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authorSoft Works <softworkz@hotmail.com>2021-09-26 04:57:25 +0000
committerMichael Niedermayer <michael@niedermayer.cc>2021-09-26 17:34:08 +0200
commit8983c3d7e4acf9b216599cce218acbea498154c7 (patch)
treeffff88da2866df1716f7117fdf1d7a6fcbf5d7dd /libavfilter/vf_elbg.c
parent0e45886e6ea272f453cb949e95c3bfd8380974c5 (diff)
downloadffmpeg-8983c3d7e4acf9b216599cce218acbea498154c7.tar.gz
avfilter/elbg: Extend filter to include alpha values in the quantization procedure
Usage example: ffmpeg -y -loglevel verbose -i "..\fate-suite\apng\o_sample.png" -filter_complex "elbg=pal8=1:use_alpha=1" -frames:v 1 out.png Signed-off-by: softworkz <softworkz@hotmail.com> Signed-off-by: Michael Niedermayer <michael@niedermayer.cc>
Diffstat (limited to 'libavfilter/vf_elbg.c')
-rw-r--r--libavfilter/vf_elbg.c25
1 files changed, 16 insertions, 9 deletions
diff --git a/libavfilter/vf_elbg.c b/libavfilter/vf_elbg.c
index 0bebcdbda5..7f40be6092 100644
--- a/libavfilter/vf_elbg.c
+++ b/libavfilter/vf_elbg.c
@@ -46,6 +46,7 @@ typedef struct ELBGFilterContext {
int codebook_length;
const AVPixFmtDescriptor *pix_desc;
uint8_t rgba_map[4];
+ int use_alpha;
int pal8;
} ELBGFilterContext;
@@ -60,6 +61,7 @@ static const AVOption elbg_options[] = {
{ "seed", "set the random seed", OFFSET(lfg_seed), AV_OPT_TYPE_INT64, {.i64 = -1}, -1, UINT32_MAX, FLAGS },
{ "s", "set the random seed", OFFSET(lfg_seed), AV_OPT_TYPE_INT64, { .i64 = -1 }, -1, UINT32_MAX, FLAGS },
{ "pal8", "set the pal8 output", OFFSET(pal8), AV_OPT_TYPE_BOOL, { .i64 = 0 }, 0, 1, FLAGS },
+ { "use_alpha", "use alpha channel for mapping", OFFSET(use_alpha), AV_OPT_TYPE_BOOL, {.i64=0}, 0, 1, FLAGS },
{ NULL }
};
@@ -105,7 +107,7 @@ static int query_formats(AVFilterContext *ctx)
return 0;
}
-#define NB_COMPONENTS 3
+#define NB_COMPONENTS 4
static int config_input(AVFilterLink *inlink)
{
@@ -138,6 +140,7 @@ static int config_input(AVFilterLink *inlink)
#define R 0
#define G 1
#define B 2
+#define A 3
static int filter_frame(AVFilterLink *inlink, AVFrame *frame)
{
@@ -148,6 +151,7 @@ static int filter_frame(AVFilterLink *inlink, AVFrame *frame)
const uint8_t r_idx = elbg->rgba_map[R];
const uint8_t g_idx = elbg->rgba_map[G];
const uint8_t b_idx = elbg->rgba_map[B];
+ const uint8_t a_idx = elbg->rgba_map[A];
/* build the codeword */
p0 = frame->data[0];
@@ -155,9 +159,10 @@ static int filter_frame(AVFilterLink *inlink, AVFrame *frame)
for (i = 0; i < inlink->h; i++) {
p = p0;
for (j = 0; j < inlink->w; j++) {
- elbg->codeword[k++] = p[r_idx];
- elbg->codeword[k++] = p[g_idx];
elbg->codeword[k++] = p[b_idx];
+ elbg->codeword[k++] = p[g_idx];
+ elbg->codeword[k++] = p[r_idx];
+ elbg->codeword[k++] = elbg->use_alpha ? p[a_idx] : 0xff;
p += elbg->pix_desc->nb_components;
}
p0 += frame->linesize[0];
@@ -188,10 +193,11 @@ static int filter_frame(AVFilterLink *inlink, AVFrame *frame)
p0 = (uint8_t *)out->data[0];
for (i = 0; i < elbg->codebook_length; i++) {
- pal[i] = 0xFFU << 24 |
- (elbg->codebook[i*3 ] << 16) |
- (elbg->codebook[i*3+1] << 8) |
- elbg->codebook[i*3+2];
+ const int al = elbg->use_alpha ? elbg->codebook[i*4+3] : 0xff;
+ pal[i] = al << 24 |
+ (elbg->codebook[i*4+2] << 16) |
+ (elbg->codebook[i*4+1] << 8) |
+ elbg->codebook[i*4 ];
}
k = 0;
@@ -214,9 +220,10 @@ static int filter_frame(AVFilterLink *inlink, AVFrame *frame)
p = p0;
for (j = 0; j < inlink->w; j++) {
int cb_idx = NB_COMPONENTS * elbg->codeword_closest_codebook_idxs[k++];
- p[r_idx] = elbg->codebook[cb_idx];
+ p[b_idx] = elbg->codebook[cb_idx];
p[g_idx] = elbg->codebook[cb_idx+1];
- p[b_idx] = elbg->codebook[cb_idx+2];
+ p[r_idx] = elbg->codebook[cb_idx+2];
+ p[a_idx] = elbg->use_alpha ? elbg->codebook[cb_idx+3] : 0xFFu;
p += elbg->pix_desc->nb_components;
}
p0 += frame->linesize[0];