/*
* Copyright (c) 2007 Bobby Bingham
*
* 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
* scale video filter
*/
#include <stdio.h>
#include <string.h>
#include "avfilter.h"
#include "formats.h"
#include "internal.h"
#include "video.h"
#include "libavutil/avstring.h"
#include "libavutil/eval.h"
#include "libavutil/internal.h"
#include "libavutil/mathematics.h"
#include "libavutil/opt.h"
#include "libavutil/parseutils.h"
#include "libavutil/pixdesc.h"
#include "libavutil/imgutils.h"
#include "libavutil/avassert.h"
#include "libswscale/swscale.h"
static const char *const var_names[] = {
"in_w", "iw",
"in_h", "ih",
"out_w", "ow",
"out_h", "oh",
"a",
"sar",
"dar",
"hsub",
"vsub",
"ohsub",
"ovsub",
NULL
};
enum var_name {
VAR_IN_W, VAR_IW,
VAR_IN_H, VAR_IH,
VAR_OUT_W, VAR_OW,
VAR_OUT_H, VAR_OH,
VAR_A,
VAR_SAR,
VAR_DAR,
VAR_HSUB,
VAR_VSUB,
VAR_OHSUB,
VAR_OVSUB,
VARS_NB
};
typedef struct {
const AVClass *class;
struct SwsContext *sws; ///< software scaler context
struct SwsContext *isws[2]; ///< software scaler context for interlaced material
AVDictionary *opts;
/**
* New dimensions. Special values are:
* 0 = original width/height
* -1 = keep original aspect
* -N = try to keep aspect but make sure it is divisible by N
*/
int w, h;
char *size_str;
unsigned int flags; ///sws flags
int hsub, vsub; ///< chroma subsampling
int slice_y; ///< top of current output slice
int input_is_pal; ///< set to 1 if the input format is paletted
int output_is_pal; ///< set to 1 if the output format is paletted
int interlaced;
char *w_expr; ///< width expression string
char *h_expr; ///< height expression string
char *flags_str;
char *in_color_matrix;
char *out_color_matrix;
int in_range;
int out_range;
int out_h_chr_pos;
int out_v_chr_pos;
int in_h_chr_pos;
int in_v_chr_pos;
int force_original_aspect_ratio;
} ScaleContext;
static av_cold int init_dict(AVFilterContext *ctx, AVDictionary **opts)
{
ScaleContext *scale = ctx->priv;
int ret;
if (scale->size_str && (scale->w_expr || scale->h_expr)) {
av_log(ctx, AV_LOG_ERROR,
"Size and width/height expressions cannot be set at the same time.\n");
return AVERROR(EINVAL);
}
if (scale->w_expr && !scale->h_expr)
FFSWAP(char *, scale->w_expr, scale->size_str);
if (scale->size_str) {
char buf[32];
if ((ret = av_parse_video_size(&scale->w, &scale->h, scale->size_str)) < 0) {
av_log(ctx, AV_LOG_ERROR,
"Invalid size '%s'\n", scale->size_str);
return ret;
}
snprintf(buf, sizeof(buf)-1, "%d", scale->w);
av_opt_set(scale, "w", buf, 0);
snprintf(buf, sizeof(buf)-1, "%d", scale->h);
av_opt_set(scale, "h", buf, 0);
}
if (!scale->w_expr)
av_opt_set(scale, "w", "iw", 0);
if (!scale->h_expr)
av_opt_set(scale, "h", "ih", 0);
av_log(ctx, AV_LOG_VERBOSE, "w:%s h:%s flags:'%s' interl:%d\n",
scale->w_expr, scale->h_expr, (char *)av_x_if_null(scale->flags_str, ""), scale->interlaced);
scale->flags = 0;
if (scale->flags_str) {
const AVClass *class = sws_get_class();
const AVOption *o = av_opt_find(&class, "sws_flags", NULL, 0,
AV_OPT_SEARCH_FAKE_OBJ);
int ret = av_opt_eval_flags(&class, o, scale->flags_str, &scale->flags);
if (ret < 0)
return ret;
}
scale->opts = *opts;
*opts = NULL;
return 0;
}
static av_cold void uninit(AVFilterContext *ctx)
{
ScaleContext *scale = ctx->priv;
sws_freeContext(scale->sws);
sws_freeContext(scale->isws[0]);
sws_freeContext(scale->isws[1]);
scale->sws = NULL;
av_dict_free(&scale->opts);
}
static int query_formats(AVFilterContext *ctx)
{
AVFilterFormats *formats;
enum AVPixelFormat pix_fmt;
int ret;
if (ctx->inputs[0]) {
formats = NULL;
for (pix_fmt = 0; pix_fmt < AV_PIX_FMT_NB; pix_fmt++)
if ((sws_isSupportedInput(pix_fmt) ||
sws_isSupportedEndiannessConversion(pix_fmt))
&& (ret = ff_add_format(&formats, pix_fmt)) < 0) {
ff_formats_unref(&formats);
return ret;
}
ff_formats_ref(formats, &ctx->inputs[0]->out_formats);
}
if (ctx->outputs[0]) {
formats = NULL;
for (pix_fmt = 0; pix_fmt < AV_PIX_FMT_NB; pix_fmt++)
if ((sws_isSupportedOutput(pix_fmt) || pix_fmt == AV_PIX_FMT_PAL8 ||
sws_isSupportedEndiannessConversion(pix_fmt))
&& (ret = ff_add_format(&formats, pix_fmt)) < 0) {
ff_formats_unref(&formats);
return ret;
}
ff_formats_ref(formats, &ctx->outputs[0]->in_formats);
}
return 0;
}
static const int *parse_yuv_type(const char *s, enum AVColorSpace colorspace)
{
if (!s)
s = "bt601";
if (s && strstr(s, "bt709")) {
colorspace = AVCOL_SPC_BT709;
} else if (s && strstr(s, "fcc")) {
colorspace = AVCOL_SPC_FCC;
} else if (s && strstr(s, "smpte240m")) {
colorspace = AVCOL_SPC_SMPTE240M;
} else if (s && (strstr(s, "bt601") || strstr(s, "bt470") || strstr(s, "smpte170m"))) {
colorspace = AVCOL_SPC_BT470BG;
}
if (colorspace < 1 || colorspace > 7) {
colorspace = AVCOL_SPC_BT470BG;
}
return sws_getCoefficients(colorspace);
}
static int config_props(AVFilterLink *outlink)
{
AVFilterContext *ctx = outlink->src;
AVFilterLink *inlink = outlink->src->inputs[0];
enum AVPixelFormat outfmt = outlink->format;
ScaleContext *scale = ctx->priv;
const AVPixFmtDescriptor *desc = av_pix_fmt_desc_get(inlink->format);
const AVPixFmtDescriptor *out_desc = av_pix_fmt_desc_get(outlink->format);
int64_t w, h;
double var_values[VARS_NB], res;
char *expr;
int ret;
int factor_w, factor_h;
var_values[VAR_IN_W] = var_values[VAR_IW] = inlink->w;
var_values[VAR_IN_H] = var_values[VAR_IH] = inlink->h;
var_values[VAR_OUT_W] = var_values[VAR_OW] = NAN;
var_values[VAR_OUT_H] = var_values[VAR_OH] = NAN;
var_values[VAR_A] = (double) inlink->w / inlink->h;
var_values[VAR_SAR] = inlink->sample_aspect_ratio.num ?
(double) inlink->sample_aspect_ratio.num / inlink->sample_aspect_ratio.den : 1;
var_values[VAR_DAR] = var_values[VAR_A] * var_values[VAR_SAR];
var_values[VAR_HSUB] = 1 << desc->log2_chroma_w;
var_values[VAR_VSUB] = 1 << desc->log2_chroma_h;
var_values[VAR_OHSUB] = 1 << out_desc->log2_chroma_w;
var_values[VAR_OVSUB] = 1 << out_desc->log2_chroma_h;
/* evaluate width and height */
av_expr_parse_and_eval(&res, (expr = scale->w_expr),
var_names, var_values,
NULL, NULL, NULL, NULL, NULL, 0, ctx);
scale->w = var_values[VAR_OUT_W] = var_values[VAR_OW] = res;
if ((ret = av_expr_parse_and_eval(&res, (expr = scale->h_expr),
var_names, var_values,
NULL, NULL, NULL, NULL, NULL, 0, ctx)) < 0)
goto fail;
scale->h = var_values[VAR_OUT_H] = var_values[VAR_OH] = res;
/* evaluate again the width, as it may depend on the output height */
if ((ret = av_expr_parse_and_eval(&res, (expr = scale->w_expr),
var_names, var_values,
NULL, NULL, NULL, NULL, NULL, 0, ctx)) < 0)
goto fail;
scale->w = res;
w = scale->w;
h = scale->h;
/* Check if it is requested that the result has to be divisible by a some
* factor (w or h = -n with n being the factor). */
factor_w = 1;
factor_h = 1;
if (w < -1) {
factor_w = -w;
}
if (h < -1) {
factor_h = -h;
}
if (w < 0 && h < 0)
scale->w = scale->h = 0;
if (!(w = scale->w))
w = inlink->w;
if (!(h = scale->h))
h = inlink->h;
/* Make sure that the result is divisible by the factor we determined
* earlier. If no factor was set, it is nothing will happen as the default
* factor is 1 */
if (w < 0)
w = av_rescale(h, inlink->w, inlink->h * factor_w) * factor_w;
if (h < 0)
h = av_rescale(w, inlink->h, inlink->w * factor_h) * factor_h;
/* Note that force_original_aspect_ratio may overwrite the previous set
* dimensions so that it is not divisible by the set factors anymore. */
if (scale->force_original_aspect_ratio) {
int tmp_w = av_rescale(h, inlink->w, inlink->h);
int tmp_h = av_rescale(w, inlink->h, inlink->w);
if (scale->force_original_aspect_ratio == 1) {
w = FFMIN(tmp_w, w);
h = FFMIN(tmp_h, h);
} else {
w = FFMAX(tmp_w, w);
h = FFMAX(tmp_h, h);
}
}
if (w > INT_MAX || h > INT_MAX ||
(h * inlink->w) > INT_MAX ||
(w * inlink->h) > INT_MAX)
av_log(ctx, AV_LOG_ERROR, "Rescaled value for width or height is too big.\n");
outlink->w = w;
outlink->h = h;
/* TODO: make algorithm configurable */
scale->input_is_pal = desc->flags & AV_PIX_FMT_FLAG_PAL ||
desc->flags & AV_PIX_FMT_FLAG_PSEUDOPAL;
if (outfmt == AV_PIX_FMT_PAL8) outfmt = AV_PIX_FMT_BGR8;
scale->output_is_pal = av_pix_fmt_desc_get(outfmt)->flags & AV_PIX_FMT_FLAG_PAL ||
av_pix_fmt_desc_get(outfmt)->flags & AV_PIX_FMT_FLAG_PSEUDOPAL;
if (scale->sws)
sws_freeContext(scale->sws);
if (scale->isws[0])
sws_freeContext(scale->isws[0]);
if (scale->isws[1])
sws_freeContext(scale->isws[1]);
scale->isws[0] = scale->isws[1] = scale->sws = NULL;
if (inlink->w == outlink->w && inlink->h == outlink->h &&
inlink->format == outlink->format)
;
else {
struct SwsContext **swscs[3] = {&scale->sws, &scale->isws[0], &scale->isws[1]};
int i;
for (i = 0; i < 3; i++) {
struct SwsContext **s = swscs[i];
*s = sws_alloc_context();
if (!*s)
return AVERROR(ENOMEM);
if (scale->opts) {
AVDictionaryEntry *e = NULL;
while ((e = av_dict_get(scale->opts, "", e, AV_DICT_IGNORE_SUFFIX))) {
if ((ret = av_opt_set(*s, e->key, e->value, 0)) < 0)
return ret;
}
}
av_opt_set_int(*s, "srcw", inlink ->w, 0);
av_opt_set_int(*s, "srch", inlink ->h >> !!i, 0);
av_opt_set_int(*s, "src_format", inlink->format, 0);
av_opt_set_int(*s, "dstw", outlink->w, 0);
av_opt_set_int(*s, "dsth", outlink->h >> !!i, 0);
av_opt_set_int(*s, "dst_format", outfmt, 0);
av_opt_set_int(*s, "sws_flags", scale->flags, 0);
av_opt_set_int(*s, "src_h_chr_pos", scale->in_h_chr_pos, 0);
av_opt_set_int(*s, "src_v_chr_pos", scale->in_v_chr_pos, 0);
av_opt_set_int(*s, "dst_h_chr_pos", scale->out_h_chr_pos, 0);
av_opt_set_int(*s, "dst_v_chr_pos", scale->out_v_chr_pos, 0);
if ((ret = sws_init_context(*s, NULL, NULL)) < 0)
return ret;
if (!scale->interlaced)
break;
}
}
if (inlink->sample_aspect_ratio.num){
outlink->sample_aspect_ratio = av_mul_q((AVRational){outlink->h * inlink->w, outlink->w * inlink->h}, inlink->sample_aspect_ratio);
} else
outlink->sample_aspect_ratio = inlink->sample_aspect_ratio;
av_log(ctx, AV_LOG_VERBOSE, "w:%d h:%d fmt:%s sar:%d/%d -> w:%d h:%d fmt:%s sar:%d/%d flags:0x%0x\n",
inlink ->w, inlink ->h, av_get_pix_fmt_name( inlink->format),
inlink->sample_aspect_ratio.num, inlink->sample_aspect_ratio.den,
outlink->w, outlink->h, av_get_pix_fmt_name(outlink->format),
outlink->sample_aspect_ratio.num, outlink->sample_aspect_ratio.den,
scale->flags);
return 0;
fail:
av_log(NULL, AV_LOG_ERROR,
"Error when evaluating the expression '%s'.\n"
"Maybe the expression for out_w:'%s' or for out_h:'%s' is self-referencing.\n",
expr, scale->w_expr, scale->h_expr);
return ret;
}
static int scale_slice(AVFilterLink *link, AVFrame *out_buf, AVFrame *cur_pic, struct SwsContext *sws, int y, int h, int mul, int field)
{
ScaleContext *scale = link->dst->priv;
const uint8_t *in[4];
uint8_t *out[4];
int in_stride[4],out_stride[4];
int i;
for(i=0; i<4; i++){
int vsub= ((i+1)&2) ? scale->vsub : 0;
in_stride[i] = cur_pic->linesize[i] * mul;
out_stride[i] = out_buf->linesize[i] * mul;
in[i] = cur_pic->data[i] + ((y>>vsub)+field) * cur_pic->linesize[i];
out[i] = out_buf->data[i] + field * out_buf->linesize[i];
}
if(scale->input_is_pal)
in[1] = cur_pic->data[1];
if(scale->output_is_pal)
out[1] = out_buf->data[1];
return sws_scale(sws, in, in_stride, y/mul, h,
out,out_stride);
}
static int filter_frame(AVFilterLink *link, AVFrame *in)
{
ScaleContext *scale = link->dst->priv;
AVFilterLink *outlink = link->dst->outputs[0];
AVFrame *out;
const AVPixFmtDescriptor *desc = av_pix_fmt_desc_get(link->format);
char buf[32];
int in_range;
if( in->width != link->w
|| in->height != link->h
|| in->format != link->format) {
int ret;
snprintf(buf, sizeof(buf)-1, "%d", outlink->w);
av_opt_set(scale, "w", buf, 0);
snprintf(buf, sizeof(buf)-1, "%d", outlink->h);
av_opt_set(scale, "h", buf, 0);
link->dst->inputs[0]->format = in->format;
link->dst->inputs[0]->w = in->width;
link->dst->inputs[0]->h = in->height;
if ((ret = config_props(outlink)) < 0)
return ret;
}
if (!scale->sws)
return ff_filter_frame(outlink, in);
scale->hsub = desc->log2_chroma_w;
scale->vsub = desc->log2_chroma_h;
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);
out->width = outlink->w;
out->height = outlink->h;
if(scale->output_is_pal)
avpriv_set_systematic_pal2((uint32_t*)out->data[1], outlink->format == AV_PIX_FMT_PAL8 ? AV_PIX_FMT_BGR8 : outlink->format);
in_range = av_frame_get_color_range(in);
if ( scale->in_color_matrix
|| scale->out_color_matrix
|| scale-> in_range != AVCOL_RANGE_UNSPECIFIED
|| in_range != AVCOL_RANGE_UNSPECIFIED
|| scale->out_range != AVCOL_RANGE_UNSPECIFIED) {
int in_full, out_full, brightness, contrast, saturation;
const int *inv_table, *table;
sws_getColorspaceDetails(scale->sws, (int **)&inv_table, &in_full,
(int **)&table, &out_full,
&brightness, &contrast, &saturation);
if (scale->in_color_matrix)
inv_table = parse_yuv_type(scale->in_color_matrix, av_frame_get_colorspace(in));
if (scale->out_color_matrix)
table = parse_yuv_type(scale->out_color_matrix, AVCOL_SPC_UNSPECIFIED);
if (scale-> in_range != AVCOL_RANGE_UNSPECIFIED)
in_full = (scale-> in_range == AVCOL_RANGE_JPEG);
else if (in_range != AVCOL_RANGE_UNSPECIFIED)
in_full = (in_range == AVCOL_RANGE_JPEG);
if (scale->out_range != AVCOL_RANGE_UNSPECIFIED)
out_full = (scale->out_range == AVCOL_RANGE_JPEG);
sws_setColorspaceDetails(scale->sws, inv_table, in_full,
table, out_full,
brightness, contrast, saturation);
if (scale->isws[0])
sws_setColorspaceDetails(scale->isws[0], inv_table, in_full,
table, out_full,
brightness, contrast, saturation);
if (scale->isws[1])
sws_setColorspaceDetails(scale->isws[1], inv_table, in_full,
table, out_full,
brightness, contrast, saturation);
}
av_reduce(&out->sample_aspect_ratio.num, &out->sample_aspect_ratio.den,
(int64_t)in->sample_aspect_ratio.num * outlink->h * link->w,
(int64_t)in->sample_aspect_ratio.den * outlink->w * link->h,
INT_MAX);
if(scale->interlaced>0 || (scale->interlaced<0 && in->interlaced_frame)){
scale_slice(link, out, in, scale->isws[0], 0, (link->h+1)/2, 2, 0);
scale_slice(link, out, in, scale->isws[1], 0, link->h /2, 2, 1);
}else{
scale_slice(link, out, in, scale->sws, 0, link->h, 1, 0);
}
av_frame_free(&in);
return ff_filter_frame(outlink, out);
}
static const AVClass *child_class_next(const AVClass *prev)
{
return prev ? NULL : sws_get_class();
}
#define OFFSET(x) offsetof(ScaleContext, x)
#define FLAGS AV_OPT_FLAG_VIDEO_PARAM|AV_OPT_FLAG_FILTERING_PARAM
static const AVOption scale_options[] = {
{ "w", "Output video width", OFFSET(w_expr), AV_OPT_TYPE_STRING, .flags = FLAGS },
{ "width", "Output video width", OFFSET(w_expr), AV_OPT_TYPE_STRING, .flags = FLAGS },
{ "h", "Output video height", OFFSET(h_expr), AV_OPT_TYPE_STRING, .flags = FLAGS },
{ "height","Output video height", OFFSET(h_expr), AV_OPT_TYPE_STRING, .flags = FLAGS },
{ "flags", "Flags to pass to libswscale", OFFSET(flags_str), AV_OPT_TYPE_STRING, { .str = "bilinear" }, .flags = FLAGS },
{ "interl", "set interlacing", OFFSET(interlaced), AV_OPT_TYPE_INT, {.i64 = 0 }, -1, 1, FLAGS },
{ "size", "set video size", OFFSET(size_str), AV_OPT_TYPE_STRING, {.str = NULL}, 0, FLAGS },
{ "s", "set video size", OFFSET(size_str), AV_OPT_TYPE_STRING, {.str = NULL}, 0, FLAGS },
{ "in_color_matrix", "set input YCbCr type", OFFSET(in_color_matrix), AV_OPT_TYPE_STRING, { .str = "auto" }, .flags = FLAGS },
{ "out_color_matrix", "set output YCbCr type", OFFSET(out_color_matrix), AV_OPT_TYPE_STRING, { .str = NULL }, .flags = FLAGS },
{ "in_range", "set input color range", OFFSET( in_range), AV_OPT_TYPE_INT, {.i64 = AVCOL_RANGE_UNSPECIFIED }, 0, 2, FLAGS, "range" },
{ "out_range", "set output color range", OFFSET(out_range), AV_OPT_TYPE_INT, {.i64 = AVCOL_RANGE_UNSPECIFIED }, 0, 2, FLAGS, "range" },
{ "auto", NULL, 0, AV_OPT_TYPE_CONST, {.i64 = AVCOL_RANGE_UNSPECIFIED }, 0, 0, FLAGS, "range" },
{ "full", NULL, 0, AV_OPT_TYPE_CONST, {.i64 = AVCOL_RANGE_JPEG}, 0, 0, FLAGS, "range" },
{ "jpeg", NULL, 0, AV_OPT_TYPE_CONST, {.i64 = AVCOL_RANGE_JPEG}, 0, 0, FLAGS, "range" },
{ "mpeg", NULL, 0, AV_OPT_TYPE_CONST, {.i64 = AVCOL_RANGE_MPEG}, 0, 0, FLAGS, "range" },
{ "tv", NULL, 0, AV_OPT_TYPE_CONST, {.i64 = AVCOL_RANGE_MPEG}, 0, 0, FLAGS, "range" },
{ "pc", NULL, 0, AV_OPT_TYPE_CONST, {.i64 = AVCOL_RANGE_JPEG}, 0, 0, FLAGS, "range" },
{ "in_v_chr_pos", "input vertical chroma position in luma grid/256" , OFFSET(in_v_chr_pos), AV_OPT_TYPE_INT, { .i64 = -1}, -1, 512, FLAGS },
{ "in_h_chr_pos", "input horizontal chroma position in luma grid/256", OFFSET(in_h_chr_pos), AV_OPT_TYPE_INT, { .i64 = -1}, -1, 512, FLAGS },
{ "out_v_chr_pos", "output vertical chroma position in luma grid/256" , OFFSET(out_v_chr_pos), AV_OPT_TYPE_INT, { .i64 = -1}, -1, 512, FLAGS },
{ "out_h_chr_pos", "output horizontal chroma position in luma grid/256", OFFSET(out_h_chr_pos), AV_OPT_TYPE_INT, { .i64 = -1}, -1, 512, FLAGS },
{ "force_original_aspect_ratio", "decrease or increase w/h if necessary to keep the original AR", OFFSET(force_original_aspect_ratio), AV_OPT_TYPE_INT, { .i64 = 0}, 0, 2, FLAGS, "force_oar" },
{ "disable", NULL, 0, AV_OPT_TYPE_CONST, {.i64 = 0 }, 0, 0, FLAGS, "force_oar" },
{ "decrease", NULL, 0, AV_OPT_TYPE_CONST, {.i64 = 1 }, 0, 0, FLAGS, "force_oar" },
{ "increase", NULL, 0, AV_OPT_TYPE_CONST, {.i64 = 2 }, 0, 0, FLAGS, "force_oar" },
{ NULL }
};
static const AVClass scale_class = {
.class_name = "scale",
.item_name = av_default_item_name,
.option = scale_options,
.version = LIBAVUTIL_VERSION_INT,
.child_class_next = child_class_next,
};
static const AVFilterPad avfilter_vf_scale_inputs[] = {
{
.name = "default",
.type = AVMEDIA_TYPE_VIDEO,
.filter_frame = filter_frame,
},
{ NULL }
};
static const AVFilterPad avfilter_vf_scale_outputs[] = {
{
.name = "default",
.type = AVMEDIA_TYPE_VIDEO,
.config_props = config_props,
},
{ NULL }
};
AVFilter ff_vf_scale = {
.name = "scale",
.description = NULL_IF_CONFIG_SMALL("Scale the input video size and/or convert the image format."),
.init_dict = init_dict,
.uninit = uninit,
.query_formats = query_formats,
.priv_size = sizeof(ScaleContext),
.priv_class = &scale_class,
.inputs = avfilter_vf_scale_inputs,
.outputs = avfilter_vf_scale_outputs,
};