/*
* Copyright (c) 2002 Michael Niedermayer <michaelni@gmx.at>
* 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 General Public License as published by
* the Free Software Foundation; either version 2 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 General Public License for more details.
*
* You should have received a copy of the GNU 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
* Apply a boxblur filter to the input video.
* Ported from MPlayer libmpcodecs/vf_boxblur.c.
*/
#include "libavutil/avstring.h"
#include "libavutil/common.h"
#include "libavutil/eval.h"
#include "libavutil/opt.h"
#include "libavutil/pixdesc.h"
#include "avfilter.h"
#include "formats.h"
#include "internal.h"
#include "video.h"
static const char *const var_names[] = {
"w",
"h",
"cw",
"ch",
"hsub",
"vsub",
NULL
};
enum var_name {
VAR_W,
VAR_H,
VAR_CW,
VAR_CH,
VAR_HSUB,
VAR_VSUB,
VARS_NB
};
typedef struct {
int radius;
int power;
char *radius_expr;
} FilterParam;
typedef struct {
const AVClass *class;
FilterParam luma_param;
FilterParam chroma_param;
FilterParam alpha_param;
int hsub, vsub;
int radius[4];
int power[4];
uint8_t *temp[2]; ///< temporary buffer used in blur_power()
} BoxBlurContext;
#define Y 0
#define U 1
#define V 2
#define A 3
static av_cold int init(AVFilterContext *ctx)
{
BoxBlurContext *s = ctx->priv;
if (!s->luma_param.radius_expr) {
av_log(ctx, AV_LOG_ERROR, "Luma radius expression is not set.\n");
return AVERROR(EINVAL);
}
/* fill missing params */
if (!s->chroma_param.radius_expr) {
s->chroma_param.radius_expr = av_strdup(s->luma_param.radius_expr);
if (!s->chroma_param.radius_expr)
return AVERROR(ENOMEM);
}
if (s->chroma_param.power < 0)
s->chroma_param.power = s->luma_param.power;
if (!s->alpha_param.radius_expr) {
s->alpha_param.radius_expr = av_strdup(s->luma_param.radius_expr);
if (!s->alpha_param.radius_expr)
return AVERROR(ENOMEM);
}
if (s->alpha_param.power < 0)
s->alpha_param.power = s->luma_param.power;
return 0;
}
static av_cold void uninit(AVFilterContext *ctx)
{
BoxBlurContext *s = ctx->priv;
av_freep(&s->temp[0]);
av_freep(&s->temp[1]);
}
static int query_formats(AVFilterContext *ctx)
{
static const enum AVPixelFormat pix_fmts[] = {
AV_PIX_FMT_YUV444P, AV_PIX_FMT_YUV422P, AV_PIX_FMT_YUV420P,
AV_PIX_FMT_YUV411P, AV_PIX_FMT_YUV410P, AV_PIX_FMT_YUVA420P,
AV_PIX_FMT_YUV440P, AV_PIX_FMT_GRAY8,
AV_PIX_FMT_YUVJ444P, AV_PIX_FMT_YUVJ422P, AV_PIX_FMT_YUVJ420P,
AV_PIX_FMT_YUVJ440P,
AV_PIX_FMT_NONE
};
ff_set_common_formats(ctx, ff_make_format_list(pix_fmts));
return 0;
}
static int config_input(AVFilterLink *inlink)
{
const AVPixFmtDescriptor *desc = av_pix_fmt_desc_get(inlink->format);
AVFilterContext *ctx = inlink->dst;
BoxBlurContext *s = ctx->priv;
int w = inlink->w, h = inlink->h;
int cw, ch;
double var_values[VARS_NB], res;
char *expr;
int ret;
if (!(s->temp[0] = av_malloc(FFMAX(w, h))) ||
!(s->temp[1] = av_malloc(FFMAX(w, h))))
return AVERROR(ENOMEM);
s->hsub = desc->log2_chroma_w;
s->vsub = desc->log2_chroma_h;
var_values[VAR_W] = inlink->w;
var_values[VAR_H] = inlink->h;
var_values[VAR_CW] = cw = w>>s->hsub;
var_values[VAR_CH] = ch = h>>s->vsub;
var_values[VAR_HSUB] = 1<<s->hsub;
var_values[VAR_VSUB] = 1<<s->vsub;
#define EVAL_RADIUS_EXPR(comp) \
expr = s->comp##_param.radius_expr; \
ret = av_expr_parse_and_eval(&res, expr, var_names, var_values, \
NULL, NULL, NULL, NULL, NULL, 0, ctx); \
s->comp##_param.radius = res; \
if (ret < 0) { \
av_log(NULL, AV_LOG_ERROR, \
"Error when evaluating " #comp " radius expression '%s'\n", expr); \
return ret; \
}
EVAL_RADIUS_EXPR(luma);
EVAL_RADIUS_EXPR(chroma);
EVAL_RADIUS_EXPR(alpha);
av_log(ctx, AV_LOG_VERBOSE,
"luma_radius:%d luma_power:%d "
"chroma_radius:%d chroma_power:%d "
"alpha_radius:%d alpha_power:%d "
"w:%d chroma_w:%d h:%d chroma_h:%d\n",
s->luma_param .radius, s->luma_param .power,
s->chroma_param.radius, s->chroma_param.power,
s->alpha_param .radius, s->alpha_param .power,
w, cw, h, ch);
#define CHECK_RADIUS_VAL(w_, h_, comp) \
if (s->comp##_param.radius < 0 || \
2*s->comp##_param.radius > FFMIN(w_, h_)) { \
av_log(ctx, AV_LOG_ERROR, \
"Invalid " #comp " radius value %d, must be >= 0 and <= %d\n", \
s->comp##_param.radius, FFMIN(w_, h_)/2); \
return AVERROR(EINVAL); \
}
CHECK_RADIUS_VAL(w, h, luma);
CHECK_RADIUS_VAL(cw, ch, chroma);
CHECK_RADIUS_VAL(w, h, alpha);
s->radius[Y] = s->luma_param.radius;
s->radius[U] = s->radius[V] = s->chroma_param.radius;
s->radius[A] = s->alpha_param.radius;
s->power[Y] = s->luma_param.power;
s->power[U] = s->power[V] = s->chroma_param.power;
s->power[A] = s->alpha_param.power;
return 0;
}
static inline void blur(uint8_t *dst, int dst_step, const uint8_t *src, int src_step,
int len, int radius)
{
/* Naive boxblur would sum source pixels from x-radius .. x+radius
* for destination pixel x. That would be O(radius*width).
* If you now look at what source pixels represent 2 consecutive
* output pixels, then you see they are almost identical and only
* differ by 2 pixels, like:
* src0 111111111
* dst0 1
* src1 111111111
* dst1 1
* src0-src1 1 -1
* so when you know one output pixel you can find the next by just adding
* and subtracting 1 input pixel.
* The following code adopts this faster variant.
*/
const int length = radius*2 + 1;
const int inv = ((1<<16) + length/2)/length;
int x, sum = 0;
for (x = 0; x < radius; x++)
sum += src[x*src_step]<<1;
sum += src[radius*src_step];
for (x = 0; x <= radius; x++) {
sum += src[(radius+x)*src_step] - src[(radius-x)*src_step];
dst[x*dst_step] = (sum*inv + (1<<15))>>16;
}
for (; x < len-radius; x++) {
sum += src[(radius+x)*src_step] - src[(x-radius-1)*src_step];
dst[x*dst_step] = (sum*inv + (1<<15))>>16;
}
for (; x < len; x++) {
sum += src[(2*len-radius-x-1)*src_step] - src[(x-radius-1)*src_step];
dst[x*dst_step] = (sum*inv + (1<<15))>>16;
}
}
static inline void blur_power(uint8_t *dst, int dst_step, const uint8_t *src, int src_step,
int len, int radius, int power, uint8_t *temp[2])
{
uint8_t *a = temp[0], *b = temp[1];
if (radius && power) {
blur(a, 1, src, src_step, len, radius);
for (; power > 2; power--) {
uint8_t *c;
blur(b, 1, a, 1, len, radius);
c = a; a = b; b = c;
}
if (power > 1) {
blur(dst, dst_step, a, 1, len, radius);
} else {
int i;
for (i = 0; i < len; i++)
dst[i*dst_step] = a[i];
}
} else {
int i;
for (i = 0; i < len; i++)
dst[i*dst_step] = src[i*src_step];
}
}
static void hblur(uint8_t *dst, int dst_linesize, const uint8_t *src, int src_linesize,
int w, int h, int radius, int power, uint8_t *temp[2])
{
int y;
if (radius == 0 && dst == src)
return;
for (y = 0; y < h; y++)
blur_power(dst + y*dst_linesize, 1, src + y*src_linesize, 1,
w, radius, power, temp);
}
static void vblur(uint8_t *dst, int dst_linesize, const uint8_t *src, int src_linesize,
int w, int h, int radius, int power, uint8_t *temp[2])
{
int x;
if (radius == 0 && dst == src)
return;
for (x = 0; x < w; x++)
blur_power(dst + x, dst_linesize, src + x, src_linesize,
h, radius, power, temp);
}
static int filter_frame(AVFilterLink *inlink, AVFrame *in)
{
AVFilterContext *ctx = inlink->dst;
BoxBlurContext *s = ctx->priv;
AVFilterLink *outlink = inlink->dst->outputs[0];
AVFrame *out;
int plane;
int cw = FF_CEIL_RSHIFT(inlink->w, s->hsub), ch = FF_CEIL_RSHIFT(in->height, s->vsub);
int w[4] = { inlink->w, cw, cw, inlink->w };
int h[4] = { in->height, ch, ch, in->height };
out = ff_get_video_buffer(outlink, outlink->w, outlink->h);
if (!out) {
av_frame_free(&in);
return AVERROR(ENOMEM);
}
av_frame_copy_props(out, in);
for (plane = 0; plane < 4 && in->data[plane] && in->linesize[plane]; plane++)
hblur(out->data[plane], out->linesize[plane],
in ->data[plane], in ->linesize[plane],
w[plane], h[plane], s->radius[plane], s->power[plane],
s->temp);
for (plane = 0; plane < 4 && in->data[plane] && in->linesize[plane]; plane++)
vblur(out->data[plane], out->linesize[plane],
out->data[plane], out->linesize[plane],
w[plane], h[plane], s->radius[plane], s->power[plane],
s->temp);
av_frame_free(&in);
return ff_filter_frame(outlink, out);
}
#define OFFSET(x) offsetof(BoxBlurContext, x)
#define FLAGS AV_OPT_FLAG_VIDEO_PARAM|AV_OPT_FLAG_FILTERING_PARAM
static const AVOption boxblur_options[] = {
{ "luma_radius", "Radius of the luma blurring box", OFFSET(luma_param.radius_expr), AV_OPT_TYPE_STRING, {.str="2"}, .flags = FLAGS },
{ "lr", "Radius of the luma blurring box", OFFSET(luma_param.radius_expr), AV_OPT_TYPE_STRING, {.str="2"}, .flags = FLAGS },
{ "luma_power", "How many times should the boxblur be applied to luma", OFFSET(luma_param.power), AV_OPT_TYPE_INT, {.i64=2}, 0, INT_MAX, .flags = FLAGS },
{ "lp", "How many times should the boxblur be applied to luma", OFFSET(luma_param.power), AV_OPT_TYPE_INT, {.i64=2}, 0, INT_MAX, .flags = FLAGS },
{ "chroma_radius", "Radius of the chroma blurring box", OFFSET(chroma_param.radius_expr), AV_OPT_TYPE_STRING, {.str=NULL}, .flags = FLAGS },
{ "cr", "Radius of the chroma blurring box", OFFSET(chroma_param.radius_expr), AV_OPT_TYPE_STRING, {.str=NULL}, .flags = FLAGS },
{ "chroma_power", "How many times should the boxblur be applied to chroma", OFFSET(chroma_param.power), AV_OPT_TYPE_INT, {.i64=-1}, -1, INT_MAX, .flags = FLAGS },
{ "cp", "How many times should the boxblur be applied to chroma", OFFSET(chroma_param.power), AV_OPT_TYPE_INT, {.i64=-1}, -1, INT_MAX, .flags = FLAGS },
{ "alpha_radius", "Radius of the alpha blurring box", OFFSET(alpha_param.radius_expr), AV_OPT_TYPE_STRING, {.str=NULL}, .flags = FLAGS },
{ "ar", "Radius of the alpha blurring box", OFFSET(alpha_param.radius_expr), AV_OPT_TYPE_STRING, {.str=NULL}, .flags = FLAGS },
{ "alpha_power", "How many times should the boxblur be applied to alpha", OFFSET(alpha_param.power), AV_OPT_TYPE_INT, {.i64=-1}, -1, INT_MAX, .flags = FLAGS },
{ "ap", "How many times should the boxblur be applied to alpha", OFFSET(alpha_param.power), AV_OPT_TYPE_INT, {.i64=-1}, -1, INT_MAX, .flags = FLAGS },
{ NULL }
};
AVFILTER_DEFINE_CLASS(boxblur);
static const AVFilterPad avfilter_vf_boxblur_inputs[] = {
{
.name = "default",
.type = AVMEDIA_TYPE_VIDEO,
.config_props = config_input,
.filter_frame = filter_frame,
},
{ NULL }
};
static const AVFilterPad avfilter_vf_boxblur_outputs[] = {
{
.name = "default",
.type = AVMEDIA_TYPE_VIDEO,
},
{ NULL }
};
AVFilter avfilter_vf_boxblur = {
.name = "boxblur",
.description = NULL_IF_CONFIG_SMALL("Blur the input."),
.priv_size = sizeof(BoxBlurContext),
.priv_class = &boxblur_class,
.init = init,
.uninit = uninit,
.query_formats = query_formats,
.inputs = avfilter_vf_boxblur_inputs,
.outputs = avfilter_vf_boxblur_outputs,
.flags = AVFILTER_FLAG_SUPPORT_TIMELINE_GENERIC,
};