[FFmpeg-cvslog] lavfi/overlay: add enable expression
Stefano Sabatini
git at videolan.org
Wed Apr 10 13:20:50 CEST 2013
ffmpeg | branch: master | Stefano Sabatini <stefasab at gmail.com> | Mon Apr 8 12:22:48 2013 +0200| [006e20bd3655443e2d709dfbee468af2805a994a] | committer: Stefano Sabatini
lavfi/overlay: add enable expression
This expression is useful to enable/disable overlaying on the fly.
Note that this can't be easily done relying on the filtergraph structure,
since this implies caching issues or a null frame overlaying in the best
case, which is better avoided for performance and convenience reasons.
> http://git.videolan.org/gitweb.cgi/ffmpeg.git/?a=commit;h=006e20bd3655443e2d709dfbee468af2805a994a
---
doc/filters.texi | 12 +++++++++---
libavfilter/version.h | 2 +-
libavfilter/vf_overlay.c | 25 ++++++++++++++++++-------
3 files changed, 28 insertions(+), 11 deletions(-)
diff --git a/doc/filters.texi b/doc/filters.texi
index 4668b7f..215e438 100644
--- a/doc/filters.texi
+++ b/doc/filters.texi
@@ -4267,8 +4267,14 @@ on the main video. Default value is "0" for both expressions. In case
the expression is invalid, it is set to a huge value (meaning that the
overlay will not be displayed within the output visible area).
+ at item enable
+Set the expression which enables the overlay. If the evaluation is
+different from 0, the overlay is displayed on top of the input
+frame. By default it is "1".
+
@item eval
-Set when the expressions for @option{x} and @option{y} are evaluated.
+Set when the expressions for @option{x}, @option{y}, and
+ at option{enable} are evaluated.
It accepts the following values:
@table @samp
@@ -4308,8 +4314,8 @@ color space. Default value is 0. This option is deprecated, use
@option{format} instead.
@end table
-The @option{x}, and @option{y} expressions can contain the following
-parameters.
+The @option{x}, @option{y}, and @option{enable} expressions can
+contain the following parameters.
@table @option
@item main_w, W
diff --git a/libavfilter/version.h b/libavfilter/version.h
index 7e9784e..e2fec54 100644
--- a/libavfilter/version.h
+++ b/libavfilter/version.h
@@ -30,7 +30,7 @@
#define LIBAVFILTER_VERSION_MAJOR 3
#define LIBAVFILTER_VERSION_MINOR 50
-#define LIBAVFILTER_VERSION_MICRO 101
+#define LIBAVFILTER_VERSION_MICRO 102
#define LIBAVFILTER_VERSION_INT AV_VERSION_INT(LIBAVFILTER_VERSION_MAJOR, \
LIBAVFILTER_VERSION_MINOR, \
diff --git a/libavfilter/vf_overlay.c b/libavfilter/vf_overlay.c
index 62bdd4e..57a0bcd 100644
--- a/libavfilter/vf_overlay.c
+++ b/libavfilter/vf_overlay.c
@@ -87,6 +87,7 @@ enum var_name {
typedef struct {
const AVClass *class;
int x, y; ///< position of overlayed picture
+ double enable; ///< tells if blending is enabled
int allow_packed_rgb;
uint8_t frame_requested;
@@ -110,8 +111,8 @@ typedef struct {
int shortest; ///< terminate stream when the shortest input terminates
double var_values[VAR_VARS_NB];
- char *x_expr, *y_expr;
- AVExpr *x_pexpr, *y_pexpr;
+ char *x_expr, *y_expr, *enable_expr;
+ AVExpr *x_pexpr, *y_pexpr, *enable_pexpr;
} OverlayContext;
#define OFFSET(x) offsetof(OverlayContext, x)
@@ -120,6 +121,7 @@ typedef struct {
static const AVOption overlay_options[] = {
{ "x", "set the x expression", OFFSET(x_expr), AV_OPT_TYPE_STRING, {.str = "0"}, CHAR_MIN, CHAR_MAX, FLAGS },
{ "y", "set the y expression", OFFSET(y_expr), AV_OPT_TYPE_STRING, {.str = "0"}, CHAR_MIN, CHAR_MAX, FLAGS },
+ { "enable", "set expression which enables overlay", OFFSET(enable_expr), AV_OPT_TYPE_STRING, {.str = "1"}, .flags = FLAGS },
{ "eval", "specify when to evaluate expressions", OFFSET(eval_mode), AV_OPT_TYPE_INT, {.i64 = EVAL_MODE_FRAME}, 0, EVAL_MODE_NB-1, FLAGS, "eval" },
{ "init", "eval expressions once during initialization", 0, AV_OPT_TYPE_CONST, {.i64=EVAL_MODE_INIT}, .flags = FLAGS, .unit = "eval" },
@@ -159,6 +161,7 @@ static av_cold void uninit(AVFilterContext *ctx)
ff_bufqueue_discard_all(&over->queue_over);
av_expr_free(over->x_pexpr); over->x_pexpr = NULL;
av_expr_free(over->y_pexpr); over->y_pexpr = NULL;
+ av_expr_free(over->enable_pexpr); over->enable_pexpr = NULL;
}
static int query_formats(AVFilterContext *ctx)
@@ -257,6 +260,7 @@ static void eval_expr(AVFilterContext *ctx)
over->var_values[VAR_X] = av_expr_eval(over->x_pexpr, over->var_values, NULL);
over->x = normalize_xy(over->var_values[VAR_X], over->hsub);
over->y = normalize_xy(over->var_values[VAR_Y], over->vsub);
+ over->enable = av_expr_eval(over->enable_pexpr, over->var_values, NULL);
}
static int config_input_overlay(AVFilterLink *inlink)
@@ -291,6 +295,10 @@ static int config_input_overlay(AVFilterLink *inlink)
if ((ret = av_expr_parse(&over->y_pexpr, expr, var_names,
NULL, NULL, NULL, NULL, 0, ctx)) < 0)
goto fail;
+ expr = over->enable_expr;
+ if ((ret = av_expr_parse(&over->enable_pexpr, expr, var_names,
+ NULL, NULL, NULL, NULL, 0, ctx)) < 0)
+ goto fail;
over->overlay_is_packed_rgb =
ff_fill_rgba_map(over->overlay_rgba_map, inlink->format) >= 0;
@@ -298,9 +306,10 @@ static int config_input_overlay(AVFilterLink *inlink)
if (over->eval_mode == EVAL_MODE_INIT) {
eval_expr(ctx);
- av_log(ctx, AV_LOG_VERBOSE, "x:%f xi:%d y:%f yi:%d\n",
+ av_log(ctx, AV_LOG_VERBOSE, "x:%f xi:%d y:%f yi:%d enable:%f\n",
over->var_values[VAR_X], over->x,
- over->var_values[VAR_Y], over->y);
+ over->var_values[VAR_Y], over->y,
+ over->enable);
}
av_log(ctx, AV_LOG_VERBOSE,
@@ -573,12 +582,14 @@ static int try_filter_frame(AVFilterContext *ctx, AVFrame *mainpic)
over->var_values[VAR_POS] = pos == -1 ? NAN : pos;
eval_expr(ctx);
- av_log(ctx, AV_LOG_DEBUG, "n:%f t:%f pos:%f x:%f xi:%d y:%f yi:%d\n",
+ av_log(ctx, AV_LOG_DEBUG, "n:%f t:%f pos:%f x:%f xi:%d y:%f yi:%d enable:%f\n",
over->var_values[VAR_N], over->var_values[VAR_T], over->var_values[VAR_POS],
over->var_values[VAR_X], over->x,
- over->var_values[VAR_Y], over->y);
+ over->var_values[VAR_Y], over->y,
+ over->enable);
}
- blend_image(ctx, mainpic, over->overpicref, over->x, over->y);
+ if (over->enable)
+ blend_image(ctx, mainpic, over->overpicref, over->x, over->y);
over->var_values[VAR_N] += 1.0;
}
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