[FFmpeg-devel] [PATCH 5/5] lavfi: addroi filter
Mark Thompson
sw at jkqxz.net
Thu Feb 28 00:00:23 EET 2019
This can be used to add region of interest side data to video frames.
---
libavfilter/Makefile | 1 +
libavfilter/allfilters.c | 1 +
libavfilter/vf_addroi.c | 237 +++++++++++++++++++++++++++++++++++++++
3 files changed, 239 insertions(+)
create mode 100644 libavfilter/vf_addroi.c
diff --git a/libavfilter/Makefile b/libavfilter/Makefile
index fef6ec5c55..31ae738a50 100644
--- a/libavfilter/Makefile
+++ b/libavfilter/Makefile
@@ -149,6 +149,7 @@ OBJS-$(CONFIG_SINE_FILTER) += asrc_sine.o
OBJS-$(CONFIG_ANULLSINK_FILTER) += asink_anullsink.o
# video filters
+OBJS-$(CONFIG_ADDROI_FILTER) += vf_addroi.o
OBJS-$(CONFIG_ALPHAEXTRACT_FILTER) += vf_extractplanes.o
OBJS-$(CONFIG_ALPHAMERGE_FILTER) += vf_alphamerge.o
OBJS-$(CONFIG_AMPLIFY_FILTER) += vf_amplify.o
diff --git a/libavfilter/allfilters.c b/libavfilter/allfilters.c
index c51ae0f3c7..52413c8f0d 100644
--- a/libavfilter/allfilters.c
+++ b/libavfilter/allfilters.c
@@ -140,6 +140,7 @@ extern AVFilter ff_asrc_sine;
extern AVFilter ff_asink_anullsink;
+extern AVFilter ff_vf_addroi;
extern AVFilter ff_vf_alphaextract;
extern AVFilter ff_vf_alphamerge;
extern AVFilter ff_vf_amplify;
diff --git a/libavfilter/vf_addroi.c b/libavfilter/vf_addroi.c
new file mode 100644
index 0000000000..c8d323e660
--- /dev/null
+++ b/libavfilter/vf_addroi.c
@@ -0,0 +1,237 @@
+/*
+ * 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/eval.h"
+#include "libavutil/opt.h"
+#include "avfilter.h"
+#include "internal.h"
+
+enum {
+ TOP,
+ BOTTOM,
+ LEFT,
+ RIGHT,
+};
+
+static const char *const addroi_var_names[] = {
+ "w",
+ "h",
+};
+
+enum {
+ VAR_W,
+ VAR_H,
+ NB_VARS,
+};
+
+typedef struct AddROIContext {
+ const AVClass *class;
+
+ char *region_str[4];
+
+ AVExpr *region_expr[4];
+ double vars[NB_VARS];
+
+ int region[4];
+ AVRational qoffset;
+} AddROIContext;
+
+static int addroi_config_input(AVFilterLink *inlink)
+{
+ AVFilterContext *avctx = inlink->dst;
+ AddROIContext *ctx = avctx->priv;
+ int i;
+ double val;
+
+ ctx->vars[VAR_W] = inlink->w;
+ ctx->vars[VAR_H] = inlink->h;
+
+ for (i = 0; i < 4; i++) {
+ val = av_expr_eval(ctx->region_expr[i], ctx->vars, NULL);
+ ctx->region[i] = av_clip(rint(val), 0,
+ i < 2 ? inlink->h : inlink->w);
+ }
+
+ return 0;
+}
+
+static int addroi_filter_frame(AVFilterLink *inlink, AVFrame *frame)
+{
+ AVFilterContext *avctx = inlink->dst;
+ AVFilterLink *outlink = avctx->outputs[0];
+ AddROIContext *ctx = avctx->priv;
+ AVRegionOfInterest *roi;
+ AVFrameSideData *sd;
+ int err;
+
+ sd = av_frame_get_side_data(frame, AV_FRAME_DATA_REGIONS_OF_INTEREST);
+ if (sd) {
+ const AVRegionOfInterest *old_roi;
+ AVBufferRef *roi_ref;
+ int nb_roi, i;
+
+ old_roi = (const AVRegionOfInterest*)sd->data;
+ nb_roi = sd->size / old_roi->self_size + 1;
+
+ roi_ref = av_buffer_alloc(sizeof(*roi) * nb_roi);
+ if (!roi_ref) {
+ err = AVERROR(ENOMEM);
+ goto fail;
+ }
+ roi = (AVRegionOfInterest*)roi_ref->data;
+
+ for (i = 0; i < nb_roi - 1; i++) {
+ old_roi = (const AVRegionOfInterest*)
+ (sd->data + old_roi->self_size * i);
+
+ roi[i] = (AVRegionOfInterest) {
+ .self_size = sizeof(*roi),
+ .top = old_roi->top,
+ .bottom = old_roi->bottom,
+ .left = old_roi->left,
+ .right = old_roi->right,
+ .qoffset = old_roi->qoffset,
+ };
+ }
+
+ roi[nb_roi - 1] = (AVRegionOfInterest) {
+ .self_size = sizeof(*roi),
+ .top = ctx->region[TOP],
+ .bottom = ctx->region[BOTTOM],
+ .left = ctx->region[LEFT],
+ .right = ctx->region[RIGHT],
+ .qoffset = ctx->qoffset,
+ };
+
+ av_frame_remove_side_data(frame, AV_FRAME_DATA_REGIONS_OF_INTEREST);
+
+ sd = av_frame_new_side_data_from_buf(frame,
+ AV_FRAME_DATA_REGIONS_OF_INTEREST,
+ roi_ref);
+ if (!sd) {
+ av_buffer_unref(&roi_ref);
+ err = AVERROR(ENOMEM);
+ goto fail;
+ }
+
+ } else {
+ sd = av_frame_new_side_data(frame, AV_FRAME_DATA_REGIONS_OF_INTEREST,
+ sizeof(AVRegionOfInterest));
+ if (!sd) {
+ err = AVERROR(ENOMEM);
+ goto fail;
+ }
+ roi = (AVRegionOfInterest*)sd->data;
+ *roi = (AVRegionOfInterest) {
+ .self_size = sizeof(*roi),
+ .top = ctx->region[TOP],
+ .bottom = ctx->region[BOTTOM],
+ .left = ctx->region[LEFT],
+ .right = ctx->region[RIGHT],
+ .qoffset = ctx->qoffset,
+ };
+ }
+
+ return ff_filter_frame(outlink, frame);
+
+fail:
+ av_frame_free(&frame);
+ return err;
+}
+
+static av_cold int addroi_init(AVFilterContext *avctx)
+{
+ AddROIContext *ctx = avctx->priv;
+ int i, err;
+
+ for (i = 0; i < 4; i++) {
+ err = av_expr_parse(&ctx->region_expr[i], ctx->region_str[i],
+ addroi_var_names, NULL, NULL, NULL, NULL,
+ 0, avctx);
+ if (err < 0) {
+ av_log(ctx, AV_LOG_ERROR,
+ "Error parsing region distance expression '%s'.\n",
+ ctx->region_str[i]);
+ return err;
+ }
+ }
+
+ return 0;
+}
+
+static av_cold void addroi_uninit(AVFilterContext *avctx)
+{
+ AddROIContext *ctx = avctx->priv;
+ int i;
+
+ for (i = 0; i < 4; i++) {
+ av_expr_free(ctx->region_expr[i]);
+ ctx->region_expr[i] = NULL;
+ }
+}
+
+#define OFFSET(x) offsetof(AddROIContext, x)
+#define FLAGS AV_OPT_FLAG_VIDEO_PARAM | AV_OPT_FLAG_FILTERING_PARAM
+static const AVOption addroi_options[] = {
+ { "top", "Region distance from top edge of frame",
+ OFFSET(region_str[TOP]), AV_OPT_TYPE_STRING, { .str = "0" }, .flags = FLAGS },
+ { "bottom", "Region distance from bottom edge of frame",
+ OFFSET(region_str[BOTTOM]), AV_OPT_TYPE_STRING, { .str = "0" }, .flags = FLAGS },
+ { "left", "Region distance from left edge of frame",
+ OFFSET(region_str[LEFT]), AV_OPT_TYPE_STRING, { .str = "0" }, .flags = FLAGS },
+ { "right", "Region distance from right edge of frame",
+ OFFSET(region_str[RIGHT]), AV_OPT_TYPE_STRING, { .str = "0" }, .flags = FLAGS },
+
+ { "qoffset", "Quantisation offset to apply in the region.",
+ OFFSET(qoffset), AV_OPT_TYPE_RATIONAL, { .dbl = 0.0 }, -1, +1, .flags = FLAGS },
+
+ { NULL }
+};
+
+AVFILTER_DEFINE_CLASS(addroi);
+
+static const AVFilterPad addroi_inputs[] = {
+ {
+ .name = "default",
+ .type = AVMEDIA_TYPE_VIDEO,
+ .config_props = addroi_config_input,
+ .filter_frame = addroi_filter_frame,
+ },
+ { NULL }
+};
+
+static const AVFilterPad addroi_outputs[] = {
+ {
+ .name = "default",
+ .type = AVMEDIA_TYPE_VIDEO,
+ },
+ { NULL }
+};
+
+AVFilter ff_vf_addroi = {
+ .name = "addroi",
+ .description = NULL_IF_CONFIG_SMALL("Add region of interest to frame."),
+ .init = addroi_init,
+ .uninit = addroi_uninit,
+
+ .priv_size = sizeof(AddROIContext),
+ .priv_class = &addroi_class,
+
+ .inputs = addroi_inputs,
+ .outputs = addroi_outputs,
+};
--
2.19.2
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