[FFmpeg-devel] [PATCH]lavfi/palettegen: Allow setting the background colour

[Carl Eugen Hoyos]

Hi!

Attached patch is useful in combination with the transparency patch
for paletteuse.

Please comment, Carl Eugen

From fc1c562748b2f7bb518df9feaa91482757ae9625 Mon Sep 17 00:00:00 2001
From: Carl Eugen Hoyos <ceffm...@gmail.com>
Date: Tue, 17 Oct 2017 23:39:59 +0200
Subject: [PATCH] lavfi/palettegen: Allow setting the background colour.

---
 libavfilter/vf_palettegen.c |    5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/libavfilter/vf_palettegen.c b/libavfilter/vf_palettegen.c
index 03de317..0c74af6 100644
--- a/libavfilter/vf_palettegen.c
+++ b/libavfilter/vf_palettegen.c
@@ -27,6 +27,7 @@
 #include "libavutil/internal.h"
 #include "libavutil/opt.h"
 #include "libavutil/qsort.h"
+#include "libavutil/intreadwrite.h"
 #include "avfilter.h"
 #include "internal.h"
 
@@ -74,6 +75,7 @@ typedef struct PaletteGenContext {
     struct range_box boxes[256];            // define the segmentation of the colorspace (the final palette)
     int nb_boxes;                           // number of boxes (increase will segmenting them)
     int palette_pushed;                     // if the palette frame is pushed into the outlink or not
+    uint32_t background;                    // background color for transparency
 } PaletteGenContext;
 
 #define OFFSET(x) offsetof(PaletteGenContext, x)
@@ -81,6 +83,7 @@ typedef struct PaletteGenContext {
 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 },
     { "reserve_transparent", "reserve a palette entry for transparency", OFFSET(reserve_transparent), AV_OPT_TYPE_BOOL, {.i64=1}, 0, 1, FLAGS },
+    { "background", "set a background color for transparency", OFFSET(background), AV_OPT_TYPE_COLOR, {.str="white"}, CHAR_MIN, CHAR_MAX, 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" },
         { "full", "compute full frame histograms", 0, AV_OPT_TYPE_CONST, {.i64=STATS_MODE_ALL_FRAMES}, INT_MIN, INT_MAX, FLAGS, "mode" },
         { "diff", "compute histograms only for the part that differs from previous frame", 0, AV_OPT_TYPE_CONST, {.i64=STATS_MODE_DIFF_FRAMES}, INT_MIN, INT_MAX, FLAGS, "mode" },
@@ -250,7 +253,7 @@ static void write_palette(AVFilterContext *ctx, AVFrame *out)
 
     if (s->reserve_transparent) {
         av_assert0(s->nb_boxes < 256);
-        pal[out->width - pal_linesize - 1] = 0x0000ff00; // add a green transparent color
+        pal[out->width - pal_linesize - 1] = AV_RB32(&s->background) >> 8;
     }
 }
 
-- 
1.7.10.4


_______________________________________________
ffmpeg-devel mailing list
ffmpeg-devel@ffmpeg.org
http://ffmpeg.org/mailman/listinfo/ffmpeg-devel