/*
* Copyright (c) 2011 Stefano Sabatini
*
* 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
* Compute a look-up table for binding the input value to the output
* value, and apply it to input video.
*/
#include "libavutil/eval.h"
#include "libavutil/opt.h"
#include "libavutil/pixdesc.h"
#include "avfilter.h"
#include "internal.h"
static const char * const var_names[] = {
"w", ///< width of the input video
"h", ///< height of the input video
"val", ///< input value for the pixel
"maxval", ///< max value for the pixel
"minval", ///< min value for the pixel
"negval", ///< negated value
"clipval",
NULL
};
enum var_name {
VAR_W,
VAR_H,
VAR_VAL,
VAR_MAXVAL,
VAR_MINVAL,
VAR_NEGVAL,
VAR_CLIPVAL,
VAR_VARS_NB
};
typedef struct {
const AVClass *class;
uint8_t lut[4][256]; ///< lookup table for each component
char *comp_expr_str[4];
AVExpr *comp_expr[4];
int hsub, vsub;
double var_values[VAR_VARS_NB];
int is_rgb, is_yuv;
int rgba_map[4];
int step;
int negate_alpha; /* only used by negate */
} LutContext;
#define Y 0
#define U 1
#define V 2
#define R 0
#define G 1
#define B 2
#define A 3
#define OFFSET(x) offsetof(LutContext, x)
static const AVOption lut_options[] = {
{"c0", "set component #0 expression", OFFSET(comp_expr_str[0]), AV_OPT_TYPE_STRING, {.str="val"}, CHAR_MIN, CHAR_MAX},
{"c1", "set component #1 expression", OFFSET(comp_expr_str[1]), AV_OPT_TYPE_STRING, {.str="val"}, CHAR_MIN, CHAR_MAX},
{"c2", "set component #2 expression", OFFSET(comp_expr_str[2]), AV_OPT_TYPE_STRING, {.str="val"}, CHAR_MIN, CHAR_MAX},
{"c3", "set component #3 expression", OFFSET(comp_expr_str[3]), AV_OPT_TYPE_STRING, {.str="val"}, CHAR_MIN, CHAR_MAX},
{"y", "set Y expression", OFFSET(comp_expr_str[Y]), AV_OPT_TYPE_STRING, {.str="val"}, CHAR_MIN, CHAR_MAX},
{"u", "set U expression", OFFSET(comp_expr_str[U]), AV_OPT_TYPE_STRING, {.str="val"}, CHAR_MIN, CHAR_MAX},
{"v", "set V expression", OFFSET(comp_expr_str[V]), AV_OPT_TYPE_STRING, {.str="val"}, CHAR_MIN, CHAR_MAX},
{"r", "set R expression", OFFSET(comp_expr_str[R]), AV_OPT_TYPE_STRING, {.str="val"}, CHAR_MIN, CHAR_MAX},
{"g", "set G expression", OFFSET(comp_expr_str[G]), AV_OPT_TYPE_STRING, {.str="val"}, CHAR_MIN, CHAR_MAX},
{"b", "set B expression", OFFSET(comp_expr_str[B]), AV_OPT_TYPE_STRING, {.str="val"}, CHAR_MIN, CHAR_MAX},
{"a", "set A expression", OFFSET(comp_expr_str[A]), AV_OPT_TYPE_STRING, {.str="val"}, CHAR_MIN, CHAR_MAX},
{NULL},
};
static const char *lut_get_name(void *ctx)
{
return "lut";
}
static const AVClass lut_class = {
"LutContext",
lut_get_name,
lut_options
};
static int init(AVFilterContext *ctx, const char *args, void *opaque)
{
LutContext *lut = ctx->priv;
int ret;
lut->class = &lut_class;
av_opt_set_defaults(lut);
lut->is_rgb = !strcmp(ctx->filter->name, "lutrgb");
lut->is_yuv = !strcmp(ctx->filter->name, "lutyuv");
if (args && (ret = av_set_options_string(lut, args, "=", ":")) < 0)
return ret;
return 0;
}
static av_cold void uninit(AVFilterContext *ctx)
{
LutContext *lut = ctx->priv;
int i;
for (i = 0; i < 4; i++) {
av_expr_free(lut->comp_expr[i]);
lut->comp_expr[i] = NULL;
av_freep(&lut->comp_expr_str[i]);
}
}
#define YUV_FORMATS \
PIX_FMT_YUV444P, PIX_FMT_YUV422P, PIX_FMT_YUV420P, \
PIX_FMT_YUV411P, PIX_FMT_YUV410P, PIX_FMT_YUV440P, \
PIX_FMT_YUVA420P, \
PIX_FMT_YUVJ444P, PIX_FMT_YUVJ422P, PIX_FMT_YUVJ420P, \
PIX_FMT_YUVJ440P
#define RGB_FORMATS \
PIX_FMT_ARGB, PIX_FMT_RGBA, \
PIX_FMT_ABGR, PIX_FMT_BGRA, \
PIX_FMT_RGB24, PIX_FMT_BGR24
static const enum PixelFormat yuv_pix_fmts[] = { YUV_FORMATS, PIX_FMT_NONE };
static const enum PixelFormat rgb_pix_fmts[] = { RGB_FORMATS, PIX_FMT_NONE };
static const enum PixelFormat all_pix_fmts[] = { RGB_FORMATS, YUV_FORMATS, PIX_FMT_NONE };
static int query_formats(AVFilterContext *ctx)
{
LutContext *lut = ctx->priv;
const enum PixelFormat *pix_fmts = lut->is_rgb ? rgb_pix_fmts :
lut->is_yuv ? yuv_pix_fmts : all_pix_fmts;
avfilter_set_common_pixel_formats(ctx, avfilter_make_format_list(pix_fmts));
return 0;
}
/**
* Clip value val in the minval - maxval range.
*/
static double clip(void *opaque, double val)
{
LutContext *lut = opaque;
double minval = lut->var_values[VAR_MINVAL];
double maxval = lut->var_values[VAR_MAXVAL];
return av_clip(val, minval, maxval);
}
/**
* Compute gamma correction for value val, assuming the minval-maxval
* range, val is clipped to a value contained in the same interval.
*/
static double compute_gammaval(void *opaque, double gamma)
{
LutContext *lut = opaque;
double val = lut->var_values[VAR_CLIPVAL];
double minval = lut->var_values[VAR_MINVAL];
double maxval = lut->var_values[VAR_MAXVAL];
return pow((val-minval)/(maxval-minval), gamma) * (maxval-minval)+minval;
}
static double (* const funcs1[])(void *, double) = {
(void *)clip,
(void *)compute_gammaval,
NULL
};
static const char * const funcs1_names[] = {
"clip",
"gammaval",
NULL
};
static int config_props(AVFilterLink *inlink)
{
AVFilterContext *ctx = inlink->dst;
LutContext *lut = ctx->priv;
const AVPixFmtDescriptor *desc = &av_pix_fmt_descriptors[inlink->format];
int min[4], max[4];
int val, comp, ret;
lut->hsub = desc->log2_chroma_w;
lut->vsub = desc->log2_chroma_h;
lut->var_values[VAR_W] = inlink->w;
lut->var_values[VAR_H] = inlink->h;
switch (inlink->format) {
case PIX_FMT_YUV410P:
case PIX_FMT_YUV411P:
case PIX_FMT_YUV420P:
case PIX_FMT_YUV422P:
case PIX_FMT_YUV440P:
case PIX_FMT_YUV444P:
case PIX_FMT_YUVA420P:
min[Y] = min[U] = min[V] = 16;
max[Y] = 235;
max[U] = max[V] = 240;
min[A] = 0; max[A] = 255;
break;
default:
min[0] = min[1] = min[2] = min[3] = 0;
max[0] = max[1] = max[2] = max[3] = 255;
}
lut->is_yuv = lut->is_rgb = 0;
if (ff_fmt_is_in(inlink->format, yuv_pix_fmts)) lut->is_yuv = 1;
else if (ff_fmt_is_in(inlink->format, rgb_pix_fmts)) lut->is_rgb = 1;
if (lut->is_rgb) {
switch (inlink->format) {
case PIX_FMT_ARGB: lut->rgba_map[A] = 0; lut->rgba_map[R] = 1; lut->rgba_map[G] = 2; lut->rgba_map[B] = 3; break;
case PIX_FMT_ABGR: lut->rgba_map[A] = 0; lut->rgba_map[B] = 1; lut->rgba_map[G] = 2; lut->rgba_map[R] = 3; break;
case PIX_FMT_RGBA:
case PIX_FMT_RGB24: lut->rgba_map[R] = 0; lut->rgba_map[G] = 1; lut->rgba_map[B] = 2; lut->rgba_map[A] = 3; break;
case PIX_FMT_BGRA:
case PIX_FMT_BGR24: lut->rgba_map[B] = 0; lut->rgba_map[G] = 1; lut->rgba_map[R] = 2; lut->rgba_map[A] = 3; break;
}
lut->step = av_get_bits_per_pixel(desc) >> 3;
}
for (comp = 0; comp < desc->nb_components; comp++) {
double res;
/* create the parsed expression */
ret = av_expr_parse(&lut->comp_expr[comp], lut->comp_expr_str[comp],
var_names, funcs1_names, funcs1, NULL, NULL, 0, ctx);
if (ret < 0) {
av_log(ctx, AV_LOG_ERROR,
"Error when parsing the expression '%s' for the component %d.\n",
lut->comp_expr_str[comp], comp);
return AVERROR(EINVAL);
}
/* compute the lut */
lut->var_values[VAR_MAXVAL] = max[comp];
lut->var_values[VAR_MINVAL] = min[comp];
for (val = 0; val < 256; val++) {
lut->var_values[VAR_VAL] = val;
lut->var_values[VAR_CLIPVAL] = av_clip(val, min[comp], max[comp]);
lut->var_values[VAR_NEGVAL] =
av_clip(min[comp] + max[comp] - lut->var_values[VAR_VAL],
min[comp], max[comp]);
res = av_expr_eval(lut->comp_expr[comp], lut->var_values, lut);
if (isnan(res)) {
av_log(ctx, AV_LOG_ERROR,
"Error when evaluating the expression '%s' for the value %d for the component #%d.\n",
lut->comp_expr_str[comp], val, comp);
return AVERROR(EINVAL);
}
lut->lut[comp][val] = av_clip((int)res, min[comp], max[comp]);
av_log(ctx, AV_LOG_DEBUG, "val[%d][%d] = %d\n", comp, val, lut->lut[comp][val]);
}
}
return 0;
}
static void draw_slice(AVFilterLink *inlink, int y, int h, int slice_dir)
{
AVFilterContext *ctx = inlink->dst;
LutContext *lut = ctx->priv;
AVFilterLink *outlink = ctx->outputs[0];
AVFilterBufferRef *inpic = inlink ->cur_buf;
AVFilterBufferRef *outpic = outlink->out_buf;
uint8_t *inrow, *outrow, *inrow0, *outrow0;
int i, j, k, plane;
if (lut->is_rgb) {
/* packed */
inrow0 = inpic ->data[0] + y * inpic ->linesize[0];
outrow0 = outpic->data[0] + y * outpic->linesize[0];
for (i = 0; i < h; i ++) {
inrow = inrow0;
outrow = outrow0;
for (j = 0; j < inlink->w; j++) {
for (k = 0; k < lut->step; k++)
outrow[k] = lut->lut[lut->rgba_map[k]][inrow[k]];
outrow += lut->step;
inrow += lut->step;
}
inrow0 += inpic ->linesize[0];
outrow0 += outpic->linesize[0];
}
} else {
/* planar */
for (plane = 0; plane < 4 && inpic->data[plane]; plane++) {
int vsub = plane == 1 || plane == 2 ? lut->vsub : 0;
int hsub = plane == 1 || plane == 2 ? lut->hsub : 0;
inrow = inpic ->data[plane] + (y>>vsub) * inpic ->linesize[plane];
outrow = outpic->data[plane] + (y>>vsub) * outpic->linesize[plane];
for (i = 0; i < h>>vsub; i ++) {
for (j = 0; j < inlink->w>>hsub; j++)
outrow[j] = lut->lut[plane][inrow[j]];
inrow += inpic ->linesize[plane];
outrow += outpic->linesize[plane];
}
}
}
avfilter_draw_slice(outlink, y, h, slice_dir);
}
#define DEFINE_LUT_FILTER(name_, description_, init_) \
AVFilter avfilter_vf_##name_ = { \
.name = #name_, \
.description = NULL_IF_CONFIG_SMALL(description_), \
.priv_size = sizeof(LutContext), \
\
.init = init_, \
.uninit = uninit, \
.query_formats = query_formats, \
\
.inputs = (const AVFilterPad[]) {{ .name = "default", \
.type = AVMEDIA_TYPE_VIDEO, \
.draw_slice = draw_slice, \
.config_props = config_props, \
.min_perms = AV_PERM_READ, }, \
{ .name = NULL}}, \
.outputs = (const AVFilterPad[]) {{ .name = "default", \
.type = AVMEDIA_TYPE_VIDEO, }, \
{ .name = NULL}}, \
}
#if CONFIG_LUT_FILTER
DEFINE_LUT_FILTER(lut, "Compute and apply a lookup table to the RGB/YUV input video.", init);
#endif
#if CONFIG_LUTYUV_FILTER
DEFINE_LUT_FILTER(lutyuv, "Compute and apply a lookup table to the YUV input video.", init);
#endif
#if CONFIG_LUTRGB_FILTER
DEFINE_LUT_FILTER(lutrgb, "Compute and apply a lookup table to the RGB input video.", init);
#endif
#if CONFIG_NEGATE_FILTER
static int negate_init(AVFilterContext *ctx, const char *args, void *opaque)
{
LutContext *lut = ctx->priv;
char lut_params[64];
if (args)
sscanf(args, "%d", &lut->negate_alpha);
av_log(ctx, AV_LOG_DEBUG, "negate_alpha:%d\n", lut->negate_alpha);
snprintf(lut_params, sizeof(lut_params), "c0=negval:c1=negval:c2=negval:a=%s",
lut->negate_alpha ? "negval" : "val");
return init(ctx, lut_params, opaque);
}
DEFINE_LUT_FILTER(negate, "Negate input video.", negate_init);
#endif