diff options
| -rw-r--r-- | doc/filters.texi | 36 | ||||
| -rw-r--r-- | libavfilter/vf_crop.c | 40 |
2 files changed, 50 insertions, 26 deletions
diff --git a/doc/filters.texi b/doc/filters.texi index bdde8f5380..c75f1198ed 100644 --- a/doc/filters.texi +++ b/doc/filters.texi @@ -623,7 +623,25 @@ testing purposes. @section crop -Crop the input video to @var{out_w}:@var{out_h}:@var{x}:@var{y}. +Crop the input video to given dimensions. + +This filter accepts the following options: + +@table @option + +@item out_w +Width of the output video. + +@item out_h +Height of the output video. + +@item x +Horizontal position, in the input video, of the left edge of the output video. + +@item y +Vertical position, in the input video, of the top edge of the output video. + +@end table The parameters are expressions containing the following constants: @@ -683,34 +701,34 @@ for @var{y} may depend on @var{x}. Follow some examples: @example # crop the central input area with size 100x100 -crop=100:100 +crop=out_w=100:out_h=100 # crop the central input area with size 2/3 of the input video -"crop=2/3*in_w:2/3*in_h" +"crop=out_w=2/3*in_w:out_h=2/3*in_h" # crop the input video central square -crop=in_h +crop=out_w=in_h # delimit the rectangle with the top-left corner placed at position # 100:100 and the right-bottom corner corresponding to the right-bottom # corner of the input image. -crop=in_w-100:in_h-100:100:100 +crop=out_w=in_w-100:out_h=in_h-100:x=100:y=100 # crop 10 pixels from the left and right borders, and 20 pixels from # the top and bottom borders -"crop=in_w-2*10:in_h-2*20" +"crop=out_w=in_w-2*10:out_h=in_h-2*20" # keep only the bottom right quarter of the input image -"crop=in_w/2:in_h/2:in_w/2:in_h/2" +"crop=out_w=in_w/2:out_h=in_h/2:x=in_w/2:y=in_h/2" # crop height for getting Greek harmony -"crop=in_w:1/PHI*in_w" +"crop=out_w=in_w:out_h=1/PHI*in_w" # trembling effect "crop=in_w/2:in_h/2:(in_w-out_w)/2+((in_w-out_w)/2)*sin(n/10):(in_h-out_h)/2 +((in_h-out_h)/2)*sin(n/7)" # erratic camera effect depending on timestamp -"crop=in_w/2:in_h/2:(in_w-out_w)/2+((in_w-out_w)/2)*sin(t*10):(in_h-out_h)/2 +((in_h-out_h)/2)*sin(t*13)" +"crop=out_w=in_w/2:out_h=in_h/2:x=(in_w-out_w)/2+((in_w-out_w)/2)*sin(t*10):y=(in_h-out_h)/2 +((in_h-out_h)/2)*sin(t*13)" # set x depending on the value of y "crop=in_w/2:in_h/2:y:10+10*sin(n/10)" diff --git a/libavfilter/vf_crop.c b/libavfilter/vf_crop.c index 2b571c4f8a..ec545b3d58 100644 --- a/libavfilter/vf_crop.c +++ b/libavfilter/vf_crop.c @@ -37,6 +37,7 @@ #include "libavutil/libm.h" #include "libavutil/imgutils.h" #include "libavutil/mathematics.h" +#include "libavutil/opt.h" static const char *const var_names[] = { "E", @@ -70,6 +71,7 @@ enum var_name { }; typedef struct { + const AVClass *class; int x; ///< x offset of the non-cropped area with respect to the input area int y; ///< y offset of the non-cropped area with respect to the input area int w; ///< width of the cropped area @@ -77,7 +79,7 @@ typedef struct { int max_step[4]; ///< max pixel step for each plane, expressed as a number of bytes int hsub, vsub; ///< chroma subsampling - char x_expr[256], y_expr[256], ow_expr[256], oh_expr[256]; + char *x_expr, *y_expr, *ow_expr, *oh_expr; AVExpr *x_pexpr, *y_pexpr; /* parsed expressions for x and y */ double var_values[VAR_VARS_NB]; } CropContext; @@ -115,21 +117,6 @@ static int query_formats(AVFilterContext *ctx) return 0; } -static av_cold int init(AVFilterContext *ctx, const char *args) -{ - CropContext *crop = ctx->priv; - - av_strlcpy(crop->ow_expr, "iw", sizeof(crop->ow_expr)); - av_strlcpy(crop->oh_expr, "ih", sizeof(crop->oh_expr)); - av_strlcpy(crop->x_expr, "(in_w-out_w)/2", sizeof(crop->x_expr)); - av_strlcpy(crop->y_expr, "(in_h-out_h)/2", sizeof(crop->y_expr)); - - if (args) - sscanf(args, "%255[^:]:%255[^:]:%255[^:]:%255[^:]", crop->ow_expr, crop->oh_expr, crop->x_expr, crop->y_expr); - - return 0; -} - static av_cold void uninit(AVFilterContext *ctx) { CropContext *crop = ctx->priv; @@ -294,6 +281,25 @@ static int filter_frame(AVFilterLink *link, AVFrame *frame) return ff_filter_frame(link->dst->outputs[0], frame); } +#define OFFSET(x) offsetof(CropContext, x) +#define FLAGS AV_OPT_FLAG_VIDEO_PARAM +static const AVOption options[] = { + { "out_w", "Output video width", OFFSET(ow_expr), AV_OPT_TYPE_STRING, { .str = "iw" }, .flags = FLAGS }, + { "out_h", "Output video height", OFFSET(oh_expr), AV_OPT_TYPE_STRING, { .str = "ih" }, .flags = FLAGS }, + { "x", "Horizontal position in the input video of the left edge of the cropped output video", + OFFSET(x_expr), AV_OPT_TYPE_STRING, { .str = "(in_w - out_w) / 2" }, .flags = FLAGS }, + { "y", "Vertical position in the input video of the top edge of the cropped output video", + OFFSET(y_expr), AV_OPT_TYPE_STRING, { .str = "(in_h - out_h) / 2" }, .flags = FLAGS }, + { NULL }, +}; + +static const AVClass crop_class = { + .class_name = "crop", + .item_name = av_default_item_name, + .option = options, + .version = LIBAVUTIL_VERSION_INT, +}; + static const AVFilterPad avfilter_vf_crop_inputs[] = { { .name = "default", @@ -319,9 +325,9 @@ AVFilter avfilter_vf_crop = { .description = NULL_IF_CONFIG_SMALL("Crop the input video to width:height:x:y."), .priv_size = sizeof(CropContext), + .priv_class = &crop_class, .query_formats = query_formats, - .init = init, .uninit = uninit, .inputs = avfilter_vf_crop_inputs, |