Signed-off-by: Paul B Mahol <one...@gmail.com>
---
libavfilter/Makefile | 1 +
libavfilter/allfilters.c | 1 +
libavfilter/vsrc_starfield.c | 191 +++++++++++++++++++++++++++++++++++++++++++
3 files changed, 193 insertions(+)
create mode 100644 libavfilter/vsrc_starfield.c
diff --git a/libavfilter/Makefile b/libavfilter/Makefile
index 1e460ab..4cc99f0 100644
--- a/libavfilter/Makefile
+++ b/libavfilter/Makefile
@@ -352,6 +352,7 @@ OBJS-$(CONFIG_NULLSRC_FILTER) +=
vsrc_testsrc.o
OBJS-$(CONFIG_RGBTESTSRC_FILTER) += vsrc_testsrc.o
OBJS-$(CONFIG_SMPTEBARS_FILTER) += vsrc_testsrc.o
OBJS-$(CONFIG_SMPTEHDBARS_FILTER) += vsrc_testsrc.o
+OBJS-$(CONFIG_STARFIELD_FILTER) += vsrc_starfield.o
OBJS-$(CONFIG_TESTSRC_FILTER) += vsrc_testsrc.o
OBJS-$(CONFIG_TESTSRC2_FILTER) += vsrc_testsrc.o
OBJS-$(CONFIG_YUVTESTSRC_FILTER) += vsrc_testsrc.o
diff --git a/libavfilter/allfilters.c b/libavfilter/allfilters.c
index 9a2cfea..f1f87ca 100644
--- a/libavfilter/allfilters.c
+++ b/libavfilter/allfilters.c
@@ -363,6 +363,7 @@ static void register_all(void)
REGISTER_FILTER(RGBTESTSRC, rgbtestsrc, vsrc);
REGISTER_FILTER(SMPTEBARS, smptebars, vsrc);
REGISTER_FILTER(SMPTEHDBARS, smptehdbars, vsrc);
+ REGISTER_FILTER(STARFIELD, starfield, vsrc);
REGISTER_FILTER(TESTSRC, testsrc, vsrc);
REGISTER_FILTER(TESTSRC2, testsrc2, vsrc);
REGISTER_FILTER(YUVTESTSRC, yuvtestsrc, vsrc);
diff --git a/libavfilter/vsrc_starfield.c b/libavfilter/vsrc_starfield.c
new file mode 100644
index 0000000..96b8667
--- /dev/null
+++ b/libavfilter/vsrc_starfield.c
@@ -0,0 +1,191 @@
+/*
+ * Copyright (c) 2017 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/internal.h"
+#include "libavutil/lfg.h"
+#include "libavutil/opt.h"
+#include "libavutil/parseutils.h"
+#include "libavutil/random_seed.h"
+#include "libavutil/avstring.h"
+#include "avfilter.h"
+#include "internal.h"
+#include "formats.h"
+#include "video.h"
+
+typedef struct Star {
+ int x, y;
+ AVRational z;
+ unsigned r, g, b;
+} Star;
+
+typedef struct StarFieldContext {
+ const AVClass *class;
+
+ int w, h;
+ uint64_t pts;
+ AVRational frame_rate;
+ AVRational speed;
+ int nb_stars;
+ int64_t seed;
+
+ AVLFG lfg;
+ Star *stars;
+} StarFieldContext;
+
+#define OFFSET(x) offsetof(StarFieldContext, x)
+#define FLAGS AV_OPT_FLAG_FILTERING_PARAM|AV_OPT_FLAG_VIDEO_PARAM
+
+static const AVOption starfield_options[] = {
+ { "size", "set video size", OFFSET(w), AV_OPT_TYPE_IMAGE_SIZE,
{.str = "hd720"}, 0, 0, FLAGS },
+ { "rate", "set video rate", OFFSET(frame_rate), AV_OPT_TYPE_VIDEO_RATE,
{.str = "25"}, 0, INT_MAX, FLAGS },
+ { "stars", "set stars number", OFFSET(nb_stars), AV_OPT_TYPE_INT,
{.i64 = 1024}, 1, 81920, FLAGS },
+ { "seed", "set seed", OFFSET(seed), AV_OPT_TYPE_INT64,
{.i64 = -1}, -1, INT64_MAX, FLAGS },
+ { "speed", "set speed", OFFSET(speed), AV_OPT_TYPE_RATIONAL,
{.dbl = 1.01}, 1, 2, FLAGS },
+ { NULL }
+};
+
+AVFILTER_DEFINE_CLASS(starfield);
+
+static void init_star(StarFieldContext *s, Star *star, int depth)
+{
+ star->x = av_lfg_get(&s->lfg) - INT_MAX;
+ star->y = av_lfg_get(&s->lfg) - INT_MAX;
+ star->z.num = star->z.den = 1;
+ star->r = av_lfg_get(&s->lfg) >> av_log2(depth / 32);
+ star->g = av_lfg_get(&s->lfg) >> av_log2(depth / 32);
+ star->b = av_lfg_get(&s->lfg) >> av_log2(depth / 32);
+}
+
+static av_cold int init(AVFilterContext *ctx)
+{
+ StarFieldContext *s = ctx->priv;
+ int i;
+
+ s->stars = av_calloc(s->nb_stars, sizeof(*s->stars));
+ if (!s->stars)
+ return AVERROR(ENOMEM);
+
+ if (s->seed == -1)
+ s->seed = av_get_random_seed();
+ av_lfg_init(&s->lfg, s->seed);
+
+ for (i = 0; i < s->nb_stars; i++) {
+ init_star(s, &s->stars[i], i+1);
+ }
+
+ return 0;
+}
+
+static av_cold void uninit(AVFilterContext *ctx)
+{
+ StarFieldContext *s = ctx->priv;
+
+ av_freep(&s->stars);
+}
+
+static int config_props(AVFilterLink *outlink)
+{
+ StarFieldContext *s = outlink->src->priv;
+
+ outlink->w = s->w;
+ outlink->h = s->h;
+ outlink->time_base = av_inv_q(s->frame_rate);
+
+ return 0;
+}
+
+static void fill_picture(AVFilterContext *ctx, AVFrame *out)
+{
+ StarFieldContext *s = ctx->priv;
+ const int divx = UINT_MAX / out->width;
+ const int divy = UINT_MAX / out->height;
+ const int hw = out->width >> 1;
+ const int hh = out->height >> 1;
+ const int linesize = out->linesize[0];
+ int i;
+
+ for (i = 0; i < out->height; i++) {
+ memset(out->data[0] + out->linesize[0] * i, 0, out->width * 4);
+ }
+
+ for (i = 0; i < s->nb_stars; i++) {
+ Star *star = &s->stars[i];
+ int x, y;
+
+ x = av_rescale(star->x / divx, star->z.num, star->z.den) + hw;
+ y = av_rescale(star->y / divy, star->z.num, star->z.den) + hh;
+ if (x < 0 || x >= out->width ||
+ y < 0 || y >= out->height) {
+ init_star(s, &s->stars[i], i+1);
+ continue;
+ }
+
+ out->data[0][y * linesize + x * 4 + 0] =
av_clip_uint8((av_rescale(star->r, star->z.num, star->z.den) >> 24));
+ out->data[0][y * linesize + x * 4 + 1] =
av_clip_uint8((av_rescale(star->g, star->z.num, star->z.den) >> 24));
+ out->data[0][y * linesize + x * 4 + 2] =
av_clip_uint8((av_rescale(star->b, star->z.num, star->z.den) >> 24));
+
+ star->z = av_mul_q(star->z, s->speed);
+ }
+}
+
+static int request_frame(AVFilterLink *outlink)
+{
+ StarFieldContext *s = outlink->src->priv;
+ AVFrame *out = ff_get_video_buffer(outlink, s->w, s->h);
+ if (!out)
+ return AVERROR(ENOMEM);
+ out->sample_aspect_ratio = (AVRational) {1, 1};
+ fill_picture(outlink->src, out);
+
+ out->pts = s->pts++;
+
+ return ff_filter_frame(outlink, out);
+}
+
+static int query_formats(AVFilterContext *ctx)
+{
+ static const enum AVPixelFormat pix_fmts[] = { AV_PIX_FMT_RGB0,
AV_PIX_FMT_NONE };
+ AVFilterFormats *fmts_list = ff_make_format_list(pix_fmts);
+ if (!fmts_list)
+ return AVERROR(ENOMEM);
+ return ff_set_common_formats(ctx, fmts_list);
+}
+
+static const AVFilterPad starfield_outputs[] = {
+ {
+ .name = "default",
+ .type = AVMEDIA_TYPE_VIDEO,
+ .request_frame = request_frame,
+ .config_props = config_props,
+ },
+ { NULL }
+};
+
+AVFilter ff_vsrc_starfield = {
+ .name = "starfield",
+ .description = NULL_IF_CONFIG_SMALL("Create retro 3D star field."),
+ .priv_size = sizeof(StarFieldContext),
+ .priv_class = &starfield_class,
+ .init = init,
+ .uninit = uninit,
+ .query_formats = query_formats,
+ .inputs = NULL,
+ .outputs = starfield_outputs,
+};
--
2.9.3
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