[FFmpeg-cvslog] lavfi/overlay: add dynamic expression evaluation support
Stefano Sabatini
git at videolan.org
Wed Apr 10 13:20:50 CEST 2013
ffmpeg | branch: master | Stefano Sabatini <stefasab at gmail.com> | Tue Feb 19 20:10:02 2013 +0100| [cc3edd99a678b9ecfe70cb3632029cb8db40e7f9] | committer: Stefano Sabatini
lavfi/overlay: add dynamic expression evaluation support
Add support for dynamic x, y expressions evaluation.
Also add support for an evaluation mode which allows to disable per-frame
evaluation, so that there is no speedloss in case the expression does not
depend on frame variables.
> http://git.videolan.org/gitweb.cgi/ffmpeg.git/?a=commit;h=cc3edd99a678b9ecfe70cb3632029cb8db40e7f9
---
doc/filters.texi | 79 +++++++++++++++++++++++-------
libavfilter/version.h | 2 +-
libavfilter/vf_overlay.c | 120 +++++++++++++++++++++++++++++++++-------------
3 files changed, 150 insertions(+), 51 deletions(-)
diff --git a/doc/filters.texi b/doc/filters.texi
index 512f943..4668b7f 100644
--- a/doc/filters.texi
+++ b/doc/filters.texi
@@ -4260,26 +4260,31 @@ arguments are interpreted according to the syntax @var{x}:@var{y}.
A description of the accepted options follows.
@table @option
- at item x, y
+ at item x
+ at item y
Set the expression for the x and y coordinates of the overlayed video
-on the main video. Default value is 0.
-
-The @var{x} and @var{y} expressions can contain the following
-parameters:
- at table @option
- at item main_w, main_h
-main input width and height
+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 W, H
-same as @var{main_w} and @var{main_h}
+ at item eval
+Set when the expressions for @option{x} and @option{y} are evaluated.
- at item overlay_w, overlay_h
-overlay input width and height
+It accepts the following values:
+ at table @samp
+ at item init
+only evaluate expressions once during the filter initialization
- at item w, h
-same as @var{overlay_w} and @var{overlay_h}
+ at item frame
+evaluate expressions for each incoming frame
@end table
+Default value is @samp{frame}.
+
+ at item shortest
+If set to 1, force the output to terminate when the shortest input
+terminates. Default value is 0.
+
@item format
Set the format for the output video.
@@ -4301,12 +4306,45 @@ Default value is @samp{yuv420}.
If set to 1, force the filter to accept inputs in the RGB
color space. Default value is 0. This option is deprecated, use
@option{format} instead.
+ at end table
- at item shortest
-If set to 1, force the output to terminate when the shortest input
-terminates. Default value is 0.
+The @option{x}, and @option{y} expressions can contain the following
+parameters.
+
+ at table @option
+ at item main_w, W
+ at item main_h, H
+main input width and height
+
+ at item overlay_w, w
+ at item overlay_h, h
+overlay input width and height
+
+ at item x
+ at item y
+the computed values for @var{x} and @var{y}. They are evaluated for
+each new frame.
+
+ at item hsub
+ at item vsub
+horizontal and vertical chroma subsample values of the output
+format. For example for the pixel format "yuv422p" @var{hsub} is 2 and
+ at var{vsub} is 1.
+
+ at item n
+the number of input frame, starting from 0
+
+ at item pos
+the position in the file of the input frame, NAN if unknown
+
+ at item t
+timestamp expressed in seconds, NAN if the input timestamp is unknown
@end table
+Note that the @var{n}, @var{pos}, @var{t} variables are available only
+when evaluation is done @emph{per frame}, and will evaluate to NAN
+when @option{eval} is set to @samp{init}.
+
Be aware that frames are taken from each input video in timestamp
order, hence, if their initial timestamps differ, it is a a good idea
to pass the two inputs through a @var{setpts=PTS-STARTPTS} filter to
@@ -4365,6 +4403,13 @@ ffplay input.avi -vf 'split[b], pad=iw*2[src], [b]deshake, [src]overlay=w'
@end example
@item
+Make a sliding overlay appearing from the left to the right top part of the
+screen starting since time 2:
+ at example
+overlay=x='if(gte(t,2), -w+(t-2)*20, NAN)':y=0
+ at end example
+
+ at item
Compose output by putting two input videos side to side:
@example
ffmpeg -i left.avi -i right.avi -filter_complex "
diff --git a/libavfilter/version.h b/libavfilter/version.h
index 2a70671..7e9784e 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 100
+#define LIBAVFILTER_VERSION_MICRO 101
#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 0dcd0b8..62bdd4e 100644
--- a/libavfilter/vf_overlay.c
+++ b/libavfilter/vf_overlay.c
@@ -47,6 +47,13 @@ static const char *const var_names[] = {
"main_h", "H", ///< height of the main video
"overlay_w", "w", ///< width of the overlay video
"overlay_h", "h", ///< height of the overlay video
+ "hsub",
+ "vsub",
+ "x",
+ "y",
+ "n", ///< number of frame
+ "pos", ///< position in the file
+ "t", ///< timestamp expressed in seconds
NULL
};
@@ -55,6 +62,13 @@ enum var_name {
VAR_MAIN_H, VAR_MH,
VAR_OVERLAY_W, VAR_OW,
VAR_OVERLAY_H, VAR_OH,
+ VAR_HSUB,
+ VAR_VSUB,
+ VAR_X,
+ VAR_Y,
+ VAR_N,
+ VAR_POS,
+ VAR_T,
VAR_VARS_NB
};
@@ -84,6 +98,7 @@ typedef struct {
uint8_t overlay_rgba_map[4];
uint8_t overlay_has_alpha;
enum OverlayFormat { OVERLAY_FORMAT_YUV420, OVERLAY_FORMAT_YUV444, OVERLAY_FORMAT_RGB, OVERLAY_FORMAT_NB} format;
+ enum EvalMode { EVAL_MODE_INIT, EVAL_MODE_FRAME, EVAL_MODE_NB } eval_mode;
AVFrame *overpicref;
struct FFBufQueue queue_main;
@@ -94,7 +109,9 @@ typedef struct {
int hsub, vsub; ///< chroma subsampling values
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;
} OverlayContext;
#define OFFSET(x) offsetof(OverlayContext, x)
@@ -103,6 +120,11 @@ 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 },
+
+ { "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" },
+ { "frame", "eval expressions per-frame", 0, AV_OPT_TYPE_CONST, {.i64=EVAL_MODE_FRAME}, .flags = FLAGS, .unit = "eval" },
+
{ "rgb", "force packed RGB in input and output (deprecated)", OFFSET(allow_packed_rgb), AV_OPT_TYPE_INT, {.i64=0}, 0, 1, FLAGS },
{ "shortest", "force termination when the shortest input terminates", OFFSET(shortest), AV_OPT_TYPE_INT, { .i64 = 0 }, 0, 1, FLAGS },
@@ -135,6 +157,8 @@ static av_cold void uninit(AVFilterContext *ctx)
av_frame_free(&over->overpicref);
ff_bufqueue_discard_all(&over->queue_main);
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;
}
static int query_formats(AVFilterContext *ctx)
@@ -217,12 +241,29 @@ static int config_input_main(AVFilterLink *inlink)
return 0;
}
+static inline int normalize_xy(double d, int chroma_sub)
+{
+ if (isnan(d))
+ return INT_MAX;
+ return (int)d & ~((1 << chroma_sub) - 1);
+}
+
+static void eval_expr(AVFilterContext *ctx)
+{
+ OverlayContext *over = ctx->priv;
+
+ over->var_values[VAR_X] = av_expr_eval(over->x_pexpr, over->var_values, NULL);
+ over->var_values[VAR_Y] = av_expr_eval(over->y_pexpr, over->var_values, NULL);
+ 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);
+}
+
static int config_input_overlay(AVFilterLink *inlink)
{
AVFilterContext *ctx = inlink->dst;
OverlayContext *over = inlink->dst->priv;
char *expr;
- double var_values[VAR_VARS_NB], res;
int ret;
const AVPixFmtDescriptor *pix_desc = av_pix_fmt_desc_get(inlink->format);
@@ -230,53 +271,49 @@ static int config_input_overlay(AVFilterLink *inlink)
/* Finish the configuration by evaluating the expressions
now when both inputs are configured. */
- var_values[VAR_MAIN_W ] = var_values[VAR_MW] = ctx->inputs[MAIN ]->w;
- var_values[VAR_MAIN_H ] = var_values[VAR_MH] = ctx->inputs[MAIN ]->h;
- var_values[VAR_OVERLAY_W] = var_values[VAR_OW] = ctx->inputs[OVERLAY]->w;
- var_values[VAR_OVERLAY_H] = var_values[VAR_OH] = ctx->inputs[OVERLAY]->h;
-
- if ((ret = av_expr_parse_and_eval(&res, (expr = over->x_expr), var_names, var_values,
- NULL, NULL, NULL, NULL, NULL, 0, ctx)) < 0)
- goto fail;
- over->x = res;
- if ((ret = av_expr_parse_and_eval(&res, (expr = over->y_expr), var_names, var_values,
- NULL, NULL, NULL, NULL, NULL, 0, ctx)))
+ over->var_values[VAR_MAIN_W ] = over->var_values[VAR_MW] = ctx->inputs[MAIN ]->w;
+ over->var_values[VAR_MAIN_H ] = over->var_values[VAR_MH] = ctx->inputs[MAIN ]->h;
+ over->var_values[VAR_OVERLAY_W] = over->var_values[VAR_OW] = ctx->inputs[OVERLAY]->w;
+ over->var_values[VAR_OVERLAY_H] = over->var_values[VAR_OH] = ctx->inputs[OVERLAY]->h;
+ over->var_values[VAR_HSUB] = 1<<pix_desc->log2_chroma_w;
+ over->var_values[VAR_VSUB] = 1<<pix_desc->log2_chroma_h;
+ over->var_values[VAR_X] = NAN;
+ over->var_values[VAR_Y] = NAN;
+ over->var_values[VAR_N] = 0;
+ over->var_values[VAR_T] = NAN;
+ over->var_values[VAR_POS] = NAN;
+
+ expr = over->x_expr;
+ if ((ret = av_expr_parse(&over->x_pexpr, expr, var_names,
+ NULL, NULL, NULL, NULL, 0, ctx)) < 0)
goto fail;
- over->y = res;
- /* x may depend on y */
- if ((ret = av_expr_parse_and_eval(&res, (expr = over->x_expr), var_names, var_values,
- NULL, NULL, NULL, NULL, NULL, 0, ctx)) < 0)
+ expr = over->y_expr;
+ if ((ret = av_expr_parse(&over->y_pexpr, expr, var_names,
+ NULL, NULL, NULL, NULL, 0, ctx)) < 0)
goto fail;
- over->x = res;
over->overlay_is_packed_rgb =
ff_fill_rgba_map(over->overlay_rgba_map, inlink->format) >= 0;
over->overlay_has_alpha = ff_fmt_is_in(inlink->format, alpha_pix_fmts);
+ 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",
+ over->var_values[VAR_X], over->x,
+ over->var_values[VAR_Y], over->y);
+ }
+
av_log(ctx, AV_LOG_VERBOSE,
- "main w:%d h:%d fmt:%s overlay x:%d y:%d w:%d h:%d fmt:%s\n",
+ "main w:%d h:%d fmt:%s overlay w:%d h:%d fmt:%s\n",
ctx->inputs[MAIN]->w, ctx->inputs[MAIN]->h,
av_get_pix_fmt_name(ctx->inputs[MAIN]->format),
- over->x, over->y,
ctx->inputs[OVERLAY]->w, ctx->inputs[OVERLAY]->h,
av_get_pix_fmt_name(ctx->inputs[OVERLAY]->format));
-
- if (over->x < 0 || over->y < 0 ||
- over->x + var_values[VAR_OVERLAY_W] > var_values[VAR_MAIN_W] ||
- over->y + var_values[VAR_OVERLAY_H] > var_values[VAR_MAIN_H]) {
- av_log(ctx, AV_LOG_WARNING,
- "Overlay area with coordinates x1:%d y1:%d x2:%d y2:%d "
- "is not completely contained within the output with size %dx%d\n",
- over->x, over->y,
- (int)(over->x + var_values[VAR_OVERLAY_W]),
- (int)(over->y + var_values[VAR_OVERLAY_H]),
- (int)var_values[VAR_MAIN_W], (int)var_values[VAR_MAIN_H]);
- }
return 0;
fail:
av_log(NULL, AV_LOG_ERROR,
- "Error when evaluating the expression '%s'\n", expr);
+ "Error when parsing the expression '%s'\n", expr);
return ret;
}
@@ -495,6 +532,7 @@ static void blend_image(AVFilterContext *ctx,
static int try_filter_frame(AVFilterContext *ctx, AVFrame *mainpic)
{
OverlayContext *over = ctx->priv;
+ AVFilterLink *inlink = ctx->inputs[0];
AVFrame *next_overpic;
int ret;
@@ -526,8 +564,24 @@ static int try_filter_frame(AVFilterContext *ctx, AVFrame *mainpic)
av_ts2str(over->overpicref->pts), av_ts2timestr(over->overpicref->pts, &ctx->inputs[OVERLAY]->time_base));
av_dlog(ctx, "\n");
- if (over->overpicref)
+ if (over->overpicref) {
+ if (over->eval_mode == EVAL_MODE_FRAME) {
+ int64_t pos = av_frame_get_pkt_pos(mainpic);
+
+ over->var_values[VAR_T] = mainpic->pts == AV_NOPTS_VALUE ?
+ NAN : mainpic->pts * av_q2d(inlink->time_base);
+ 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",
+ 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);
+ }
blend_image(ctx, mainpic, over->overpicref, over->x, over->y);
+
+ over->var_values[VAR_N] += 1.0;
+ }
ret = ff_filter_frame(ctx->outputs[0], mainpic);
av_assert1(ret != AVERROR(EAGAIN));
over->frame_requested = 0;
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