1 = q * (ref[2][0] - ref[0][0]) * w + x7 * ref[2][0];
+ x2 = q * ref[0][0] * w * h;
+ x3 = q * (ref[1][1] - ref[0][1]) * h + x6 * ref[1][1];
+ x4 = q * (ref[2][1] - ref[0][1]) * w + x7 * ref[2][1];
+ x5 = q * ref[0][1] * w * h;
+
+ for (y = 0; y < h; y++){
+ for (x = 0; x < w; x++){
+ int u, v;
+
+ u = (int)floor(SUB_PIXELS * (x0 * x + x1 * y + x2) /
+ (x6 * x + x7 * y + q * w * h) + 0.5);
+ v = (int)floor(SUB_PIXELS * (x3 * x + x4 * y + x5) /
+ (x6 * x + x7 * y + q * w * h) + 0.5);
+
+ s->pv[x + y * w][0] = u;
+ s->pv[x + y * w][1] = v;
+ }
+ }
+
+ for (i = 0; i < SUB_PIXELS; i++){
+ double d = i / (double)SUB_PIXELS;
+ double temp[4];
+ double sum = 0;
+
+ for (j = 0; j < 4; j++)
+ temp[j] = get_coeff(j - d - 1);
+
+ for (j = 0; j < 4; j++)
+ sum += temp[j];
+
+ for (j = 0; j < 4; j++)
+ s->coeff[i][j] = (int)floor((1 << COEFF_BITS) * temp[j] / sum + 0.5);
+ }
+
+ return 0;
+}
+
+static void resample_cubic(PerspectiveContext *s,
+ uint8_t *dst, int dst_linesize,
+ uint8_t *src, int src_linesize,
+ int w, int h, int hsub, int vsub)
+{
+ const int linesize = s->linesize[0];
+ int x, y;
+
+ for (y = 0; y < h; y++) {
+ int sy = y << vsub;
+ for (x = 0; x < w; x++) {
+ int u, v, subU, subV, sum, sx;
+
+ sx = x << hsub;
+ u = s->pv[sx + sy * linesize][0] >> hsub;
+ v = s->pv[sx + sy * linesize][1] >> vsub;
+ subU = u & (SUB_PIXELS - 1);
+ subV = v & (SUB_PIXELS - 1);
+ u >>= SUB_PIXEL_BITS;
+ v >>= SUB_PIXEL_BITS;
+
+ if (u > 0 && v > 0 && u < w - 2 && v < h - 2){
+ const int index = u + v*src_linesize;
+ const int a = s->coeff[subU][0];
+ const int b = s->coeff[subU][1];
+ const int c = s->coeff[subU][2];
+ const int d = s->coeff[subU][3];
+
+ sum = s->coeff[subV][0] * (a * src[index - 1 - src_linesize] + b * src[index - 0 - src_linesize] +
+ c * src[index + 1 - src_linesize] + d * src[index + 2 - src_linesize]) +
+ s->coeff[subV][1] * (a * src[index - 1 ] + b * src[index - 0 ] +
+ c * src[index + 1 ] + d * src[index + 2 ]) +
+ s->coeff[subV][2] * (a * src[index - 1 + src_linesize] + b * src[index - 0 + src_linesize] +
+ c * src[index + 1 + src_linesize] + d * src[index + 2 + src_linesize]) +
+ s->coeff[subV][3] * (a * src[index - 1 + 2 * src_linesize] + b * src[index - 0 + 2 * src_linesize] +
+ c * src[index + 1 + 2 * src_linesize] + d * src[index + 2 + 2 * src_linesize]);
+ } else {
+ int dx, dy;
+
+ sum = 0;
+
+ for (dy = 0; dy < 4; dy++) {
+ int iy = v + dy - 1;
+
+ if (iy < 0)
+ iy = 0;
+ else if (iy >= h)
+ iy = h-1;
+ for (dx = 0; dx < 4; dx++) {
+ int ix = u + dx - 1;
+
+ if (ix < 0)
+ ix = 0;
+ else if (ix >= w)
+ ix = w - 1;
+
+ sum += s->coeff[subU][dx] * s->coeff[subV][dy] * src[ ix + iy * src_linesize];
+ }
+ }
+ }
+
+ sum = (sum + (1<<(COEFF_BITS * 2 - 1))) >> (COEFF_BITS * 2);
+ sum = av_clip(sum, 0, 255);
+ dst[x + y * dst_linesize] = sum;
+ }
+ }
+}
+
+static void resample_linear(PerspectiveContext *s,
+ uint8_t *dst, int dst_linesize,
+ uint8_t *src, int src_linesize,
+ int w, int h, int hsub, int vsub)
+{
+ const int linesize = s->linesize[0];
+ int x, y;
+
+ for (y = 0; y < h; y++){
+ int sy = y << vsub;
+ for (x = 0; x < w; x++){
+ int u, v, subU, subV, sum, sx, index, subUI, subVI;
+
+ sx = x << hsub;
+ u = s->pv[sx + sy * linesize][0] >> hsub;
+ v = s->pv[sx + sy * linesize][1] >> vsub;
+ subU = u & (SUB_PIXELS - 1);
+ subV = v & (SUB_PIXELS - 1);
+ u >>= SUB_PIXEL_BITS;
+ v >>= SUB_PIXEL_BITS;
+
+ index = u + v * src_linesize;
+ subUI = SUB_PIXELS - subU;
+ subVI = SUB_PIXELS - subV;
+
+ if ((unsigned)u < (unsigned)(w - 1)){
+ if((unsigned)v < (unsigned)(h - 1)){
+ sum = subVI * (subUI * src[index] + subU * src[index + 1]) +
+ subV * (subUI * src[index + src_linesize] + subU * src[index + src_linesize + 1]);
+ sum = (sum + (1 << (SUB_PIXEL_BITS * 2 - 1)))>> (SUB_PIXEL_BITS * 2);
+ } else {
+ if (v < 0)
+ v = 0;
+ else
+ v = h - 1;
+ index = u + v * src_linesize;
+ sum = subUI * src[index] + subU * src[index + 1];
+ sum = (sum + (1 << (SUB_PIXEL_BITS - 1))) >> SUB_PIXEL_BITS;
+ }
+ } else {
+ if ((unsigned)v < (unsigned)(h - 1)){
+ if (u < 0)
+ u = 0;
+ else
+ u = w - 1;
+ index = u + v * src_linesize;
+ sum = subVI * src[index] + subV * src[index + src_linesize];
+ sum = (sum + (1 << (SUB_PIXEL_BITS - 1))) >> SUB_PIXEL_BITS;
+ } else {
+ if (u < 0)
+ u = 0;
+ else
+ u = w - 1;
+ if (v < 0)
+ v = 0;
+ else
+ v = h - 1;
+ index = u + v * src_linesize;
+ sum = src[index];
+ }
+ }
+
+ sum = av_clip(sum, 0, 255);
+ dst[x + y * dst_linesize] = sum;
+ }
+ }
+}
+
+static av_cold int init(AVFilterContext *ctx)
+{
+ PerspectiveContext *s = ctx->priv;
+
+ switch (s->interpolation) {
+ case LINEAR: s->perspective = resample_linear; break;
+ case CUBIC: s->perspective = resample_cubic; break;
+ }
+
+ return 0;
+}
+
+static int filter_frame(AVFilterLink *inlink, AVFrame *frame)
+{
+ AVFilterContext *ctx = inlink->dst;
+ AVFilterLink *outlink = ctx->outputs[0];
+ PerspectiveContext *s = ctx->priv;
+ AVFrame *out;
+ int plane;
+
+ out = ff_get_video_buffer(outlink, outlink->w, outlink->h);
+ if (!out) {
+ av_frame_free(&frame);
+ return AVERROR(ENOMEM);
+ }
+ av_frame_copy_props(out, frame);
+
+ for (plane = 0; plane < s->nb_planes; plane++) {
+ int hsub = plane == 1 || plane == 2 ? s->hsub : 0;
+ int vsub = plane == 1 || plane == 2 ? s->vsub : 0;
+ s->perspective(s, out->data[plane], out->linesize[plane],
+ frame->data[plane], frame->linesize[plane],
+ s->linesize[plane], s->height[plane], hsub, vsub);
+ }
+
+ av_frame_free(&frame);
+ return ff_filter_frame(outlink, out);
+}
+
+static av_cold void uninit(AVFilterContext *ctx)
+{
+ PerspectiveContext *s = ctx->priv;
+
+ av_freep(&s->pv);
+}
+
+static const AVFilterPad perspective_inputs[] = {
+ {
+ .name = "default",
+ .type = AVMEDIA_TYPE_VIDEO,
+ .filter_frame = filter_frame,
+ .config_props = config_input,
+ },
+ { NULL }
+};
+
+static const AVFilterPad perspective_outputs[] = {
+ {
+ .name = "default",
+ .type = AVMEDIA_TYPE_VIDEO,
+ },
+ { NULL }
+};
+
+AVFilter avfilter_vf_perspective = {
+ .name = "perspective",
+ .description = NULL_IF_CONFIG_SMALL("Correct the perspective of video."),
+ .priv_size = sizeof(PerspectiveContext),
+ .init = init,
+ .uninit = uninit,
+ .query_formats = query_formats,
+ .inputs = perspective_inputs,
+ .outputs = perspective_outputs,
+ .priv_class = &perspective_class,
+ .flags = AVFILTER_FLAG_SUPPORT_TIMELINE_GENERIC,
+};

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