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/*
* Copyright (c) 2002 A'rpi
* This file is part of FFmpeg.
*
* FFmpeg is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 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 General Public License for more details.
*
* You should have received a copy of the GNU 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
* border detection filter
* Ported from MPlayer libmpcodecs/vf_cropdetect.c.
*/
#include "libavutil/imgutils.h"
#include "avfilter.h"
#include "video.h"
typedef struct {
int x1, y1, x2, y2;
int limit;
int round;
int reset_count;
int frame_nb;
int max_pixsteps[4];
} CropDetectContext;
static int query_formats(AVFilterContext *ctx)
{
static const enum PixelFormat pix_fmts[] = {
PIX_FMT_YUV420P, PIX_FMT_YUVJ420P,
PIX_FMT_YUV422P, PIX_FMT_YUVJ422P,
PIX_FMT_YUV444P, PIX_FMT_YUVJ444P,
PIX_FMT_YUV411P, PIX_FMT_GRAY8,
PIX_FMT_NV12, PIX_FMT_NV21,
PIX_FMT_NONE
};
avfilter_set_common_pixel_formats(ctx, avfilter_make_format_list(pix_fmts));
return 0;
}
static int checkline(void *ctx, const unsigned char *src, int stride, int len, int bpp)
{
int total = 0;
int div = len;
switch (bpp) {
case 1:
while (--len >= 0) {
total += src[0];
src += stride;
}
break;
case 3:
case 4:
while (--len >= 0) {
total += src[0] + src[1] + src[2];
src += stride;
}
div *= 3;
break;
}
total /= div;
av_log(ctx, AV_LOG_DEBUG, "total:%d\n", total);
return total;
}
static av_cold int init(AVFilterContext *ctx, const char *args, void *opaque)
{
CropDetectContext *cd = ctx->priv;
cd->limit = 24;
cd->round = 0;
cd->reset_count = 0;
cd->frame_nb = -2;
if (args)
sscanf(args, "%d:%d:%d", &cd->limit, &cd->round, &cd->reset_count);
av_log(ctx, AV_LOG_INFO, "limit:%d round:%d reset_count:%d\n",
cd->limit, cd->round, cd->reset_count);
return 0;
}
static int config_input(AVFilterLink *inlink)
{
AVFilterContext *ctx = inlink->dst;
CropDetectContext *cd = ctx->priv;
av_image_fill_max_pixsteps(cd->max_pixsteps, NULL,
&av_pix_fmt_descriptors[inlink->format]);
cd->x1 = inlink->w - 1;
cd->y1 = inlink->h - 1;
cd->x2 = 0;
cd->y2 = 0;
return 0;
}
static void end_frame(AVFilterLink *inlink)
{
AVFilterContext *ctx = inlink->dst;
CropDetectContext *cd = ctx->priv;
AVFilterBufferRef *picref = inlink->cur_buf;
int bpp = cd->max_pixsteps[0];
int w, h, x, y, shrink_by;
// ignore first 2 frames - they may be empty
if (++cd->frame_nb > 0) {
// Reset the crop area every reset_count frames, if reset_count is > 0
if (cd->reset_count > 0 && cd->frame_nb > cd->reset_count) {
cd->x1 = picref->video->w-1;
cd->y1 = picref->video->h-1;
cd->x2 = 0;
cd->y2 = 0;
cd->frame_nb = 1;
}
for (y = 0; y < cd->y1; y++) {
if (checkline(ctx, picref->data[0] + picref->linesize[0] * y, bpp, picref->video->w, bpp) > cd->limit) {
cd->y1 = y;
break;
}
}
for (y = picref->video->h-1; y > cd->y2; y--) {
if (checkline(ctx, picref->data[0] + picref->linesize[0] * y, bpp, picref->video->w, bpp) > cd->limit) {
cd->y2 = y;
break;
}
}
for (y = 0; y < cd->x1; y++) {
if (checkline(ctx, picref->data[0] + bpp*y, picref->linesize[0], picref->video->h, bpp) > cd->limit) {
cd->x1 = y;
break;
}
}
for (y = picref->video->w-1; y > cd->x2; y--) {
if (checkline(ctx, picref->data[0] + bpp*y, picref->linesize[0], picref->video->h, bpp) > cd->limit) {
cd->x2 = y;
break;
}
}
// round x and y (up), important for yuv colorspaces
// make sure they stay rounded!
x = (cd->x1+1) & ~1;
y = (cd->y1+1) & ~1;
w = cd->x2 - x + 1;
h = cd->y2 - y + 1;
// w and h must be divisible by 2 as well because of yuv
// colorspace problems.
if (cd->round <= 1)
cd->round = 16;
if (cd->round % 2)
cd->round *= 2;
shrink_by = w % cd->round;
w -= shrink_by;
x += (shrink_by/2 + 1) & ~1;
shrink_by = h % cd->round;
h -= shrink_by;
y += (shrink_by/2 + 1) & ~1;
av_log(ctx, AV_LOG_INFO,
"x1:%d x2:%d y1:%d y2:%d w:%d h:%d x:%d y:%d pos:%"PRId64" pts:%"PRId64" t:%f crop=%d:%d:%d:%d\n",
cd->x1, cd->x2, cd->y1, cd->y2, w, h, x, y, picref->pos, picref->pts,
picref->pts == AV_NOPTS_VALUE ? -1 : picref->pts * av_q2d(inlink->time_base),
w, h, x, y);
}
avfilter_end_frame(inlink->dst->outputs[0]);
}
AVFilter avfilter_vf_cropdetect = {
.name = "cropdetect",
.description = NULL_IF_CONFIG_SMALL("Auto-detect crop size."),
.priv_size = sizeof(CropDetectContext),
.init = init,
.query_formats = query_formats,
.inputs = (const AVFilterPad[]) {{ .name = "default",
.type = AVMEDIA_TYPE_VIDEO,
.config_props = config_input,
.get_video_buffer = ff_null_get_video_buffer,
.start_frame = ff_null_start_frame,
.end_frame = end_frame, },
{ .name = NULL}},
.outputs = (const AVFilterPad[]) {{ .name = "default",
.type = AVMEDIA_TYPE_VIDEO },
{ .name = NULL}},
};
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