libavfilter/vf_stack.c - manifest_repos/ffmpeg - Git at Google

 /*
  * 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
  */

 #include "libavutil/avstring.h"
 #include "libavutil/imgutils.h"
 #include "libavutil/opt.h"
 #include "libavutil/parseutils.h"
 #include "libavutil/pixdesc.h"

 #include "avfilter.h"
 #include "drawutils.h"
 #include "formats.h"
 #include "internal.h"
 #include "framesync.h"
 #include "video.h"

 typedef struct StackItem {
     int x[4], y[4];
     int linesize[4];
     int height[4];
 } StackItem;

 typedef struct StackContext {
     const AVClass *class;
     const AVPixFmtDescriptor *desc;
     int nb_inputs;
     char *layout;
     int shortest;
     int is_vertical;
     int is_horizontal;
     int nb_planes;
     uint8_t fillcolor[4];
     char *fillcolor_str;
     int fillcolor_enable;

     FFDrawContext draw;
     FFDrawColor color;

     StackItem *items;
     AVFrame **frames;
     FFFrameSync fs;
 } StackContext;

 static int query_formats(AVFilterContext *ctx)
 {
     AVFilterFormats *pix_fmts = NULL;
     StackContext *s = ctx->priv;
     int fmt, ret;

     if (s->fillcolor_enable) {
         return ff_set_common_formats(ctx, ff_draw_supported_pixel_formats(0));
     }

     for (fmt = 0; av_pix_fmt_desc_get(fmt); fmt++) {
         const AVPixFmtDescriptor *desc = av_pix_fmt_desc_get(fmt);
         if (!(desc->flags & AV_PIX_FMT_FLAG_PAL ||
               desc->flags & AV_PIX_FMT_FLAG_HWACCEL ||
               desc->flags & AV_PIX_FMT_FLAG_BITSTREAM) &&
             (ret = ff_add_format(&pix_fmts, fmt)) < 0)
             return ret;
     }

     return ff_set_common_formats(ctx, pix_fmts);
 }

 static av_cold int init(AVFilterContext *ctx)
 {
     StackContext *s = ctx->priv;
     int i, ret;

     if (!strcmp(ctx->filter->name, "vstack"))
         s->is_vertical = 1;

     if (!strcmp(ctx->filter->name, "hstack"))
         s->is_horizontal = 1;

     s->frames = av_calloc(s->nb_inputs, sizeof(*s->frames));
     if (!s->frames)
         return AVERROR(ENOMEM);

     s->items = av_calloc(s->nb_inputs, sizeof(*s->items));
     if (!s->items)
         return AVERROR(ENOMEM);

     if (!strcmp(ctx->filter->name, "xstack")) {
         if (strcmp(s->fillcolor_str, "none") &&
             av_parse_color(s->fillcolor, s->fillcolor_str, -1, ctx) >= 0) {
             s->fillcolor_enable = 1;
         } else {
             s->fillcolor_enable = 0;
         }
         if (!s->layout) {
             if (s->nb_inputs == 2) {
                 s->layout = av_strdup("0_0|w0_0");
                 if (!s->layout)
                     return AVERROR(ENOMEM);
             } else {
                 av_log(ctx, AV_LOG_ERROR, "No layout specified.\n");
                 return AVERROR(EINVAL);
             }
         }
     }

     for (i = 0; i < s->nb_inputs; i++) {
         AVFilterPad pad = { 0 };

         pad.type = AVMEDIA_TYPE_VIDEO;
         pad.name = av_asprintf("input%d", i);
         if (!pad.name)
             return AVERROR(ENOMEM);

         if ((ret = ff_insert_inpad(ctx, i, &pad)) < 0) {
             av_freep(&pad.name);
             return ret;
         }
     }

     return 0;
 }

 static int process_slice(AVFilterContext *ctx, void *arg, int job, int nb_jobs)
 {
     StackContext *s = ctx->priv;
     AVFrame *out = arg;
     AVFrame **in = s->frames;
     const int start = (s->nb_inputs *  job   ) / nb_jobs;
     const int end   = (s->nb_inputs * (job+1)) / nb_jobs;

     for (int i = start; i < end; i++) {
         StackItem *item = &s->items[i];

         for (int p = 0; p < s->nb_planes; p++) {
             av_image_copy_plane(out->data[p] + out->linesize[p] * item->y[p] + item->x[p],
                                 out->linesize[p],
                                 in[i]->data[p],
                                 in[i]->linesize[p],
                                 item->linesize[p], item->height[p]);
         }
     }

     return 0;
 }

 static int process_frame(FFFrameSync *fs)
 {
     AVFilterContext *ctx = fs->parent;
     AVFilterLink *outlink = ctx->outputs[0];
     StackContext *s = fs->opaque;
     AVFrame **in = s->frames;
     AVFrame *out;
     int i, ret;

     for (i = 0; i < s->nb_inputs; i++) {
         if ((ret = ff_framesync_get_frame(&s->fs, i, &in[i], 0)) < 0)
             return ret;
     }

     out = ff_get_video_buffer(outlink, outlink->w, outlink->h);
     if (!out)
         return AVERROR(ENOMEM);
     out->pts = av_rescale_q(s->fs.pts, s->fs.time_base, outlink->time_base);
     out->sample_aspect_ratio = outlink->sample_aspect_ratio;

     if (s->fillcolor_enable)
         ff_fill_rectangle(&s->draw, &s->color, out->data, out->linesize,
                           0, 0, outlink->w, outlink->h);

     ctx->internal->execute(ctx, process_slice, out, NULL, FFMIN(s->nb_inputs, ff_filter_get_nb_threads(ctx)));

     return ff_filter_frame(outlink, out);
 }

 static int config_output(AVFilterLink *outlink)
 {
     AVFilterContext *ctx = outlink->src;
     StackContext *s = ctx->priv;
     AVRational frame_rate = ctx->inputs[0]->frame_rate;
     AVRational sar = ctx->inputs[0]->sample_aspect_ratio;
     int height = ctx->inputs[0]->h;
     int width = ctx->inputs[0]->w;
     FFFrameSyncIn *in;
     int i, ret;

     s->desc = av_pix_fmt_desc_get(outlink->format);
     if (!s->desc)
         return AVERROR_BUG;

     if (s->is_vertical) {
         for (i = 0; i < s->nb_inputs; i++) {
             AVFilterLink *inlink = ctx->inputs[i];
             StackItem *item = &s->items[i];

             if (ctx->inputs[i]->w != width) {
                 av_log(ctx, AV_LOG_ERROR, "Input %d width %d does not match input %d width %d.\n", i, ctx->inputs[i]->w, 0, width);
                 return AVERROR(EINVAL);
             }

             if ((ret = av_image_fill_linesizes(item->linesize, inlink->format, inlink->w)) < 0) {
                 return ret;
             }

             item->height[1] = item->height[2] = AV_CEIL_RSHIFT(inlink->h, s->desc->log2_chroma_h);
             item->height[0] = item->height[3] = inlink->h;

             if (i) {
                 item->y[1] = item->y[2] = AV_CEIL_RSHIFT(height, s->desc->log2_chroma_h);
                 item->y[0] = item->y[3] = height;

                 height += ctx->inputs[i]->h;
             }
         }
     } else if (s->is_horizontal) {
         for (i = 0; i < s->nb_inputs; i++) {
             AVFilterLink *inlink = ctx->inputs[i];
             StackItem *item = &s->items[i];

             if (ctx->inputs[i]->h != height) {
                 av_log(ctx, AV_LOG_ERROR, "Input %d height %d does not match input %d height %d.\n", i, ctx->inputs[i]->h, 0, height);
                 return AVERROR(EINVAL);
             }

             if ((ret = av_image_fill_linesizes(item->linesize, inlink->format, inlink->w)) < 0) {
                 return ret;
             }

             item->height[1] = item->height[2] = AV_CEIL_RSHIFT(inlink->h, s->desc->log2_chroma_h);
             item->height[0] = item->height[3] = inlink->h;

             if (i) {
                 if ((ret = av_image_fill_linesizes(item->x, inlink->format, width)) < 0) {
                     return ret;
                 }

                 width += ctx->inputs[i]->w;
             }
         }
     } else {
         char *arg, *p = s->layout, *saveptr = NULL;
         char *arg2, *p2, *saveptr2 = NULL;
         char *arg3, *p3, *saveptr3 = NULL;
         int inw, inh, size;

         if (s->fillcolor_enable) {
             ff_draw_init(&s->draw, ctx->inputs[0]->format, 0);
             ff_draw_color(&s->draw, &s->color, s->fillcolor);
         }

         for (i = 0; i < s->nb_inputs; i++) {
             AVFilterLink *inlink = ctx->inputs[i];
             StackItem *item = &s->items[i];

             if (!(arg = av_strtok(p, "|", &saveptr)))
                 return AVERROR(EINVAL);

             p = NULL;

             if ((ret = av_image_fill_linesizes(item->linesize, inlink->format, inlink->w)) < 0) {
                 return ret;
             }

             item->height[1] = item->height[2] = AV_CEIL_RSHIFT(inlink->h, s->desc->log2_chroma_h);
             item->height[0] = item->height[3] = inlink->h;

             p2 = arg;
             inw = inh = 0;

             for (int j = 0; j < 2; j++) {
                 if (!(arg2 = av_strtok(p2, "_", &saveptr2)))
                     return AVERROR(EINVAL);

                 p2 = NULL;
                 p3 = arg2;
                 while ((arg3 = av_strtok(p3, "+", &saveptr3))) {
                     p3 = NULL;
                     if (sscanf(arg3, "w%d", &size) == 1) {
                         if (size == i || size < 0 || size >= s->nb_inputs)
                             return AVERROR(EINVAL);

                         if (!j)
                             inw += ctx->inputs[size]->w;
                         else
                             inh += ctx->inputs[size]->w;
                     } else if (sscanf(arg3, "h%d", &size) == 1) {
                         if (size == i || size < 0 || size >= s->nb_inputs)
                             return AVERROR(EINVAL);

                         if (!j)
                             inw += ctx->inputs[size]->h;
                         else
                             inh += ctx->inputs[size]->h;
                     } else if (sscanf(arg3, "%d", &size) == 1) {
                         if (size < 0)
                             return AVERROR(EINVAL);

                         if (!j)
                             inw += size;
                         else
                             inh += size;
                     } else {
                         return AVERROR(EINVAL);
                     }
                 }
             }

             if ((ret = av_image_fill_linesizes(item->x, inlink->format, inw)) < 0) {
                 return ret;
             }

             item->y[1] = item->y[2] = AV_CEIL_RSHIFT(inh, s->desc->log2_chroma_h);
             item->y[0] = item->y[3] = inh;

             width  = FFMAX(width,  inlink->w + inw);
             height = FFMAX(height, inlink->h + inh);
         }
     }

     s->nb_planes = av_pix_fmt_count_planes(outlink->format);

     outlink->w          = width;
     outlink->h          = height;
     outlink->frame_rate = frame_rate;
     outlink->sample_aspect_ratio = sar;

     for (i = 1; i < s->nb_inputs; i++) {
         AVFilterLink *inlink = ctx->inputs[i];
         if (outlink->frame_rate.num != inlink->frame_rate.num ||
             outlink->frame_rate.den != inlink->frame_rate.den) {
             av_log(ctx, AV_LOG_VERBOSE,
                     "Video inputs have different frame rates, output will be VFR\n");
             outlink->frame_rate = av_make_q(1, 0);
             break;
         }
     }

     if ((ret = ff_framesync_init(&s->fs, ctx, s->nb_inputs)) < 0)
         return ret;

     in = s->fs.in;
     s->fs.opaque = s;
     s->fs.on_event = process_frame;

     for (i = 0; i < s->nb_inputs; i++) {
         AVFilterLink *inlink = ctx->inputs[i];

         in[i].time_base = inlink->time_base;
         in[i].sync   = 1;
         in[i].before = EXT_STOP;
         in[i].after  = s->shortest ? EXT_STOP : EXT_INFINITY;
     }

     ret = ff_framesync_configure(&s->fs);
     outlink->time_base = s->fs.time_base;

     return ret;
 }

 static av_cold void uninit(AVFilterContext *ctx)
 {
     StackContext *s = ctx->priv;
     int i;

     ff_framesync_uninit(&s->fs);
     av_freep(&s->frames);
     av_freep(&s->items);

     for (i = 0; i < ctx->nb_inputs; i++)
         av_freep(&ctx->input_pads[i].name);
 }

 static int activate(AVFilterContext *ctx)
 {
     StackContext *s = ctx->priv;
     return ff_framesync_activate(&s->fs);
 }

 #define OFFSET(x) offsetof(StackContext, x)
 #define FLAGS AV_OPT_FLAG_VIDEO_PARAM | AV_OPT_FLAG_FILTERING_PARAM
 static const AVOption stack_options[] = {
     { "inputs", "set number of inputs", OFFSET(nb_inputs), AV_OPT_TYPE_INT, {.i64=2}, 2, INT_MAX, .flags = FLAGS },
     { "shortest", "force termination when the shortest input terminates", OFFSET(shortest), AV_OPT_TYPE_BOOL, {.i64=0}, 0, 1, .flags = FLAGS },
     { NULL },
 };

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

 #if CONFIG_HSTACK_FILTER

 #define hstack_options stack_options
 AVFILTER_DEFINE_CLASS(hstack);

 AVFilter ff_vf_hstack = {
     .name          = "hstack",
     .description   = NULL_IF_CONFIG_SMALL("Stack video inputs horizontally."),
     .priv_size     = sizeof(StackContext),
     .priv_class    = &hstack_class,
     .query_formats = query_formats,
     .outputs       = outputs,
     .init          = init,
     .uninit        = uninit,
     .activate      = activate,
     .flags         = AVFILTER_FLAG_DYNAMIC_INPUTS | AVFILTER_FLAG_SLICE_THREADS,
 };

 #endif /* CONFIG_HSTACK_FILTER */

 #if CONFIG_VSTACK_FILTER

 #define vstack_options stack_options
 AVFILTER_DEFINE_CLASS(vstack);

 AVFilter ff_vf_vstack = {
     .name          = "vstack",
     .description   = NULL_IF_CONFIG_SMALL("Stack video inputs vertically."),
     .priv_size     = sizeof(StackContext),
     .priv_class    = &vstack_class,
     .query_formats = query_formats,
     .outputs       = outputs,
     .init          = init,
     .uninit        = uninit,
     .activate      = activate,
     .flags         = AVFILTER_FLAG_DYNAMIC_INPUTS | AVFILTER_FLAG_SLICE_THREADS,
 };

 #endif /* CONFIG_VSTACK_FILTER */

 #if CONFIG_XSTACK_FILTER

 static const AVOption xstack_options[] = {
     { "inputs", "set number of inputs", OFFSET(nb_inputs), AV_OPT_TYPE_INT, {.i64=2}, 2, INT_MAX, .flags = FLAGS },
     { "layout", "set custom layout", OFFSET(layout), AV_OPT_TYPE_STRING, {.str=NULL}, 0, 0, .flags = FLAGS },
     { "shortest", "force termination when the shortest input terminates", OFFSET(shortest), AV_OPT_TYPE_BOOL, {.i64=0}, 0, 1, .flags = FLAGS },
     { "fill",  "set the color for unused pixels", OFFSET(fillcolor_str), AV_OPT_TYPE_STRING, {.str = "none"}, .flags = FLAGS },
     { NULL },
 };

 AVFILTER_DEFINE_CLASS(xstack);

 AVFilter ff_vf_xstack = {
     .name          = "xstack",
     .description   = NULL_IF_CONFIG_SMALL("Stack video inputs into custom layout."),
     .priv_size     = sizeof(StackContext),
     .priv_class    = &xstack_class,
     .query_formats = query_formats,
     .outputs       = outputs,
     .init          = init,
     .uninit        = uninit,
     .activate      = activate,
     .flags         = AVFILTER_FLAG_DYNAMIC_INPUTS | AVFILTER_FLAG_SLICE_THREADS,
 };

 #endif /* CONFIG_XSTACK_FILTER */
	/*
	* 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
	*/

	#include "libavutil/avstring.h"
	#include "libavutil/imgutils.h"
	#include "libavutil/opt.h"
	#include "libavutil/parseutils.h"
	#include "libavutil/pixdesc.h"

	#include "avfilter.h"
	#include "drawutils.h"
	#include "formats.h"
	#include "internal.h"
	#include "framesync.h"
	#include "video.h"

	typedef struct StackItem {
	int x[4], y[4];
	int linesize[4];
	int height[4];
	} StackItem;

	typedef struct StackContext {
	const AVClass *class;
	const AVPixFmtDescriptor *desc;
	int nb_inputs;
	char *layout;
	int shortest;
	int is_vertical;
	int is_horizontal;
	int nb_planes;
	uint8_t fillcolor[4];
	char *fillcolor_str;
	int fillcolor_enable;

	FFDrawContext draw;
	FFDrawColor color;

	StackItem *items;
	AVFrame **frames;
	FFFrameSync fs;
	} StackContext;

	static int query_formats(AVFilterContext *ctx)
	{
	AVFilterFormats *pix_fmts = NULL;
	StackContext *s = ctx->priv;
	int fmt, ret;

	if (s->fillcolor_enable) {
	return ff_set_common_formats(ctx, ff_draw_supported_pixel_formats(0));
	}

	for (fmt = 0; av_pix_fmt_desc_get(fmt); fmt++) {
	const AVPixFmtDescriptor *desc = av_pix_fmt_desc_get(fmt);
	if (!(desc->flags & AV_PIX_FMT_FLAG_PAL \|\|
	desc->flags & AV_PIX_FMT_FLAG_HWACCEL \|\|
	desc->flags & AV_PIX_FMT_FLAG_BITSTREAM) &&
	(ret = ff_add_format(&pix_fmts, fmt)) < 0)
	return ret;
	}

	return ff_set_common_formats(ctx, pix_fmts);
	}

	static av_cold int init(AVFilterContext *ctx)
	{
	StackContext *s = ctx->priv;
	int i, ret;

	if (!strcmp(ctx->filter->name, "vstack"))
	s->is_vertical = 1;

	if (!strcmp(ctx->filter->name, "hstack"))
	s->is_horizontal = 1;

	s->frames = av_calloc(s->nb_inputs, sizeof(*s->frames));
	if (!s->frames)
	return AVERROR(ENOMEM);

	s->items = av_calloc(s->nb_inputs, sizeof(*s->items));
	if (!s->items)
	return AVERROR(ENOMEM);

	if (!strcmp(ctx->filter->name, "xstack")) {
	if (strcmp(s->fillcolor_str, "none") &&
	av_parse_color(s->fillcolor, s->fillcolor_str, -1, ctx) >= 0) {
	s->fillcolor_enable = 1;
	} else {
	s->fillcolor_enable = 0;
	}
	if (!s->layout) {
	if (s->nb_inputs == 2) {
	s->layout = av_strdup("0_0\|w0_0");
	if (!s->layout)
	return AVERROR(ENOMEM);
	} else {
	av_log(ctx, AV_LOG_ERROR, "No layout specified.\n");
	return AVERROR(EINVAL);
	}
	}
	}

	for (i = 0; i < s->nb_inputs; i++) {
	AVFilterPad pad = { 0 };

	pad.type = AVMEDIA_TYPE_VIDEO;
	pad.name = av_asprintf("input%d", i);
	if (!pad.name)
	return AVERROR(ENOMEM);

	if ((ret = ff_insert_inpad(ctx, i, &pad)) < 0) {
	av_freep(&pad.name);
	return ret;
	}
	}

	return 0;
	}

	static int process_slice(AVFilterContext ctx, void arg, int job, int nb_jobs)
	{
	StackContext *s = ctx->priv;
	AVFrame *out = arg;
	AVFrame **in = s->frames;
	const int start = (s->nb_inputs * job ) / nb_jobs;
	const int end = (s->nb_inputs * (job+1)) / nb_jobs;

	for (int i = start; i < end; i++) {
	StackItem *item = &s->items[i];

	for (int p = 0; p < s->nb_planes; p++) {
	av_image_copy_plane(out->data[p] + out->linesize[p] * item->y[p] + item->x[p],
	out->linesize[p],
	in[i]->data[p],
	in[i]->linesize[p],
	item->linesize[p], item->height[p]);
	}
	}

	return 0;
	}

	static int process_frame(FFFrameSync *fs)
	{
	AVFilterContext *ctx = fs->parent;
	AVFilterLink *outlink = ctx->outputs[0];
	StackContext *s = fs->opaque;
	AVFrame **in = s->frames;
	AVFrame *out;
	int i, ret;

	for (i = 0; i < s->nb_inputs; i++) {
	if ((ret = ff_framesync_get_frame(&s->fs, i, &in[i], 0)) < 0)
	return ret;
	}

	out = ff_get_video_buffer(outlink, outlink->w, outlink->h);
	if (!out)
	return AVERROR(ENOMEM);
	out->pts = av_rescale_q(s->fs.pts, s->fs.time_base, outlink->time_base);
	out->sample_aspect_ratio = outlink->sample_aspect_ratio;

	if (s->fillcolor_enable)
	ff_fill_rectangle(&s->draw, &s->color, out->data, out->linesize,
	0, 0, outlink->w, outlink->h);

	ctx->internal->execute(ctx, process_slice, out, NULL, FFMIN(s->nb_inputs, ff_filter_get_nb_threads(ctx)));

	return ff_filter_frame(outlink, out);
	}

	static int config_output(AVFilterLink *outlink)
	{
	AVFilterContext *ctx = outlink->src;
	StackContext *s = ctx->priv;
	AVRational frame_rate = ctx->inputs[0]->frame_rate;
	AVRational sar = ctx->inputs[0]->sample_aspect_ratio;
	int height = ctx->inputs[0]->h;
	int width = ctx->inputs[0]->w;
	FFFrameSyncIn *in;
	int i, ret;

	s->desc = av_pix_fmt_desc_get(outlink->format);
	if (!s->desc)
	return AVERROR_BUG;

	if (s->is_vertical) {
	for (i = 0; i < s->nb_inputs; i++) {
	AVFilterLink *inlink = ctx->inputs[i];
	StackItem *item = &s->items[i];

	if (ctx->inputs[i]->w != width) {
	av_log(ctx, AV_LOG_ERROR, "Input %d width %d does not match input %d width %d.\n", i, ctx->inputs[i]->w, 0, width);
	return AVERROR(EINVAL);
	}

	if ((ret = av_image_fill_linesizes(item->linesize, inlink->format, inlink->w)) < 0) {
	return ret;
	}

	item->height[1] = item->height[2] = AV_CEIL_RSHIFT(inlink->h, s->desc->log2_chroma_h);
	item->height[0] = item->height[3] = inlink->h;

	if (i) {
	item->y[1] = item->y[2] = AV_CEIL_RSHIFT(height, s->desc->log2_chroma_h);
	item->y[0] = item->y[3] = height;

	height += ctx->inputs[i]->h;
	}
	}
	} else if (s->is_horizontal) {
	for (i = 0; i < s->nb_inputs; i++) {
	AVFilterLink *inlink = ctx->inputs[i];
	StackItem *item = &s->items[i];

	if (ctx->inputs[i]->h != height) {
	av_log(ctx, AV_LOG_ERROR, "Input %d height %d does not match input %d height %d.\n", i, ctx->inputs[i]->h, 0, height);
	return AVERROR(EINVAL);
	}

	if ((ret = av_image_fill_linesizes(item->linesize, inlink->format, inlink->w)) < 0) {
	return ret;
	}

	item->height[1] = item->height[2] = AV_CEIL_RSHIFT(inlink->h, s->desc->log2_chroma_h);
	item->height[0] = item->height[3] = inlink->h;

	if (i) {
	if ((ret = av_image_fill_linesizes(item->x, inlink->format, width)) < 0) {
	return ret;
	}

	width += ctx->inputs[i]->w;
	}
	}
	} else {
	char arg, p = s->layout, *saveptr = NULL;
	char arg2, p2, *saveptr2 = NULL;
	char arg3, p3, *saveptr3 = NULL;
	int inw, inh, size;

	if (s->fillcolor_enable) {
	ff_draw_init(&s->draw, ctx->inputs[0]->format, 0);
	ff_draw_color(&s->draw, &s->color, s->fillcolor);
	}

	for (i = 0; i < s->nb_inputs; i++) {
	AVFilterLink *inlink = ctx->inputs[i];
	StackItem *item = &s->items[i];

	if (!(arg = av_strtok(p, "\|", &saveptr)))
	return AVERROR(EINVAL);

	p = NULL;

	if ((ret = av_image_fill_linesizes(item->linesize, inlink->format, inlink->w)) < 0) {
	return ret;
	}

	item->height[1] = item->height[2] = AV_CEIL_RSHIFT(inlink->h, s->desc->log2_chroma_h);
	item->height[0] = item->height[3] = inlink->h;

	p2 = arg;
	inw = inh = 0;

	for (int j = 0; j < 2; j++) {
	if (!(arg2 = av_strtok(p2, "_", &saveptr2)))
	return AVERROR(EINVAL);

	p2 = NULL;
	p3 = arg2;
	while ((arg3 = av_strtok(p3, "+", &saveptr3))) {
	p3 = NULL;
	if (sscanf(arg3, "w%d", &size) == 1) {
	if (size == i \|\| size < 0 \|\| size >= s->nb_inputs)
	return AVERROR(EINVAL);

	if (!j)
	inw += ctx->inputs[size]->w;
	else
	inh += ctx->inputs[size]->w;
	} else if (sscanf(arg3, "h%d", &size) == 1) {
	if (size == i \|\| size < 0 \|\| size >= s->nb_inputs)
	return AVERROR(EINVAL);

	if (!j)
	inw += ctx->inputs[size]->h;
	else
	inh += ctx->inputs[size]->h;
	} else if (sscanf(arg3, "%d", &size) == 1) {
	if (size < 0)
	return AVERROR(EINVAL);

	if (!j)
	inw += size;
	else
	inh += size;
	} else {
	return AVERROR(EINVAL);
	}
	}
	}

	if ((ret = av_image_fill_linesizes(item->x, inlink->format, inw)) < 0) {
	return ret;
	}

	item->y[1] = item->y[2] = AV_CEIL_RSHIFT(inh, s->desc->log2_chroma_h);
	item->y[0] = item->y[3] = inh;

	width = FFMAX(width, inlink->w + inw);
	height = FFMAX(height, inlink->h + inh);
	}
	}

	s->nb_planes = av_pix_fmt_count_planes(outlink->format);

	outlink->w = width;
	outlink->h = height;
	outlink->frame_rate = frame_rate;
	outlink->sample_aspect_ratio = sar;

	for (i = 1; i < s->nb_inputs; i++) {
	AVFilterLink *inlink = ctx->inputs[i];
	if (outlink->frame_rate.num != inlink->frame_rate.num \|\|
	outlink->frame_rate.den != inlink->frame_rate.den) {
	av_log(ctx, AV_LOG_VERBOSE,
	"Video inputs have different frame rates, output will be VFR\n");
	outlink->frame_rate = av_make_q(1, 0);
	break;
	}
	}

	if ((ret = ff_framesync_init(&s->fs, ctx, s->nb_inputs)) < 0)
	return ret;

	in = s->fs.in;
	s->fs.opaque = s;
	s->fs.on_event = process_frame;

	for (i = 0; i < s->nb_inputs; i++) {
	AVFilterLink *inlink = ctx->inputs[i];

	in[i].time_base = inlink->time_base;
	in[i].sync = 1;
	in[i].before = EXT_STOP;
	in[i].after = s->shortest ? EXT_STOP : EXT_INFINITY;
	}

	ret = ff_framesync_configure(&s->fs);
	outlink->time_base = s->fs.time_base;

	return ret;
	}

	static av_cold void uninit(AVFilterContext *ctx)
	{
	StackContext *s = ctx->priv;
	int i;

	ff_framesync_uninit(&s->fs);
	av_freep(&s->frames);
	av_freep(&s->items);

	for (i = 0; i < ctx->nb_inputs; i++)
	av_freep(&ctx->input_pads[i].name);
	}

	static int activate(AVFilterContext *ctx)
	{
	StackContext *s = ctx->priv;
	return ff_framesync_activate(&s->fs);
	}

	#define OFFSET(x) offsetof(StackContext, x)
	#define FLAGS AV_OPT_FLAG_VIDEO_PARAM \| AV_OPT_FLAG_FILTERING_PARAM
	static const AVOption stack_options[] = {
	{ "inputs", "set number of inputs", OFFSET(nb_inputs), AV_OPT_TYPE_INT, {.i64=2}, 2, INT_MAX, .flags = FLAGS },
	{ "shortest", "force termination when the shortest input terminates", OFFSET(shortest), AV_OPT_TYPE_BOOL, {.i64=0}, 0, 1, .flags = FLAGS },
	{ NULL },
	};

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

	#if CONFIG_HSTACK_FILTER

	#define hstack_options stack_options
	AVFILTER_DEFINE_CLASS(hstack);

	AVFilter ff_vf_hstack = {
	.name = "hstack",
	.description = NULL_IF_CONFIG_SMALL("Stack video inputs horizontally."),
	.priv_size = sizeof(StackContext),
	.priv_class = &hstack_class,
	.query_formats = query_formats,
	.outputs = outputs,
	.init = init,
	.uninit = uninit,
	.activate = activate,
	.flags = AVFILTER_FLAG_DYNAMIC_INPUTS \| AVFILTER_FLAG_SLICE_THREADS,
	};

	#endif /* CONFIG_HSTACK_FILTER */

	#if CONFIG_VSTACK_FILTER

	#define vstack_options stack_options
	AVFILTER_DEFINE_CLASS(vstack);

	AVFilter ff_vf_vstack = {
	.name = "vstack",
	.description = NULL_IF_CONFIG_SMALL("Stack video inputs vertically."),
	.priv_size = sizeof(StackContext),
	.priv_class = &vstack_class,
	.query_formats = query_formats,
	.outputs = outputs,
	.init = init,
	.uninit = uninit,
	.activate = activate,
	.flags = AVFILTER_FLAG_DYNAMIC_INPUTS \| AVFILTER_FLAG_SLICE_THREADS,
	};

	#endif /* CONFIG_VSTACK_FILTER */

	#if CONFIG_XSTACK_FILTER

	static const AVOption xstack_options[] = {
	{ "inputs", "set number of inputs", OFFSET(nb_inputs), AV_OPT_TYPE_INT, {.i64=2}, 2, INT_MAX, .flags = FLAGS },
	{ "layout", "set custom layout", OFFSET(layout), AV_OPT_TYPE_STRING, {.str=NULL}, 0, 0, .flags = FLAGS },
	{ "shortest", "force termination when the shortest input terminates", OFFSET(shortest), AV_OPT_TYPE_BOOL, {.i64=0}, 0, 1, .flags = FLAGS },
	{ "fill", "set the color for unused pixels", OFFSET(fillcolor_str), AV_OPT_TYPE_STRING, {.str = "none"}, .flags = FLAGS },
	{ NULL },
	};

	AVFILTER_DEFINE_CLASS(xstack);

	AVFilter ff_vf_xstack = {
	.name = "xstack",
	.description = NULL_IF_CONFIG_SMALL("Stack video inputs into custom layout."),
	.priv_size = sizeof(StackContext),
	.priv_class = &xstack_class,
	.query_formats = query_formats,
	.outputs = outputs,
	.init = init,
	.uninit = uninit,
	.activate = activate,
	.flags = AVFILTER_FLAG_DYNAMIC_INPUTS \| AVFILTER_FLAG_SLICE_THREADS,
	};

	#endif /* CONFIG_XSTACK_FILTER */