Skip to content

feat(avif): add chroma subsampling control for AVIF export #19595

New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Merged
merged 3 commits into from
Oct 29, 2025
+97 −14
Merged

feat(avif): add chroma subsampling control for AVIF export #19595

Show file tree
Hide file tree
Changes from 2 commits
Commits
Show all changes
3 commits
Select commit Hold shift + click to select a range
8ffa3ea
feat(avif): add chroma subsampling control for AVIF export
kadykov Oct 26, 2025
78c9b7e
feat(avif): add chroma subsampling configuration
kadykov Oct 27, 2025
8cb0db4
feat(avif): conditionally disable chroma subsampling UI for lossless …
kadykov Oct 28, 2025
File filter

Filter by extension

Filter by extension
Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
7 changes: 7 additions & 0 deletions data/darktableconfig.xml.in
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -2907,6 +2907,13 @@
<shortdescription/>
<longdescription/>
</dtconfig>
<dtconfig>
<name>plugins/imageio/format/avif/subsample</name>
<type min="0" max="3">int</type>
<default>0</default>
<shortdescription>AVIF chroma subsampling</shortdescription>
<longdescription/>
</dtconfig>
<dtconfig>
<name>plugins/imageio/format/xcf/bpp</name>
<type>
Expand Down
100 changes: 86 additions & 14 deletions src/imageio/format/avif.c
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -51,6 +51,14 @@ enum avif_tiling_e
AVIF_TILING_OFF
};

enum avif_subsample_e
{
AVIF_SUBSAMPLE_AUTO = 0,
AVIF_SUBSAMPLE_444,
AVIF_SUBSAMPLE_422,
AVIF_SUBSAMPLE_420
};

enum avif_color_mode_e
{
AVIF_COLOR_MODE_RGB = 0,
Expand All @@ -65,6 +73,7 @@ typedef struct dt_imageio_avif_t
uint32_t compression_type;
uint32_t quality;
uint32_t tiling;
uint32_t subsample;
} dt_imageio_avif_t;

typedef struct dt_imageio_avif_gui_t
Expand All @@ -74,6 +83,7 @@ typedef struct dt_imageio_avif_gui_t
GtkWidget *compression_type;
GtkWidget *quality;
GtkWidget *tiling;
GtkWidget *subsample;
} dt_imageio_avif_gui_t;

static const struct
Expand Down Expand Up @@ -207,6 +217,28 @@ void init(dt_imageio_module_format_t *self)
dt_imageio_avif_t,
quality,
int);

/* subsample */
luaA_enum(darktable.lua_state.state,
enum avif_subsample_e);
luaA_enum_value(darktable.lua_state.state,
enum avif_subsample_e,
AVIF_SUBSAMPLE_AUTO);
luaA_enum_value(darktable.lua_state.state,
enum avif_subsample_e,
AVIF_SUBSAMPLE_444);
luaA_enum_value(darktable.lua_state.state,
enum avif_subsample_e,
AVIF_SUBSAMPLE_422);
luaA_enum_value(darktable.lua_state.state,
enum avif_subsample_e,
AVIF_SUBSAMPLE_420);

dt_lua_register_module_member(darktable.lua_state.state,
self,
dt_imageio_avif_t,
subsample,
enum avif_subsample_e);
#endif
}

Expand Down Expand Up @@ -250,17 +282,33 @@ int write_image(struct dt_imageio_module_data_t *data,
format = AVIF_PIXEL_FORMAT_YUV444;
break;
case AVIF_COMP_LOSSY:
if(d->quality > 90)
// Determine pixel format based on subsample setting
switch(d->subsample)
{
case AVIF_SUBSAMPLE_AUTO:
// Auto mode: use quality thresholds
if(d->quality > 90)
{
format = AVIF_PIXEL_FORMAT_YUV444;
}
else if(d->quality > 80)
{
format = AVIF_PIXEL_FORMAT_YUV422;
}
else
{
format = AVIF_PIXEL_FORMAT_YUV420;
}
break;
case AVIF_SUBSAMPLE_444:
format = AVIF_PIXEL_FORMAT_YUV444;
}
else if(d->quality > 80)
{
break;
case AVIF_SUBSAMPLE_422:
format = AVIF_PIXEL_FORMAT_YUV422;
}
else
{
format = AVIF_PIXEL_FORMAT_YUV420;
break;
case AVIF_SUBSAMPLE_420:
format = AVIF_PIXEL_FORMAT_YUV420;
break;
}
break;
}
Expand Down Expand Up @@ -703,6 +751,7 @@ void *get_params(dt_imageio_module_format_t *self)
}

d->tiling = !dt_conf_get_bool("plugins/imageio/format/avif/tiling");
d->subsample = dt_conf_get_int("plugins/imageio/format/avif/subsample");

return d;
}
Expand All @@ -721,6 +770,7 @@ int set_params(dt_imageio_module_format_t *self,
dt_bauhaus_combobox_set(g->tiling, d->tiling);
dt_bauhaus_combobox_set(g->compression_type, d->compression_type);
dt_bauhaus_slider_set(g->quality, d->quality);
dt_bauhaus_combobox_set(g->subsample, d->subsample);

return 0;
}
Expand Down Expand Up @@ -818,6 +868,12 @@ static void quality_changed(GtkWidget *slider, gpointer user_data)
dt_conf_set_int("plugins/imageio/format/avif/quality", quality);
}

static void subsample_changed(GtkWidget *widget, gpointer user_data)
{
const enum avif_subsample_e subsample = dt_bauhaus_combobox_get(widget);
dt_conf_set_int("plugins/imageio/format/avif/subsample", subsample);
}

void gui_init(dt_imageio_module_format_t *self)
{
dt_imageio_avif_gui_t *gui = malloc(sizeof(dt_imageio_avif_gui_t));
Expand Down Expand Up @@ -904,17 +960,31 @@ void gui_init(dt_imageio_module_format_t *self)
dt_bauhaus_widget_set_label(gui->quality, NULL, N_("quality"));

gtk_widget_set_tooltip_text(gui->quality,
_("the quality of an image, less quality means fewer details.\n"
"\n"
"pixel format is controlled by quality:\n"
"\n"
"5-80: YUV420, 81-90: YUV422, 91-100: YUV444"));
_("the quality of an image, less quality means fewer details"));

dt_bauhaus_slider_set(gui->quality, quality);

gtk_widget_set_visible(gui->quality, compression_type != AVIF_COMP_LOSSLESS);
gtk_widget_set_no_show_all(gui->quality, TRUE);

/*
* Chroma subsampling combo box
*/
const enum avif_subsample_e subsample = dt_conf_get_int("plugins/imageio/format/avif/subsample");

DT_BAUHAUS_COMBOBOX_NEW_FULL(gui->subsample, self, NULL, N_("chroma subsampling"),
_("chroma subsampling setting for AVIF encoder.\n"
"auto - use subsampling determined by the quality value\n"
" (5-80: YUV420, 81-90: YUV422, 91-100: YUV444)\n"
"4:4:4 - no chroma subsampling\n"
"4:2:2 - color sampling rate halved horizontally\n"
"4:2:0 - color sampling rate halved horizontally and vertically"),
subsample, subsample_changed, self,
N_("auto"), N_("4:4:4"), N_("4:2:2"), N_("4:2:0"));

dt_bauhaus_combobox_set_default(gui->subsample,
dt_confgen_get_int("plugins/imageio/format/avif/subsample", DT_DEFAULT));

g_signal_connect(G_OBJECT(gui->bit_depth),
"value-changed",
G_CALLBACK(bit_depth_changed),
Expand All @@ -929,7 +999,7 @@ void gui_init(dt_imageio_module_format_t *self)
NULL);

self->widget = dt_gui_vbox(gui->bit_depth, gui->color_mode, gui->tiling,
gui->compression_type, gui->quality);
gui->compression_type, gui->quality, gui->subsample);
}

void gui_cleanup(dt_imageio_module_format_t *self)
Expand All @@ -946,6 +1016,7 @@ void gui_reset(dt_imageio_module_format_t *self)
const enum avif_tiling_e tiling = !dt_confgen_get_bool("plugins/imageio/format/avif/tiling", DT_DEFAULT);
const enum avif_compression_type_e compression_type = dt_confgen_get_int("plugins/imageio/format/avif/compression_type", DT_DEFAULT);
const uint32_t quality = dt_confgen_get_int("plugins/imageio/format/avif/quality", DT_DEFAULT);
const enum avif_subsample_e subsample = dt_confgen_get_int("plugins/imageio/format/avif/subsample", DT_DEFAULT);

size_t idx = 0;
for(size_t i = 0; avif_bit_depth[i].name != NULL; ++i)
Expand All @@ -961,6 +1032,7 @@ void gui_reset(dt_imageio_module_format_t *self)
dt_bauhaus_combobox_set(gui->tiling, tiling);
dt_bauhaus_combobox_set(gui->compression_type, compression_type);
dt_bauhaus_slider_set(gui->quality, quality);
dt_bauhaus_combobox_set(gui->subsample, subsample);
}

// clang-format off
Expand Down
Loading