avfilter: add freezeframes video filter

1 files changed, 167 insertions, 0 deletions

diff --git a/libavfilter/vf_freezeframes.c b/libavfilter/vf_freezeframes.c
new file mode 100644
index 0000000000..b6cd5dba68
--- /dev/null
+++ b/libavfilter/vf_freezeframes.c
@@ -0,0 +1,167 @@
+/*
+ * Copyright (c) 2019 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/avassert.h"
+#include "libavutil/avstring.h"
+#include "libavutil/common.h"
+#include "libavutil/internal.h"
+#include "libavutil/opt.h"
+
+#include "avfilter.h"
+#include "filters.h"
+#include "internal.h"
+#include "video.h"
+
+typedef struct FreezeFramesContext {
+    const AVClass *class;
+    int64_t first, last, replace;
+
+    AVFrame *replace_frame;
+} FreezeFramesContext;
+
+#define OFFSET(x) offsetof(FreezeFramesContext, x)
+#define FLAGS (AV_OPT_FLAG_FILTERING_PARAM | AV_OPT_FLAG_VIDEO_PARAM)
+
+static const AVOption freezeframes_options[] = {
+    { "first",   "set first frame to freeze", OFFSET(first),   AV_OPT_TYPE_INT64, {.i64=0}, 0, INT64_MAX, FLAGS },
+    { "last",    "set last frame to freeze",  OFFSET(last),    AV_OPT_TYPE_INT64, {.i64=0}, 0, INT64_MAX, FLAGS },
+    { "replace", "set frame to replace",      OFFSET(replace), AV_OPT_TYPE_INT64, {.i64=0}, 0, INT64_MAX, FLAGS },
+    { NULL },
+};
+
+AVFILTER_DEFINE_CLASS(freezeframes);
+
+static int config_output(AVFilterLink *outlink)
+{
+    AVFilterContext *ctx = outlink->src;
+    AVFilterLink *sourcelink = ctx->inputs[0];
+    AVFilterLink *replacelink = ctx->inputs[1];
+
+    if (sourcelink->w != replacelink->w || sourcelink->h != replacelink->h) {
+        av_log(ctx, AV_LOG_ERROR,
+               "Input frame sizes do not match (%dx%d vs %dx%d).\n",
+               sourcelink->w, sourcelink->h,
+               replacelink->w, replacelink->h);
+        return AVERROR(EINVAL);
+    }
+
+    outlink->w = sourcelink->w;
+    outlink->h = sourcelink->h;
+    outlink->time_base = sourcelink->time_base;
+    outlink->sample_aspect_ratio = sourcelink->sample_aspect_ratio;
+    outlink->frame_rate = sourcelink->frame_rate;
+
+    return 0;
+}
+
+static int activate(AVFilterContext *ctx)
+{
+    AVFilterLink *outlink = ctx->outputs[0];
+    FreezeFramesContext *s = ctx->priv;
+    AVFrame *frame = NULL;
+    int drop = ctx->inputs[0]->frame_count_out >= s->first &&
+               ctx->inputs[0]->frame_count_out <= s->last;
+    int replace = ctx->inputs[1]->frame_count_out == s->replace;
+    int ret;
+
+    FF_FILTER_FORWARD_STATUS_BACK_ALL(outlink, ctx);
+
+    if (drop && s->replace_frame) {
+        ret = ff_inlink_consume_frame(ctx->inputs[0], &frame);
+        if (ret < 0)
+            return ret;
+
+        if (frame) {
+            int64_t dropped_pts = frame->pts;
+
+            av_frame_free(&frame);
+            frame = av_frame_clone(s->replace_frame);
+            if (!frame)
+                return AVERROR(ENOMEM);
+            frame->pts = dropped_pts;
+            return ff_filter_frame(outlink, frame);
+        }
+    } else if (!drop) {
+        ret = ff_inlink_consume_frame(ctx->inputs[0], &frame);
+        if (ret < 0)
+            return ret;
+
+        if (frame)
+            return ff_filter_frame(outlink, frame);
+    }
+
+    ret = ff_inlink_consume_frame(ctx->inputs[1], &frame);
+    if (ret < 0)
+        return ret;
+    if (replace && frame) {
+        s->replace_frame = frame;
+    } else if (frame) {
+        av_frame_free(&frame);
+    }
+
+    FF_FILTER_FORWARD_STATUS(ctx->inputs[0], outlink);
+    FF_FILTER_FORWARD_STATUS(ctx->inputs[1], outlink);
+
+    if (!drop || (drop && s->replace_frame))
+        FF_FILTER_FORWARD_WANTED(outlink, ctx->inputs[0]);
+    if (!s->replace_frame)
+        FF_FILTER_FORWARD_WANTED(outlink, ctx->inputs[1]);
+
+    return FFERROR_NOT_READY;
+}
+
+static av_cold void uninit(AVFilterContext *ctx)
+{
+    FreezeFramesContext *s = ctx->priv;
+
+    av_frame_free(&s->replace_frame);
+}
+
+static const AVFilterPad freezeframes_inputs[] = {
+    {
+        .name = "source",
+        .type = AVMEDIA_TYPE_VIDEO,
+    },
+    {
+        .name = "replace",
+        .type = AVMEDIA_TYPE_VIDEO,
+    },
+    { NULL },
+};
+
+static const AVFilterPad freezeframes_outputs[] = {
+    {
+        .name         = "default",
+        .type         = AVMEDIA_TYPE_VIDEO,
+        .config_props = config_output,
+    },
+    { NULL },
+};
+
+AVFilter ff_vf_freezeframes = {
+    .name          = "freezeframes",
+    .description   = NULL_IF_CONFIG_SMALL("Freeze video frames."),
+    .priv_size     = sizeof(FreezeFramesContext),
+    .priv_class    = &freezeframes_class,
+    .inputs        = freezeframes_inputs,
+    .outputs       = freezeframes_outputs,
+    .activate      = activate,
+    .uninit        = uninit,
+};