avfilter: add tpad filter

Changelog

@@ -2,6 +2,7 @@ Entries are sorted chronologically from oldest to youngest within each release,
 releases are sorted from youngest to oldest.
 
 version <next>:
+- tpad filter
 
 version 4.1:
 - deblock filter

doc/filters.texi

@@ -16755,6 +16755,46 @@ embedded peak information in display metadata is not reliable or when tone
 mapping from a lower range to a higher range.
 @end table
 
+@section tpad
+
+Temporarily pad video frames.
+
+The filter accepts the following options:
+
+@table @option
+@item start
+Specify number of delay frames before input video stream.
+
+@item stop
+Specify number of padding frames after input video stream.
+Set to -1 to pad indefinitely.
+
+@item start_mode
+Set kind of frames added to beginning of stream.
+Can be either @var{add} or @var{clone}.
+With @var{add} frames of solid-color are added.
+With @var{clone} frames are clones of first frame.
+
+@item stop_mode
+Set kind of frames added to end of stream.
+Can be either @var{add} or @var{clone}.
+With @var{add} frames of solid-color are added.
+With @var{clone} frames are clones of last frame.
+
+@item start_duration, stop_duration
+Specify the duration of the start/stop delay. See
+@ref{time duration syntax,,the Time duration section in the ffmpeg-utils(1) manual,ffmpeg-utils}
+for the accepted syntax.
+These options override @var{start} and @var{stop}.
+
+@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".
+@end table
+
 @anchor{transpose}
 @section transpose
 

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

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;

libavfilter/version.h

@@ -30,7 +30,7 @@
 #include "libavutil/version.h"
 
 #define LIBAVFILTER_VERSION_MAJOR   7
-#define LIBAVFILTER_VERSION_MINOR  41
+#define LIBAVFILTER_VERSION_MINOR  42
 #define LIBAVFILTER_VERSION_MICRO 100
 
 #define LIBAVFILTER_VERSION_INT AV_VERSION_INT(LIBAVFILTER_VERSION_MAJOR, \

libavfilter/vf_tpad.c

@@ -0,0 +1,218 @@
+/*
+ * 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;
+    int start_mode;
+    int stop_mode;
+    int64_t start_duration;
+    int64_t stop_duration;
+    uint8_t rgba_color[4];  ///< color for the padding area
+
+    FFDrawContext draw;
+    FFDrawColor color;
+    int64_t pts;
+    int eof;
+    AVFrame *cache_start;
+    AVFrame *cache_stop;
+} 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 },
+    { "start_mode", "set the mode of added frames to start",           OFFSET(start_mode), AV_OPT_TYPE_INT,   {.i64=0},        0,         1, VF, "mode" },
+    { "add",   "add solid-color frames",                               0,                  AV_OPT_TYPE_CONST, {.i64=0},        0,         0, VF, "mode" },
+    { "clone", "clone first/last frame",                               0,                  AV_OPT_TYPE_CONST, {.i64=1},        0,         0, VF, "mode" },
+    { "stop_mode",  "set the mode of added frames to end",             OFFSET(stop_mode),  AV_OPT_TYPE_INT,   {.i64=0},        0,         1, VF, "mode" },
+    { "start_duration", "set the duration to delay input",             OFFSET(start_duration), AV_OPT_TYPE_DURATION, {.i64=0}, 0, INT64_MAX, VF },
+    { "stop_duration",  "set the duration to pad input",               OFFSET(stop_duration),  AV_OPT_TYPE_DURATION, {.i64=0}, 0, INT64_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->start_mode == 0 && 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->start_mode == 1 && s->pad_start > 0) {
+        if (!s->cache_start && ff_inlink_queued_frames(inlink)) {
+            s->cache_start = ff_inlink_peek_frame(inlink, 0);
+        } else if (!s->cache_start) {
+            FF_FILTER_FORWARD_WANTED(outlink, inlink);
+        }
+        frame = av_frame_clone(s->cache_start);
+        if (!frame)
+            return AVERROR(ENOMEM);
+        frame->pts = s->pts;
+        s->pts += av_rescale_q(1, av_inv_q(outlink->frame_rate), outlink->time_base);
+        s->pad_start--;
+        if (s->pad_start == 0)
+            s->cache_start = NULL;
+        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) {
+            if (s->stop_mode == 1 && s->pad_stop != 0) {
+                av_frame_free(&s->cache_stop);
+                s->cache_stop = av_frame_clone(frame);
+            }
+            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;
+        }
+        if (s->stop_mode == 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);
+        } else if (s->stop_mode == 1) {
+            frame = av_frame_clone(s->cache_stop);
+            if (!frame)
+                return AVERROR(ENOMEM);
+        }
+        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);
+
+    if (s->start_duration)
+        s->pad_start = av_rescale_q(s->start_duration, inlink->frame_rate, av_inv_q(AV_TIME_BASE_Q));
+    if (s->stop_duration)
+        s->pad_stop = av_rescale_q(s->stop_duration, inlink->frame_rate, av_inv_q(AV_TIME_BASE_Q));
+
+    return 0;
+}
+
+static void uninit(AVFilterContext *ctx)
+{
+    TPadContext *s = ctx->priv;
+
+    av_frame_free(&s->cache_stop);
+}
+
+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,
+    .activate      = activate,
+    .uninit        = uninit,
+    .inputs        = tpad_inputs,
+    .outputs       = tpad_outputs,
+};