[FFmpeg-devel] [PATCH] avfilter: add tpad filter

Paul B Mahol onemda at gmail.com
Tue Oct 30 11:56:39 EET 2018


Signed-off-by: Paul B Mahol <onemda at gmail.com>
---
 doc/filters.texi         |  22 ++++++
 libavfilter/Makefile     |   1 +
 libavfilter/allfilters.c |   1 +
 libavfilter/vf_tpad.c    | 166 +++++++++++++++++++++++++++++++++++++++
 4 files changed, 190 insertions(+)
 create mode 100644 libavfilter/vf_tpad.c

diff --git a/doc/filters.texi b/doc/filters.texi
index 9b84b1145b..6dda780aa0 100644
--- a/doc/filters.texi
+++ b/doc/filters.texi
@@ -16676,6 +16676,28 @@ embedded peak information in display metadata is not reliable or when tone
 mapping from a lower range to a higher range.
 @end table
 
+ at section tpad
+
+Temporarily pad video frames.
+
+The filter accepts the following options:
+
+ at table @option
+ at item start
+Specify number of delay frames before input video stream.
+
+ at item stop
+Specify number of padding frames after input video stream.
+Set to -1 to pad indefinitely.
+
+ at item color
+Specify the color of the padded area. For the syntax of this option,
+check the @ref{color syntax,,"Color" section in the ffmpeg-utils
+manual,ffmpeg-utils}.
+
+The default value of @var{color} is "black".
+ at end table
+
 @anchor{transpose}
 @section transpose
 
diff --git a/libavfilter/Makefile b/libavfilter/Makefile
index c35cd8f422..51e48efc2e 100644
--- a/libavfilter/Makefile
+++ b/libavfilter/Makefile
@@ -383,6 +383,7 @@ OBJS-$(CONFIG_TMIX_FILTER)                   += vf_mix.o framesync.o
 OBJS-$(CONFIG_TONEMAP_FILTER)                += vf_tonemap.o colorspace.o
 OBJS-$(CONFIG_TONEMAP_OPENCL_FILTER)         += vf_tonemap_opencl.o colorspace.o opencl.o \
                                                 opencl/tonemap.o opencl/colorspace_common.o
+OBJS-$(CONFIG_TPAD_FILTER)                   += vf_tpad.o
 OBJS-$(CONFIG_TRANSPOSE_FILTER)              += vf_transpose.o
 OBJS-$(CONFIG_TRANSPOSE_NPP_FILTER)          += vf_transpose_npp.o
 OBJS-$(CONFIG_TRIM_FILTER)                   += trim.o
diff --git a/libavfilter/allfilters.c b/libavfilter/allfilters.c
index d5a211bda5..6052cb8c3c 100644
--- a/libavfilter/allfilters.c
+++ b/libavfilter/allfilters.c
@@ -365,6 +365,7 @@ extern AVFilter ff_vf_tlut2;
 extern AVFilter ff_vf_tmix;
 extern AVFilter ff_vf_tonemap;
 extern AVFilter ff_vf_tonemap_opencl;
+extern AVFilter ff_vf_tpad;
 extern AVFilter ff_vf_transpose;
 extern AVFilter ff_vf_transpose_npp;
 extern AVFilter ff_vf_trim;
diff --git a/libavfilter/vf_tpad.c b/libavfilter/vf_tpad.c
new file mode 100644
index 0000000000..e59037ca56
--- /dev/null
+++ b/libavfilter/vf_tpad.c
@@ -0,0 +1,166 @@
+/*
+ * Copyright (c) 2018 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/channel_layout.h"
+#include "libavutil/opt.h"
+#include "avfilter.h"
+#include "audio.h"
+#include "filters.h"
+#include "internal.h"
+#include "formats.h"
+#include "drawutils.h"
+
+typedef struct TPadContext {
+    const AVClass *class;
+    int pad_start;
+    int pad_stop;
+    uint8_t rgba_color[4];  ///< color for the padding area
+
+    FFDrawContext draw;
+    FFDrawColor color;
+    int64_t pts;
+    int eof;
+} TPadContext;
+
+#define OFFSET(x) offsetof(TPadContext, x)
+#define VF AV_OPT_FLAG_VIDEO_PARAM|AV_OPT_FLAG_FILTERING_PARAM
+
+static const AVOption tpad_options[] = {
+    { "start", "set the number of frames to delay input",              OFFSET(pad_start),  AV_OPT_TYPE_INT,   {.i64=0},        0, INT_MAX, VF },
+    { "stop",  "set the number of frames to add after input finished", OFFSET(pad_stop),   AV_OPT_TYPE_INT,   {.i64=0},       -1, INT_MAX, VF },
+    { "color", "set the color of the added frames",                    OFFSET(rgba_color), AV_OPT_TYPE_COLOR, {.str="black"},  0,       0, VF },
+    { NULL }
+};
+
+AVFILTER_DEFINE_CLASS(tpad);
+
+static int query_formats(AVFilterContext *ctx)
+{
+    return ff_set_common_formats(ctx, ff_draw_supported_pixel_formats(0));
+}
+
+static int activate(AVFilterContext *ctx)
+{
+    AVFilterLink *inlink = ctx->inputs[0];
+    AVFilterLink *outlink = ctx->outputs[0];
+    TPadContext *s = ctx->priv;
+    AVFrame *frame = NULL;
+    int ret, status;
+    int64_t pts;
+
+    FF_FILTER_FORWARD_STATUS_BACK(outlink, inlink);
+
+    if (s->pad_start > 0 && ff_outlink_frame_wanted(outlink)) {
+        frame = ff_get_video_buffer(outlink, outlink->w, outlink->h);
+        if (!frame)
+            return AVERROR(ENOMEM);
+        ff_fill_rectangle(&s->draw, &s->color,
+                          frame->data, frame->linesize,
+                          0, 0, frame->width, frame->height);
+        frame->pts = s->pts;
+        s->pts += av_rescale_q(1, av_inv_q(outlink->frame_rate), outlink->time_base);
+        s->pad_start--;
+        return ff_filter_frame(outlink, frame);
+    }
+
+    if (!s->eof && !s->pad_start) {
+        ret = ff_inlink_consume_frame(inlink, &frame);
+        if (ret < 0)
+            return ret;
+        if (ret > 0) {
+            frame->pts += s->pts;
+            return ff_filter_frame(outlink, frame);
+        }
+    }
+
+    if (!s->eof && ff_inlink_acknowledge_status(inlink, &status, &pts)) {
+        if (status == AVERROR_EOF) {
+            if (!s->pad_stop) {
+                ff_outlink_set_status(outlink, status, pts);
+                return 0;
+            }
+            s->eof = 1;
+            s->pts += pts;
+        }
+    }
+
+    if (s->eof) {
+        if (!s->pad_stop) {
+            ff_outlink_set_status(outlink, AVERROR_EOF, s->pts);
+            return 0;
+        }
+        frame = ff_get_video_buffer(outlink, outlink->w, outlink->h);
+        if (!frame)
+            return AVERROR(ENOMEM);
+        ff_fill_rectangle(&s->draw, &s->color,
+                          frame->data, frame->linesize,
+                          0, 0, frame->width, frame->height);
+        frame->pts = s->pts;
+        s->pts += av_rescale_q(1, av_inv_q(outlink->frame_rate), outlink->time_base);
+        if (s->pad_stop > 0)
+            s->pad_stop--;
+        return ff_filter_frame(outlink, frame);
+    }
+
+    if (!s->pad_start)
+        FF_FILTER_FORWARD_WANTED(outlink, inlink);
+
+    return FFERROR_NOT_READY;
+}
+
+static int config_input(AVFilterLink *inlink)
+{
+    AVFilterContext *ctx = inlink->dst;
+    TPadContext *s = ctx->priv;
+
+    ff_draw_init(&s->draw, inlink->format, 0);
+    ff_draw_color(&s->draw, &s->color, s->rgba_color);
+
+    return 0;
+}
+
+static const AVFilterPad tpad_inputs[] = {
+    {
+        .name         = "default",
+        .type         = AVMEDIA_TYPE_VIDEO,
+        .config_props = config_input,
+    },
+    { NULL }
+};
+
+static const AVFilterPad tpad_outputs[] = {
+    {
+        .name = "default",
+        .type = AVMEDIA_TYPE_VIDEO,
+    },
+    { NULL }
+};
+
+AVFilter ff_vf_tpad = {
+    .name          = "tpad",
+    .description   = NULL_IF_CONFIG_SMALL("Temporarily pad video frames."),
+    .priv_size     = sizeof(TPadContext),
+    .priv_class    = &tpad_class,
+    .query_formats = query_formats,
+    .inputs        = tpad_inputs,
+    .outputs       = tpad_outputs,
+    .activate      = activate,
+};
-- 
2.17.1



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