mpv/libmpcodecs/vf_blackframe.c

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/* vf_blackframe.c - detect frames that are (almost) black
*
* $Id$
*
* search for black frames to detect scene transitions
* (c) 2006 Julian Hall
*
* based on code designed for skipping commercials
* (c) 2002-2003 Brian J. Murrell
*
* cleanup, simplify, speedup (c) 2006 by Ivo van Poorten
*
* This program 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.
*
* This program 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 this program; if not, write to the Free Software
* Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
*/
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include "config.h"
#include "mp_msg.h"
#include "img_format.h"
#include "mp_image.h"
#include "vf.h"
struct vf_priv_s {
unsigned int bamount, bthresh, frame, lastkeyframe;
};
static int config(struct vf_instance_s* vf, int width, int height, int d_width,
int d_height, unsigned int flags, unsigned int outfmt) {
return vf_next_config(vf,width,height,d_width,d_height,flags,outfmt);
}
static int query_format(struct vf_instance_s *vf, unsigned fmt) {
switch(fmt) {
case IMGFMT_YVU9:
case IMGFMT_IF09:
case IMGFMT_YV12:
case IMGFMT_I420:
case IMGFMT_IYUV:
case IMGFMT_CLPL:
case IMGFMT_Y800:
case IMGFMT_Y8:
case IMGFMT_NV12:
case IMGFMT_NV21:
case IMGFMT_444P:
case IMGFMT_422P:
case IMGFMT_411P:
case IMGFMT_HM12:
return vf_next_query_format(vf, fmt);
}
return 0;
}
static int put_image(struct vf_instance_s* vf, mp_image_t *mpi, double pts){
mp_image_t *dmpi;
int x, y;
int nblack=0, pblack=0;
unsigned char *yplane = mpi->planes[0];
unsigned int ystride = mpi->stride[0];
int pict_type = mpi->pict_type;
int w = mpi->w, h = mpi->h;
int bthresh = vf->priv->bthresh;
int bamount = vf->priv->bamount;
static const char *const picttypes[4] = { "unknown", "I", "P", "B" };
for (y=1; y<=h; y++) {
for (x=0; x<w; x++)
nblack += yplane[x] < bthresh;
pblack = nblack*100/(w*y);
if (pblack < bamount) break;
yplane += ystride;
}
if (pict_type > 3 || pict_type < 0) pict_type = 0;
if (pict_type == 1) vf->priv->lastkeyframe = vf->priv->frame;
if (pblack >= bamount)
mp_msg(MSGT_VFILTER, MSGL_INFO,"vf_blackframe: %u, %i%%, %s (I:%u)\n",
vf->priv->frame, pblack, picttypes[pict_type],
vf->priv->lastkeyframe);
vf->priv->frame++;
dmpi = vf_get_image(vf->next, mpi->imgfmt, MP_IMGTYPE_EXPORT, 0,
mpi->width, mpi->height);
dmpi->planes[0] = mpi->planes[0];
dmpi->stride[0] = mpi->stride[0];
dmpi->planes[1] = mpi->planes[1];
dmpi->stride[1] = mpi->stride[1];
dmpi->planes[2] = mpi->planes[2];
dmpi->stride[2] = mpi->stride[2];
vf_clone_mpi_attributes(dmpi, mpi);
return vf_next_put_image(vf, dmpi, pts);
}
static int control(struct vf_instance_s* vf, int request, void* data){
return vf_next_control(vf,request,data);
}
static void uninit(struct vf_instance_s *vf) {
if (vf->priv) free(vf->priv);
}
static int open(vf_instance_t *vf, char* args){
vf->priv = malloc(sizeof(struct vf_priv_s));
if (!vf->priv) return 0;
vf->config = config;
vf->put_image = put_image;
vf->control = control;
vf->uninit = uninit;
vf->query_format = query_format;
vf->priv->bamount = 98;
vf->priv->bthresh = 0x20;
vf->priv->frame = 0;
vf->priv->lastkeyframe = 0;
if (args)
sscanf(args, "%u:%u", &vf->priv->bamount, &vf->priv->bthresh);
return 1;
}
const vf_info_t vf_info_blackframe = {
"detects black frames",
"blackframe",
"Brian J. Murrell, Julian Hall, Ivo van Poorten",
"Useful for detecting scene transitions",
open,
NULL
};