avfilter: add swaprect filter

Signed-off-by: Paul B Mahol <onemda@gmail.com>

Changelog

@@ -65,6 +65,7 @@ version <next>:
 - significant performance improvements in Windows Television (WTV) demuxer
 - nnedi deinterlacer
 - streamselect video and astreamselect audio filter
+- swaprect filter
 
 
 version 2.8:

doc/filters.texi

@@ -11473,6 +11473,60 @@ Interpolate) pixel art scaling algorithm.
 
 Useful for enlarging pixel art images without reducing sharpness.
 
+@section swaprect
+
+Swap two rectangular objects in video.
+
+This filter accepts the following options:
+
+@table @option
+@item w
+Set object width.
+
+@item h
+Set object height.
+
+@item x1
+Set 1st rect x coordinate.
+
+@item y1
+Set 1st rect y coordinate.
+
+@item x2
+Set 2nd rect x coordinate.
+
+@item y2
+Set 2nd rect y coordinate.
+
+All expressions are evaluated once for each frame.
+@end table
+
+The all options are expressions containing the following constants:
+
+@table @option
+@item w
+@item h
+The input width and height.
+
+@item a
+same as @var{w} / @var{h}
+
+@item sar
+input sample aspect ratio
+
+@item dar
+input display aspect ratio, it is the same as (@var{w} / @var{h}) * @var{sar}
+
+@item n
+The number of the input frame, starting from 0.
+
+@item t
+The timestamp expressed in seconds. It's NAN if the input timestamp is unknown.
+
+@item pos
+the position in the file of the input frame, NAN if unknown
+@end table
+
 @section swapuv
 Swap U & V plane.
 

libavfilter/Makefile

@@ -241,6 +241,7 @@ OBJS-$(CONFIG_STEREO3D_FILTER)               += vf_stereo3d.o
 OBJS-$(CONFIG_STREAMSELECT_FILTER)           += f_streamselect.o
 OBJS-$(CONFIG_SUBTITLES_FILTER)              += vf_subtitles.o
 OBJS-$(CONFIG_SUPER2XSAI_FILTER)             += vf_super2xsai.o
+OBJS-$(CONFIG_SWAPRECT_FILTER)               += vf_swaprect.o
 OBJS-$(CONFIG_SWAPUV_FILTER)                 += vf_swapuv.o
 OBJS-$(CONFIG_TBLEND_FILTER)                 += vf_blend.o dualinput.o framesync.o
 OBJS-$(CONFIG_TELECINE_FILTER)               += vf_telecine.o

libavfilter/allfilters.c

@@ -261,6 +261,7 @@ void avfilter_register_all(void)
     REGISTER_FILTER(STREAMSELECT,   streamselect,   vf);
     REGISTER_FILTER(SUBTITLES,      subtitles,      vf);
     REGISTER_FILTER(SUPER2XSAI,     super2xsai,     vf);
+    REGISTER_FILTER(SWAPRECT,       swaprect,       vf);
     REGISTER_FILTER(SWAPUV,         swapuv,         vf);
     REGISTER_FILTER(TBLEND,         tblend,         vf);
     REGISTER_FILTER(TELECINE,       telecine,       vf);

libavfilter/version.h

@@ -30,7 +30,7 @@
 #include "libavutil/version.h"
 
 #define LIBAVFILTER_VERSION_MAJOR   6
-#define LIBAVFILTER_VERSION_MINOR  29
+#define LIBAVFILTER_VERSION_MINOR  30
 #define LIBAVFILTER_VERSION_MICRO 100
 
 #define LIBAVFILTER_VERSION_INT AV_VERSION_INT(LIBAVFILTER_VERSION_MAJOR, \

libavfilter/vf_swaprect.c

@@ -0,0 +1,255 @@
+/*
+ * Copyright (c) 2015 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/avstring.h"
+#include "libavutil/eval.h"
+#include "libavutil/imgutils.h"
+#include "libavutil/opt.h"
+#include "libavutil/pixdesc.h"
+
+#include "avfilter.h"
+#include "formats.h"
+#include "internal.h"
+#include "video.h"
+
+typedef struct SwapRectContext {
+    const AVClass *class;
+    char *w, *h;
+    char *x1, *y1;
+    char *x2, *y2;
+
+    int nb_planes;
+    int pixsteps[4];
+
+    const AVPixFmtDescriptor *desc;
+    uint8_t *temp;
+} SwapRectContext;
+
+#define OFFSET(x) offsetof(SwapRectContext, x)
+#define FLAGS AV_OPT_FLAG_VIDEO_PARAM | AV_OPT_FLAG_FILTERING_PARAM
+static const AVOption swaprect_options[] = {
+    { "w",  "set rect width",                     OFFSET(w),  AV_OPT_TYPE_STRING, {.str="w/2"}, 0, 0, .flags = FLAGS },
+    { "h",  "set rect height",                    OFFSET(h),  AV_OPT_TYPE_STRING, {.str="h/2"}, 0, 0, .flags = FLAGS },
+    { "x1", "set 1st rect x top left coordinate", OFFSET(x1), AV_OPT_TYPE_STRING, {.str="w/2"}, 0, 0, .flags = FLAGS },
+    { "y1", "set 1st rect y top left coordinate", OFFSET(y1), AV_OPT_TYPE_STRING, {.str="h/2"}, 0, 0, .flags = FLAGS },
+    { "x2", "set 2nd rect x top left coordinate", OFFSET(x2), AV_OPT_TYPE_STRING, {.str="0"},   0, 0, .flags = FLAGS },
+    { "y2", "set 2nd rect y top left coordinate", OFFSET(y2), AV_OPT_TYPE_STRING, {.str="0"},   0, 0, .flags = FLAGS },
+    { NULL },
+};
+
+AVFILTER_DEFINE_CLASS(swaprect);
+
+static int query_formats(AVFilterContext *ctx)
+{
+    AVFilterFormats *pix_fmts = NULL;
+    int fmt, ret;
+
+    for (fmt = 0; av_pix_fmt_desc_get(fmt); fmt++) {
+        const AVPixFmtDescriptor *desc = av_pix_fmt_desc_get(fmt);
+        if (!(desc->flags & AV_PIX_FMT_FLAG_PAL ||
+              desc->flags & AV_PIX_FMT_FLAG_HWACCEL ||
+              desc->flags & AV_PIX_FMT_FLAG_BITSTREAM) &&
+            (ret = ff_add_format(&pix_fmts, fmt)) < 0)
+            return ret;
+    }
+
+    return ff_set_common_formats(ctx, pix_fmts);
+}
+
+static const char *const var_names[] = {   "w",   "h",   "a",   "n",   "t",   "pos",   "sar",   "dar",        NULL };
+enum                                   { VAR_W, VAR_H, VAR_A, VAR_N, VAR_T, VAR_POS, VAR_SAR, VAR_DAR, VAR_VARS_NB };
+
+static int filter_frame(AVFilterLink *inlink, AVFrame *in)
+{
+    AVFilterContext *ctx = inlink->dst;
+    AVFilterLink *outlink = ctx->outputs[0];
+    SwapRectContext *s = ctx->priv;
+    double var_values[VAR_VARS_NB];
+    int x1[4], y1[4];
+    int x2[4], y2[4];
+    int aw[4], ah[4];
+    int lw[4], lh[4];
+    int pw[4], ph[4];
+    double dw,  dh;
+    double dx1, dy1;
+    double dx2, dy2;
+    int y, p, w, h, ret;
+
+    var_values[VAR_W]   = inlink->w;
+    var_values[VAR_H]   = inlink->h;
+    var_values[VAR_A]   = (float) inlink->w / inlink->h;
+    var_values[VAR_SAR] = inlink->sample_aspect_ratio.num ? av_q2d(inlink->sample_aspect_ratio) : 1;
+    var_values[VAR_DAR] = var_values[VAR_A] * var_values[VAR_SAR];
+    var_values[VAR_N]   = inlink->frame_count;
+    var_values[VAR_T]   = in->pts == AV_NOPTS_VALUE ? NAN : in->pts * av_q2d(inlink->time_base);
+    var_values[VAR_POS] = av_frame_get_pkt_pos(in) == -1 ? NAN : av_frame_get_pkt_pos(in);
+
+    ret = av_expr_parse_and_eval(&dw, s->w,
+                                 var_names, &var_values[0],
+                                 NULL, NULL, NULL, NULL,
+                                 0, 0, ctx);
+    if (ret < 0)
+        return ret;
+
+    ret = av_expr_parse_and_eval(&dh, s->h,
+                                 var_names, &var_values[0],
+                                 NULL, NULL, NULL, NULL,
+                                 0, 0, ctx);
+    if (ret < 0)
+        return ret;
+
+    ret = av_expr_parse_and_eval(&dx1, s->x1,
+                                 var_names, &var_values[0],
+                                 NULL, NULL, NULL, NULL,
+                                 0, 0, ctx);
+    if (ret < 0)
+        return ret;
+
+    ret = av_expr_parse_and_eval(&dy1, s->y1,
+                                 var_names, &var_values[0],
+                                 NULL, NULL, NULL, NULL,
+                                 0, 0, ctx);
+    if (ret < 0)
+        return ret;
+
+    ret = av_expr_parse_and_eval(&dx2, s->x2,
+                                 var_names, &var_values[0],
+                                 NULL, NULL, NULL, NULL,
+                                 0, 0, ctx);
+    if (ret < 0)
+        return ret;
+
+    ret = av_expr_parse_and_eval(&dy2, s->y2,
+                                 var_names, &var_values[0],
+                                 NULL, NULL, NULL, NULL,
+                                 0, 0, ctx);
+    if (ret < 0)
+        return ret;
+
+    w = dw; h = dh; x1[0] = dx1; y1[0] = dy1; x2[0] = dx2; y2[0] = dy2;
+
+    x1[0] = av_clip(x1[0], 0, inlink->w - 1);
+    y1[0] = av_clip(y1[0], 0, inlink->w - 1);
+
+    x2[0] = av_clip(x2[0], 0, inlink->w - 1);
+    y2[0] = av_clip(y2[0], 0, inlink->w - 1);
+
+    ah[1] = ah[2] = FF_CEIL_RSHIFT(h, s->desc->log2_chroma_h);
+    ah[0] = ah[3] = h;
+    aw[1] = aw[2] = FF_CEIL_RSHIFT(w, s->desc->log2_chroma_w);
+    aw[0] = aw[3] = w;
+
+    w = FFMIN3(w, inlink->w - x1[0], inlink->w - x2[0]);
+    h = FFMIN3(h, inlink->h - y1[0], inlink->h - y2[0]);
+
+    ph[1] = ph[2] = FF_CEIL_RSHIFT(h, s->desc->log2_chroma_h);
+    ph[0] = ph[3] = h;
+    pw[1] = pw[2] = FF_CEIL_RSHIFT(w, s->desc->log2_chroma_w);
+    pw[0] = pw[3] = w;
+
+    lh[1] = lh[2] = FF_CEIL_RSHIFT(inlink->h, s->desc->log2_chroma_h);
+    lh[0] = lh[3] = inlink->h;
+    lw[1] = lw[2] = FF_CEIL_RSHIFT(inlink->w, s->desc->log2_chroma_w);
+    lw[0] = lw[3] = inlink->w;
+
+    x1[1] = x1[2] = FF_CEIL_RSHIFT(x1[0], s->desc->log2_chroma_w);
+    x1[0] = x1[3] = x1[0];
+    y1[1] = y1[2] = FF_CEIL_RSHIFT(y1[0], s->desc->log2_chroma_h);
+    y1[0] = y1[3] = y1[0];
+
+    x2[1] = x2[2] = FF_CEIL_RSHIFT(x2[0], s->desc->log2_chroma_w);
+    x2[0] = x2[3] = x2[0];
+    y2[1] = y2[2] = FF_CEIL_RSHIFT(y2[0], s->desc->log2_chroma_h);
+    y2[0] = y2[3] = y2[0];
+
+    for (p = 0; p < s->nb_planes; p++) {
+        if (ph[p] == ah[p] && pw[p] == aw[p]) {
+            uint8_t *src = in->data[p] + y1[p] * in->linesize[p] + x1[p] * s->pixsteps[p];
+            uint8_t *dst = in->data[p] + y2[p] * in->linesize[p] + x2[p] * s->pixsteps[p];
+
+            for (y = 0; y < ph[p]; y++) {
+                memcpy(s->temp, src, pw[p] * s->pixsteps[p]);
+                memmove(src, dst, pw[p] * s->pixsteps[p]);
+                memcpy(dst, s->temp, pw[p] * s->pixsteps[p]);
+                src += in->linesize[p];
+                dst += in->linesize[p];
+            }
+        }
+    }
+
+    return ff_filter_frame(outlink, in);
+}
+
+static int config_input(AVFilterLink *inlink)
+{
+    AVFilterContext *ctx = inlink->dst;
+    SwapRectContext *s = ctx->priv;
+
+    if (!s->w  || !s->h  ||
+        !s->x1 || !s->y1 ||
+        !s->x2 || !s->y2)
+        return AVERROR(EINVAL);
+
+    s->desc = av_pix_fmt_desc_get(inlink->format);
+    av_image_fill_max_pixsteps(s->pixsteps, NULL, s->desc);
+    s->nb_planes = av_pix_fmt_count_planes(inlink->format);
+
+    s->temp = av_malloc_array(inlink->w, s->pixsteps[0]);
+    if (!s->temp)
+        return AVERROR(ENOMEM);
+
+    return 0;
+}
+
+static av_cold void uninit(AVFilterContext *ctx)
+{
+    SwapRectContext *s = ctx->priv;
+    av_freep(&s->temp);
+}
+
+static const AVFilterPad inputs[] = {
+    {
+        .name           = "default",
+        .type           = AVMEDIA_TYPE_VIDEO,
+        .filter_frame   = filter_frame,
+        .config_props   = config_input,
+        .needs_writable = 1,
+    },
+    { NULL }
+};
+
+static const AVFilterPad outputs[] = {
+    {
+        .name = "default",
+        .type = AVMEDIA_TYPE_VIDEO,
+    },
+    { NULL }
+};
+
+AVFilter ff_vf_swaprect = {
+    .name          = "swaprect",
+    .description   = NULL_IF_CONFIG_SMALL("Swap 2 rectangular objects in video."),
+    .priv_size     = sizeof(SwapRectContext),
+    .priv_class    = &swaprect_class,
+    .query_formats = query_formats,
+    .uninit        = uninit,
+    .inputs        = inputs,
+    .outputs       = outputs,
+};