/*
* Copyright (c) 2015 Stupeflix
*
* This file is part of FFmpeg.
*
* FFmpeg is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation; either
* version 2.1 of the License, or (at your option) any later version.
*
* FFmpeg is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with FFmpeg; if not, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
*/
/**
* @file
* Use a palette to downsample an input video stream.
*/
#include "libavutil/bprint.h"
#include "libavutil/internal.h"
#include "libavutil/opt.h"
#include "libavutil/qsort.h"
#include "avfilter.h"
#include "filters.h"
#include "framesync.h"
#include "internal.h"
enum dithering_mode {
DITHERING_NONE,
DITHERING_BAYER,
DITHERING_HECKBERT,
DITHERING_FLOYD_STEINBERG,
DITHERING_SIERRA2,
DITHERING_SIERRA2_4A,
NB_DITHERING
};
enum color_search_method {
COLOR_SEARCH_NNS_ITERATIVE,
COLOR_SEARCH_NNS_RECURSIVE,
COLOR_SEARCH_BRUTEFORCE,
NB_COLOR_SEARCHES
};
enum diff_mode {
DIFF_MODE_NONE,
DIFF_MODE_RECTANGLE,
NB_DIFF_MODE
};
struct color_node {
uint8_t val[4];
uint8_t palette_id;
int split;
int left_id, right_id;
};
#define NBITS 5
#define CACHE_SIZE (1<<(3*NBITS))
struct cached_color {
uint32_t color;
uint8_t pal_entry;
};
struct cache_node {
struct cached_color *entries;
int nb_entries;
};
struct PaletteUseContext;
typedef int (*set_frame_func)(struct PaletteUseContext *s, AVFrame *out, AVFrame *in,
int x_start, int y_start, int width, int height);
typedef struct PaletteUseContext {
const AVClass *class;
FFFrameSync fs;
struct cache_node cache[CACHE_SIZE]; /* lookup cache */
struct color_node map[AVPALETTE_COUNT]; /* 3D-Tree (KD-Tree with K=3) for reverse colormap */
uint32_t palette[AVPALETTE_COUNT];
int transparency_index; /* index in the palette of transparency. -1 if there is no transparency in the palette. */
int trans_thresh;
int palette_loaded;
int dither;
int new;
set_frame_func set_frame;
int bayer_scale;
int ordered_dither[8*8];
int diff_mode;
AVFrame *last_in;
AVFrame *last_out;
/* debug options */
char *dot_filename;
int color_search_method;
int calc_mean_err;
uint64_t total_mean_err;
int debug_accuracy;
} PaletteUseContext;
#define OFFSET(x) offsetof(PaletteUseContext, x)
#define FLAGS AV_OPT_FLAG_FILTERING_PARAM|AV_OPT_FLAG_VIDEO_PARAM
static const AVOption paletteuse_options[] = {
{ "dither", "select dithering mode", OFFSET(dither), AV_OPT_TYPE_INT, {.i64=DITHERING_SIERRA2_4A}, 0, NB_DITHERING-1, FLAGS, "dithering_mode" },
{ "bayer", "ordered 8x8 bayer dithering (deterministic)", 0, AV_OPT_TYPE_CONST, {.i64=DITHERING_BAYER}, INT_MIN, INT_MAX, FLAGS, "dithering_mode" },
{ "heckbert", "dithering as defined by Paul Heckbert in 1982 (simple error diffusion)", 0, AV_OPT_TYPE_CONST, {.i64=DITHERING_HECKBERT}, INT_MIN, INT_MAX, FLAGS, "dithering_mode" },
{ "floyd_steinberg", "Floyd and Steingberg dithering (error diffusion)", 0, AV_OPT_TYPE_CONST, {.i64=DITHERING_FLOYD_STEINBERG}, INT_MIN, INT_MAX, FLAGS, "dithering_mode" },
{ "sierra2", "Frankie Sierra dithering v2 (error diffusion)", 0, AV_OPT_TYPE_CONST, {.i64=DITHERING_SIERRA2}, INT_MIN, INT_MAX, FLAGS, "dithering_mode" },
{ "sierra2_4a", "Frankie Sierra dithering v2 \"Lite\" (error diffusion)", 0, AV_OPT_TYPE_CONST, {.i64=DITHERING_SIERRA2_4A}, INT_MIN, INT_MAX, FLAGS, "dithering_mode" },
{ "bayer_scale", "set scale for bayer dithering", OFFSET(bayer_scale), AV_OPT_TYPE_INT, {.i64=2}, 0, 5, FLAGS },
{ "diff_mode", "set frame difference mode", OFFSET(diff_mode), AV_OPT_TYPE_INT, {.i64=DIFF_MODE_NONE}, 0, NB_DIFF_MODE-1, FLAGS, "diff_mode" },
{ "rectangle", "process smallest different rectangle", 0, AV_OPT_TYPE_CONST, {.i64=DIFF_MODE_RECTANGLE}, INT_MIN, INT_MAX, FLAGS, "diff_mode" },
{ "new", "take new palette for each output frame", OFFSET(new), AV_OPT_TYPE_BOOL, {.i64=0}, 0, 1, FLAGS },
{ "alpha_threshold", "set the alpha threshold for transparency", OFFSET(trans_thresh), AV_OPT_TYPE_INT, {.i64=128}, 0, 255 },
/* following are the debug options, not part of the official API */
{ "debug_kdtree", "save Graphviz graph of the kdtree in specified file", OFFSET(dot_filename), AV_OPT_TYPE_STRING, {.str=NULL}, CHAR_MIN, CHAR_MAX, FLAGS },
{ "color_search", "set reverse colormap color search method", OFFSET(color_search_method), AV_OPT_TYPE_INT, {.i64=COLOR_SEARCH_NNS_ITERATIVE}, 0, NB_COLOR_SEARCHES-1, FLAGS, "search" },
{ "nns_iterative", "iterative search", 0, AV_OPT_TYPE_CONST, {.i64=COLOR_SEARCH_NNS_ITERATIVE}, INT_MIN, INT_MAX, FLAGS, "search" },
{ "nns_recursive", "recursive search", 0, AV_OPT_TYPE_CONST, {.i64=COLOR_SEARCH_NNS_RECURSIVE}, INT_MIN, INT_MAX, FLAGS, "search" },
{ "bruteforce", "brute-force into the palette", 0, AV_OPT_TYPE_CONST, {.i64=COLOR_SEARCH_BRUTEFORCE}, INT_MIN, INT_MAX, FLAGS, "search" },
{ "mean_err", "compute and print mean error", OFFSET(calc_mean_err), AV_OPT_TYPE_BOOL, {.i64=0}, 0, 1, FLAGS },
{ "debug_accuracy", "test color search accuracy", OFFSET(debug_accuracy), AV_OPT_TYPE_BOOL, {.i64=0}, 0, 1, FLAGS },
{ NULL }
};
AVFILTER_DEFINE_CLASS(paletteuse);
static int load_apply_palette(FFFrameSync *fs);
static int query_formats(AVFilterContext *ctx)
{
static const enum AVPixelFormat in_fmts[] = {AV_PIX_FMT_RGB32, AV_PIX_FMT_NONE};
static const enum AVPixelFormat inpal_fmts[] = {AV_PIX_FMT_RGB32, AV_PIX_FMT_NONE};
static const enum AVPixelFormat out_fmts[] = {AV_PIX_FMT_PAL8, AV_PIX_FMT_NONE};
int ret;
AVFilterFormats *in = ff_make_format_list(in_fmts);
AVFilterFormats *inpal = ff_make_format_list(inpal_fmts);
AVFilterFormats *out = ff_make_format_list(out_fmts);
if (!in || !inpal || !out) {
av_freep(&in);
av_freep(&inpal);
av_freep(&out);
return AVERROR(ENOMEM);
}
if ((ret = ff_formats_ref(in , &ctx->inputs[0]->out_formats)) < 0 ||
(ret = ff_formats_ref(inpal, &ctx->inputs[1]->out_formats)) < 0 ||
(ret = ff_formats_ref(out , &ctx->outputs[0]->in_formats)) < 0)
return ret;
return 0;
}
static av_always_inline int dither_color(uint32_t px, int er, int eg, int eb, int scale, int shift)
{
return av_clip_uint8( px >> 24 ) << 24
| av_clip_uint8((px >> 16 & 0xff) + ((er * scale) / (1<<shift))) << 16
| av_clip_uint8((px >> 8 & 0xff) + ((eg * scale) / (1<<shift))) << 8
| av_clip_uint8((px & 0xff) + ((eb * scale) / (1<<shift)));
}
static av_always_inline int diff(const uint8_t *c1, const uint8_t *c2, const int trans_thresh)
{
// XXX: try L*a*b with CIE76 (dL*dL + da*da + db*db)
const int dr = c1[1] - c2[1];
const int dg = c1[2] - c2[2];
const int db = c1[3] - c2[3];
if (c1[0] < trans_thresh && c2[0] < trans_thresh) {
return 0;
} else if (c1[0] >= trans_thresh && c2[0] >= trans_thresh) {
return dr*dr + dg*dg + db*db;
} else {
return 255*255 + 255*255 + 255*255;
}
}
static av_always_inline uint8_t colormap_nearest_bruteforce(const uint32_t *palette, const uint8_t *argb, const int trans_thresh)
{
int i, pal_id = -1, min_dist = INT_MAX;
for (i = 0; i < AVPALETTE_COUNT; i++) {
const uint32_t c = palette[i];
if (c >> 24 >= trans_thresh) { // ignore transparent entry
const uint8_t palargb[] = {
palette[i]>>24 & 0xff,
palette[i]>>16 & 0xff,
palette[i]>> 8 & 0xff,
palette[i] & 0xff,
};
const int d = diff(palargb, argb, trans_thresh);
if (d < min_dist) {
pal_id = i;
min_dist = d;
}
}
}
return pal_id;
}
/* Recursive form, simpler but a bit slower. Kept for reference. */
struct nearest_color {
int node_pos;
int dist_sqd;
};
static void colormap_nearest_node(const struct color_node *map,
const int node_pos,
const uint8_t *target,
const int trans_thresh,
struct nearest_color *nearest)
{
const struct color_node *kd = map + node_pos;
const int s = kd->split;
int dx, nearer_kd_id, further_kd_id;
const uint8_t *current = kd->val;
const int current_to_target = diff(target, current, trans_thresh);
if (current_to_target < nearest->dist_sqd) {
nearest->node_pos = node_pos;
nearest->dist_sqd = current_to_target;
}
if (kd->left_id != -1 || kd->right_id != -1) {
dx = target[s] - current[s];
if (dx <= 0) nearer_kd_id = kd->left_id, further_kd_id = kd->right_id;
else nearer_kd_id = kd->right_id, further_kd_id = kd->left_id;
if (nearer_kd_id != -1)
colormap_nearest_node(map, nearer_kd_id, target, trans_thresh, nearest);
if (further_kd_id != -1 && dx*dx < nearest->dist_sqd)
colormap_nearest_node(map, further_kd_id, target, trans_thresh, nearest);
}
}
static av_always_inline uint8_t colormap_nearest_recursive(const struct color_node *node, const uint8_t *rgb, const int trans_thresh)
{
struct nearest_color res = {.dist_sqd = INT_MAX, .node_pos = -1};
colormap_nearest_node(node, 0, rgb, trans_thresh, &res);
return node[res.node_pos].palette_id;
}
struct stack_node {
int color_id;
int dx2;
};
static av_always_inline uint8_t colormap_nearest_iterative(const struct color_node *root, const uint8_t *target, const int trans_thresh)
{
int pos = 0, best_node_id = -1, best_dist = INT_MAX, cur_color_id = 0;
struct stack_node nodes[16];
struct stack_node *node = &nodes[0];
for (;;) {
const struct color_node *kd = &root[cur_color_id];
const uint8_t *current = kd->val;
const int current_to_target = diff(target, current, trans_thresh);
/* Compare current color node to the target and update our best node if
* it's actually better. */
if (current_to_target < best_dist) {
best_node_id = cur_color_id;
if (!current_to_target)
goto end; // exact match, we can return immediately
best_dist = current_to_target;
}
/* Check if it's not a leaf */
if (kd->left_id != -1 || kd->right_id != -1) {
const int split = kd->split;
const int dx = target[split] - current[split];
int nearer_kd_id, further_kd_id;
/* Define which side is the most interesting. */
if (dx <= 0) nearer_kd_id = kd->left_id, further_kd_id = kd->right_id;
else nearer_kd_id = kd->right_id, further_kd_id = kd->left_id;
if (nearer_kd_id != -1) {
if (further_kd_id != -1) {
/* Here, both paths are defined, so we push a state for
* when we are going back. */
node->color_id = further_kd_id;
node->dx2 = dx*dx;
pos++;
node++;
}
/* We can now update current color with the most probable path
* (no need to create a state since there is nothing to save
* anymore). */
cur_color_id = nearer_kd_id;
continue;
} else if (dx*dx < best_dist) {
/* The nearest path isn't available, so there is only one path
* possible and it's the least probable. We enter it only if the
* distance from the current point to the hyper rectangle is
* less than our best distance. */
cur_color_id = further_kd_id;
continue;
}
}
/* Unstack as much as we can, typically as long as the least probable
* branch aren't actually probable. */
do {
if (--pos < 0)
goto end;
node--;
} while (node->dx2 >= best_dist);
/* We got a node where the least probable branch might actually contain
* a relevant color. */
cur_color_id = node->color_id;
}
end:
return root[best_node_id].palette_id;
}
#define COLORMAP_NEAREST(search, palette, root, target, trans_thresh) \
search == COLOR_SEARCH_NNS_ITERATIVE ? colormap_nearest_iterative(root, target, trans_thresh) : \
search == COLOR_SEARCH_NNS_RECURSIVE ? colormap_nearest_recursive(root, target, trans_thresh) : \
colormap_nearest_bruteforce(palette, target, trans_thresh)
/**
* Check if the requested color is in the cache already. If not, find it in the
* color tree and cache it.
* Note: a, r, g, and b are the components of color, but are passed as well to avoid
* recomputing them (they are generally computed by the caller for other uses).
*/
static av_always_inline int color_get(PaletteUseContext *s, uint32_t color,
uint8_t a, uint8_t r, uint8_t g, uint8_t b,
const enum color_search_method search_method)
{
int i;
const uint8_t argb_elts[] = {a, r, g, b};
const uint8_t rhash = r & ((1<<NBITS)-1);
const uint8_t ghash = g & ((1<<NBITS)-1);
const uint8_t bhash = b & ((1<<NBITS)-1);
const unsigned hash = rhash<<(NBITS*2) | ghash<<NBITS | bhash;
struct cache_node *node = &s->cache[hash];
struct cached_color *e;
// first, check for transparency
if (a < s->trans_thresh && s->transparency_index >= 0) {
return s->transparency_index;
}
for (i = 0; i < node->nb_entries; i++) {
e = &node->entries[i];
if (e->color == color)
return e->pal_entry;
}
e = av_dynarray2_add((void**)&node->entries, &node->nb_entries,
sizeof(*node->entries), NULL);
if (!e)
return AVERROR(ENOMEM);
e->color = color;
e->pal_entry = COLORMAP_NEAREST(search_method, s->palette, s->map, argb_elts, s->trans_thresh);
return e->pal_entry;
}
static av_always_inline int get_dst_color_err(PaletteUseContext *s,
uint32_t c, int *er, int *eg, int *eb,
const enum color_search_method search_method)
{
const uint8_t a = c >> 24 & 0xff;
const uint8_t r = c >> 16 & 0xff;
const uint8_t g = c >> 8 & 0xff;
const uint8_t b = c & 0xff;
uint32_t dstc;
const int dstx = color_get(s, c, a, r, g, b, search_method);
if (dstx < 0)
return dstx;
dstc = s->palette[dstx];
*er = r - (dstc >> 16 & 0xff);
*eg = g - (dstc >> 8 & 0xff);
*eb = b - (dstc & 0xff);
return dstx;
}
static av_always_inline int set_frame(PaletteUseContext *s, AVFrame *out, AVFrame *in,
int x_start, int y_start, int w, int h,
enum dithering_mode dither,
const enum color_search_method search_method)
{
int x, y;
const int src_linesize = in ->linesize[0] >> 2;
const int dst_linesize = out->linesize[0];
uint32_t *src = ((uint32_t *)in ->data[0]) + y_start*src_linesize;
uint8_t *dst = out->data[0] + y_start*dst_linesize;
w += x_start;
h += y_start;
for (y = y_start; y < h; y++) {
for (x = x_start; x < w; x++) {
int er, eg, eb;
if (dither == DITHERING_BAYER) {
const int d = s->ordered_dither[(y & 7)<<3 | (x & 7)];
const uint8_t a8 = src[x] >> 24 & 0xff;
const uint8_t r8 = src[x] >> 16 & 0xff;
const uint8_t g8 = src[x] >> 8 & 0xff;
const uint8_t b8 = src[x] & 0xff;
const uint8_t r = av_clip_uint8(r8 + d);
const uint8_t g = av_clip_uint8(g8 + d);
const uint8_t b = av_clip_uint8(b8 + d);
const int color = color_get(s, src[x], a8, r, g, b, search_method);
if (color < 0)
return color;
dst[x] = color;
} else if (dither == DITHERING_HECKBERT) {
const int right = x < w - 1, down = y < h - 1;
const int color = get_dst_color_err(s, src[x], &er, &eg, &eb, search_method);
if (color < 0)
return color;
dst[x] = color;
if (right) src[ x + 1] = dither_color(src[ x + 1], er, eg, eb, 3, 3);
if ( down) src[src_linesize + x ] = dither_color(src[src_linesize + x ], er, eg, eb, 3, 3);
if (right && down) src[src_linesize + x + 1] = dither_color(src[src_linesize + x + 1], er, eg, eb, 2, 3);
} else if (dither == DITHERING_FLOYD_STEINBERG) {
const int right = x < w - 1, down = y < h - 1, left = x > x_start;
const int color = get_dst_color_err(s, src[x], &er, &eg, &eb, search_method);
if (color < 0)
return color;
dst[x] = color;
if (right) src[ x + 1] = dither_color(src[ x + 1], er, eg, eb, 7, 4);
if (left && down) src[src_linesize + x - 1] = dither_color(src[src_linesize + x - 1], er, eg, eb, 3, 4);
if ( down) src[src_linesize + x ] = dither_color(src[src_linesize + x ], er, eg, eb, 5, 4);
if (right && down) src[src_linesize + x + 1] = dither_color(src[src_linesize + x + 1], er, eg, eb, 1, 4);
} else if (dither == DITHERING_SIERRA2) {
const int right = x < w - 1, down = y < h - 1, left = x > x_start;
const int right2 = x < w - 2, left2 = x > x_start + 1;
const int color = get_dst_color_err(s, src[x], &er, &eg, &eb, search_method);
if (color < 0)
return color;
dst[x] = color;
if (right) src[ x + 1] = dither_color(src[ x + 1], er, eg, eb, 4, 4);
if (right2) src[ x + 2] = dither_color(src[ x + 2], er, eg, eb, 3, 4);
if (down) {
if (left2) src[ src_linesize + x - 2] = dither_color(src[ src_linesize + x - 2], er, eg, eb, 1, 4);
if (left) src[ src_linesize + x - 1] = dither_color(src[ src_linesize + x - 1], er, eg, eb, 2, 4);
if (1) src[ src_linesize + x ] = dither_color(src[ src_linesize + x ], er, eg, eb, 3, 4);
if (right) src[ src_linesize + x + 1] = dither_color(src[ src_linesize + x + 1], er, eg, eb, 2, 4);
if (right2) src[ src_linesize + x + 2] = dither_color(src[ src_linesize + x + 2], er, eg, eb, 1, 4);
}
} else if (dither == DITHERING_SIERRA2_4A) {
const int right = x < w - 1, down = y < h - 1, left = x > x_start;
const int color = get_dst_color_err(s, src[x], &er, &eg, &eb, search_method);
if (color < 0)
return color;
dst[x] = color;
if (right) src[ x + 1] = dither_color(src[ x + 1], er, eg, eb, 2, 2);
if (left && down) src[src_linesize + x - 1] = dither_color(src[src_linesize + x - 1], er, eg, eb, 1, 2);
if ( down) src[src_linesize + x ] = dither_color(src[src_linesize + x ], er, eg, eb, 1, 2);
} else {
const uint8_t a = src[x] >> 24 & 0xff;
const uint8_t r = src[x] >> 16 & 0xff;
const uint8_t g = src[x] >> 8 & 0xff;
const uint8_t b = src[x] & 0xff;
const int color = color_get(s, src[x], a, r, g, b, search_method);
if (color < 0)
return color;
dst[x] = color;
}
}
src += src_linesize;
dst += dst_linesize;
}
return 0;
}
#define INDENT 4
static void disp_node(AVBPrint *buf,
const struct color_node *map,
int parent_id, int node_id,
int depth)
{
const struct color_node *node = &map[node_id];
const uint32_t fontcolor = node->val[1] > 0x50 &&
node->val[2] > 0x50 &&
node->val[3] > 0x50 ? 0 : 0xffffff;
const int rgb_comp = node->split - 1;
av_bprintf(buf, "%*cnode%d ["
"label=\"%c%02X%c%02X%c%02X%c\" "
"fillcolor=\"#%02x%02x%02x\" "
"fontcolor=\"#%06"PRIX32"\"]\n",
depth*INDENT, ' ', node->palette_id,
"[ "[rgb_comp], node->val[1],
"][ "[rgb_comp], node->val[2],
" ]["[rgb_comp], node->val[3],
" ]"[rgb_comp],
node->val[1], node->val[2], node->val[3],
fontcolor);
if (parent_id != -1)
av_bprintf(buf, "%*cnode%d -> node%d\n", depth*INDENT, ' ',
map[parent_id].palette_id, node->palette_id);
if (node->left_id != -1) disp_node(buf, map, node_id, node->left_id, depth + 1);
if (node->right_id != -1) disp_node(buf, map, node_id, node->right_id, depth + 1);
}
// debug_kdtree=kdtree.dot -> dot -Tpng kdtree.dot > kdtree.png
static int disp_tree(const struct color_node *node, const char *fname)
{
AVBPrint buf;
FILE *f = av_fopen_utf8(fname, "w");
if (!f) {
int ret = AVERROR(errno);
av_log(NULL, AV_LOG_ERROR, "Cannot open file '%s' for writing: %s\n",
fname, av_err2str(ret));
return ret;
}
av_bprint_init(&buf, 0, AV_BPRINT_SIZE_UNLIMITED);
av_bprintf(&buf, "digraph {\n");
av_bprintf(&buf, " node [style=filled fontsize=10 shape=box]\n");
disp_node(&buf, node, -1, 0, 0);
av_bprintf(&buf, "}\n");
fwrite(buf.str, 1, buf.len, f);
fclose(f);
av_bprint_finalize(&buf, NULL);
return 0;
}
static int debug_accuracy(const struct color_node *node, const uint32_t *palette, const int trans_thresh,
const enum color_search_method search_method)
{
int r, g, b, ret = 0;
for (r = 0; r < 256; r++) {
for (g = 0; g < 256; g++) {
for (b = 0; b < 256; b++) {
const uint8_t argb[] = {0xff, r, g, b};
const int r1 = COLORMAP_NEAREST(search_method, palette, node, argb, trans_thresh);
const int r2 = colormap_nearest_bruteforce(palette, argb, trans_thresh);
if (r1 != r2) {
const uint32_t c1 = palette[r1];
const uint32_t c2 = palette[r2];
const uint8_t palargb1[] = { 0xff, c1>>16 & 0xff, c1>> 8 & 0xff, c1 & 0xff };
const uint8_t palargb2[] = { 0xff, c2>>16 & 0xff, c2>> 8 & 0xff, c2 & 0xff };
const int d1 = diff(palargb1, argb, trans_thresh);
const int d2 = diff(palargb2, argb, trans_thresh);
if (d1 != d2) {
av_log(NULL, AV_LOG_ERROR,
"/!\\ %02X%02X%02X: %d ! %d (%06"PRIX32" ! %06"PRIX32") / dist: %d ! %d\n",
r, g, b, r1, r2, c1 & 0xffffff, c2 & 0xffffff, d1, d2);
ret = 1;
}
}
}
}
}
return ret;
}
struct color {
uint32_t value;
uint8_t pal_id;
};
struct color_rect {
uint8_t min[3];
uint8_t max[3];
};
typedef int (*cmp_func)(const void *, const void *);
#define DECLARE_CMP_FUNC(name, pos) \
static int cmp_##name(const void *pa, const void *pb) \
{ \
const struct color *a = pa; \
const struct color *b = pb; \
return (a->value >> (8 * (3 - (pos))) & 0xff) \
- (b->value >> (8 * (3 - (pos))) & 0xff); \
}
DECLARE_CMP_FUNC(a, 0)
DECLARE_CMP_FUNC(r, 1)
DECLARE_CMP_FUNC(g, 2)
DECLARE_CMP_FUNC(b, 3)
static const cmp_func cmp_funcs[] = {cmp_a, cmp_r, cmp_g, cmp_b};
static int get_next_color(const uint8_t *color_used, const uint32_t *palette,
const int trans_thresh,
int *component, const struct color_rect *box)
{
int wr, wg, wb;
int i, longest = 0;
unsigned nb_color = 0;
struct color_rect ranges;
struct color tmp_pal[256];
cmp_func cmpf;
ranges.min[0] = ranges.min[1] = ranges.min[2] = 0xff;
ranges.max[0] = ranges.max[1] = ranges.max[2] = 0x00;
for (i = 0; i < AVPALETTE_COUNT; i++) {
const uint32_t c = palette[i];
const uint8_t a = c >> 24 & 0xff;
const uint8_t r = c >> 16 & 0xff;
const uint8_t g = c >> 8 & 0xff;
const uint8_t b = c & 0xff;
if (a < trans_thresh) {
continue;
}
if (color_used[i] || (a != 0xff) ||
r < box->min[0] || g < box->min[1] || b < box->min[2] ||
r > box->max[0] || g > box->max[1] || b > box->max[2])
continue;
if (r < ranges.min[0]) ranges.min[0] = r;
if (g < ranges.min[1]) ranges.min[1] = g;
if (b < ranges.min[2]) ranges.min[2] = b;
if (r > ranges.max[0]) ranges.max[0] = r;
if (g > ranges.max[1]) ranges.max[1] = g;
if (b > ranges.max[2]) ranges.max[2] = b;
tmp_pal[nb_color].value = c;
tmp_pal[nb_color].pal_id = i;
nb_color++;
}
if (!nb_color)
return -1;
/* define longest axis that will be the split component */
wr = ranges.max[0] - ranges.min[0];
wg = ranges.max[1] - ranges.min[1];
wb = ranges.max[2] - ranges.min[2];
if (wr >= wg && wr >= wb) longest = 1;
if (wg >= wr && wg >= wb) longest = 2;
if (wb >= wr && wb >= wg) longest = 3;
cmpf = cmp_funcs[longest];
*component = longest;
/* sort along this axis to get median */
AV_QSORT(tmp_pal, nb_color, struct color, cmpf);
return tmp_pal[nb_color >> 1].pal_id;
}
static int colormap_insert(struct color_node *map,
uint8_t *color_used,
int *nb_used,
const uint32_t *palette,
const int trans_thresh,
const struct color_rect *box)
{
uint32_t c;
int component, cur_id;
int node_left_id = -1, node_right_id = -1;
struct color_node *node;
struct color_rect box1, box2;
const int pal_id = get_next_color(color_used, palette, trans_thresh, &component, box);
if (pal_id < 0)
return -1;
/* create new node with that color */
cur_id = (*nb_used)++;
c = palette[pal_id];
node = &map[cur_id];
node->split = component;
node->palette_id = pal_id;
node->val[0] = c>>24 & 0xff;
node->val[1] = c>>16 & 0xff;
node->val[2] = c>> 8 & 0xff;
node->val[3] = c & 0xff;
color_used[pal_id] = 1;
/* get the two boxes this node creates */
box1 = box2 = *box;
box1.max[component-1] = node->val[component];
box2.min[component-1] = node->val[component] + 1;
node_left_id = colormap_insert(map, color_used, nb_used, palette, trans_thresh, &box1);
if (box2.min[component-1] <= box2.max[component-1])
node_right_id = colormap_insert(map, color_used, nb_used, palette, trans_thresh, &box2);
node->left_id = node_left_id;
node->right_id = node_right_id;
return cur_id;
}
static int cmp_pal_entry(const void *a, const void *b)
{
const int c1 = *(const uint32_t *)a & 0xffffff;
const int c2 = *(const uint32_t *)b & 0xffffff;
return c1 - c2;
}
static void load_colormap(PaletteUseContext *s)
{
int i, nb_used = 0;
uint8_t color_used[AVPALETTE_COUNT] = {0};
uint32_t last_color = 0;
struct color_rect box;
/* disable transparent colors and dups */
qsort(s->palette, AVPALETTE_COUNT, sizeof(*s->palette), cmp_pal_entry);
// update transparency index:
if (s->transparency_index >= 0) {
for (i = 0; i < AVPALETTE_COUNT; i++) {
if ((s->palette[i]>>24 & 0xff) == 0) {
s->transparency_index = i; // we are assuming at most one transparent color in palette
break;
}
}
}
for (i = 0; i < AVPALETTE_COUNT; i++) {
const uint32_t c = s->palette[i];
if (i != 0 && c == last_color) {
color_used[i] = 1;
continue;
}
last_color = c;
if (c >> 24 < s->trans_thresh) {
color_used[i] = 1; // ignore transparent color(s)
continue;
}
}
box.min[0] = box.min[1] = box.min[2] = 0x00;
box.max[0] = box.max[1] = box.max[2] = 0xff;
colormap_insert(s->map, color_used, &nb_used, s->palette, s->trans_thresh, &box);
if (s->dot_filename)
disp_tree(s->map, s->dot_filename);
if (s->debug_accuracy) {
if (!debug_accuracy(s->map, s->palette, s->trans_thresh, s->color_search_method))
av_log(NULL, AV_LOG_INFO, "Accuracy check passed\n");
}
}
static void debug_mean_error(PaletteUseContext *s, const AVFrame *in1,
const AVFrame *in2, int frame_count)
{
int x, y;
const uint32_t *palette = s->palette;
uint32_t *src1 = (uint32_t *)in1->data[0];
uint8_t *src2 = in2->data[0];
const int src1_linesize = in1->linesize[0] >> 2;
const int src2_linesize = in2->linesize[0];
const float div = in1->width * in1->height * 3;
unsigned mean_err = 0;
for (y = 0; y < in1->height; y++) {
for (x = 0; x < in1->width; x++) {
const uint32_t c1 = src1[x];
const uint32_t c2 = palette[src2[x]];
const uint8_t argb1[] = {0xff, c1 >> 16 & 0xff, c1 >> 8 & 0xff, c1 & 0xff};
const uint8_t argb2[] = {0xff, c2 >> 16 & 0xff, c2 >> 8 & 0xff, c2 & 0xff};
mean_err += diff(argb1, argb2, s->trans_thresh);
}
src1 += src1_linesize;
src2 += src2_linesize;
}
s->total_mean_err += mean_err;
av_log(NULL, AV_LOG_INFO, "MEP:%.3f TotalMEP:%.3f\n",
mean_err / div, s->total_mean_err / (div * frame_count));
}
static void set_processing_window(enum diff_mode diff_mode,
const AVFrame *prv_src, const AVFrame *cur_src,
const AVFrame *prv_dst, AVFrame *cur_dst,
int *xp, int *yp, int *wp, int *hp)
{
int x_start = 0, y_start = 0;
int width = cur_src->width;
int height = cur_src->height;
if (prv_src && diff_mode == DIFF_MODE_RECTANGLE) {
int y;
int x_end = cur_src->width - 1,
y_end = cur_src->height - 1;
const uint32_t *prv_srcp = (const uint32_t *)prv_src->data[0];
const uint32_t *cur_srcp = (const uint32_t *)cur_src->data[0];
const uint8_t *prv_dstp = prv_dst->data[0];
uint8_t *cur_dstp = cur_dst->data[0];
const int prv_src_linesize = prv_src->linesize[0] >> 2;
const int cur_src_linesize = cur_src->linesize[0] >> 2;
const int prv_dst_linesize = prv_dst->linesize[0];
const int cur_dst_linesize = cur_dst->linesize[0];
/* skip common lines */
while (y_start < y_end && !memcmp(prv_srcp + y_start*prv_src_linesize,
cur_srcp + y_start*cur_src_linesize,
cur_src->width * 4)) {
memcpy(cur_dstp + y_start*cur_dst_linesize,
prv_dstp + y_start*prv_dst_linesize,
cur_dst->width);
y_start++;
}
while (y_end > y_start && !memcmp(prv_srcp + y_end*prv_src_linesize,
cur_srcp + y_end*cur_src_linesize,
cur_src->width * 4)) {
memcpy(cur_dstp + y_end*cur_dst_linesize,
prv_dstp + y_end*prv_dst_linesize,
cur_dst->width);
y_end--;
}
height = y_end + 1 - y_start;
/* skip common columns */
while (x_start < x_end) {
int same_column = 1;
for (y = y_start; y <= y_end; y++) {
if (prv_srcp[y*prv_src_linesize + x_start] != cur_srcp[y*cur_src_linesize + x_start]) {
same_column = 0;
break;
}
}
if (!same_column)
break;
x_start++;
}
while (x_end > x_start) {
int same_column = 1;
for (y = y_start; y <= y_end; y++) {
if (prv_srcp[y*prv_src_linesize + x_end] != cur_srcp[y*cur_src_linesize + x_end]) {
same_column = 0;
break;
}
}
if (!same_column)
break;
x_end--;
}
width = x_end + 1 - x_start;
if (x_start) {
for (y = y_start; y <= y_end; y++)
memcpy(cur_dstp + y*cur_dst_linesize,
prv_dstp + y*prv_dst_linesize, x_start);
}
if (x_end != cur_src->width - 1) {
const int copy_len = cur_src->width - 1 - x_end;
for (y = y_start; y <= y_end; y++)
memcpy(cur_dstp + y*cur_dst_linesize + x_end + 1,
prv_dstp + y*prv_dst_linesize + x_end + 1,
copy_len);
}
}
*xp = x_start;
*yp = y_start;
*wp = width;
*hp = height;
}
static AVFrame *apply_palette(AVFilterLink *inlink, AVFrame *in)
{
int x, y, w, h;
AVFilterContext *ctx = inlink->dst;
PaletteUseContext *s = ctx->priv;
AVFilterLink *outlink = inlink->dst->outputs[0];
AVFrame *out = ff_get_video_buffer(outlink, outlink->w, outlink->h);
if (!out) {
av_frame_free(&in);
return NULL;
}
av_frame_copy_props(out, in);
set_processing_window(s->diff_mode, s->last_in, in,
s->last_out, out, &x, &y, &w, &h);
av_frame_free(&s->last_in);
av_frame_free(&s->last_out);
s->last_in = av_frame_clone(in);
s->last_out = av_frame_clone(out);
if (!s->last_in || !s->last_out ||
av_frame_make_writable(s->last_in) < 0) {
av_frame_free(&in);
av_frame_free(&out);
return NULL;
}
ff_dlog(ctx, "%dx%d rect: (%d;%d) -> (%d,%d) [area:%dx%d]\n",
w, h, x, y, x+w, y+h, in->width, in->height);
if (s->set_frame(s, out, in, x, y, w, h) < 0) {
av_frame_free(&out);
return NULL;
}
memcpy(out->data[1], s->palette, AVPALETTE_SIZE);
if (s->calc_mean_err)
debug_mean_error(s, in, out, inlink->frame_count_out);
av_frame_free(&in);
return out;
}
static int config_output(AVFilterLink *outlink)
{
int ret;
AVFilterContext *ctx = outlink->src;
PaletteUseContext *s = ctx->priv;
ret = ff_framesync_init_dualinput(&s->fs, ctx);
if (ret < 0)
return ret;
s->fs.opt_repeatlast = 1; // only 1 frame in the palette
s->fs.in[1].before = s->fs.in[1].after = EXT_INFINITY;
s->fs.on_event = load_apply_palette;
outlink->w = ctx->inputs[0]->w;
outlink->h = ctx->inputs[0]->h;
outlink->time_base = ctx->inputs[0]->time_base;
if ((ret = ff_framesync_configure(&s->fs)) < 0)
return ret;
return 0;
}
static int config_input_palette(AVFilterLink *inlink)
{
AVFilterContext *ctx = inlink->dst;
if (inlink->w * inlink->h != AVPALETTE_COUNT) {
av_log(ctx, AV_LOG_ERROR,
"Palette input must contain exactly %d pixels. "
"Specified input has %dx%d=%d pixels\n",
AVPALETTE_COUNT, inlink->w, inlink->h,
inlink->w * inlink->h);
return AVERROR(EINVAL);
}
return 0;
}
static void load_palette(PaletteUseContext *s, const AVFrame *palette_frame)
{
int i, x, y;
const uint32_t *p = (const uint32_t *)palette_frame->data[0];
const int p_linesize = palette_frame->linesize[0] >> 2;
s->transparency_index = -1;
if (s->new) {
memset(s->palette, 0, sizeof(s->palette));
memset(s->map, 0, sizeof(s->map));
for (i = 0; i < CACHE_SIZE; i++)
av_freep(&s->cache[i].entries);
memset(s->cache, 0, sizeof(s->cache));
}
i = 0;
for (y = 0; y < palette_frame->height; y++) {
for (x = 0; x < palette_frame->width; x++) {
s->palette[i] = p[x];
if (p[x]>>24 < s->trans_thresh) {
s->transparency_index = i; // we are assuming at most one transparent color in palette
}
i++;
}
p += p_linesize;
}
load_colormap(s);
if (!s->new)
s->palette_loaded = 1;
}
static int load_apply_palette(FFFrameSync *fs)
{
AVFilterContext *ctx = fs->parent;
AVFilterLink *inlink = ctx->inputs[0];
PaletteUseContext *s = ctx->priv;
AVFrame *master, *second, *out;
int ret;
// writable for error diffusal dithering
ret = ff_framesync_dualinput_get_writable(fs, &master, &second);
if (ret < 0)
return ret;
if (!master || !second) {
ret = AVERROR_BUG;
goto error;
}
if (!s->palette_loaded) {
load_palette(s, second);
}
out = apply_palette(inlink, master);
return ff_filter_frame(ctx->outputs[0], out);
error:
av_frame_free(&master);
av_frame_free(&second);
return ret;
}
#define DEFINE_SET_FRAME(color_search, name, value) \
static int set_frame_##name(PaletteUseContext *s, AVFrame *out, AVFrame *in, \
int x_start, int y_start, int w, int h) \
{ \
return set_frame(s, out, in, x_start, y_start, w, h, value, color_search); \
}
#define DEFINE_SET_FRAME_COLOR_SEARCH(color_search, color_search_macro) \
DEFINE_SET_FRAME(color_search_macro, color_search##_##none, DITHERING_NONE) \
DEFINE_SET_FRAME(color_search_macro, color_search##_##bayer, DITHERING_BAYER) \
DEFINE_SET_FRAME(color_search_macro, color_search##_##heckbert, DITHERING_HECKBERT) \
DEFINE_SET_FRAME(color_search_macro, color_search##_##floyd_steinberg, DITHERING_FLOYD_STEINBERG) \
DEFINE_SET_FRAME(color_search_macro, color_search##_##sierra2, DITHERING_SIERRA2) \
DEFINE_SET_FRAME(color_search_macro, color_search##_##sierra2_4a, DITHERING_SIERRA2_4A) \
DEFINE_SET_FRAME_COLOR_SEARCH(nns_iterative, COLOR_SEARCH_NNS_ITERATIVE)
DEFINE_SET_FRAME_COLOR_SEARCH(nns_recursive, COLOR_SEARCH_NNS_RECURSIVE)
DEFINE_SET_FRAME_COLOR_SEARCH(bruteforce, COLOR_SEARCH_BRUTEFORCE)
#define DITHERING_ENTRIES(color_search) { \
set_frame_##color_search##_none, \
set_frame_##color_search##_bayer, \
set_frame_##color_search##_heckbert, \
set_frame_##color_search##_floyd_steinberg, \
set_frame_##color_search##_sierra2, \
set_frame_##color_search##_sierra2_4a, \
}
static const set_frame_func set_frame_lut[NB_COLOR_SEARCHES][NB_DITHERING] = {
DITHERING_ENTRIES(nns_iterative),
DITHERING_ENTRIES(nns_recursive),
DITHERING_ENTRIES(bruteforce),
};
static int dither_value(int p)
{
const int q = p ^ (p >> 3);
return (p & 4) >> 2 | (q & 4) >> 1 \
| (p & 2) << 1 | (q & 2) << 2 \
| (p & 1) << 4 | (q & 1) << 5;
}
static av_cold int init(AVFilterContext *ctx)
{
PaletteUseContext *s = ctx->priv;
s->set_frame = set_frame_lut[s->color_search_method][s->dither];
if (s->dither == DITHERING_BAYER) {
int i;
const int delta = 1 << (5 - s->bayer_scale); // to avoid too much luma
for (i = 0; i < FF_ARRAY_ELEMS(s->ordered_dither); i++)
s->ordered_dither[i] = (dither_value(i) >> s->bayer_scale) - delta;
}
return 0;
}
static int activate(AVFilterContext *ctx)
{
PaletteUseContext *s = ctx->priv;
return ff_framesync_activate(&s->fs);
}
static av_cold void uninit(AVFilterContext *ctx)
{
int i;
PaletteUseContext *s = ctx->priv;
ff_framesync_uninit(&s->fs);
for (i = 0; i < CACHE_SIZE; i++)
av_freep(&s->cache[i].entries);
av_frame_free(&s->last_in);
av_frame_free(&s->last_out);
}
static const AVFilterPad paletteuse_inputs[] = {
{
.name = "default",
.type = AVMEDIA_TYPE_VIDEO,
},{
.name = "palette",
.type = AVMEDIA_TYPE_VIDEO,
.config_props = config_input_palette,
},
{ NULL }
};
static const AVFilterPad paletteuse_outputs[] = {
{
.name = "default",
.type = AVMEDIA_TYPE_VIDEO,
.config_props = config_output,
},
{ NULL }
};
AVFilter ff_vf_paletteuse = {
.name = "paletteuse",
.description = NULL_IF_CONFIG_SMALL("Use a palette to downsample an input video stream."),
.priv_size = sizeof(PaletteUseContext),
.query_formats = query_formats,
.init = init,
.uninit = uninit,
.activate = activate,
.inputs = paletteuse_inputs,
.outputs = paletteuse_outputs,
.priv_class = &paletteuse_class,
};