/*
  * Copyright (c) 2015 Paul B Mahol
  *
  * 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
  * zscale video filter using z.lib library
  */
 

 #include <float.h>

 #include <stdio.h>
 #include <string.h>
 
 #include <zimg.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/intreadwrite.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"
 
 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 ZScaleContext {
     const AVClass *class;
 
     /**
      * 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;
     int dither;
     int filter;
     int colorspace;
     int trc;
     int primaries;
     int range;

     int chromal;

     int colorspace_in;
     int trc_in;
     int primaries_in;
     int range_in;

     int chromal_in;

     char *size_str;

     double nominal_peak_luminance;

     int approximate_gamma;

 
     char *w_expr;               ///< width  expression string
     char *h_expr;               ///< height expression string
 
     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;
 
     void *tmp;
     size_t tmp_size;
 
     zimg_image_format src_format, dst_format;
     zimg_image_format alpha_src_format, alpha_dst_format;
     zimg_graph_builder_params alpha_params, params;
     zimg_filter_graph *alpha_graph, *graph;
 
     enum AVColorSpace in_colorspace, out_colorspace;
     enum AVColorTransferCharacteristic in_trc, out_trc;
     enum AVColorPrimaries in_primaries, out_primaries;
     enum AVColorRange in_range, out_range;

     enum AVChromaLocation in_chromal, out_chromal;

 } ZScaleContext;
 
 static av_cold int init_dict(AVFilterContext *ctx, AVDictionary **opts)
 {
     ZScaleContext *s = ctx->priv;
     int ret;
 
     if (s->size_str && (s->w_expr || s->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 (s->w_expr && !s->h_expr)
         FFSWAP(char *, s->w_expr, s->size_str);
 
     if (s->size_str) {
         char buf[32];
         if ((ret = av_parse_video_size(&s->w, &s->h, s->size_str)) < 0) {
             av_log(ctx, AV_LOG_ERROR,
                    "Invalid size '%s'\n", s->size_str);
             return ret;
         }
         snprintf(buf, sizeof(buf)-1, "%d", s->w);
         av_opt_set(s, "w", buf, 0);
         snprintf(buf, sizeof(buf)-1, "%d", s->h);
         av_opt_set(s, "h", buf, 0);
     }
     if (!s->w_expr)
         av_opt_set(s, "w", "iw", 0);
     if (!s->h_expr)
         av_opt_set(s, "h", "ih", 0);
 
     return 0;
 }
 
 static int query_formats(AVFilterContext *ctx)
 {
     static const enum AVPixelFormat pixel_fmts[] = {
         AV_PIX_FMT_YUV410P, AV_PIX_FMT_YUV411P,
         AV_PIX_FMT_YUV420P, AV_PIX_FMT_YUV422P,
         AV_PIX_FMT_YUV440P, AV_PIX_FMT_YUV444P,
         AV_PIX_FMT_YUVJ420P, AV_PIX_FMT_YUVJ422P,
         AV_PIX_FMT_YUVJ440P, AV_PIX_FMT_YUVJ444P,
         AV_PIX_FMT_YUVJ411P,
         AV_PIX_FMT_YUV420P9, AV_PIX_FMT_YUV422P9, AV_PIX_FMT_YUV444P9,
         AV_PIX_FMT_YUV420P10, AV_PIX_FMT_YUV422P10, AV_PIX_FMT_YUV444P10,
         AV_PIX_FMT_YUV420P12, AV_PIX_FMT_YUV422P12, AV_PIX_FMT_YUV444P12,
         AV_PIX_FMT_YUV420P14, AV_PIX_FMT_YUV422P14, AV_PIX_FMT_YUV444P14,
         AV_PIX_FMT_YUV420P16, AV_PIX_FMT_YUV422P16, AV_PIX_FMT_YUV444P16,
         AV_PIX_FMT_YUVA420P, AV_PIX_FMT_YUVA422P, AV_PIX_FMT_YUVA444P,
         AV_PIX_FMT_YUVA420P9, AV_PIX_FMT_YUVA422P9, AV_PIX_FMT_YUVA444P9,
         AV_PIX_FMT_YUVA420P10, AV_PIX_FMT_YUVA422P10, AV_PIX_FMT_YUVA444P10,
         AV_PIX_FMT_YUVA420P16, AV_PIX_FMT_YUVA422P16, AV_PIX_FMT_YUVA444P16,
         AV_PIX_FMT_GBRP, AV_PIX_FMT_GBRP9, AV_PIX_FMT_GBRP10,
         AV_PIX_FMT_GBRP12, AV_PIX_FMT_GBRP14, AV_PIX_FMT_GBRP16,
         AV_PIX_FMT_GBRAP, AV_PIX_FMT_GBRAP16,

         AV_PIX_FMT_GBRPF32, AV_PIX_FMT_GBRAPF32,

         AV_PIX_FMT_NONE
     };
     int ret;
 
     ret = ff_formats_ref(ff_make_format_list(pixel_fmts), &ctx->inputs[0]->out_formats);
     if (ret < 0)
         return ret;
     return ff_formats_ref(ff_make_format_list(pixel_fmts), &ctx->outputs[0]->in_formats);
 }
 
 static int config_props(AVFilterLink *outlink)
 {
     AVFilterContext *ctx = outlink->src;
     AVFilterLink *inlink = outlink->src->inputs[0];
     ZScaleContext *s = 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 = s->w_expr),
                            var_names, var_values,
                            NULL, NULL, NULL, NULL, NULL, 0, ctx);
     s->w = var_values[VAR_OUT_W] = var_values[VAR_OW] = res;
     if ((ret = av_expr_parse_and_eval(&res, (expr = s->h_expr),
                                       var_names, var_values,
                                       NULL, NULL, NULL, NULL, NULL, 0, ctx)) < 0)
         goto fail;
     s->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 = s->w_expr),
                                       var_names, var_values,
                                       NULL, NULL, NULL, NULL, NULL, 0, ctx)) < 0)
         goto fail;
     s->w = res;
 
     w = s->w;
     h = s->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)
         s->w = s->h = 0;
 
     if (!(w = s->w))
         w = inlink->w;
     if (!(h = s->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 (s->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 (s->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;
 
     if (inlink->w == outlink->w &&
         inlink->h == outlink->h &&
         inlink->format == outlink->format)
         ;
     else {
     }
 
     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\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);
     return 0;
 
 fail:
     av_log(ctx, 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, s->w_expr, s->h_expr);
     return ret;
 }
 
 static int print_zimg_error(AVFilterContext *ctx)
 {
     char err_msg[1024];
     int err_code = zimg_get_last_error(err_msg, sizeof(err_msg));
 
     av_log(ctx, AV_LOG_ERROR, "code %d: %s\n", err_code, err_msg);
 

     return AVERROR_EXTERNAL;

 }
 

 static int convert_chroma_location(enum AVChromaLocation chroma_location)
 {
     switch (chroma_location) {
     case AVCHROMA_LOC_UNSPECIFIED:
     case AVCHROMA_LOC_LEFT:
         return ZIMG_CHROMA_LEFT;
     case AVCHROMA_LOC_CENTER:
         return ZIMG_CHROMA_CENTER;
     case AVCHROMA_LOC_TOPLEFT:
         return ZIMG_CHROMA_TOP_LEFT;
     case AVCHROMA_LOC_TOP:
         return ZIMG_CHROMA_TOP;
     case AVCHROMA_LOC_BOTTOMLEFT:
         return ZIMG_CHROMA_BOTTOM_LEFT;
     case AVCHROMA_LOC_BOTTOM:
         return ZIMG_CHROMA_BOTTOM;
     }
     return ZIMG_CHROMA_LEFT;
 }
 

 static int convert_matrix(enum AVColorSpace colorspace)
 {
     switch (colorspace) {
     case AVCOL_SPC_RGB:
         return ZIMG_MATRIX_RGB;
     case AVCOL_SPC_BT709:
         return ZIMG_MATRIX_709;
     case AVCOL_SPC_UNSPECIFIED:
         return ZIMG_MATRIX_UNSPECIFIED;

     case AVCOL_SPC_FCC:
         return ZIMG_MATRIX_FCC;

     case AVCOL_SPC_BT470BG:
         return ZIMG_MATRIX_470BG;
     case AVCOL_SPC_SMPTE170M:
         return ZIMG_MATRIX_170M;

     case AVCOL_SPC_SMPTE240M:
         return ZIMG_MATRIX_240M;

     case AVCOL_SPC_YCGCO:
         return ZIMG_MATRIX_YCGCO;
     case AVCOL_SPC_BT2020_NCL:
         return ZIMG_MATRIX_2020_NCL;
     case AVCOL_SPC_BT2020_CL:
         return ZIMG_MATRIX_2020_CL;

     case AVCOL_SPC_CHROMA_DERIVED_NCL:
         return ZIMG_MATRIX_CHROMATICITY_DERIVED_NCL;
     case AVCOL_SPC_CHROMA_DERIVED_CL:
         return ZIMG_MATRIX_CHROMATICITY_DERIVED_CL;
     case AVCOL_SPC_ICTCP:
         return ZIMG_MATRIX_ICTCP;

     }
     return ZIMG_MATRIX_UNSPECIFIED;
 }
 
 static int convert_trc(enum AVColorTransferCharacteristic color_trc)
 {
     switch (color_trc) {
     case AVCOL_TRC_UNSPECIFIED:
         return ZIMG_TRANSFER_UNSPECIFIED;
     case AVCOL_TRC_BT709:
         return ZIMG_TRANSFER_709;

     case AVCOL_TRC_GAMMA22:
         return ZIMG_TRANSFER_470_M;
     case AVCOL_TRC_GAMMA28:
         return ZIMG_TRANSFER_470_BG;

     case AVCOL_TRC_SMPTE170M:
         return ZIMG_TRANSFER_601;

     case AVCOL_TRC_SMPTE240M:
         return ZIMG_TRANSFER_240M;

     case AVCOL_TRC_LINEAR:
         return ZIMG_TRANSFER_LINEAR;

     case AVCOL_TRC_LOG:
         return ZIMG_TRANSFER_LOG_100;
     case AVCOL_TRC_LOG_SQRT:
         return ZIMG_TRANSFER_LOG_316;
     case AVCOL_TRC_IEC61966_2_4:
         return ZIMG_TRANSFER_IEC_61966_2_4;

     case AVCOL_TRC_BT2020_10:
         return ZIMG_TRANSFER_2020_10;
     case AVCOL_TRC_BT2020_12:
         return ZIMG_TRANSFER_2020_12;

     case AVCOL_TRC_SMPTE2084:
         return ZIMG_TRANSFER_ST2084;
     case AVCOL_TRC_ARIB_STD_B67:
         return ZIMG_TRANSFER_ARIB_B67;
     case AVCOL_TRC_IEC61966_2_1:
         return ZIMG_TRANSFER_IEC_61966_2_1;

     }
     return ZIMG_TRANSFER_UNSPECIFIED;
 }
 
 static int convert_primaries(enum AVColorPrimaries color_primaries)
 {
     switch (color_primaries) {
     case AVCOL_PRI_UNSPECIFIED:
         return ZIMG_PRIMARIES_UNSPECIFIED;
     case AVCOL_PRI_BT709:
         return ZIMG_PRIMARIES_709;

     case AVCOL_PRI_BT470M:
         return ZIMG_PRIMARIES_470_M;
     case AVCOL_PRI_BT470BG:
         return ZIMG_PRIMARIES_470_BG;

     case AVCOL_PRI_SMPTE170M:
         return ZIMG_PRIMARIES_170M;
     case AVCOL_PRI_SMPTE240M:
         return ZIMG_PRIMARIES_240M;

     case AVCOL_PRI_FILM:
         return ZIMG_PRIMARIES_FILM;

     case AVCOL_PRI_BT2020:
         return ZIMG_PRIMARIES_2020;

     case AVCOL_PRI_SMPTE428:
         return ZIMG_PRIMARIES_ST428;
     case AVCOL_PRI_SMPTE431:
         return ZIMG_PRIMARIES_ST431_2;

     case AVCOL_PRI_SMPTE432:
         return ZIMG_PRIMARIES_ST432_1;

     case AVCOL_PRI_JEDEC_P22:
         return ZIMG_PRIMARIES_EBU3213_E;

     }
     return ZIMG_PRIMARIES_UNSPECIFIED;
 }
 
 static int convert_range(enum AVColorRange color_range)
 {
     switch (color_range) {
     case AVCOL_RANGE_UNSPECIFIED:
     case AVCOL_RANGE_MPEG:
         return ZIMG_RANGE_LIMITED;
     case AVCOL_RANGE_JPEG:
         return ZIMG_RANGE_FULL;
     }
     return ZIMG_RANGE_LIMITED;
 }
 

 static void format_init(zimg_image_format *format, AVFrame *frame, const AVPixFmtDescriptor *desc,
                         int colorspace, int primaries, int transfer, int range, int location)
 {
     format->width = frame->width;
     format->height = frame->height;
     format->subsample_w = desc->log2_chroma_w;
     format->subsample_h = desc->log2_chroma_h;
     format->depth = desc->comp[0].depth;

     format->pixel_type = (desc->flags & AV_PIX_FMT_FLAG_FLOAT) ? ZIMG_PIXEL_FLOAT : desc->comp[0].depth > 8 ? ZIMG_PIXEL_WORD : ZIMG_PIXEL_BYTE;

     format->color_family = (desc->flags & AV_PIX_FMT_FLAG_RGB) ? ZIMG_COLOR_RGB : ZIMG_COLOR_YUV;
     format->matrix_coefficients = (desc->flags & AV_PIX_FMT_FLAG_RGB) ? ZIMG_MATRIX_RGB : colorspace == -1 ? convert_matrix(frame->colorspace) : colorspace;
     format->color_primaries = primaries == -1 ? convert_primaries(frame->color_primaries) : primaries;
     format->transfer_characteristics = transfer == - 1 ? convert_trc(frame->color_trc) : transfer;
     format->pixel_range = (desc->flags & AV_PIX_FMT_FLAG_RGB) ? ZIMG_RANGE_FULL : range == -1 ? convert_range(frame->color_range) : range;
     format->chroma_location = location == -1 ? convert_chroma_location(frame->chroma_location) : location;
 }
 

 static int graph_build(zimg_filter_graph **graph, zimg_graph_builder_params *params,
                        zimg_image_format *src_format, zimg_image_format *dst_format,
                        void **tmp, size_t *tmp_size)
 {
     int ret;
     size_t size;
 
     zimg_filter_graph_free(*graph);
     *graph = zimg_filter_graph_build(src_format, dst_format, params);
     if (!*graph)
         return print_zimg_error(NULL);
 
     ret = zimg_filter_graph_get_tmp_size(*graph, &size);
     if (ret)
         return print_zimg_error(NULL);
 
     if (size > *tmp_size) {
         av_freep(tmp);
         *tmp = av_malloc(size);
         if (!*tmp)
             return AVERROR(ENOMEM);
 
         *tmp_size = size;
     }
 
     return 0;
 }
 

 static int filter_frame(AVFilterLink *link, AVFrame *in)
 {
     ZScaleContext *s = link->dst->priv;
     AVFilterLink *outlink = link->dst->outputs[0];
     const AVPixFmtDescriptor *desc = av_pix_fmt_desc_get(link->format);
     const AVPixFmtDescriptor *odesc = av_pix_fmt_desc_get(outlink->format);
     zimg_image_buffer_const src_buf = { ZIMG_API_VERSION };
     zimg_image_buffer dst_buf = { ZIMG_API_VERSION };
     char buf[32];
     int ret = 0, plane;
     AVFrame *out;
 
     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(   in->width  != link->w
        || in->height != link->h
        || in->format != link->format
        || s->in_colorspace != in->colorspace
        || s->in_trc  != in->color_trc
        || s->in_primaries != in->color_primaries
        || s->in_range != in->color_range
        || s->out_colorspace != out->colorspace
        || s->out_trc  != out->color_trc
        || s->out_primaries != out->color_primaries

        || s->out_range != out->color_range
        || s->in_chromal != in->chroma_location
        || s->out_chromal != out->chroma_location) {

         snprintf(buf, sizeof(buf)-1, "%d", outlink->w);
         av_opt_set(s, "w", buf, 0);
         snprintf(buf, sizeof(buf)-1, "%d", outlink->h);
         av_opt_set(s, "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) {
             av_frame_free(&in);
             av_frame_free(&out);
             return ret;
         }
 
         zimg_image_format_default(&s->src_format, ZIMG_API_VERSION);
         zimg_image_format_default(&s->dst_format, ZIMG_API_VERSION);
         zimg_graph_builder_params_default(&s->params, ZIMG_API_VERSION);
 
         s->params.dither_type = s->dither;
         s->params.cpu_type = ZIMG_CPU_AUTO;
         s->params.resample_filter = s->filter;
         s->params.resample_filter_uv = s->filter;

         s->params.nominal_peak_luminance = s->nominal_peak_luminance;

         s->params.allow_approximate_gamma = s->approximate_gamma;

         format_init(&s->src_format, in, desc, s->colorspace_in,
                     s->primaries_in, s->trc_in, s->range_in, s->chromal_in);
         format_init(&s->dst_format, out, odesc, s->colorspace,
                     s->primaries, s->trc, s->range, s->chromal);

 
         if (s->colorspace != -1)
             out->colorspace = (int)s->dst_format.matrix_coefficients;
 
         if (s->primaries != -1)
             out->color_primaries = (int)s->dst_format.color_primaries;
 
         if (s->range != -1)
             out->color_range = (int)s->dst_format.pixel_range + 1;
 
         if (s->trc != -1)
             out->color_trc = (int)s->dst_format.transfer_characteristics;
 

         if (s->chromal != -1)
             out->chroma_location = (int)s->dst_format.chroma_location - 1;
 

         ret = graph_build(&s->graph, &s->params, &s->src_format, &s->dst_format,
                           &s->tmp, &s->tmp_size);
         if (ret < 0)

             goto fail;
 
         s->in_colorspace  = in->colorspace;
         s->in_trc         = in->color_trc;
         s->in_primaries   = in->color_primaries;
         s->in_range       = in->color_range;
         s->out_colorspace = out->colorspace;
         s->out_trc        = out->color_trc;
         s->out_primaries  = out->color_primaries;
         s->out_range      = out->color_range;
 
         if (desc->flags & AV_PIX_FMT_FLAG_ALPHA && odesc->flags & AV_PIX_FMT_FLAG_ALPHA) {
             zimg_image_format_default(&s->alpha_src_format, ZIMG_API_VERSION);
             zimg_image_format_default(&s->alpha_dst_format, ZIMG_API_VERSION);
             zimg_graph_builder_params_default(&s->alpha_params, ZIMG_API_VERSION);
 
             s->alpha_params.dither_type = s->dither;
             s->alpha_params.cpu_type = ZIMG_CPU_AUTO;
             s->alpha_params.resample_filter = s->filter;
 
             s->alpha_src_format.width = in->width;
             s->alpha_src_format.height = in->height;
             s->alpha_src_format.depth = desc->comp[0].depth;

             s->alpha_src_format.pixel_type = (desc->flags & AV_PIX_FMT_FLAG_FLOAT) ? ZIMG_PIXEL_FLOAT : desc->comp[0].depth > 8 ? ZIMG_PIXEL_WORD : ZIMG_PIXEL_BYTE;

             s->alpha_src_format.color_family = ZIMG_COLOR_GREY;
 
             s->alpha_dst_format.width = out->width;
             s->alpha_dst_format.height = out->height;
             s->alpha_dst_format.depth = odesc->comp[0].depth;

             s->alpha_dst_format.pixel_type = (desc->flags & AV_PIX_FMT_FLAG_FLOAT) ? ZIMG_PIXEL_FLOAT : odesc->comp[0].depth > 8 ? ZIMG_PIXEL_WORD : ZIMG_PIXEL_BYTE;

             s->alpha_dst_format.color_family = ZIMG_COLOR_GREY;
 
             zimg_filter_graph_free(s->alpha_graph);
             s->alpha_graph = zimg_filter_graph_build(&s->alpha_src_format, &s->alpha_dst_format, &s->alpha_params);
             if (!s->alpha_graph) {
                 ret = print_zimg_error(link->dst);
                 goto fail;
             }
         }
     }
 
     if (s->colorspace != -1)
         out->colorspace = (int)s->dst_format.matrix_coefficients;
 
     if (s->primaries != -1)
         out->color_primaries = (int)s->dst_format.color_primaries;
 
     if (s->range != -1)
         out->color_range = (int)s->dst_format.pixel_range;
 
     if (s->trc != -1)
         out->color_trc = (int)s->dst_format.transfer_characteristics;
 
     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);
 
     for (plane = 0; plane < 3; plane++) {
         int p = desc->comp[plane].plane;
         src_buf.plane[plane].data   = in->data[p];
         src_buf.plane[plane].stride = in->linesize[p];
         src_buf.plane[plane].mask   = -1;
 
         p = odesc->comp[plane].plane;
         dst_buf.plane[plane].data   = out->data[p];
         dst_buf.plane[plane].stride = out->linesize[p];
         dst_buf.plane[plane].mask   = -1;
     }
 
     ret = zimg_filter_graph_process(s->graph, &src_buf, &dst_buf, s->tmp, 0, 0, 0, 0);
     if (ret) {

         ret = print_zimg_error(link->dst);

         goto fail;
     }
 
     if (desc->flags & AV_PIX_FMT_FLAG_ALPHA && odesc->flags & AV_PIX_FMT_FLAG_ALPHA) {
         src_buf.plane[0].data   = in->data[3];
         src_buf.plane[0].stride = in->linesize[3];
         src_buf.plane[0].mask   = -1;
 
         dst_buf.plane[0].data   = out->data[3];
         dst_buf.plane[0].stride = out->linesize[3];
         dst_buf.plane[0].mask   = -1;
 
         ret = zimg_filter_graph_process(s->alpha_graph, &src_buf, &dst_buf, s->tmp, 0, 0, 0, 0);
         if (ret) {

             ret = print_zimg_error(link->dst);

             goto fail;
         }
     } else if (odesc->flags & AV_PIX_FMT_FLAG_ALPHA) {

         int x, y;
 
         if (odesc->flags & AV_PIX_FMT_FLAG_FLOAT) {
             for (y = 0; y < out->height; y++) {
                 for (x = 0; x < out->width; x++) {
                     AV_WN32(out->data[3] + x * odesc->comp[3].step + y * out->linesize[3],
                             av_float2int(1.0f));
                 }
             }
         } else {
             for (y = 0; y < outlink->h; y++)
                 memset(out->data[3] + y * out->linesize[3], 0xff, outlink->w);
         }

     }
 
 fail:
     av_frame_free(&in);
     if (ret) {
         av_frame_free(&out);
         return ret;
     }
 
     return ff_filter_frame(outlink, out);
 }
 
 static void uninit(AVFilterContext *ctx)
 {
     ZScaleContext *s = ctx->priv;
 
     zimg_filter_graph_free(s->graph);

     zimg_filter_graph_free(s->alpha_graph);

     av_freep(&s->tmp);
     s->tmp_size = 0;
 }
 
 static int process_command(AVFilterContext *ctx, const char *cmd, const char *args,
                            char *res, int res_len, int flags)
 {
     ZScaleContext *s = ctx->priv;
     int ret;
 
     if (   !strcmp(cmd, "width")  || !strcmp(cmd, "w")
         || !strcmp(cmd, "height") || !strcmp(cmd, "h")) {
 
         int old_w = s->w;
         int old_h = s->h;
         AVFilterLink *outlink = ctx->outputs[0];
 
         av_opt_set(s, cmd, args, 0);
         if ((ret = config_props(outlink)) < 0) {
             s->w = old_w;
             s->h = old_h;
         }
     } else
         ret = AVERROR(ENOSYS);
 
     return ret;
 }
 
 #define OFFSET(x) offsetof(ZScaleContext, x)
 #define FLAGS AV_OPT_FLAG_VIDEO_PARAM|AV_OPT_FLAG_FILTERING_PARAM
 
 static const AVOption zscale_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 },
     { "size",   "set video size",      OFFSET(size_str),  AV_OPT_TYPE_STRING, {.str = NULL}, 0, 0, FLAGS },
     { "s",      "set video size",      OFFSET(size_str),  AV_OPT_TYPE_STRING, {.str = NULL}, 0, 0, FLAGS },
     { "dither", "set dither type",     OFFSET(dither),    AV_OPT_TYPE_INT, {.i64 = 0}, 0, ZIMG_DITHER_ERROR_DIFFUSION, FLAGS, "dither" },
     { "d",      "set dither type",     OFFSET(dither),    AV_OPT_TYPE_INT, {.i64 = 0}, 0, ZIMG_DITHER_ERROR_DIFFUSION, FLAGS, "dither" },
     {     "none",             0,       0,                 AV_OPT_TYPE_CONST, {.i64 = ZIMG_DITHER_NONE},     0, 0, FLAGS, "dither" },
     {     "ordered",          0,       0,                 AV_OPT_TYPE_CONST, {.i64 = ZIMG_DITHER_ORDERED},  0, 0, FLAGS, "dither" },
     {     "random",           0,       0,                 AV_OPT_TYPE_CONST, {.i64 = ZIMG_DITHER_RANDOM},   0, 0, FLAGS, "dither" },
     {     "error_diffusion",  0,       0,                 AV_OPT_TYPE_CONST, {.i64 = ZIMG_DITHER_ERROR_DIFFUSION}, 0, 0, FLAGS, "dither" },
     { "filter", "set filter type",     OFFSET(filter),    AV_OPT_TYPE_INT, {.i64 = ZIMG_RESIZE_BILINEAR}, 0, ZIMG_RESIZE_LANCZOS, FLAGS, "filter" },
     { "f",      "set filter type",     OFFSET(filter),    AV_OPT_TYPE_INT, {.i64 = ZIMG_RESIZE_BILINEAR}, 0, ZIMG_RESIZE_LANCZOS, FLAGS, "filter" },
     {     "point",            0,       0,                 AV_OPT_TYPE_CONST, {.i64 = ZIMG_RESIZE_POINT},    0, 0, FLAGS, "filter" },
     {     "bilinear",         0,       0,                 AV_OPT_TYPE_CONST, {.i64 = ZIMG_RESIZE_BILINEAR}, 0, 0, FLAGS, "filter" },
     {     "bicubic",          0,       0,                 AV_OPT_TYPE_CONST, {.i64 = ZIMG_RESIZE_BICUBIC},  0, 0, FLAGS, "filter" },
     {     "spline16",         0,       0,                 AV_OPT_TYPE_CONST, {.i64 = ZIMG_RESIZE_SPLINE16}, 0, 0, FLAGS, "filter" },

     {     "spline36",         0,       0,                 AV_OPT_TYPE_CONST, {.i64 = ZIMG_RESIZE_SPLINE36}, 0, 0, FLAGS, "filter" },

     {     "lanczos",          0,       0,                 AV_OPT_TYPE_CONST, {.i64 = ZIMG_RESIZE_LANCZOS},  0, 0, FLAGS, "filter" },

     { "out_range", "set color range",  OFFSET(range),     AV_OPT_TYPE_INT, {.i64 = -1}, -1, ZIMG_RANGE_FULL, FLAGS, "range" },

     { "range", "set color range",      OFFSET(range),     AV_OPT_TYPE_INT, {.i64 = -1}, -1, ZIMG_RANGE_FULL, FLAGS, "range" },
     { "r",     "set color range",      OFFSET(range),     AV_OPT_TYPE_INT, {.i64 = -1}, -1, ZIMG_RANGE_FULL, FLAGS, "range" },
     {     "input",            0,       0,                 AV_OPT_TYPE_CONST, {.i64 = -1},                 0, 0, FLAGS, "range" },
     {     "limited",          0,       0,                 AV_OPT_TYPE_CONST, {.i64 = ZIMG_RANGE_LIMITED}, 0, 0, FLAGS, "range" },
     {     "full",             0,       0,                 AV_OPT_TYPE_CONST, {.i64 = ZIMG_RANGE_FULL},    0, 0, FLAGS, "range" },

     {     "unknown",          0,       0,                 AV_OPT_TYPE_CONST, {.i64 = -1},                 0, 0, FLAGS, "range" },
     {     "tv",               0,       0,                 AV_OPT_TYPE_CONST, {.i64 = ZIMG_RANGE_LIMITED}, 0, 0, FLAGS, "range" },
     {     "pc",               0,       0,                 AV_OPT_TYPE_CONST, {.i64 = ZIMG_RANGE_FULL},    0, 0, FLAGS, "range" },

     { "primaries", "set color primaries", OFFSET(primaries), AV_OPT_TYPE_INT, {.i64 = -1}, -1, INT_MAX, FLAGS, "primaries" },
     { "p",         "set color primaries", OFFSET(primaries), AV_OPT_TYPE_INT, {.i64 = -1}, -1, INT_MAX, FLAGS, "primaries" },

     {     "input",            0,       0,                 AV_OPT_TYPE_CONST, {.i64 = -1},                         0, 0, FLAGS, "primaries" },
     {     "709",              0,       0,                 AV_OPT_TYPE_CONST, {.i64 = ZIMG_PRIMARIES_709},         0, 0, FLAGS, "primaries" },
     {     "unspecified",      0,       0,                 AV_OPT_TYPE_CONST, {.i64 = ZIMG_PRIMARIES_UNSPECIFIED}, 0, 0, FLAGS, "primaries" },
     {     "170m",             0,       0,                 AV_OPT_TYPE_CONST, {.i64 = ZIMG_PRIMARIES_170M},        0, 0, FLAGS, "primaries" },
     {     "240m",             0,       0,                 AV_OPT_TYPE_CONST, {.i64 = ZIMG_PRIMARIES_240M},        0, 0, FLAGS, "primaries" },
     {     "2020",             0,       0,                 AV_OPT_TYPE_CONST, {.i64 = ZIMG_PRIMARIES_2020},        0, 0, FLAGS, "primaries" },

     {     "unknown",          0,       0,                 AV_OPT_TYPE_CONST, {.i64 = ZIMG_PRIMARIES_UNSPECIFIED}, 0, 0, FLAGS, "primaries" },
     {     "bt709",            0,       0,                 AV_OPT_TYPE_CONST, {.i64 = ZIMG_PRIMARIES_709},         0, 0, FLAGS, "primaries" },

     {     "bt470m",           0,       0,                 AV_OPT_TYPE_CONST, {.i64 = ZIMG_PRIMARIES_470_M},       0, 0, FLAGS, "primaries" },
     {     "bt470bg",          0,       0,                 AV_OPT_TYPE_CONST, {.i64 = ZIMG_PRIMARIES_470_BG},      0, 0, FLAGS, "primaries" },

     {     "smpte170m",        0,       0,                 AV_OPT_TYPE_CONST, {.i64 = ZIMG_PRIMARIES_170M},        0, 0, FLAGS, "primaries" },
     {     "smpte240m",        0,       0,                 AV_OPT_TYPE_CONST, {.i64 = ZIMG_PRIMARIES_240M},        0, 0, FLAGS, "primaries" },

     {     "film",             0,       0,                 AV_OPT_TYPE_CONST, {.i64 = ZIMG_PRIMARIES_FILM},        0, 0, FLAGS, "primaries" },

     {     "bt2020",           0,       0,                 AV_OPT_TYPE_CONST, {.i64 = ZIMG_PRIMARIES_2020},        0, 0, FLAGS, "primaries" },

     {     "smpte428",         0,       0,                 AV_OPT_TYPE_CONST, {.i64 = ZIMG_PRIMARIES_ST428},       0, 0, FLAGS, "primaries" },
     {     "smpte431",         0,       0,                 AV_OPT_TYPE_CONST, {.i64 = ZIMG_PRIMARIES_ST431_2},     0, 0, FLAGS, "primaries" },

     {     "smpte432",         0,       0,                 AV_OPT_TYPE_CONST, {.i64 = ZIMG_PRIMARIES_ST432_1},     0, 0, FLAGS, "primaries" },

     {     "jedec-p22",        0,       0,                 AV_OPT_TYPE_CONST, {.i64 = ZIMG_PRIMARIES_EBU3213_E},   0, 0, FLAGS, "primaries" },

     { "transfer", "set transfer characteristic", OFFSET(trc), AV_OPT_TYPE_INT, {.i64 = -1}, -1, INT_MAX, FLAGS, "transfer" },
     { "t",        "set transfer characteristic", OFFSET(trc), AV_OPT_TYPE_INT, {.i64 = -1}, -1, INT_MAX, FLAGS, "transfer" },

     {     "input",            0,       0,                 AV_OPT_TYPE_CONST, {.i64 = -1},                         0, 0, FLAGS, "transfer" },
     {     "709",              0,       0,                 AV_OPT_TYPE_CONST, {.i64 = ZIMG_TRANSFER_709},         0, 0, FLAGS, "transfer" },
     {     "unspecified",      0,       0,                 AV_OPT_TYPE_CONST, {.i64 = ZIMG_TRANSFER_UNSPECIFIED}, 0, 0, FLAGS, "transfer" },
     {     "601",              0,       0,                 AV_OPT_TYPE_CONST, {.i64 = ZIMG_TRANSFER_601},         0, 0, FLAGS, "transfer" },
     {     "linear",           0,       0,                 AV_OPT_TYPE_CONST, {.i64 = ZIMG_TRANSFER_LINEAR},      0, 0, FLAGS, "transfer" },
     {     "2020_10",          0,       0,                 AV_OPT_TYPE_CONST, {.i64 = ZIMG_TRANSFER_2020_10},     0, 0, FLAGS, "transfer" },
     {     "2020_12",          0,       0,                 AV_OPT_TYPE_CONST, {.i64 = ZIMG_TRANSFER_2020_12},     0, 0, FLAGS, "transfer" },

     {     "unknown",          0,       0,                 AV_OPT_TYPE_CONST, {.i64 = ZIMG_TRANSFER_UNSPECIFIED}, 0, 0, FLAGS, "transfer" },

     {     "bt470m",           0,       0,                 AV_OPT_TYPE_CONST, {.i64 = ZIMG_TRANSFER_470_M},       0, 0, FLAGS, "transfer" },
     {     "bt470bg",          0,       0,                 AV_OPT_TYPE_CONST, {.i64 = ZIMG_TRANSFER_470_BG},      0, 0, FLAGS, "transfer" },

     {     "smpte170m",        0,       0,                 AV_OPT_TYPE_CONST, {.i64 = ZIMG_TRANSFER_601},         0, 0, FLAGS, "transfer" },
     {     "bt709",            0,       0,                 AV_OPT_TYPE_CONST, {.i64 = ZIMG_TRANSFER_709},         0, 0, FLAGS, "transfer" },
     {     "linear",           0,       0,                 AV_OPT_TYPE_CONST, {.i64 = ZIMG_TRANSFER_LINEAR},      0, 0, FLAGS, "transfer" },

     {     "log100",           0,       0,                 AV_OPT_TYPE_CONST, {.i64 = ZIMG_TRANSFER_LOG_100},     0, 0, FLAGS, "transfer" },
     {     "log316",           0,       0,                 AV_OPT_TYPE_CONST, {.i64 = ZIMG_TRANSFER_LOG_316},     0, 0, FLAGS, "transfer" },

     {     "bt2020-10",        0,       0,                 AV_OPT_TYPE_CONST, {.i64 = ZIMG_TRANSFER_2020_10},     0, 0, FLAGS, "transfer" },
     {     "bt2020-12",        0,       0,                 AV_OPT_TYPE_CONST, {.i64 = ZIMG_TRANSFER_2020_12},     0, 0, FLAGS, "transfer" },

     {     "smpte2084",        0,       0,                 AV_OPT_TYPE_CONST, {.i64 = ZIMG_TRANSFER_ST2084},      0, 0, FLAGS, "transfer" },

     {     "iec61966-2-4",     0,       0,                 AV_OPT_TYPE_CONST, {.i64 = ZIMG_TRANSFER_IEC_61966_2_4},0, 0, FLAGS, "transfer" },

     {     "iec61966-2-1",     0,       0,                 AV_OPT_TYPE_CONST, {.i64 = ZIMG_TRANSFER_IEC_61966_2_1},0, 0, FLAGS, "transfer" },
     {     "arib-std-b67",     0,       0,                 AV_OPT_TYPE_CONST, {.i64 = ZIMG_TRANSFER_ARIB_B67},    0, 0, FLAGS, "transfer" },

     { "matrix", "set colorspace matrix", OFFSET(colorspace), AV_OPT_TYPE_INT, {.i64 = -1}, -1, INT_MAX, FLAGS, "matrix" },
     { "m",      "set colorspace matrix", OFFSET(colorspace), AV_OPT_TYPE_INT, {.i64 = -1}, -1, INT_MAX, FLAGS, "matrix" },

     {     "input",            0,       0,                 AV_OPT_TYPE_CONST, {.i64 = -1},                      0, 0, FLAGS, "matrix" },
     {     "709",              0,       0,                 AV_OPT_TYPE_CONST, {.i64 = ZIMG_MATRIX_709},         0, 0, FLAGS, "matrix" },
     {     "unspecified",      0,       0,                 AV_OPT_TYPE_CONST, {.i64 = ZIMG_MATRIX_UNSPECIFIED}, 0, 0, FLAGS, "matrix" },
     {     "470bg",            0,       0,                 AV_OPT_TYPE_CONST, {.i64 = ZIMG_MATRIX_470BG},       0, 0, FLAGS, "matrix" },
     {     "170m",             0,       0,                 AV_OPT_TYPE_CONST, {.i64 = ZIMG_MATRIX_170M},        0, 0, FLAGS, "matrix" },
     {     "2020_ncl",         0,       0,                 AV_OPT_TYPE_CONST, {.i64 = ZIMG_MATRIX_2020_NCL},    0, 0, FLAGS, "matrix" },
     {     "2020_cl",          0,       0,                 AV_OPT_TYPE_CONST, {.i64 = ZIMG_MATRIX_2020_CL},     0, 0, FLAGS, "matrix" },

     {     "unknown",          0,       0,                 AV_OPT_TYPE_CONST, {.i64 = ZIMG_MATRIX_UNSPECIFIED}, 0, 0, FLAGS, "matrix" },

     {     "gbr",              0,       0,                 AV_OPT_TYPE_CONST, {.i64 = ZIMG_MATRIX_RGB},         0, 0, FLAGS, "matrix" },

     {     "bt709",            0,       0,                 AV_OPT_TYPE_CONST, {.i64 = ZIMG_MATRIX_709},         0, 0, FLAGS, "matrix" },

     {     "fcc",              0,       0,                 AV_OPT_TYPE_CONST, {.i64 = ZIMG_MATRIX_FCC},         0, 0, FLAGS, "matrix" },

     {     "bt470bg",          0,       0,                 AV_OPT_TYPE_CONST, {.i64 = ZIMG_MATRIX_470BG},       0, 0, FLAGS, "matrix" },
     {     "smpte170m",        0,       0,                 AV_OPT_TYPE_CONST, {.i64 = ZIMG_MATRIX_170M},        0, 0, FLAGS, "matrix" },

     {     "smpte2400m",       0,       0,                 AV_OPT_TYPE_CONST, {.i64 = ZIMG_MATRIX_240M},        0, 0, FLAGS, "matrix" },

     {     "ycgco",            0,       0,                 AV_OPT_TYPE_CONST, {.i64 = ZIMG_MATRIX_YCGCO},       0, 0, FLAGS, "matrix" },
     {     "bt2020nc",         0,       0,                 AV_OPT_TYPE_CONST, {.i64 = ZIMG_MATRIX_2020_NCL},    0, 0, FLAGS, "matrix" },
     {     "bt2020c",          0,       0,                 AV_OPT_TYPE_CONST, {.i64 = ZIMG_MATRIX_2020_CL},     0, 0, FLAGS, "matrix" },

     {     "chroma-derived-nc",0,       0,                 AV_OPT_TYPE_CONST, {.i64 = ZIMG_MATRIX_CHROMATICITY_DERIVED_NCL}, 0, 0, FLAGS, "matrix" },
     {     "chroma-derived-c", 0,       0,                 AV_OPT_TYPE_CONST, {.i64 = ZIMG_MATRIX_CHROMATICITY_DERIVED_CL}, 0, 0, FLAGS, "matrix" },
     {     "ictcp",            0,       0,                 AV_OPT_TYPE_CONST, {.i64 = ZIMG_MATRIX_ICTCP},       0, 0, FLAGS, "matrix" },

     { "in_range", "set input color range", OFFSET(range_in),    AV_OPT_TYPE_INT, {.i64 = -1}, -1, ZIMG_RANGE_FULL, FLAGS, "range" },

     { "rangein", "set input color range", OFFSET(range_in),     AV_OPT_TYPE_INT, {.i64 = -1}, -1, ZIMG_RANGE_FULL, FLAGS, "range" },
     { "rin",     "set input color range", OFFSET(range_in),     AV_OPT_TYPE_INT, {.i64 = -1}, -1, ZIMG_RANGE_FULL, FLAGS, "range" },

     { "primariesin", "set input color primaries", OFFSET(primaries_in), AV_OPT_TYPE_INT, {.i64 = -1}, -1, INT_MAX, FLAGS, "primaries" },
     { "pin",         "set input color primaries", OFFSET(primaries_in), AV_OPT_TYPE_INT, {.i64 = -1}, -1, INT_MAX, FLAGS, "primaries" },
     { "transferin", "set input transfer characteristic", OFFSET(trc_in), AV_OPT_TYPE_INT, {.i64 = -1}, -1, INT_MAX, FLAGS, "transfer" },
     { "tin",        "set input transfer characteristic", OFFSET(trc_in), AV_OPT_TYPE_INT, {.i64 = -1}, -1, INT_MAX, FLAGS, "transfer" },
     { "matrixin", "set input colorspace matrix", OFFSET(colorspace_in), AV_OPT_TYPE_INT, {.i64 = -1}, -1, INT_MAX, FLAGS, "matrix" },
     { "min",      "set input colorspace matrix", OFFSET(colorspace_in), AV_OPT_TYPE_INT, {.i64 = -1}, -1, INT_MAX, FLAGS, "matrix" },

     { "chromal",  "set output chroma location", OFFSET(chromal), AV_OPT_TYPE_INT, {.i64 = -1}, -1, ZIMG_CHROMA_BOTTOM, FLAGS, "chroma" },
     { "c",        "set output chroma location", OFFSET(chromal), AV_OPT_TYPE_INT, {.i64 = -1}, -1, ZIMG_CHROMA_BOTTOM, FLAGS, "chroma" },
     {     "input",     0, 0, AV_OPT_TYPE_CONST, {.i64 = -1},                       0, 0, FLAGS, "chroma" },
     {     "left",      0, 0, AV_OPT_TYPE_CONST, {.i64 = ZIMG_CHROMA_LEFT},         0, 0, FLAGS, "chroma" },
     {     "center",    0, 0, AV_OPT_TYPE_CONST, {.i64 = ZIMG_CHROMA_CENTER},       0, 0, FLAGS, "chroma" },
     {     "topleft",   0, 0, AV_OPT_TYPE_CONST, {.i64 = ZIMG_CHROMA_TOP_LEFT},     0, 0, FLAGS, "chroma" },
     {     "top",       0, 0, AV_OPT_TYPE_CONST, {.i64 = ZIMG_CHROMA_TOP},          0, 0, FLAGS, "chroma" },
     {     "bottomleft",0, 0, AV_OPT_TYPE_CONST, {.i64 = ZIMG_CHROMA_BOTTOM_LEFT},  0, 0, FLAGS, "chroma" },
     {     "bottom",    0, 0, AV_OPT_TYPE_CONST, {.i64 = ZIMG_CHROMA_BOTTOM},       0, 0, FLAGS, "chroma" },
     { "chromalin",  "set input chroma location", OFFSET(chromal_in), AV_OPT_TYPE_INT, {.i64 = -1}, -1, ZIMG_CHROMA_BOTTOM, FLAGS, "chroma" },
     { "cin",        "set input chroma location", OFFSET(chromal_in), AV_OPT_TYPE_INT, {.i64 = -1}, -1, ZIMG_CHROMA_BOTTOM, FLAGS, "chroma" },

     { "npl",       "set nominal peak luminance", OFFSET(nominal_peak_luminance), AV_OPT_TYPE_DOUBLE, {.dbl = NAN}, 0, DBL_MAX, FLAGS },

     { "agamma",       "allow approximate gamma", OFFSET(approximate_gamma),      AV_OPT_TYPE_BOOL,   {.i64 = 1},   0, 1,       FLAGS },

     { NULL }
 };
 
 static const AVClass zscale_class = {
     .class_name       = "zscale",
     .item_name        = av_default_item_name,
     .option           = zscale_options,
     .version          = LIBAVUTIL_VERSION_INT,
     .category         = AV_CLASS_CATEGORY_FILTER,
 };
 
 static const AVFilterPad avfilter_vf_zscale_inputs[] = {
     {
         .name         = "default",
         .type         = AVMEDIA_TYPE_VIDEO,
         .filter_frame = filter_frame,
     },
     { NULL }
 };
 
 static const AVFilterPad avfilter_vf_zscale_outputs[] = {
     {
         .name         = "default",
         .type         = AVMEDIA_TYPE_VIDEO,
         .config_props = config_props,
     },
     { NULL }
 };
 
 AVFilter ff_vf_zscale = {
     .name            = "zscale",
     .description     = NULL_IF_CONFIG_SMALL("Apply resizing, colorspace and bit depth conversion."),
     .init_dict       = init_dict,
     .query_formats   = query_formats,
     .priv_size       = sizeof(ZScaleContext),
     .priv_class      = &zscale_class,
     .uninit          = uninit,
     .inputs          = avfilter_vf_zscale_inputs,
     .outputs         = avfilter_vf_zscale_outputs,
     .process_command = process_command,
 };