/*
  * Copyright (c) 2012 Stefano Sabatini
  *
  * This file is part of FFmpeg.
  *
  * FFmpeg is free software; you can redistribute it and/or
  * modify it under the terms of the GNU 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
  * bounding box detection filter
  */
 

 #include "libavutil/opt.h"

 #include "libavutil/pixdesc.h"
 #include "libavutil/timestamp.h"
 #include "avfilter.h"
 #include "bbox.h"

 #include "internal.h"

 typedef struct BBoxContext {

     const AVClass *class;
     int min_val;

 } BBoxContext;
 

 #define OFFSET(x) offsetof(BBoxContext, x)
 #define FLAGS AV_OPT_FLAG_VIDEO_PARAM|AV_OPT_FLAG_FILTERING_PARAM
 
 static const AVOption bbox_options[] = {
     { "min_val", "set minimum luminance value for bounding box", OFFSET(min_val), AV_OPT_TYPE_INT, { .i64 = 16 }, 0, 254, FLAGS },
     { NULL }
 };
 
 AVFILTER_DEFINE_CLASS(bbox);
 

 static int query_formats(AVFilterContext *ctx)
 {

     static const enum AVPixelFormat pix_fmts[] = {
         AV_PIX_FMT_YUV420P,
         AV_PIX_FMT_YUV444P,
         AV_PIX_FMT_YUV440P,
         AV_PIX_FMT_YUV422P,
         AV_PIX_FMT_YUV411P,
         AV_PIX_FMT_NONE,

     };
 

     AVFilterFormats *fmts_list = ff_make_format_list(pix_fmts);
     if (!fmts_list)
         return AVERROR(ENOMEM);
     return ff_set_common_formats(ctx, fmts_list);

 }
 

 #define SET_META(key, value) \

     av_dict_set_int(metadata, key, value, 0);

 static int filter_frame(AVFilterLink *inlink, AVFrame *frame)

 {
     AVFilterContext *ctx = inlink->dst;
     BBoxContext *bbox = ctx->priv;
     FFBoundingBox box;
     int has_bbox, w, h;
 
     has_bbox =
         ff_calculate_bounding_box(&box,

                                   frame->data[0], frame->linesize[0],

                                   inlink->w, inlink->h, bbox->min_val);

     w = box.x2 - box.x1 + 1;
     h = box.y2 - box.y1 + 1;
 
     av_log(ctx, AV_LOG_INFO,

            "n:%"PRId64" pts:%s pts_time:%s", inlink->frame_count_out,

            av_ts2str(frame->pts), av_ts2timestr(frame->pts, &inlink->time_base));

 
     if (has_bbox) {

         AVDictionary **metadata = &frame->metadata;

 
         SET_META("lavfi.bbox.x1", box.x1)
         SET_META("lavfi.bbox.x2", box.x2)
         SET_META("lavfi.bbox.y1", box.y1)
         SET_META("lavfi.bbox.y2", box.y2)
         SET_META("lavfi.bbox.w",  w)
         SET_META("lavfi.bbox.h",  h)
 

         av_log(ctx, AV_LOG_INFO,

                " x1:%d x2:%d y1:%d y2:%d w:%d h:%d"

                " crop=%d:%d:%d:%d drawbox=%d:%d:%d:%d",
                box.x1, box.x2, box.y1, box.y2, w, h,
                w, h, box.x1, box.y1,    /* crop params */
                box.x1, box.y1, w, h);   /* drawbox params */
     }
     av_log(ctx, AV_LOG_INFO, "\n");
 

     return ff_filter_frame(inlink->dst->outputs[0], frame);

 }
 

 static const AVFilterPad bbox_inputs[] = {
     {

         .name         = "default",
         .type         = AVMEDIA_TYPE_VIDEO,
         .filter_frame = filter_frame,

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

 AVFilter ff_vf_bbox = {

     .name          = "bbox",
     .description   = NULL_IF_CONFIG_SMALL("Compute bounding box for each frame."),
     .priv_size     = sizeof(BBoxContext),

     .priv_class    = &bbox_class,

     .query_formats = query_formats,

     .inputs        = bbox_inputs,
     .outputs       = bbox_outputs,

     .flags         = AVFILTER_FLAG_SUPPORT_TIMELINE_GENERIC,

 };