@section geq
-The filter takes one, two or three equations as parameter, separated by ':'.
+The filter takes one, two, three or four equations as parameter, separated by ':'.
The first equation is mandatory and applies to the luma plane. The two
following are respectively for chroma blue and chroma red planes.
the chrominance blue expression
@item cr_expr
the chrominance red expression
+@item alpha_expr
+the alpha expression
@end table
If one of the chrominance expression is not defined, it falls back on the other
-one. If none of them are specified, they will evaluate the luminance
-expression.
+one. If no alpha expression is specified it will evaluate to opaque value.
+If none of chrominance expressions are
+specified, they will evaluate the luminance expression.
The expressions can use the following variables and functions:
@item cb(x, y)
Return the value of the pixel at location (@var{x},@var{y}) of the
-blue-difference chroma plane.
+blue-difference chroma plane. Returns 0 if there is no such plane.
@item cr(x, y)
Return the value of the pixel at location (@var{x},@var{y}) of the
-red-difference chroma plane.
+red-difference chroma plane. Returns 0 if there is no such plane.
+
+@item alpha(x, y)
+Return the value of the pixel at location (@var{x},@var{y}) of the alpha
+plane. Returns 0 if there is no such plane.
@end table
For functions, if @var{x} and @var{y} are outside the area, the value will be
typedef struct {
const AVClass *class;
- AVExpr *e[3]; ///< expressions for each plane
- char *expr_str[3]; ///< expression strings for each plane
+ AVExpr *e[4]; ///< expressions for each plane
+ char *expr_str[4]; ///< expression strings for each plane
int framenum; ///< frame counter
AVFilterBufferRef *picref; ///< current input buffer
int hsub, vsub; ///< chroma subsampling
+ int planes; ///< number of planes
} GEQContext;
#define OFFSET(x) offsetof(GEQContext, x)
#define FLAGS AV_OPT_FLAG_VIDEO_PARAM|AV_OPT_FLAG_FILTERING_PARAM
static const AVOption geq_options[] = {
- { "lum_expr", "set luminance expression", OFFSET(expr_str), AV_OPT_TYPE_STRING, {.str=NULL}, CHAR_MIN, CHAR_MAX, FLAGS },
- { "cb_expr", "set chroma blue expression", OFFSET(expr_str) + sizeof(char*), AV_OPT_TYPE_STRING, {.str=NULL}, CHAR_MIN, CHAR_MAX, FLAGS },
- { "cr_expr", "set chroma red expression", OFFSET(expr_str) + 2*sizeof(char*), AV_OPT_TYPE_STRING, {.str=NULL}, CHAR_MIN, CHAR_MAX, FLAGS },
+ { "lum_expr", "set luminance expression", OFFSET(expr_str[0]), AV_OPT_TYPE_STRING, {.str=NULL}, CHAR_MIN, CHAR_MAX, FLAGS },
+ { "cb_expr", "set chroma blue expression", OFFSET(expr_str[1]), AV_OPT_TYPE_STRING, {.str=NULL}, CHAR_MIN, CHAR_MAX, FLAGS },
+ { "cr_expr", "set chroma red expression", OFFSET(expr_str[2]), AV_OPT_TYPE_STRING, {.str=NULL}, CHAR_MIN, CHAR_MAX, FLAGS },
+ { "alpha_expr", "set alpha expression", OFFSET(expr_str[3]), AV_OPT_TYPE_STRING, {.str=NULL}, CHAR_MIN, CHAR_MAX, FLAGS },
{NULL},
};
AVFilterBufferRef *picref = geq->picref;
const uint8_t *src = picref->data[plane];
const int linesize = picref->linesize[plane];
- const int w = picref->video->w >> (plane ? geq->hsub : 0);
- const int h = picref->video->h >> (plane ? geq->vsub : 0);
+ const int w = picref->video->w >> ((plane == 1 || plane == 2) ? geq->hsub : 0);
+ const int h = picref->video->h >> ((plane == 1 || plane == 2) ? geq->vsub : 0);
+
+ if (!src)
+ return 0;
xi = x = av_clipf(x, 0, w - 2);
yi = y = av_clipf(y, 0, h - 2);
static double lum(void *priv, double x, double y) { return getpix(priv, x, y, 0); }
static double cb(void *priv, double x, double y) { return getpix(priv, x, y, 1); }
static double cr(void *priv, double x, double y) { return getpix(priv, x, y, 2); }
+static double alpha(void *priv, double x, double y) { return getpix(priv, x, y, 3); }
static const char *const var_names[] = { "X", "Y", "W", "H", "N", "SW", "SH", "T", NULL };
enum { VAR_X, VAR_Y, VAR_W, VAR_H, VAR_N, VAR_SW, VAR_SH, VAR_T, VAR_VARS_NB };
{
GEQContext *geq = ctx->priv;
int plane, ret = 0;
- static const char *shorthand[] = { "lum_expr", "cb_expr", "cr_expr", NULL };
+ static const char *shorthand[] = { "lum_expr", "cb_expr", "cr_expr", "alpha_expr", NULL };
geq->class = &geq_class;
av_opt_set_defaults(geq);
if (!geq->expr_str[2]) geq->expr_str[2] = av_strdup(geq->expr_str[1]);
}
- if (!geq->expr_str[1] || !geq->expr_str[2]) {
+ if (!geq->expr_str[3])
+ geq->expr_str[3] = av_strdup("255");
+
+ if (!geq->expr_str[1] || !geq->expr_str[2] || !geq->expr_str[3]) {
ret = AVERROR(ENOMEM);
goto end;
}
- for (plane = 0; plane < 3; plane++) {
- static double (*p[])(void *, double, double) = { lum, cb, cr };
- static const char *const func2_names[] = { "lum", "cb", "cr", "p", NULL };
- double (*func2[])(void *, double, double) = { lum, cb, cr, p[plane], NULL };
+ for (plane = 0; plane < 4; plane++) {
+ static double (*p[])(void *, double, double) = { lum, cb, cr, alpha };
+ static const char *const func2_names[] = { "lum", "cb", "cr", "alpha", "p", NULL };
+ double (*func2[])(void *, double, double) = { lum, cb, cr, alpha, p[plane], NULL };
ret = av_expr_parse(&geq->e[plane], geq->expr_str[plane], var_names,
NULL, NULL, func2_names, func2, 0, ctx);
static const enum PixelFormat pix_fmts[] = {
AV_PIX_FMT_YUV444P, AV_PIX_FMT_YUV422P, AV_PIX_FMT_YUV420P,
AV_PIX_FMT_YUV411P, AV_PIX_FMT_YUV410P, AV_PIX_FMT_YUV440P,
- AV_PIX_FMT_YUVA420P,
+ AV_PIX_FMT_YUVA444P, AV_PIX_FMT_YUVA422P, AV_PIX_FMT_YUVA420P,
+ AV_PIX_FMT_GRAY8,
AV_PIX_FMT_NONE
};
ff_set_common_formats(ctx, ff_make_format_list(pix_fmts));
geq->hsub = desc->log2_chroma_w;
geq->vsub = desc->log2_chroma_h;
+ geq->planes = desc->nb_components;
return 0;
}
}
avfilter_copy_buffer_ref_props(out, in);
- for (plane = 0; plane < 3; plane++) {
+ for (plane = 0; plane < geq->planes && out->data[plane]; plane++) {
int x, y;
uint8_t *dst = out->data[plane];
const int linesize = out->linesize[plane];
- const int w = inlink->w >> (plane ? geq->hsub : 0);
- const int h = inlink->h >> (plane ? geq->vsub : 0);
+ const int w = inlink->w >> ((plane == 1 || plane == 2) ? geq->hsub : 0);
+ const int h = inlink->h >> ((plane == 1 || plane == 2) ? geq->vsub : 0);
values[VAR_W] = w;
values[VAR_H] = h;