vf_pad: center image on padded area if negative x/y

or if x/y go beyond padded area.

This is mostly useful when paired with the aspect option.
Defaults aren't changed.

Idea for this was taken from mpv's soon-to-be-removed expand vf.

Reviewed-by: Paul B Mahol <onemda@gmail.com>
This commit is contained in:
Ricardo Constantino 2017-04-03 19:34:09 +01:00 committed by Rostislav Pehlivanov
parent 3f8d7342c3
commit 57c3670896
2 changed files with 10 additions and 5 deletions

View File

@ -10430,6 +10430,9 @@ expression, and vice versa.
The default value of @var{x} and @var{y} is 0.
If @var{x} or @var{y} evaluate to a negative number, they'll be changed
so the input image is centered on the padded area.
@item color
Specify the color of the padded area. For the syntax of this option,
check the "Color" section in the ffmpeg-utils manual.

View File

@ -173,8 +173,13 @@ static int config_input(AVFilterLink *inlink)
goto eval_fail;
s->x = var_values[VAR_X] = res;
if (s->x < 0 || s->x + inlink->w > s->w)
s->x = var_values[VAR_X] = (s->w - inlink->w) / 2;
if (s->y < 0 || s->y + inlink->h > s->h)
s->y = var_values[VAR_Y] = (s->h - inlink->h) / 2;
/* sanity check params */
if (s->w < 0 || s->h < 0 || s->x < 0 || s->y < 0) {
if (s->w < 0 || s->h < 0) {
av_log(ctx, AV_LOG_ERROR, "Negative values are not acceptable.\n");
return AVERROR(EINVAL);
}
@ -192,10 +197,7 @@ static int config_input(AVFilterLink *inlink)
inlink->w, inlink->h, s->w, s->h, s->x, s->y,
s->rgba_color[0], s->rgba_color[1], s->rgba_color[2], s->rgba_color[3]);
if (s->x < 0 || s->y < 0 ||
s->w <= 0 || s->h <= 0 ||
(unsigned)s->x + (unsigned)inlink->w > s->w ||
(unsigned)s->y + (unsigned)inlink->h > s->h) {
if (s->w <= 0 || s->h <= 0) {
av_log(ctx, AV_LOG_ERROR,
"Input area %d:%d:%d:%d not within the padded area 0:0:%d:%d or zero-sized\n",
s->x, s->y, s->x + inlink->w, s->y + inlink->h, s->w, s->h);