yading@10: /*
yading@10:  * Copyright (c) 2002 A'rpi
yading@10:  * This file is part of FFmpeg.
yading@10:  *
yading@10:  * FFmpeg is free software; you can redistribute it and/or modify
yading@10:  * it under the terms of the GNU General Public License as published by
yading@10:  * the Free Software Foundation; either version 2 of the License, or
yading@10:  * (at your option) any later version.
yading@10:  *
yading@10:  * FFmpeg is distributed in the hope that it will be useful,
yading@10:  * but WITHOUT ANY WARRANTY; without even the implied warranty of
yading@10:  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
yading@10:  * GNU General Public License for more details.
yading@10:  *
yading@10:  * You should have received a copy of the GNU General Public License along
yading@10:  * with FFmpeg; if not, write to the Free Software Foundation, Inc.,
yading@10:  * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
yading@10:  */
yading@10: 
yading@10: /**
yading@10:  * @file
yading@10:  * border detection filter
yading@10:  * Ported from MPlayer libmpcodecs/vf_cropdetect.c.
yading@10:  */
yading@10: 
yading@10: #include "libavutil/imgutils.h"
yading@10: #include "libavutil/internal.h"
yading@10: #include "libavutil/opt.h"
yading@10: 
yading@10: #include "avfilter.h"
yading@10: #include "formats.h"
yading@10: #include "internal.h"
yading@10: #include "video.h"
yading@10: 
yading@10: typedef struct {
yading@10:     const AVClass *class;
yading@10:     int x1, y1, x2, y2;
yading@10:     int limit;
yading@10:     int round;
yading@10:     int reset_count;
yading@10:     int frame_nb;
yading@10:     int max_pixsteps[4];
yading@10: } CropDetectContext;
yading@10: 
yading@10: static int query_formats(AVFilterContext *ctx)
yading@10: {
yading@10:     static const enum AVPixelFormat pix_fmts[] = {
yading@10:         AV_PIX_FMT_YUV420P, AV_PIX_FMT_YUVJ420P,
yading@10:         AV_PIX_FMT_YUV422P, AV_PIX_FMT_YUVJ422P,
yading@10:         AV_PIX_FMT_YUV444P, AV_PIX_FMT_YUVJ444P,
yading@10:         AV_PIX_FMT_YUV411P, AV_PIX_FMT_GRAY8,
yading@10:         AV_PIX_FMT_NV12,    AV_PIX_FMT_NV21,
yading@10:         AV_PIX_FMT_NONE
yading@10:     };
yading@10: 
yading@10:     ff_set_common_formats(ctx, ff_make_format_list(pix_fmts));
yading@10:     return 0;
yading@10: }
yading@10: 
yading@10: static int checkline(void *ctx, const unsigned char *src, int stride, int len, int bpp)
yading@10: {
yading@10:     int total = 0;
yading@10:     int div = len;
yading@10: 
yading@10:     switch (bpp) {
yading@10:     case 1:
yading@10:         while (--len >= 0) {
yading@10:             total += src[0];
yading@10:             src += stride;
yading@10:         }
yading@10:         break;
yading@10:     case 3:
yading@10:     case 4:
yading@10:         while (--len >= 0) {
yading@10:             total += src[0] + src[1] + src[2];
yading@10:             src += stride;
yading@10:         }
yading@10:         div *= 3;
yading@10:         break;
yading@10:     }
yading@10:     total /= div;
yading@10: 
yading@10:     av_log(ctx, AV_LOG_DEBUG, "total:%d\n", total);
yading@10:     return total;
yading@10: }
yading@10: 
yading@10: static av_cold int init(AVFilterContext *ctx)
yading@10: {
yading@10:     CropDetectContext *cd = ctx->priv;
yading@10: 
yading@10:     cd->frame_nb = -2;
yading@10: 
yading@10:     av_log(ctx, AV_LOG_VERBOSE, "limit:%d round:%d reset_count:%d\n",
yading@10:            cd->limit, cd->round, cd->reset_count);
yading@10: 
yading@10:     return 0;
yading@10: }
yading@10: 
yading@10: static int config_input(AVFilterLink *inlink)
yading@10: {
yading@10:     AVFilterContext *ctx = inlink->dst;
yading@10:     CropDetectContext *cd = ctx->priv;
yading@10: 
yading@10:     av_image_fill_max_pixsteps(cd->max_pixsteps, NULL,
yading@10:                                av_pix_fmt_desc_get(inlink->format));
yading@10: 
yading@10:     cd->x1 = inlink->w - 1;
yading@10:     cd->y1 = inlink->h - 1;
yading@10:     cd->x2 = 0;
yading@10:     cd->y2 = 0;
yading@10: 
yading@10:     return 0;
yading@10: }
yading@10: 
yading@10: static int filter_frame(AVFilterLink *inlink, AVFrame *frame)
yading@10: {
yading@10:     AVFilterContext *ctx = inlink->dst;
yading@10:     CropDetectContext *cd = ctx->priv;
yading@10:     int bpp = cd->max_pixsteps[0];
yading@10:     int w, h, x, y, shrink_by;
yading@10: 
yading@10:     // ignore first 2 frames - they may be empty
yading@10:     if (++cd->frame_nb > 0) {
yading@10:         // Reset the crop area every reset_count frames, if reset_count is > 0
yading@10:         if (cd->reset_count > 0 && cd->frame_nb > cd->reset_count) {
yading@10:             cd->x1 = frame->width  - 1;
yading@10:             cd->y1 = frame->height - 1;
yading@10:             cd->x2 = 0;
yading@10:             cd->y2 = 0;
yading@10:             cd->frame_nb = 1;
yading@10:         }
yading@10: 
yading@10:         for (y = 0; y < cd->y1; y++) {
yading@10:             if (checkline(ctx, frame->data[0] + frame->linesize[0] * y, bpp, frame->width, bpp) > cd->limit) {
yading@10:                 cd->y1 = y;
yading@10:                 break;
yading@10:             }
yading@10:         }
yading@10: 
yading@10:         for (y = frame->height - 1; y > cd->y2; y--) {
yading@10:             if (checkline(ctx, frame->data[0] + frame->linesize[0] * y, bpp, frame->width, bpp) > cd->limit) {
yading@10:                 cd->y2 = y;
yading@10:                 break;
yading@10:             }
yading@10:         }
yading@10: 
yading@10:         for (y = 0; y < cd->x1; y++) {
yading@10:             if (checkline(ctx, frame->data[0] + bpp*y, frame->linesize[0], frame->height, bpp) > cd->limit) {
yading@10:                 cd->x1 = y;
yading@10:                 break;
yading@10:             }
yading@10:         }
yading@10: 
yading@10:         for (y = frame->width - 1; y > cd->x2; y--) {
yading@10:             if (checkline(ctx, frame->data[0] + bpp*y, frame->linesize[0], frame->height, bpp) > cd->limit) {
yading@10:                 cd->x2 = y;
yading@10:                 break;
yading@10:             }
yading@10:         }
yading@10: 
yading@10:         // round x and y (up), important for yuv colorspaces
yading@10:         // make sure they stay rounded!
yading@10:         x = (cd->x1+1) & ~1;
yading@10:         y = (cd->y1+1) & ~1;
yading@10: 
yading@10:         w = cd->x2 - x + 1;
yading@10:         h = cd->y2 - y + 1;
yading@10: 
yading@10:         // w and h must be divisible by 2 as well because of yuv
yading@10:         // colorspace problems.
yading@10:         if (cd->round <= 1)
yading@10:             cd->round = 16;
yading@10:         if (cd->round % 2)
yading@10:             cd->round *= 2;
yading@10: 
yading@10:         shrink_by = w % cd->round;
yading@10:         w -= shrink_by;
yading@10:         x += (shrink_by/2 + 1) & ~1;
yading@10: 
yading@10:         shrink_by = h % cd->round;
yading@10:         h -= shrink_by;
yading@10:         y += (shrink_by/2 + 1) & ~1;
yading@10: 
yading@10:         av_log(ctx, AV_LOG_INFO,
yading@10:                "x1:%d x2:%d y1:%d y2:%d w:%d h:%d x:%d y:%d pts:%"PRId64" t:%f crop=%d:%d:%d:%d\n",
yading@10:                cd->x1, cd->x2, cd->y1, cd->y2, w, h, x, y, frame->pts,
yading@10:                frame->pts == AV_NOPTS_VALUE ? -1 : frame->pts * av_q2d(inlink->time_base),
yading@10:                w, h, x, y);
yading@10:     }
yading@10: 
yading@10:     return ff_filter_frame(inlink->dst->outputs[0], frame);
yading@10: }
yading@10: 
yading@10: #define OFFSET(x) offsetof(CropDetectContext, x)
yading@10: #define FLAGS AV_OPT_FLAG_VIDEO_PARAM|AV_OPT_FLAG_FILTERING_PARAM
yading@10: 
yading@10: static const AVOption cropdetect_options[] = {
yading@10:     { "limit", "Threshold below which the pixel is considered black", OFFSET(limit),       AV_OPT_TYPE_INT, { .i64 = 24 }, 0, 255, FLAGS },
yading@10:     { "round", "Value by which the width/height should be divisible", OFFSET(round),       AV_OPT_TYPE_INT, { .i64 = 16 }, 0, INT_MAX, FLAGS },
yading@10:     { "reset", "Recalculate the crop area after this many frames",    OFFSET(reset_count), AV_OPT_TYPE_INT, { .i64 = 0 },  0, INT_MAX, FLAGS },
yading@10:     { "reset_count", "Recalculate the crop area after this many frames",OFFSET(reset_count),AV_OPT_TYPE_INT,{ .i64 = 0 },  0, INT_MAX, FLAGS },
yading@10:     { NULL },
yading@10: };
yading@10: 
yading@10: AVFILTER_DEFINE_CLASS(cropdetect);
yading@10: 
yading@10: static const AVFilterPad avfilter_vf_cropdetect_inputs[] = {
yading@10:     {
yading@10:         .name             = "default",
yading@10:         .type             = AVMEDIA_TYPE_VIDEO,
yading@10:         .config_props     = config_input,
yading@10:         .get_video_buffer = ff_null_get_video_buffer,
yading@10:         .filter_frame     = filter_frame,
yading@10:     },
yading@10:     { NULL }
yading@10: };
yading@10: 
yading@10: static const AVFilterPad avfilter_vf_cropdetect_outputs[] = {
yading@10:     {
yading@10:         .name = "default",
yading@10:         .type = AVMEDIA_TYPE_VIDEO
yading@10:     },
yading@10:     { NULL }
yading@10: };
yading@10: 
yading@10: AVFilter avfilter_vf_cropdetect = {
yading@10:     .name        = "cropdetect",
yading@10:     .description = NULL_IF_CONFIG_SMALL("Auto-detect crop size."),
yading@10: 
yading@10:     .priv_size = sizeof(CropDetectContext),
yading@10:     .priv_class = &cropdetect_class,
yading@10:     .init      = init,
yading@10:     .query_formats = query_formats,
yading@10:     .inputs    = avfilter_vf_cropdetect_inputs,
yading@10:     .outputs   = avfilter_vf_cropdetect_outputs,
yading@10: };