avfilter: add shuffleframes filter

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

Changelog

@@ -24,6 +24,7 @@ version <next>:
 - zscale filter
 - wve demuxer
 - zero-copy Intel QSV transcoding in ffmpeg
+- shuffleframes filter
 
 
 version 2.8:

doc/filters.texi

@@ -9946,6 +9946,26 @@ Set the size of the box used to represent one palette color entry. Default is
 @code{30} (for a @code{30x30} pixel box).
 @end table
 
+@section shuffleframes
+
+Reorder and/or duplicate video frames.
+
+It accepts the following parameters:
+
+@table @option
+@item mapping
+Set the destination indexes of input frames.
+This is space or '|' separated list of indexes that maps input frames to output
+frames. Number of indexes also sets maximal value that each index may have.
+@end table
+
+The first frame has the index 0. The default is to keep the input unchanged.
+
+Swap second and third frame of every three frames of the input:
+@example
+ffmpeg -i INPUT -vf "shuffleframes=0 2 1" OUTPUT
+@end example
+
 @section shuffleplanes
 
 Reorder and/or duplicate video planes.

libavfilter/Makefile

@@ -215,6 +215,7 @@ OBJS-$(CONFIG_SETSAR_FILTER)                 += vf_aspect.o
 OBJS-$(CONFIG_SETTB_FILTER)                  += settb.o
 OBJS-$(CONFIG_SHOWINFO_FILTER)               += vf_showinfo.o
 OBJS-$(CONFIG_SHOWPALETTE_FILTER)            += vf_showpalette.o
+OBJS-$(CONFIG_SHUFFLEFRAMES_FILTER)          += vf_shuffleframes.o
 OBJS-$(CONFIG_SHUFFLEPLANES_FILTER)          += vf_shuffleplanes.o
 OBJS-$(CONFIG_SIGNALSTATS_FILTER)            += vf_signalstats.o
 OBJS-$(CONFIG_SMARTBLUR_FILTER)              += vf_smartblur.o

libavfilter/allfilters.c

@@ -236,6 +236,7 @@ void avfilter_register_all(void)
     REGISTER_FILTER(SETTB,          settb,          vf);
     REGISTER_FILTER(SHOWINFO,       showinfo,       vf);
     REGISTER_FILTER(SHOWPALETTE,    showpalette,    vf);
+    REGISTER_FILTER(SHUFFLEFRAMES,  shuffleframes,  vf);
     REGISTER_FILTER(SHUFFLEPLANES,  shuffleplanes,  vf);
     REGISTER_FILTER(SIGNALSTATS,    signalstats,    vf);
     REGISTER_FILTER(SMARTBLUR,      smartblur,      vf);

libavfilter/version.h

@@ -30,7 +30,7 @@
 #include "libavutil/version.h"
 
 #define LIBAVFILTER_VERSION_MAJOR   6
-#define LIBAVFILTER_VERSION_MINOR  12
+#define LIBAVFILTER_VERSION_MINOR  13
 #define LIBAVFILTER_VERSION_MICRO 100
 
 #define LIBAVFILTER_VERSION_INT AV_VERSION_INT(LIBAVFILTER_VERSION_MAJOR, \

libavfilter/vf_shuffleframes.c

@@ -0,0 +1,162 @@
+/*
+ * 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/common.h"
+#include "libavutil/internal.h"
+#include "libavutil/opt.h"
+
+#include "avfilter.h"
+#include "internal.h"
+#include "video.h"
+
+typedef struct ShuffleFramesContext {
+    const AVClass *class;
+    char *mapping;
+    AVFrame **frames;
+    int *map;
+    int64_t *pts;
+    int in_frames;
+    int nb_frames;
+} ShuffleFramesContext;
+
+static av_cold int init(AVFilterContext *ctx)
+{
+    ShuffleFramesContext *s = ctx->priv;
+    char *mapping, *saveptr = NULL, *p;
+    int n, nb_items;
+
+    nb_items = 1;
+    for (p = s->mapping; *p; p++) {
+        if (*p == '|' || *p == ' ')
+            nb_items++;
+    }
+
+    s->frames = av_calloc(nb_items, sizeof(*s->frames));
+    s->map    = av_calloc(nb_items, sizeof(*s->map));
+    s->pts    = av_calloc(nb_items, sizeof(*s->pts));
+    if (!s->map || !s->frames || !s->pts) {
+        return AVERROR(ENOMEM);
+    }
+
+    mapping = av_strdup(s->mapping);
+    if (!mapping)
+        return AVERROR(ENOMEM);
+
+    for (n = 0; n < nb_items; n++) {
+        char *map = av_strtok(n == 0 ? mapping : NULL, " |", &saveptr);
+        if (!map || sscanf(map, "%d", &s->map[n]) != 1) {
+            av_free(mapping);
+            return AVERROR(EINVAL);
+        }
+
+        if (s->map[n] < 0 || s->map[n] >= nb_items) {
+            av_log(ctx, AV_LOG_ERROR, "Index out of range.\n");
+            av_free(mapping);
+            return AVERROR(EINVAL);
+        }
+    }
+
+    s->nb_frames = nb_items;
+    av_free(mapping);
+    return 0;
+}
+
+static int filter_frame(AVFilterLink *inlink, AVFrame *frame)
+{
+    AVFilterContext    *ctx = inlink->dst;
+    ShuffleFramesContext *s = ctx->priv;
+    int ret;
+
+    if (s->in_frames < s->nb_frames) {
+        s->frames[s->in_frames] = frame;
+        s->pts[s->in_frames] = frame->pts;
+        s->in_frames++;
+        ret = 0;
+    }
+
+    if (s->in_frames == s->nb_frames) {
+        int n, x;
+
+        for (n = 0; n < s->nb_frames; n++) {
+            AVFrame *out;
+
+            x = s->map[n];
+            out = av_frame_clone(s->frames[x]);
+            if (!out)
+                return AVERROR(ENOMEM);
+            out->pts = s->pts[n];
+            ret = ff_filter_frame(ctx->outputs[0], out);
+            s->in_frames--;
+        }
+
+        for (n = 0; n < s->nb_frames; n++)
+            av_frame_free(&s->frames[n]);
+    }
+
+    return ret;
+}
+
+static av_cold void uninit(AVFilterContext *ctx)
+{
+    ShuffleFramesContext *s = ctx->priv;
+
+    av_freep(&s->frames);
+    av_freep(&s->map);
+    av_freep(&s->pts);
+}
+
+#define OFFSET(x) offsetof(ShuffleFramesContext, x)
+#define FLAGS (AV_OPT_FLAG_FILTERING_PARAM | AV_OPT_FLAG_VIDEO_PARAM)
+static const AVOption shuffleframes_options[] = {
+    { "mapping", "set destination indexes of input frames",  OFFSET(mapping), AV_OPT_TYPE_STRING, {.str="0"}, 0, 0, FLAGS },
+    { NULL },
+};
+
+AVFILTER_DEFINE_CLASS(shuffleframes);
+
+static const AVFilterPad shuffleframes_inputs[] = {
+    {
+        .name         = "default",
+        .type         = AVMEDIA_TYPE_VIDEO,
+        .filter_frame = filter_frame,
+    },
+    { NULL },
+};
+
+static const AVFilterPad shuffleframes_outputs[] = {
+    {
+        .name = "default",
+        .type = AVMEDIA_TYPE_VIDEO,
+    },
+    { NULL },
+};
+
+AVFilter ff_vf_shuffleframes = {
+    .name          = "shuffleframes",
+    .description   = NULL_IF_CONFIG_SMALL("Shuffle video frames"),
+    .priv_size     = sizeof(ShuffleFramesContext),
+    .priv_class    = &shuffleframes_class,
+    .init          = init,
+    .uninit        = uninit,
+    .inputs        = shuffleframes_inputs,
+    .outputs       = shuffleframes_outputs,
+    .flags         = AVFILTER_FLAG_SUPPORT_TIMELINE_GENERIC,
+};