diff options
| -rw-r--r-- | doc/filters.texi | 10 | ||||
| -rw-r--r-- | libavfilter/vf_curves.c | 64 |
2 files changed, 74 insertions, 0 deletions
diff --git a/doc/filters.texi b/doc/filters.texi index 03da9b0..5a64853 100644 --- a/doc/filters.texi +++ b/doc/filters.texi @@ -5750,6 +5750,8 @@ options. In this case, the unset component(s) will fallback on this @option{all} setting. @item psfile Specify a Photoshop curves file (@code{.acv}) to import the settings from. +@item plot +Save Gnuplot script of the curves in specified file. @end table To avoid some filtergraph syntax conflicts, each key points list need to be @@ -5796,6 +5798,14 @@ Use a Photoshop preset and redefine the points of the green component: @example curves=psfile='MyCurvesPresets/purple.acv':green='0/0 0.45/0.53 1/1' @end example + +@item +Check out the curves of the @code{cross_process} profile using @command{ffmpeg} +and @command{gnuplot}: +@example +ffmpeg -f lavfi -i color -vf curves=cross_process:plot=/tmp/curves.plt -frames:v 1 -f null - +gnuplot -p /tmp/curves.plt +@end example @end itemize @section datascope diff --git a/libavfilter/vf_curves.c b/libavfilter/vf_curves.c index 7128fbe..84df448 100644 --- a/libavfilter/vf_curves.c +++ b/libavfilter/vf_curves.c @@ -67,6 +67,7 @@ typedef struct { char *psfile; uint8_t rgba_map[4]; int step; + char *plot_filename; } CurvesContext; typedef struct ThreadData { @@ -98,6 +99,7 @@ static const AVOption curves_options[] = { { "b", "set blue points coordinates", OFFSET(comp_points_str[2]), AV_OPT_TYPE_STRING, {.str=NULL}, .flags = FLAGS }, { "all", "set points coordinates for all components", OFFSET(comp_points_str_all), AV_OPT_TYPE_STRING, {.str=NULL}, .flags = FLAGS }, { "psfile", "set Photoshop curves file name", OFFSET(psfile), AV_OPT_TYPE_STRING, {.str=NULL}, .flags = FLAGS }, + { "plot", "save Gnuplot script of the curves in specified file", OFFSET(plot_filename), AV_OPT_TYPE_STRING, {.str=NULL}, .flags = FLAGS }, { NULL } }; @@ -377,6 +379,65 @@ end: return ret; } +static int dump_curves(const char *fname, uint8_t graph[NB_COMP + 1][256], + struct keypoint *comp_points[NB_COMP + 1]) +{ + int i; + AVBPrint buf; + static const char * const colors[] = { "red", "green", "blue", "#404040", }; + FILE *f = av_fopen_utf8(fname, "w"); + + av_assert0(FF_ARRAY_ELEMS(colors) == NB_COMP + 1); + + if (!f) { + int ret = AVERROR(errno); + av_log(NULL, AV_LOG_ERROR, "Cannot open file '%s' for writing: %s\n", + fname, av_err2str(ret)); + return ret; + } + + av_bprint_init(&buf, 0, AV_BPRINT_SIZE_UNLIMITED); + + av_bprintf(&buf, "set xtics 0.1\n"); + av_bprintf(&buf, "set ytics 0.1\n"); + av_bprintf(&buf, "set size square\n"); + av_bprintf(&buf, "set grid\n"); + + for (i = 0; i < FF_ARRAY_ELEMS(colors); i++) { + av_bprintf(&buf, "%s'-' using 1:2 with lines lc '%s' title ''", + i ? ", " : "plot ", colors[i]); + if (comp_points[i]) + av_bprintf(&buf, ", '-' using 1:2 with points pointtype 3 lc '%s' title ''", + colors[i]); + } + av_bprintf(&buf, "\n"); + + for (i = 0; i < FF_ARRAY_ELEMS(colors); i++) { + int x; + + /* plot generated values */ + for (x = 0; x < 256; x++) + av_bprintf(&buf, "%f %f\n", x/255., graph[i][x]/255.); + av_bprintf(&buf, "e\n"); + + /* plot user knots */ + if (comp_points[i]) { + const struct keypoint *point = comp_points[i]; + + while (point) { + av_bprintf(&buf, "%f %f\n", point->x, point->y); + point = point->next; + } + av_bprintf(&buf, "e\n"); + } + } + + fwrite(buf.str, 1, buf.len, f); + fclose(f); + av_bprint_finalize(&buf, NULL); + return 0; +} + static av_cold int init(AVFilterContext *ctx) { int i, j, ret; @@ -448,6 +509,9 @@ static av_cold int init(AVFilterContext *ctx) } } + if (curves->plot_filename) + dump_curves(curves->plot_filename, curves->graph, comp_points); + for (i = 0; i < NB_COMP + 1; i++) { struct keypoint *point = comp_points[i]; while (point) { |
