From cad9d7fc85bde0b30823ae7b8ce17e97b6f7a387 Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?Cl=C3=A9ment=20B=C5=93sch?= Date: Tue, 27 Dec 2022 22:06:23 +0100 Subject: [PATCH] avfilter/palettegen: allow a minimum of 2 colors --- libavfilter/vf_palettegen.c | 7 ++++++- 1 file changed, 6 insertions(+), 1 deletion(-) diff --git a/libavfilter/vf_palettegen.c b/libavfilter/vf_palettegen.c index 27f74fd147..c03f62b942 100644 --- a/libavfilter/vf_palettegen.c +++ b/libavfilter/vf_palettegen.c @@ -82,7 +82,7 @@ typedef struct PaletteGenContext { #define OFFSET(x) offsetof(PaletteGenContext, x) #define FLAGS AV_OPT_FLAG_FILTERING_PARAM|AV_OPT_FLAG_VIDEO_PARAM static const AVOption palettegen_options[] = { - { "max_colors", "set the maximum number of colors to use in the palette", OFFSET(max_colors), AV_OPT_TYPE_INT, {.i64=256}, 4, 256, FLAGS }, + { "max_colors", "set the maximum number of colors to use in the palette", OFFSET(max_colors), AV_OPT_TYPE_INT, {.i64=256}, 2, 256, FLAGS }, { "reserve_transparent", "reserve a palette entry for transparency", OFFSET(reserve_transparent), AV_OPT_TYPE_BOOL, {.i64=1}, 0, 1, FLAGS }, { "transparency_color", "set a background color for transparency", OFFSET(transparency_color), AV_OPT_TYPE_COLOR, {.str="lime"}, 0, 0, FLAGS }, { "stats_mode", "set statistics mode", OFFSET(stats_mode), AV_OPT_TYPE_INT, {.i64=STATS_MODE_ALL_FRAMES}, 0, NB_STATS_MODE-1, FLAGS, "mode" }, @@ -586,6 +586,11 @@ static int init(AVFilterContext *ctx) if (s->use_alpha && s->reserve_transparent) s->reserve_transparent = 0; + if (s->max_colors - s->reserve_transparent < 2) { + av_log(ctx, AV_LOG_ERROR, "max_colors=2 is only allowed without reserving a transparent color slot\n"); + return AVERROR(EINVAL); + } + return 0; }