libavfilter/vf_histogram.c - nest-android-app/ffmpeg - Git at Google

 /*
  * Copyright (c) 2012-2013 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
  */

 #include "libavutil/avassert.h"
 #include "libavutil/opt.h"
 #include "libavutil/parseutils.h"
 #include "libavutil/pixdesc.h"
 #include "libavutil/imgutils.h"
 #include "libavutil/intreadwrite.h"
 #include "avfilter.h"
 #include "formats.h"
 #include "internal.h"
 #include "video.h"

 typedef struct HistogramContext {
     const AVClass *class;               ///< AVClass context for log and options purpose
     unsigned       histogram[256*256];
     int            histogram_size;
     int            mult;
     int            ncomp;
     const uint8_t  *bg_color;
     const uint8_t  *fg_color;
     int            level_height;
     int            scale_height;
     int            display_mode;
     int            levels_mode;
     const AVPixFmtDescriptor *desc, *odesc;
     int            components;
     int            planewidth[4];
     int            planeheight[4];
 } HistogramContext;

 #define OFFSET(x) offsetof(HistogramContext, x)
 #define FLAGS AV_OPT_FLAG_FILTERING_PARAM|AV_OPT_FLAG_VIDEO_PARAM

 static const AVOption histogram_options[] = {
     { "level_height", "set level height", OFFSET(level_height), AV_OPT_TYPE_INT, {.i64=200}, 50, 2048, FLAGS},
     { "scale_height", "set scale height", OFFSET(scale_height), AV_OPT_TYPE_INT, {.i64=12}, 0, 40, FLAGS},
     { "display_mode", "set display mode", OFFSET(display_mode), AV_OPT_TYPE_INT, {.i64=1}, 0, 1, FLAGS, "display_mode"},
     { "parade",  NULL, 0, AV_OPT_TYPE_CONST, {.i64=1}, 0, 0, FLAGS, "display_mode" },
     { "overlay", NULL, 0, AV_OPT_TYPE_CONST, {.i64=0}, 0, 0, FLAGS, "display_mode" },
     { "levels_mode", "set levels mode", OFFSET(levels_mode), AV_OPT_TYPE_INT, {.i64=0}, 0, 1, FLAGS, "levels_mode"},
     { "linear",      NULL, 0, AV_OPT_TYPE_CONST, {.i64=0}, 0, 0, FLAGS, "levels_mode" },
     { "logarithmic", NULL, 0, AV_OPT_TYPE_CONST, {.i64=1}, 0, 0, FLAGS, "levels_mode" },
     { "components", "set color components to display", OFFSET(components), AV_OPT_TYPE_INT, {.i64=7}, 1, 15, FLAGS},
     { NULL }
 };

 AVFILTER_DEFINE_CLASS(histogram);

 static const enum AVPixelFormat levels_in_pix_fmts[] = {
     AV_PIX_FMT_YUVA420P, AV_PIX_FMT_YUV420P, AV_PIX_FMT_YUVJ420P,
     AV_PIX_FMT_YUVA422P, AV_PIX_FMT_YUV422P, AV_PIX_FMT_YUVJ422P,
     AV_PIX_FMT_YUV411P,  AV_PIX_FMT_YUVJ411P,
     AV_PIX_FMT_YUV440P,  AV_PIX_FMT_YUV410P,
     AV_PIX_FMT_YUVA444P, AV_PIX_FMT_YUV444P, AV_PIX_FMT_YUVJ444P,
     AV_PIX_FMT_YUV420P9, AV_PIX_FMT_YUV422P9, AV_PIX_FMT_YUV444P9,
     AV_PIX_FMT_YUVA420P9, AV_PIX_FMT_YUVA422P9, AV_PIX_FMT_YUVA444P9,
     AV_PIX_FMT_YUV420P10, AV_PIX_FMT_YUV422P10, AV_PIX_FMT_YUV444P10,
     AV_PIX_FMT_YUVA420P10, AV_PIX_FMT_YUVA422P10, AV_PIX_FMT_YUVA444P10,
     AV_PIX_FMT_GBRAP,    AV_PIX_FMT_GBRP,
     AV_PIX_FMT_GBRP9,    AV_PIX_FMT_GBRP10,
     AV_PIX_FMT_GRAY8,
     AV_PIX_FMT_NONE
 };

 static const enum AVPixelFormat levels_out_yuv8_pix_fmts[] = {
     AV_PIX_FMT_YUVA444P, AV_PIX_FMT_YUV444P,
     AV_PIX_FMT_NONE
 };

 static const enum AVPixelFormat levels_out_yuv9_pix_fmts[] = {
     AV_PIX_FMT_YUVA444P9, AV_PIX_FMT_YUV444P9,
     AV_PIX_FMT_NONE
 };

 static const enum AVPixelFormat levels_out_yuv10_pix_fmts[] = {
     AV_PIX_FMT_YUVA444P10, AV_PIX_FMT_YUV444P10,
     AV_PIX_FMT_NONE
 };

 static const enum AVPixelFormat levels_out_rgb8_pix_fmts[] = {
     AV_PIX_FMT_GBRAP,    AV_PIX_FMT_GBRP,
     AV_PIX_FMT_NONE
 };

 static const enum AVPixelFormat levels_out_rgb9_pix_fmts[] = {
     AV_PIX_FMT_GBRP9,
     AV_PIX_FMT_NONE
 };

 static const enum AVPixelFormat levels_out_rgb10_pix_fmts[] = {
     AV_PIX_FMT_GBRP10,
     AV_PIX_FMT_NONE
 };

 static int query_formats(AVFilterContext *ctx)
 {
     AVFilterFormats *avff;
     const AVPixFmtDescriptor *desc;
     const enum AVPixelFormat *out_pix_fmts;
     int rgb, i, bits;
     int ret;

     if (!ctx->inputs[0]->in_formats ||
         !ctx->inputs[0]->in_formats->nb_formats) {
         return AVERROR(EAGAIN);
     }

     if (!ctx->inputs[0]->out_formats)
         if ((ret = ff_formats_ref(ff_make_format_list(levels_in_pix_fmts), &ctx->inputs[0]->out_formats)) < 0)
             return ret;
     avff = ctx->inputs[0]->in_formats;
     desc = av_pix_fmt_desc_get(avff->formats[0]);
     rgb = desc->flags & AV_PIX_FMT_FLAG_RGB;
     bits = desc->comp[0].depth;
     for (i = 1; i < avff->nb_formats; i++) {
         desc = av_pix_fmt_desc_get(avff->formats[i]);
         if ((rgb != (desc->flags & AV_PIX_FMT_FLAG_RGB)) ||
             (bits != desc->comp[0].depth))
             return AVERROR(EAGAIN);
     }

     if (rgb && bits == 8)
         out_pix_fmts = levels_out_rgb8_pix_fmts;
     else if (rgb && bits == 9)
         out_pix_fmts = levels_out_rgb9_pix_fmts;
     else if (rgb && bits == 10)
         out_pix_fmts = levels_out_rgb10_pix_fmts;
     else if (bits == 8)
         out_pix_fmts = levels_out_yuv8_pix_fmts;
     else if (bits == 9)
         out_pix_fmts = levels_out_yuv9_pix_fmts;
     else // if (bits == 10)
         out_pix_fmts = levels_out_yuv10_pix_fmts;
     if ((ret = ff_formats_ref(ff_make_format_list(out_pix_fmts), &ctx->outputs[0]->in_formats)) < 0)
         return ret;

     return 0;
 }

 static const uint8_t black_yuva_color[4] = { 0, 127, 127, 255 };
 static const uint8_t black_gbrp_color[4] = { 0, 0, 0, 255 };
 static const uint8_t white_yuva_color[4] = { 255, 127, 127, 255 };
 static const uint8_t white_gbrp_color[4] = { 255, 255, 255, 255 };

 static int config_input(AVFilterLink *inlink)
 {
     HistogramContext *h = inlink->dst->priv;

     h->desc  = av_pix_fmt_desc_get(inlink->format);
     h->ncomp = h->desc->nb_components;
     h->histogram_size = 1 << h->desc->comp[0].depth;
     h->mult = h->histogram_size / 256;

     switch (inlink->format) {
     case AV_PIX_FMT_GBRP10:
     case AV_PIX_FMT_GBRP9:
     case AV_PIX_FMT_GBRAP:
     case AV_PIX_FMT_GBRP:
         h->bg_color = black_gbrp_color;
         h->fg_color = white_gbrp_color;
         break;
     default:
         h->bg_color = black_yuva_color;
         h->fg_color = white_yuva_color;
     }

     h->planeheight[1] = h->planeheight[2] = AV_CEIL_RSHIFT(inlink->h, h->desc->log2_chroma_h);
     h->planeheight[0] = h->planeheight[3] = inlink->h;
     h->planewidth[1]  = h->planewidth[2]  = AV_CEIL_RSHIFT(inlink->w, h->desc->log2_chroma_w);
     h->planewidth[0]  = h->planewidth[3]  = inlink->w;

     return 0;
 }

 static int config_output(AVFilterLink *outlink)
 {
     AVFilterContext *ctx = outlink->src;
     HistogramContext *h = ctx->priv;
     int ncomp = 0, i;

     for (i = 0; i < h->ncomp; i++) {
         if ((1 << i) & h->components)
             ncomp++;
     }
     outlink->w = h->histogram_size;
     outlink->h = (h->level_height + h->scale_height) * FFMAX(ncomp * h->display_mode, 1);

     h->odesc = av_pix_fmt_desc_get(outlink->format);
     outlink->sample_aspect_ratio = (AVRational){1,1};

     return 0;
 }

 static int filter_frame(AVFilterLink *inlink, AVFrame *in)
 {
     HistogramContext *h   = inlink->dst->priv;
     AVFilterContext *ctx  = inlink->dst;
     AVFilterLink *outlink = ctx->outputs[0];
     AVFrame *out;
     int i, j, k, l, m;

     out = ff_get_video_buffer(outlink, outlink->w, outlink->h);
     if (!out) {
         av_frame_free(&in);
         return AVERROR(ENOMEM);
     }

     out->pts = in->pts;

     for (k = 0; k < 4 && out->data[k]; k++) {
         const int is_chroma = (k == 1 || k == 2);
         const int dst_h = AV_CEIL_RSHIFT(outlink->h, (is_chroma ? h->odesc->log2_chroma_h : 0));
         const int dst_w = AV_CEIL_RSHIFT(outlink->w, (is_chroma ? h->odesc->log2_chroma_w : 0));

         if (h->histogram_size <= 256) {
             for (i = 0; i < dst_h ; i++)
                 memset(out->data[h->odesc->comp[k].plane] +
                        i * out->linesize[h->odesc->comp[k].plane],
                        h->bg_color[k], dst_w);
         } else {
             const int mult = h->mult;

             for (i = 0; i < dst_h ; i++)
                 for (j = 0; j < dst_w; j++)
                     AV_WN16(out->data[h->odesc->comp[k].plane] +
                         i * out->linesize[h->odesc->comp[k].plane] + j * 2,
                         h->bg_color[k] * mult);
         }
     }

     for (m = 0, k = 0; k < h->ncomp; k++) {
         const int p = h->desc->comp[k].plane;
         const int height = h->planeheight[p];
         const int width = h->planewidth[p];
         double max_hval_log;
         unsigned max_hval = 0;
         int start;

         if (!((1 << k) & h->components))
             continue;
         start = m++ * (h->level_height + h->scale_height) * h->display_mode;

         if (h->histogram_size <= 256) {
             for (i = 0; i < height; i++) {
                 const uint8_t *src = in->data[p] + i * in->linesize[p];
                 for (j = 0; j < width; j++)
                     h->histogram[src[j]]++;
             }
         } else {
             for (i = 0; i < height; i++) {
                 const uint16_t *src = (const uint16_t *)(in->data[p] + i * in->linesize[p]);
                 for (j = 0; j < width; j++)
                     h->histogram[src[j]]++;
             }
         }

         for (i = 0; i < h->histogram_size; i++)
             max_hval = FFMAX(max_hval, h->histogram[i]);
         max_hval_log = log2(max_hval + 1);

         for (i = 0; i < outlink->w; i++) {
             int col_height;

             if (h->levels_mode)
                 col_height = lrint(h->level_height * (1. - (log2(h->histogram[i] + 1) / max_hval_log)));
             else
                 col_height = h->level_height - (h->histogram[i] * (int64_t)h->level_height + max_hval - 1) / max_hval;

             if (h->histogram_size <= 256) {
                 for (j = h->level_height - 1; j >= col_height; j--) {
                     if (h->display_mode) {
                         for (l = 0; l < h->ncomp; l++)
                             out->data[l][(j + start) * out->linesize[l] + i] = h->fg_color[l];
                     } else {
                         out->data[p][(j + start) * out->linesize[p] + i] = 255;
                     }
                 }
                 for (j = h->level_height + h->scale_height - 1; j >= h->level_height; j--)
                     out->data[p][(j + start) * out->linesize[p] + i] = i;
             } else {
                 const int mult = h->mult;

                 for (j = h->level_height - 1; j >= col_height; j--) {
                     if (h->display_mode) {
                         for (l = 0; l < h->ncomp; l++)
                             AV_WN16(out->data[l] + (j + start) * out->linesize[l] + i * 2, h->fg_color[l] * mult);
                     } else {
                         AV_WN16(out->data[p] + (j + start) * out->linesize[p] + i * 2, 255 * mult);
                     }
                 }
                 for (j = h->level_height + h->scale_height - 1; j >= h->level_height; j--)
                     AV_WN16(out->data[p] + (j + start) * out->linesize[p] + i * 2, i);
             }
         }

         memset(h->histogram, 0, h->histogram_size * sizeof(unsigned));
     }

     av_frame_free(&in);
     return ff_filter_frame(outlink, out);
 }

 static const AVFilterPad inputs[] = {
     {
         .name         = "default",
         .type         = AVMEDIA_TYPE_VIDEO,
         .filter_frame = filter_frame,
         .config_props = config_input,
     },
     { NULL }
 };

 static const AVFilterPad outputs[] = {
     {
         .name         = "default",
         .type         = AVMEDIA_TYPE_VIDEO,
         .config_props = config_output,
     },
     { NULL }
 };

 AVFilter ff_vf_histogram = {
     .name          = "histogram",
     .description   = NULL_IF_CONFIG_SMALL("Compute and draw a histogram."),
     .priv_size     = sizeof(HistogramContext),
     .query_formats = query_formats,
     .inputs        = inputs,
     .outputs       = outputs,
     .priv_class    = &histogram_class,
 };
	/*
	* Copyright (c) 2012-2013 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
	*/

	#include "libavutil/avassert.h"
	#include "libavutil/opt.h"
	#include "libavutil/parseutils.h"
	#include "libavutil/pixdesc.h"
	#include "libavutil/imgutils.h"
	#include "libavutil/intreadwrite.h"
	#include "avfilter.h"
	#include "formats.h"
	#include "internal.h"
	#include "video.h"

	typedef struct HistogramContext {
	const AVClass *class; ///< AVClass context for log and options purpose
	unsigned histogram[256*256];
	int histogram_size;
	int mult;
	int ncomp;
	const uint8_t *bg_color;
	const uint8_t *fg_color;
	int level_height;
	int scale_height;
	int display_mode;
	int levels_mode;
	const AVPixFmtDescriptor desc, odesc;
	int components;
	int planewidth[4];
	int planeheight[4];
	} HistogramContext;

	#define OFFSET(x) offsetof(HistogramContext, x)
	#define FLAGS AV_OPT_FLAG_FILTERING_PARAM\|AV_OPT_FLAG_VIDEO_PARAM

	static const AVOption histogram_options[] = {
	{ "level_height", "set level height", OFFSET(level_height), AV_OPT_TYPE_INT, {.i64=200}, 50, 2048, FLAGS},
	{ "scale_height", "set scale height", OFFSET(scale_height), AV_OPT_TYPE_INT, {.i64=12}, 0, 40, FLAGS},
	{ "display_mode", "set display mode", OFFSET(display_mode), AV_OPT_TYPE_INT, {.i64=1}, 0, 1, FLAGS, "display_mode"},
	{ "parade", NULL, 0, AV_OPT_TYPE_CONST, {.i64=1}, 0, 0, FLAGS, "display_mode" },
	{ "overlay", NULL, 0, AV_OPT_TYPE_CONST, {.i64=0}, 0, 0, FLAGS, "display_mode" },
	{ "levels_mode", "set levels mode", OFFSET(levels_mode), AV_OPT_TYPE_INT, {.i64=0}, 0, 1, FLAGS, "levels_mode"},
	{ "linear", NULL, 0, AV_OPT_TYPE_CONST, {.i64=0}, 0, 0, FLAGS, "levels_mode" },
	{ "logarithmic", NULL, 0, AV_OPT_TYPE_CONST, {.i64=1}, 0, 0, FLAGS, "levels_mode" },
	{ "components", "set color components to display", OFFSET(components), AV_OPT_TYPE_INT, {.i64=7}, 1, 15, FLAGS},
	{ NULL }
	};

	AVFILTER_DEFINE_CLASS(histogram);

	static const enum AVPixelFormat levels_in_pix_fmts[] = {
	AV_PIX_FMT_YUVA420P, AV_PIX_FMT_YUV420P, AV_PIX_FMT_YUVJ420P,
	AV_PIX_FMT_YUVA422P, AV_PIX_FMT_YUV422P, AV_PIX_FMT_YUVJ422P,
	AV_PIX_FMT_YUV411P, AV_PIX_FMT_YUVJ411P,
	AV_PIX_FMT_YUV440P, AV_PIX_FMT_YUV410P,
	AV_PIX_FMT_YUVA444P, AV_PIX_FMT_YUV444P, AV_PIX_FMT_YUVJ444P,
	AV_PIX_FMT_YUV420P9, AV_PIX_FMT_YUV422P9, AV_PIX_FMT_YUV444P9,
	AV_PIX_FMT_YUVA420P9, AV_PIX_FMT_YUVA422P9, AV_PIX_FMT_YUVA444P9,
	AV_PIX_FMT_YUV420P10, AV_PIX_FMT_YUV422P10, AV_PIX_FMT_YUV444P10,
	AV_PIX_FMT_YUVA420P10, AV_PIX_FMT_YUVA422P10, AV_PIX_FMT_YUVA444P10,
	AV_PIX_FMT_GBRAP, AV_PIX_FMT_GBRP,
	AV_PIX_FMT_GBRP9, AV_PIX_FMT_GBRP10,
	AV_PIX_FMT_GRAY8,
	AV_PIX_FMT_NONE
	};

	static const enum AVPixelFormat levels_out_yuv8_pix_fmts[] = {
	AV_PIX_FMT_YUVA444P, AV_PIX_FMT_YUV444P,
	AV_PIX_FMT_NONE
	};

	static const enum AVPixelFormat levels_out_yuv9_pix_fmts[] = {
	AV_PIX_FMT_YUVA444P9, AV_PIX_FMT_YUV444P9,
	AV_PIX_FMT_NONE
	};

	static const enum AVPixelFormat levels_out_yuv10_pix_fmts[] = {
	AV_PIX_FMT_YUVA444P10, AV_PIX_FMT_YUV444P10,
	AV_PIX_FMT_NONE
	};

	static const enum AVPixelFormat levels_out_rgb8_pix_fmts[] = {
	AV_PIX_FMT_GBRAP, AV_PIX_FMT_GBRP,
	AV_PIX_FMT_NONE
	};

	static const enum AVPixelFormat levels_out_rgb9_pix_fmts[] = {
	AV_PIX_FMT_GBRP9,
	AV_PIX_FMT_NONE
	};

	static const enum AVPixelFormat levels_out_rgb10_pix_fmts[] = {
	AV_PIX_FMT_GBRP10,
	AV_PIX_FMT_NONE
	};

	static int query_formats(AVFilterContext *ctx)
	{
	AVFilterFormats *avff;
	const AVPixFmtDescriptor *desc;
	const enum AVPixelFormat *out_pix_fmts;
	int rgb, i, bits;
	int ret;

	if (!ctx->inputs[0]->in_formats \|\|
	!ctx->inputs[0]->in_formats->nb_formats) {
	return AVERROR(EAGAIN);
	}

	if (!ctx->inputs[0]->out_formats)
	if ((ret = ff_formats_ref(ff_make_format_list(levels_in_pix_fmts), &ctx->inputs[0]->out_formats)) < 0)
	return ret;
	avff = ctx->inputs[0]->in_formats;
	desc = av_pix_fmt_desc_get(avff->formats[0]);
	rgb = desc->flags & AV_PIX_FMT_FLAG_RGB;
	bits = desc->comp[0].depth;
	for (i = 1; i < avff->nb_formats; i++) {
	desc = av_pix_fmt_desc_get(avff->formats[i]);
	if ((rgb != (desc->flags & AV_PIX_FMT_FLAG_RGB)) \|\|
	(bits != desc->comp[0].depth))
	return AVERROR(EAGAIN);
	}

	if (rgb && bits == 8)
	out_pix_fmts = levels_out_rgb8_pix_fmts;
	else if (rgb && bits == 9)
	out_pix_fmts = levels_out_rgb9_pix_fmts;
	else if (rgb && bits == 10)
	out_pix_fmts = levels_out_rgb10_pix_fmts;
	else if (bits == 8)
	out_pix_fmts = levels_out_yuv8_pix_fmts;
	else if (bits == 9)
	out_pix_fmts = levels_out_yuv9_pix_fmts;
	else // if (bits == 10)
	out_pix_fmts = levels_out_yuv10_pix_fmts;
	if ((ret = ff_formats_ref(ff_make_format_list(out_pix_fmts), &ctx->outputs[0]->in_formats)) < 0)
	return ret;

	return 0;
	}

	static const uint8_t black_yuva_color[4] = { 0, 127, 127, 255 };
	static const uint8_t black_gbrp_color[4] = { 0, 0, 0, 255 };
	static const uint8_t white_yuva_color[4] = { 255, 127, 127, 255 };
	static const uint8_t white_gbrp_color[4] = { 255, 255, 255, 255 };

	static int config_input(AVFilterLink *inlink)
	{
	HistogramContext *h = inlink->dst->priv;

	h->desc = av_pix_fmt_desc_get(inlink->format);
	h->ncomp = h->desc->nb_components;
	h->histogram_size = 1 << h->desc->comp[0].depth;
	h->mult = h->histogram_size / 256;

	switch (inlink->format) {
	case AV_PIX_FMT_GBRP10:
	case AV_PIX_FMT_GBRP9:
	case AV_PIX_FMT_GBRAP:
	case AV_PIX_FMT_GBRP:
	h->bg_color = black_gbrp_color;
	h->fg_color = white_gbrp_color;
	break;
	default:
	h->bg_color = black_yuva_color;
	h->fg_color = white_yuva_color;
	}

	h->planeheight[1] = h->planeheight[2] = AV_CEIL_RSHIFT(inlink->h, h->desc->log2_chroma_h);
	h->planeheight[0] = h->planeheight[3] = inlink->h;
	h->planewidth[1] = h->planewidth[2] = AV_CEIL_RSHIFT(inlink->w, h->desc->log2_chroma_w);
	h->planewidth[0] = h->planewidth[3] = inlink->w;

	return 0;
	}

	static int config_output(AVFilterLink *outlink)
	{
	AVFilterContext *ctx = outlink->src;
	HistogramContext *h = ctx->priv;
	int ncomp = 0, i;

	for (i = 0; i < h->ncomp; i++) {
	if ((1 << i) & h->components)
	ncomp++;
	}
	outlink->w = h->histogram_size;
	outlink->h = (h->level_height + h->scale_height) * FFMAX(ncomp * h->display_mode, 1);

	h->odesc = av_pix_fmt_desc_get(outlink->format);
	outlink->sample_aspect_ratio = (AVRational){1,1};

	return 0;
	}

	static int filter_frame(AVFilterLink inlink, AVFrame in)
	{
	HistogramContext *h = inlink->dst->priv;
	AVFilterContext *ctx = inlink->dst;
	AVFilterLink *outlink = ctx->outputs[0];
	AVFrame *out;
	int i, j, k, l, m;

	out = ff_get_video_buffer(outlink, outlink->w, outlink->h);
	if (!out) {
	av_frame_free(&in);
	return AVERROR(ENOMEM);
	}

	out->pts = in->pts;

	for (k = 0; k < 4 && out->data[k]; k++) {
	const int is_chroma = (k == 1 \|\| k == 2);
	const int dst_h = AV_CEIL_RSHIFT(outlink->h, (is_chroma ? h->odesc->log2_chroma_h : 0));
	const int dst_w = AV_CEIL_RSHIFT(outlink->w, (is_chroma ? h->odesc->log2_chroma_w : 0));

	if (h->histogram_size <= 256) {
	for (i = 0; i < dst_h ; i++)
	memset(out->data[h->odesc->comp[k].plane] +
	i * out->linesize[h->odesc->comp[k].plane],
	h->bg_color[k], dst_w);
	} else {
	const int mult = h->mult;

	for (i = 0; i < dst_h ; i++)
	for (j = 0; j < dst_w; j++)
	AV_WN16(out->data[h->odesc->comp[k].plane] +
	i * out->linesize[h->odesc->comp[k].plane] + j * 2,
	h->bg_color[k] * mult);
	}
	}

	for (m = 0, k = 0; k < h->ncomp; k++) {
	const int p = h->desc->comp[k].plane;
	const int height = h->planeheight[p];
	const int width = h->planewidth[p];
	double max_hval_log;
	unsigned max_hval = 0;
	int start;

	if (!((1 << k) & h->components))
	continue;
	start = m++ * (h->level_height + h->scale_height) * h->display_mode;

	if (h->histogram_size <= 256) {
	for (i = 0; i < height; i++) {
	const uint8_t src = in->data[p] + i in->linesize[p];
	for (j = 0; j < width; j++)
	h->histogram[src[j]]++;
	}
	} else {
	for (i = 0; i < height; i++) {
	const uint16_t src = (const uint16_t )(in->data[p] + i * in->linesize[p]);
	for (j = 0; j < width; j++)
	h->histogram[src[j]]++;
	}
	}

	for (i = 0; i < h->histogram_size; i++)
	max_hval = FFMAX(max_hval, h->histogram[i]);
	max_hval_log = log2(max_hval + 1);

	for (i = 0; i < outlink->w; i++) {
	int col_height;

	if (h->levels_mode)
	col_height = lrint(h->level_height * (1. - (log2(h->histogram[i] + 1) / max_hval_log)));
	else
	col_height = h->level_height - (h->histogram[i] * (int64_t)h->level_height + max_hval - 1) / max_hval;

	if (h->histogram_size <= 256) {
	for (j = h->level_height - 1; j >= col_height; j--) {
	if (h->display_mode) {
	for (l = 0; l < h->ncomp; l++)
	out->data[l][(j + start) * out->linesize[l] + i] = h->fg_color[l];
	} else {
	out->data[p][(j + start) * out->linesize[p] + i] = 255;
	}
	}
	for (j = h->level_height + h->scale_height - 1; j >= h->level_height; j--)
	out->data[p][(j + start) * out->linesize[p] + i] = i;
	} else {
	const int mult = h->mult;

	for (j = h->level_height - 1; j >= col_height; j--) {
	if (h->display_mode) {
	for (l = 0; l < h->ncomp; l++)
	AV_WN16(out->data[l] + (j + start) * out->linesize[l] + i * 2, h->fg_color[l] * mult);
	} else {
	AV_WN16(out->data[p] + (j + start) * out->linesize[p] + i * 2, 255 * mult);
	}
	}
	for (j = h->level_height + h->scale_height - 1; j >= h->level_height; j--)
	AV_WN16(out->data[p] + (j + start) * out->linesize[p] + i * 2, i);
	}
	}

	memset(h->histogram, 0, h->histogram_size * sizeof(unsigned));
	}

	av_frame_free(&in);
	return ff_filter_frame(outlink, out);
	}

	static const AVFilterPad inputs[] = {
	{
	.name = "default",
	.type = AVMEDIA_TYPE_VIDEO,
	.filter_frame = filter_frame,
	.config_props = config_input,
	},
	{ NULL }
	};

	static const AVFilterPad outputs[] = {
	{
	.name = "default",
	.type = AVMEDIA_TYPE_VIDEO,
	.config_props = config_output,
	},
	{ NULL }
	};

	AVFilter ff_vf_histogram = {
	.name = "histogram",
	.description = NULL_IF_CONFIG_SMALL("Compute and draw a histogram."),
	.priv_size = sizeof(HistogramContext),
	.query_formats = query_formats,
	.inputs = inputs,
	.outputs = outputs,
	.priv_class = &histogram_class,
	};