@@ -19,6 +19,7 @@ version <next>:

 - erosion, dilation, deflate and inflate video filters

 - Dynamic Audio Normalizer as dynaudnorm filter

 - Reverse filter

+- Random filter

 version 2.7:

@@ -8279,6 +8279,24 @@ qp=2+2*sin(PI*qp)

 @end example

 @end itemize

+@section random

+

+Flush video frames from internal cache of frames into a random order.

+No frame is discarded.

+Inspired by @ref{frei0r} nervous filter.

+

+@table @option

+@item frames

+Set size in number of frames of internal cache, in range from @code{2} to

+@code{512}. Default is @code{30}.

+

+@item seed

+Set seed for random number generator, must be an integer included between

+@code{0} and @code{UINT32_MAX}. If not specified, or if explicitly set to

+less than @code{0}, the filter will try to use a good random seed on a

+best effort basis.

+@end table

+

 @section removegrain

 The removegrain filter is a spatial denoiser for progressive video.

@@ -183,6 +183,7 @@ OBJS-$(CONFIG_PP7_FILTER)                    += vf_pp7.o

 OBJS-$(CONFIG_PSNR_FILTER)                   += vf_psnr.o dualinput.o framesync.o

 OBJS-$(CONFIG_PULLUP_FILTER)                 += vf_pullup.o

 OBJS-$(CONFIG_QP_FILTER)                     += vf_qp.o

+OBJS-$(CONFIG_RANDOM_FILTER)                 += vf_random.o

 OBJS-$(CONFIG_REMOVEGRAIN_FILTER)            += vf_removegrain.o

 OBJS-$(CONFIG_REMOVELOGO_FILTER)             += bbox.o lswsutils.o lavfutils.o vf_removelogo.o

 OBJS-$(CONFIG_REPEATFIELDS_FILTER)           += vf_repeatfields.o

@@ -198,6 +198,7 @@ void avfilter_register_all(void)

     REGISTER_FILTER(PSNR,           psnr,           vf);

     REGISTER_FILTER(PULLUP,         pullup,         vf);

     REGISTER_FILTER(QP,             qp,             vf);

+    REGISTER_FILTER(RANDOM,         random,         vf);

     REGISTER_FILTER(REMOVEGRAIN,    removegrain,    vf);

     REGISTER_FILTER(REMOVELOGO,     removelogo,     vf);

     REGISTER_FILTER(REPEATFIELDS,   repeatfields,   vf);

@@ -30,7 +30,7 @@

 #include "libavutil/version.h"

 #define LIBAVFILTER_VERSION_MAJOR  5

-#define LIBAVFILTER_VERSION_MINOR  24

+#define LIBAVFILTER_VERSION_MINOR  25

 #define LIBAVFILTER_VERSION_MICRO 100

 #define LIBAVFILTER_VERSION_INT AV_VERSION_INT(LIBAVFILTER_VERSION_MAJOR, \

new file mode 100644

@@ -0,0 +1,144 @@

+/*

+ * 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/lfg.h"

+#include "libavutil/opt.h"

+#include "libavutil/random_seed.h"

+#include "avfilter.h"

+#include "formats.h"

+#include "internal.h"

+#include "video.h"

+

+#define MAX_FRAMES 512

+

+typedef struct RandomContext {

+    const AVClass *class;

+

+    AVLFG lfg;

+    int nb_frames;

+    int64_t random_seed;

+    int nb_frames_filled;

+    AVFrame *frames[MAX_FRAMES];

+    int64_t pts[MAX_FRAMES];

+    int flush_idx;

+} RandomContext;

+

+#define OFFSET(x) offsetof(RandomContext, x)

+#define FLAGS AV_OPT_FLAG_VIDEO_PARAM|AV_OPT_FLAG_FILTERING_PARAM

+

+static const AVOption random_options[] = {

+    { "frames", "set number of frames in cache", OFFSET(nb_frames),   AV_OPT_TYPE_INT,   {.i64=30},  2, MAX_FRAMES, FLAGS },

+    { "seed",   "set the seed",                  OFFSET(random_seed), AV_OPT_TYPE_INT64, {.i64=-1}, -1, UINT32_MAX, FLAGS },

+    { NULL }

+};

+

+AVFILTER_DEFINE_CLASS(random);

+

+static av_cold int init(AVFilterContext *ctx)

+{

+    RandomContext *s = ctx->priv;

+    uint32_t seed;

+

+    if (s->random_seed < 0)

+        s->random_seed = av_get_random_seed();

+    seed = s->random_seed;

+    av_lfg_init(&s->lfg, seed);

+

+    return 0;

+}

+

+static int config_output(AVFilterLink *outlink)

+{

+    outlink->flags |= FF_LINK_FLAG_REQUEST_LOOP;

+    return 0;

+}

+

+static int filter_frame(AVFilterLink *inlink, AVFrame *in)

+{

+    AVFilterContext *ctx = inlink->dst;

+    RandomContext *s = ctx->priv;

+    AVFilterLink *outlink = ctx->outputs[0];

+    AVFrame *out;

+    int idx;

+

+    if (s->nb_frames_filled < s->nb_frames) {

+        s->frames[s->nb_frames_filled] = in;

+        s->pts[s->nb_frames_filled++] = in->pts;

+        return 0;

+    }

+

+    idx = av_lfg_get(&s->lfg) % s->nb_frames;

+

+    out = s->frames[idx];

+    out->pts = s->pts[0];

+    memmove(&s->pts[0], &s->pts[1], (s->nb_frames - 1) * sizeof(s->pts[0]));

+    s->frames[idx] = in;

+    s->pts[s->nb_frames - 1] = in->pts;

+

+    return ff_filter_frame(outlink, out);

+}

+

+static int request_frame(AVFilterLink *outlink)

+{

+    AVFilterContext *ctx = outlink->src;

+    RandomContext *s = ctx->priv;

+    int ret;

+

+    ret = ff_request_frame(ctx->inputs[0]);

+

+    if (ret == AVERROR_EOF && !ctx->is_disabled && s->nb_frames > 0) {

+        AVFrame *out = s->frames[s->nb_frames - 1];

+        out->pts = s->pts[s->flush_idx++];

+        ret = ff_filter_frame(outlink, out);

+        s->frames[s->nb_frames - 1] = NULL;

+        s->nb_frames--;

+    }

+

+    return ret;

+}

+

+static const AVFilterPad random_inputs[] = {

+    {

+        .name         = "default",

+        .type         = AVMEDIA_TYPE_VIDEO,

+        .filter_frame = filter_frame,

+    },

+    { NULL }

+};

+

+static const AVFilterPad random_outputs[] = {

+    {

+        .name          = "default",

+        .type          = AVMEDIA_TYPE_VIDEO,

+        .request_frame = request_frame,

+        .config_props  = config_output,

+    },

+    { NULL }

+};

+

+AVFilter ff_vf_random = {

+    .name        = "random",

+    .description = NULL_IF_CONFIG_SMALL("Return random frames."),

+    .priv_size   = sizeof(RandomContext),

+    .priv_class  = &random_class,

+    .init        = init,

+    .inputs      = random_inputs,

+    .outputs     = random_outputs,

+};