[FFmpeg-cvslog] lavfi: add framestep filter
Stefano Sabatini
git at videolan.org
Sat Aug 18 12:16:17 CEST 2012
ffmpeg | branch: master | Stefano Sabatini <stefasab at gmail.com> | Thu Aug 16 19:04:26 2012 +0200| [48d116400cb321dd045bcf6836d1270b1d2b6f74] | committer: Stefano Sabatini
lavfi: add framestep filter
This filter is inspired upon libmpcodecs/vf_framestep.c, by Daniele
Forghieri.
Only-keyframe output is not supported, since that feature can be achieved
through the more versatile select filter.
> http://git.videolan.org/gitweb.cgi/ffmpeg.git/?a=commit;h=48d116400cb321dd045bcf6836d1270b1d2b6f74
---
Changelog | 1 +
doc/filters.texi | 7 +++
libavfilter/Makefile | 1 +
libavfilter/allfilters.c | 1 +
libavfilter/version.h | 4 +-
libavfilter/vf_framestep.c | 142 ++++++++++++++++++++++++++++++++++++++++++++
6 files changed, 154 insertions(+), 2 deletions(-)
diff --git a/Changelog b/Changelog
index 1f7ca21..904c1cd 100644
--- a/Changelog
+++ b/Changelog
@@ -48,6 +48,7 @@ version next:
- ICO muxer
- SubRip encoder and decoder without embedded timing
- edge detection filter
+- framestep filter
version 0.11:
diff --git a/doc/filters.texi b/doc/filters.texi
index e6279bd..da69e56 100644
--- a/doc/filters.texi
+++ b/doc/filters.texi
@@ -2084,6 +2084,13 @@ Desired output framerate.
@end table
+ at section framestep
+
+Select one frame every N.
+
+This filter accepts in input a string representing a positive
+integer. Default argument is @code{1}.
+
@anchor{frei0r}
@section frei0r
diff --git a/libavfilter/Makefile b/libavfilter/Makefile
index 5b2ccdb..bdeabc2 100644
--- a/libavfilter/Makefile
+++ b/libavfilter/Makefile
@@ -95,6 +95,7 @@ OBJS-$(CONFIG_FADE_FILTER) += vf_fade.o
OBJS-$(CONFIG_FIELDORDER_FILTER) += vf_fieldorder.o
OBJS-$(CONFIG_FIFO_FILTER) += fifo.o
OBJS-$(CONFIG_FORMAT_FILTER) += vf_format.o
+OBJS-$(CONFIG_FRAMESTEP_FILTER) += vf_framestep.o
OBJS-$(CONFIG_FPS_FILTER) += vf_fps.o
OBJS-$(CONFIG_FREI0R_FILTER) += vf_frei0r.o
OBJS-$(CONFIG_GRADFUN_FILTER) += vf_gradfun.o
diff --git a/libavfilter/allfilters.c b/libavfilter/allfilters.c
index e395baa..a9344c2 100644
--- a/libavfilter/allfilters.c
+++ b/libavfilter/allfilters.c
@@ -87,6 +87,7 @@ void avfilter_register_all(void)
REGISTER_FILTER (FIFO, fifo, vf);
REGISTER_FILTER (FORMAT, format, vf);
REGISTER_FILTER (FPS, fps, vf);
+ REGISTER_FILTER (FRAMESTEP, framestep, vf);
REGISTER_FILTER (FREI0R, frei0r, vf);
REGISTER_FILTER (GRADFUN, gradfun, vf);
REGISTER_FILTER (HFLIP, hflip, vf);
diff --git a/libavfilter/version.h b/libavfilter/version.h
index 7110156..01f1189 100644
--- a/libavfilter/version.h
+++ b/libavfilter/version.h
@@ -29,8 +29,8 @@
#include "libavutil/avutil.h"
#define LIBAVFILTER_VERSION_MAJOR 3
-#define LIBAVFILTER_VERSION_MINOR 10
-#define LIBAVFILTER_VERSION_MICRO 101
+#define LIBAVFILTER_VERSION_MINOR 11
+#define LIBAVFILTER_VERSION_MICRO 100
#define LIBAVFILTER_VERSION_INT AV_VERSION_INT(LIBAVFILTER_VERSION_MAJOR, \
LIBAVFILTER_VERSION_MINOR, \
diff --git a/libavfilter/vf_framestep.c b/libavfilter/vf_framestep.c
new file mode 100644
index 0000000..e903765
--- /dev/null
+++ b/libavfilter/vf_framestep.c
@@ -0,0 +1,142 @@
+/*
+ * Copyright (c) 2012 Stefano Sabatini
+ *
+ * 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
+ */
+
+/**
+ * @file framestep filter, inspired on libmpcodecs/vf_framestep.c by
+ * Daniele Fornighieri <guru AT digitalfantasy it>.
+ */
+
+#include "avfilter.h"
+#include "internal.h"
+#include "video.h"
+
+typedef struct {
+ int frame_step, frame_count, frame_selected;
+} FrameStepContext;
+
+static av_cold int init(AVFilterContext *ctx, const char *args)
+{
+ FrameStepContext *framestep = ctx->priv;
+ char *tailptr;
+ long int n;
+
+ framestep->frame_step = 1;
+
+ if (args) {
+ n = strtol(args, &tailptr, 10);
+ if (*tailptr || n <= 0 || n >= INT_MAX) {
+ av_log(ctx, AV_LOG_ERROR,
+ "Invalid argument '%s', must be a positive integer <= INT_MAX\n", args);
+ return AVERROR(EINVAL);
+ }
+ }
+
+ framestep->frame_step = n;
+ return 0;
+}
+
+static int config_output_props(AVFilterLink *outlink)
+{
+ AVFilterContext *ctx = outlink->src;
+ FrameStepContext *framestep = ctx->priv;
+ AVFilterLink *inlink = ctx->inputs[0];
+
+ outlink->frame_rate =
+ av_div_q(inlink->frame_rate, (AVRational){framestep->frame_step, 1});
+
+ av_log(ctx, AV_LOG_VERBOSE, "step:%d frame_rate:%d/%d(%f) -> frame_rate:%d/%d(%f)\n",
+ framestep->frame_step,
+ inlink->frame_rate.num, inlink->frame_rate.den, av_q2d(inlink->frame_rate),
+ outlink->frame_rate.num, outlink->frame_rate.den, av_q2d(outlink->frame_rate));
+ return 0;
+}
+
+static int start_frame(AVFilterLink *inlink, AVFilterBufferRef *ref)
+{
+ FrameStepContext *framestep = inlink->dst->priv;
+
+ framestep->frame_selected = 0;
+ if (!(framestep->frame_count++ % framestep->frame_step)) {
+ inlink->cur_buf = NULL;
+ framestep->frame_selected = 1;
+ return ff_start_frame(inlink->dst->outputs[0], ref);
+ }
+ return 0;
+}
+
+static int draw_slice(AVFilterLink *inlink, int y, int h, int slice_dir)
+{
+ FrameStepContext *framestep = inlink->dst->priv;
+
+ if (framestep->frame_selected)
+ return ff_draw_slice(inlink->dst->outputs[0], y, h, slice_dir);
+ return 0;
+}
+
+static int end_frame(AVFilterLink *inlink)
+{
+ FrameStepContext *framestep = inlink->dst->priv;
+
+ if (framestep->frame_selected)
+ return ff_end_frame(inlink->dst->outputs[0]);
+ return 0;
+}
+
+static int request_frame(AVFilterLink *outlink)
+{
+ FrameStepContext *framestep = outlink->src->priv;
+ AVFilterLink *inlink = outlink->src->inputs[0];
+ int ret;
+
+ framestep->frame_selected = 0;
+ do {
+ ret = ff_request_frame(inlink);
+ } while (!framestep->frame_selected && ret >= 0);
+
+ return ret;
+}
+
+AVFilter avfilter_vf_framestep = {
+ .name = "framestep",
+ .description = NULL_IF_CONFIG_SMALL("Select one frame every N frames."),
+ .init = init,
+ .priv_size = sizeof(FrameStepContext),
+
+ .inputs = (const AVFilterPad[]) {
+ {
+ .name = "default",
+ .type = AVMEDIA_TYPE_VIDEO,
+ .get_video_buffer = ff_null_get_video_buffer,
+ .start_frame = start_frame,
+ .draw_slice = draw_slice,
+ .end_frame = end_frame,
+ },
+ { .name = NULL }
+ },
+ .outputs = (const AVFilterPad[]) {
+ {
+ .name = "default",
+ .type = AVMEDIA_TYPE_VIDEO,
+ .config_props = config_output_props,
+ .request_frame = request_frame,
+ },
+ { .name = NULL }
+ },
+};
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