#include "libavutil/avassert.h"
#include "libavutil/internal.h"
#include "libavutil/mem.h"
#include "libavutil/opt.h"
#include "libavutil/intreadwrite.h"
#include "avfilter.h"
#include "filters.h"
#include "formats.h"
#include "palette.h"
#include "video.h"

Data Structures
struct	color_ref

struct	range_box

struct	hist_node

struct	PaletteGenContext

Macros
#define	HIST_SIZE (1<<15)

#define	OFFSET(x) offsetof(PaletteGenContext, x)

#define	FLAGS AV_OPT_FLAG_FILTERING_PARAM\|AV_OPT_FLAG_VIDEO_PARAM

#define	DECLARE_CMP_FUNC(k0, k1, k2)

Typedefs
typedef int(*	cmp_func) (const void , const void )

Enumerations
enum	{ STATS_MODE_ALL_FRAMES, STATS_MODE_DIFF_FRAMES, STATS_MODE_SINGLE_FRAMES, NB_STATS_MODE }

enum	{ ID_XYZ, ID_XZY, ID_ZXY, ID_YXZ, ID_ZYX, ID_YZX }

Functions
	AVFILTER_DEFINE_CLASS (palettegen)

static int	query_formats (const AVFilterContext ctx, AVFilterFormatsConfig cfg_in, AVFilterFormatsConfig *cfg_out)

static int	sort3id (int64_t x, int64_t y, int64_t z)

static int	cmp_color (const void a, const void b)
	Simple color comparison for sorting the final palette. More...

static void	compute_box_stats (PaletteGenContext s, struct range_box box)

static int	get_next_box_id_to_split (PaletteGenContext *s)
	Find the next box to split: pick the one with the highest cut score. More...

static void	split_box (PaletteGenContext s, struct range_box box, int n)
	Split given box in two at position n. More...

static void	write_palette (AVFilterContext ctx, AVFrame out)
	Write the palette into the output frame. More...

static struct color_ref **	load_color_refs (const struct hist_node *hist, int nb_refs)
	Crawl the histogram to get all the defined colors, and create a linear list of them (each color reference entry is a pointer to the value in the histogram/hash table). More...

static double	set_colorquant_ratio_meta (AVFrame *out, int nb_out, int nb_in)

static AVFrame *	get_palette_frame (AVFilterContext *ctx)
	Main function implementing the Median Cut Algorithm defined by Paul Heckbert in Color Image Quantization for Frame Buffer Display (1982) More...

static int	color_inc (struct hist_node *hist, uint32_t color)
	Locate the color in the hash table and increment its counter. More...

static int	update_histogram_diff (struct hist_node hist, const AVFrame f1, const AVFrame *f2)
	Update histogram when pixels differ from previous frame. More...

static int	update_histogram_frame (struct hist_node hist, const AVFrame f)
	Simple histogram of the frame. More...

static int	filter_frame (AVFilterLink inlink, AVFrame in)
	Update the histogram for each passing frame. More...

static int	request_frame (AVFilterLink *outlink)
	Returns only one frame at the end containing the full palette. More...

static int	config_output (AVFilterLink *outlink)
	The output is one simple 16x16 squared-pixels palette. More...

static int	init (AVFilterContext *ctx)

static av_cold void	uninit (AVFilterContext *ctx)

Variables
static const AVOption	palettegen_options []

static const char *const	sortstr [] = { "Lab", "Lba", "bLa", "aLb", "baL", "abL" }

static const cmp_func	cmp_funcs []

static const AVFilterPad	palettegen_inputs []

static const AVFilterPad	palettegen_outputs []

const AVFilter	ff_vf_palettegen

Detailed Description

Generate one palette for a whole video stream.

Definition in file vf_palettegen.c.

Macro Definition Documentation

◆ HIST_SIZE

#define HIST_SIZE (1<<15)

Definition at line 69 of file vf_palettegen.c.

◆ OFFSET

#define OFFSET ( x ) offsetof(PaletteGenContext, x)

Definition at line 88 of file vf_palettegen.c.

◆ FLAGS

#define FLAGS AV_OPT_FLAG_FILTERING_PARAM|AV_OPT_FLAG_VIDEO_PARAM

Definition at line 89 of file vf_palettegen.c.

◆ DECLARE_CMP_FUNC

#define DECLARE_CMP_FUNC	(	k0,
		k1,
		k2
	)

Value:

static int cmp_##k0##k1##k2(const void *pa, const void *pb) \
{                                                           \
    const struct color_ref * const *a = pa;                 \
    const struct color_ref * const *b = pb;                 \
    const int c0 = FFDIFFSIGN((*a)->lab.k0, (*b)->lab.k0);  \
    const int c1 = FFDIFFSIGN((*a)->lab.k1, (*b)->lab.k1);  \
    const int c2 = FFDIFFSIGN((*a)->lab.k2, (*b)->lab.k2);  \
    return c0 ? c0 : c1 ? c1 : c2;                          \
}

Definition at line 120 of file vf_palettegen.c.

Typedef Documentation

◆ cmp_func

typedef int(* cmp_func) (const void *, const void *)

Definition at line 118 of file vf_palettegen.c.

Enumeration Type Documentation

◆ anonymous enum

anonymous enum

Enumerator
STATS_MODE_ALL_FRAMES
STATS_MODE_DIFF_FRAMES
STATS_MODE_SINGLE_FRAMES
NB_STATS_MODE

Definition at line 62 of file vf_palettegen.c.

◆ anonymous enum

anonymous enum

Enumerator
ID_XYZ
ID_XZY
ID_ZXY
ID_YXZ
ID_ZYX
ID_YZX

Definition at line 138 of file vf_palettegen.c.

Function Documentation

◆ AVFILTER_DEFINE_CLASS()

AVFILTER_DEFINE_CLASS ( palettegen )

◆ query_formats()

static int query_formats	(	const AVFilterContext *	ctx,
		AVFilterFormatsConfig **	cfg_in,
		AVFilterFormatsConfig **	cfg_out
	)

static

Definition at line 103 of file vf_palettegen.c.

◆ sort3id()

static int sort3id	(	int64_t	x,
		int64_t	y,
		int64_t	z
	)

static

Definition at line 154 of file vf_palettegen.c.

Referenced by compute_box_stats().

◆ cmp_color()

static int cmp_color	(	const void *	a,
		const void *	b
	)

static

Simple color comparison for sorting the final palette.

Definition at line 169 of file vf_palettegen.c.

Referenced by get_palette_frame().

◆ compute_box_stats()

static void compute_box_stats	(	PaletteGenContext *	s,
		struct range_box *	box
	)

static

Definition at line 176 of file vf_palettegen.c.

Referenced by get_palette_frame(), and split_box().

◆ get_next_box_id_to_split()

static int get_next_box_id_to_split ( PaletteGenContext * s )

static

Find the next box to split: pick the one with the highest cut score.

Definition at line 215 of file vf_palettegen.c.

Referenced by get_palette_frame().

◆ split_box()

static void split_box	(	PaletteGenContext *	s,
		struct range_box *	box,
		int	n
	)

static

Split given box in two at position n.

The original box becomes the left part of the split, and the new index box is the right part.

Definition at line 237 of file vf_palettegen.c.

Referenced by get_palette_frame().

◆ write_palette()

static void write_palette	(	AVFilterContext *	ctx,
		AVFrame *	out
	)

static

Write the palette into the output frame.

Definition at line 255 of file vf_palettegen.c.

Referenced by get_palette_frame().

◆ load_color_refs()

static struct color_ref** load_color_refs	(	const struct hist_node *	hist,
		int	nb_refs
	)

static

Crawl the histogram to get all the defined colors, and create a linear list of them (each color reference entry is a pointer to the value in the histogram/hash table).

Definition at line 288 of file vf_palettegen.c.

Referenced by get_palette_frame().

◆ set_colorquant_ratio_meta()

static double set_colorquant_ratio_meta	(	AVFrame *	out,
		int	nb_out,
		int	nb_in
	)

static

Definition at line 306 of file vf_palettegen.c.

Referenced by get_palette_frame().

◆ get_palette_frame()

static AVFrame* get_palette_frame ( AVFilterContext * ctx )

static

Main function implementing the Median Cut Algorithm defined by Paul Heckbert in Color Image Quantization for Frame Buffer Display (1982)

Definition at line 319 of file vf_palettegen.c.

Referenced by filter_frame(), and request_frame().

◆ color_inc()

static int color_inc	(	struct hist_node *	hist,
		uint32_t	color
	)

static

Locate the color in the hash table and increment its counter.

Definition at line 397 of file vf_palettegen.c.

Referenced by update_histogram_diff(), and update_histogram_frame().

◆ update_histogram_diff()

static int update_histogram_diff	(	struct hist_node *	hist,
		const AVFrame *	f1,
		const AVFrame *	f2
	)

static

Update histogram when pixels differ from previous frame.

Definition at line 424 of file vf_palettegen.c.

Referenced by filter_frame().

◆ update_histogram_frame()

static int update_histogram_frame	(	struct hist_node *	hist,
		const AVFrame *	f
	)

static

Simple histogram of the frame.

Definition at line 448 of file vf_palettegen.c.

Referenced by filter_frame().

◆ filter_frame()

static int filter_frame	(	AVFilterLink *	inlink,
		AVFrame *	in
	)

static

Update the histogram for each passing frame.

No frame will be pushed here.

Definition at line 468 of file vf_palettegen.c.

◆ request_frame()

static int request_frame ( AVFilterLink * outlink )

static

Returns only one frame at the end containing the full palette.

Definition at line 510 of file vf_palettegen.c.

◆ config_output()

static int config_output ( AVFilterLink * outlink )

static

The output is one simple 16x16 squared-pixels palette.

Definition at line 529 of file vf_palettegen.c.

◆ init()

static int init ( AVFilterContext * ctx )

static

Definition at line 536 of file vf_palettegen.c.

◆ uninit()

static av_cold void uninit ( AVFilterContext * ctx )

static

Definition at line 548 of file vf_palettegen.c.

Variable Documentation

◆ palettegen_options

const AVOption palettegen_options[]

static

Initial value:

= {
    { "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, .unit = "mode" },
        { "full", "compute full frame histograms", 0, AV_OPT_TYPE_CONST, {.i64=STATS_MODE_ALL_FRAMES}, INT_MIN, INT_MAX, FLAGS, .unit = "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, .unit = "mode" },
        { "single", "compute new histogram for each frame", 0, AV_OPT_TYPE_CONST, {.i64=STATS_MODE_SINGLE_FRAMES}, INT_MIN, INT_MAX, FLAGS, .unit = "mode" },
    { NULL }
}

Definition at line 90 of file vf_palettegen.c.

◆ sortstr

const char* const sortstr[] = { "Lab", "Lba", "bLa", "aLb", "baL", "abL" }

static

Definition at line 139 of file vf_palettegen.c.

Referenced by get_palette_frame().

◆ cmp_funcs

const cmp_func cmp_funcs[]

static

Initial value:

= {
    [ID_XYZ] = cmp_Lab,
    [ID_XZY] = cmp_Lba,
    [ID_ZXY] = cmp_bLa,
    [ID_YXZ] = cmp_aLb,
    [ID_ZYX] = cmp_baL,
    [ID_YZX] = cmp_abL,
}

Definition at line 141 of file vf_palettegen.c.

Referenced by get_palette_frame().

◆ palettegen_inputs

const AVFilterPad palettegen_inputs[]

static

Initial value:

= {
    {
        .name         = "default",
        .type         = AVMEDIA_TYPE_VIDEO,
        .filter_frame = filter_frame,
    },
}

Definition at line 559 of file vf_palettegen.c.

◆ palettegen_outputs

const AVFilterPad palettegen_outputs[]

static

Initial value:

= {
    {
        .name          = "default",
        .type          = AVMEDIA_TYPE_VIDEO,
        .config_props  = config_output,
        .request_frame = request_frame,
    },
}

Definition at line 567 of file vf_palettegen.c.

◆ ff_vf_palettegen

const AVFilter ff_vf_palettegen

Initial value:

= {
    .name          = "palettegen",
    .description   = NULL_IF_CONFIG_SMALL("Find the optimal palette for a given stream."),
    .priv_size     = sizeof(PaletteGenContext),
    .init          = init,
    .uninit        = uninit,
    FILTER_INPUTS(palettegen_inputs),
    FILTER_OUTPUTS(palettegen_outputs),
    FILTER_QUERY_FUNC2(query_formats),
    .priv_class    = &palettegen_class,
}

Definition at line 576 of file vf_palettegen.c.

Data Structures

Macros

Typedefs

Enumerations

Functions

Variables

Detailed Description

Macro Definition Documentation

◆ HIST_SIZE

◆ OFFSET

◆ FLAGS

◆ DECLARE_CMP_FUNC

Typedef Documentation

◆ cmp_func

Enumeration Type Documentation

◆ anonymous enum

◆ anonymous enum

Function Documentation

◆ AVFILTER_DEFINE_CLASS()

◆ query_formats()

◆ sort3id()

◆ cmp_color()

◆ compute_box_stats()

◆ get_next_box_id_to_split()

◆ split_box()

◆ write_palette()

◆ load_color_refs()

◆ set_colorquant_ratio_meta()

◆ get_palette_frame()

◆ color_inc()

◆ update_histogram_diff()

◆ update_histogram_frame()

◆ filter_frame()

◆ request_frame()

◆ config_output()

◆ init()

◆ uninit()

Variable Documentation

◆ palettegen_options

◆ sortstr

◆ cmp_funcs

◆ palettegen_inputs

◆ palettegen_outputs

◆ ff_vf_palettegen