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/*
* Copyright (c) 2003 Rich Felker
* 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 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 mpdecimate filter, ported from libmpcodecs/vf_decimate.c by
* Rich Felker.
*/
#include "libavutil/opt.h"
#include "libavutil/pixdesc.h"
#include "libavutil/pixelutils.h"
#include "libavutil/timestamp.h"
#include "avfilter.h"
#include "internal.h"
#include "video.h"
typedef struct DecimateContext {
const AVClass *class;
int lo, hi; ///< lower and higher threshold number of differences
///< values for 8x8 blocks
float frac; ///< threshold of changed pixels over the total fraction
int max_drop_count; ///< if positive: maximum number of sequential frames to drop
///< if negative: minimum number of frames between two drops
int drop_count; ///< if positive: number of frames sequentially dropped
///< if negative: number of sequential frames which were not dropped
int max_keep_count; ///< number of similar frames to ignore before to start dropping them
int keep_count; ///< number of similar frames already ignored
int hsub, vsub; ///< chroma subsampling values
AVFrame *ref; ///< reference picture
av_pixelutils_sad_fn sad; ///< sum of absolute difference function
} DecimateContext;
#define OFFSET(x) offsetof(DecimateContext, x)
#define FLAGS AV_OPT_FLAG_VIDEO_PARAM|AV_OPT_FLAG_FILTERING_PARAM
static const AVOption mpdecimate_options[] = {
{ "max", "set the maximum number of consecutive dropped frames (positive), or the minimum interval between dropped frames (negative)",
OFFSET(max_drop_count), AV_OPT_TYPE_INT, {.i64=0}, INT_MIN, INT_MAX, FLAGS },
{ "keep", "set the number of similar consecutive frames to be kept before starting to drop similar frames",
OFFSET(max_keep_count), AV_OPT_TYPE_INT, {.i64=0}, 0, INT_MAX, FLAGS },
{ "hi", "set high dropping threshold", OFFSET(hi), AV_OPT_TYPE_INT, {.i64=64*12}, INT_MIN, INT_MAX, FLAGS },
{ "lo", "set low dropping threshold", OFFSET(lo), AV_OPT_TYPE_INT, {.i64=64*5}, INT_MIN, INT_MAX, FLAGS },
{ "frac", "set fraction dropping threshold", OFFSET(frac), AV_OPT_TYPE_FLOAT, {.dbl=0.33}, 0, 1, FLAGS },
{ NULL }
};
AVFILTER_DEFINE_CLASS(mpdecimate);
/**
* Return 1 if the two planes are different, 0 otherwise.
*/
static int diff_planes(AVFilterContext *ctx,
uint8_t *cur, int cur_linesize,
uint8_t *ref, int ref_linesize,
int w, int h)
{
DecimateContext *decimate = ctx->priv;
int x, y;
int d, c = 0;
int t = (w/16)*(h/16)*decimate->frac;
/* compute difference for blocks of 8x8 bytes */
for (y = 0; y < h-7; y += 4) {
for (x = 8; x < w-7; x += 4) {
d = decimate->sad(cur + y*cur_linesize + x, cur_linesize,
ref + y*ref_linesize + x, ref_linesize);
if (d > decimate->hi) {
av_log(ctx, AV_LOG_DEBUG, "%d>=hi ", d);
return 1;
}
if (d > decimate->lo) {
c++;
if (c > t) {
av_log(ctx, AV_LOG_DEBUG, "lo:%d>=%d ", c, t);
return 1;
}
}
}
}
av_log(ctx, AV_LOG_DEBUG, "lo:%d<%d ", c, t);
return 0;
}
/**
* Tell if the frame should be decimated, for example if it is no much
* different with respect to the reference frame ref.
*/
static int decimate_frame(AVFilterContext *ctx,
AVFrame *cur, AVFrame *ref)
{
DecimateContext *decimate = ctx->priv;
int plane;
if (decimate->max_keep_count > 0 &&
decimate->keep_count > -1 &&
decimate->keep_count < decimate->max_keep_count) {
decimate->keep_count++;
return 0;
}
if (decimate->max_drop_count > 0 &&
decimate->drop_count >= decimate->max_drop_count)
return 0;
if (decimate->max_drop_count < 0 &&
(decimate->drop_count-1) > decimate->max_drop_count)
return 0;
for (plane = 0; ref->data[plane] && ref->linesize[plane]; plane++) {
/* use 8x8 SAD even on subsampled planes. The blocks won't match up with
* luma blocks, but hopefully nobody is depending on this to catch
* localized chroma changes that wouldn't exceed the thresholds when
* diluted by using what's effectively a larger block size.
*/
int vsub = plane == 1 || plane == 2 ? decimate->vsub : 0;
int hsub = plane == 1 || plane == 2 ? decimate->hsub : 0;
if (diff_planes(ctx,
cur->data[plane], cur->linesize[plane],
ref->data[plane], ref->linesize[plane],
AV_CEIL_RSHIFT(ref->width, hsub),
AV_CEIL_RSHIFT(ref->height, vsub))) {
emms_c();
return 0;
}
}
emms_c();
return 1;
}
static av_cold int init(AVFilterContext *ctx)
{
DecimateContext *decimate = ctx->priv;
decimate->sad = av_pixelutils_get_sad_fn(3, 3, 0, ctx); // 8x8, not aligned on blocksize
if (!decimate->sad)
return AVERROR(EINVAL);
av_log(ctx, AV_LOG_VERBOSE, "max_drop_count:%d hi:%d lo:%d frac:%f\n",
decimate->max_drop_count, decimate->hi, decimate->lo, decimate->frac);
return 0;
}
static av_cold void uninit(AVFilterContext *ctx)
{
DecimateContext *decimate = ctx->priv;
av_frame_free(&decimate->ref);
}
static const enum AVPixelFormat pix_fmts[] = {
AV_PIX_FMT_YUV444P, AV_PIX_FMT_YUV422P,
AV_PIX_FMT_YUV420P, AV_PIX_FMT_YUV411P,
AV_PIX_FMT_YUV410P, AV_PIX_FMT_YUV440P,
AV_PIX_FMT_YUVJ444P, AV_PIX_FMT_YUVJ422P,
AV_PIX_FMT_YUVJ420P, AV_PIX_FMT_YUVJ440P,
AV_PIX_FMT_YUVA420P,
AV_PIX_FMT_GBRP,
AV_PIX_FMT_YUVA444P,
AV_PIX_FMT_YUVA422P,
AV_PIX_FMT_NONE
};
static int config_input(AVFilterLink *inlink)
{
AVFilterContext *ctx = inlink->dst;
DecimateContext *decimate = ctx->priv;
const AVPixFmtDescriptor *pix_desc = av_pix_fmt_desc_get(inlink->format);
decimate->hsub = pix_desc->log2_chroma_w;
decimate->vsub = pix_desc->log2_chroma_h;
return 0;
}
static int filter_frame(AVFilterLink *inlink, AVFrame *cur)
{
DecimateContext *decimate = inlink->dst->priv;
AVFilterLink *outlink = inlink->dst->outputs[0];
int ret;
if (decimate->ref && decimate_frame(inlink->dst, cur, decimate->ref)) {
decimate->drop_count = FFMAX(1, decimate->drop_count+1);
decimate->keep_count = -1; // do not keep any more frames until non-similar frames are detected
} else {
av_frame_free(&decimate->ref);
decimate->ref = cur;
decimate->drop_count = FFMIN(-1, decimate->drop_count-1);
if (decimate->keep_count < 0) // re-enable counting similiar frames to ignore before dropping
decimate->keep_count = 0;
if ((ret = ff_filter_frame(outlink, av_frame_clone(cur))) < 0)
return ret;
}
av_log(inlink->dst, AV_LOG_DEBUG,
"%s pts:%s pts_time:%s drop_count:%d keep_count:%d\n",
decimate->drop_count > 0 ? "drop" : "keep",
av_ts2str(cur->pts), av_ts2timestr(cur->pts, &inlink->time_base),
decimate->drop_count,
decimate->keep_count);
if (decimate->drop_count > 0)
av_frame_free(&cur);
return 0;
}
static const AVFilterPad mpdecimate_inputs[] = {
{
.name = "default",
.type = AVMEDIA_TYPE_VIDEO,
.config_props = config_input,
.filter_frame = filter_frame,
},
};
const AVFilter ff_vf_mpdecimate = {
.name = "mpdecimate",
.description = NULL_IF_CONFIG_SMALL("Remove near-duplicate frames."),
.init = init,
.uninit = uninit,
.priv_size = sizeof(DecimateContext),
.priv_class = &mpdecimate_class,
FILTER_INPUTS(mpdecimate_inputs),
FILTER_OUTPUTS(ff_video_default_filterpad),
FILTER_PIXFMTS_ARRAY(pix_fmts),
};
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