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path: root/libavfilter/vf_mpdecimate.c (plain)
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1/*
2 * Copyright (c) 2003 Rich Felker
3 * Copyright (c) 2012 Stefano Sabatini
4 *
5 * This file is part of FFmpeg.
6 *
7 * FFmpeg is free software; you can redistribute it and/or modify
8 * it under the terms of the GNU General Public License as published by
9 * the Free Software Foundation; either version 2 of the License, or
10 * (at your option) any later version.
11 *
12 * FFmpeg is distributed in the hope that it will be useful,
13 * but WITHOUT ANY WARRANTY; without even the implied warranty of
14 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
15 * GNU General Public License for more details.
16 *
17 * You should have received a copy of the GNU General Public License along
18 * with FFmpeg; if not, write to the Free Software Foundation, Inc.,
19 * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
20 */
21
22/**
23 * @file mpdecimate filter, ported from libmpcodecs/vf_decimate.c by
24 * Rich Felker.
25 */
26
27#include "libavutil/opt.h"
28#include "libavutil/pixdesc.h"
29#include "libavutil/pixelutils.h"
30#include "libavutil/timestamp.h"
31#include "avfilter.h"
32#include "internal.h"
33#include "formats.h"
34#include "video.h"
35
36typedef struct {
37 const AVClass *class;
38 int lo, hi; ///< lower and higher threshold number of differences
39 ///< values for 8x8 blocks
40
41 float frac; ///< threshold of changed pixels over the total fraction
42
43 int max_drop_count; ///< if positive: maximum number of sequential frames to drop
44 ///< if negative: minimum number of frames between two drops
45
46 int drop_count; ///< if positive: number of frames sequentially dropped
47 ///< if negative: number of sequential frames which were not dropped
48
49 int hsub, vsub; ///< chroma subsampling values
50 AVFrame *ref; ///< reference picture
51 av_pixelutils_sad_fn sad; ///< sum of absolute difference function
52} DecimateContext;
53
54#define OFFSET(x) offsetof(DecimateContext, x)
55#define FLAGS AV_OPT_FLAG_VIDEO_PARAM|AV_OPT_FLAG_FILTERING_PARAM
56
57static const AVOption mpdecimate_options[] = {
58 { "max", "set the maximum number of consecutive dropped frames (positive), or the minimum interval between dropped frames (negative)",
59 OFFSET(max_drop_count), AV_OPT_TYPE_INT, {.i64=0}, INT_MIN, INT_MAX, FLAGS },
60 { "hi", "set high dropping threshold", OFFSET(hi), AV_OPT_TYPE_INT, {.i64=64*12}, INT_MIN, INT_MAX, FLAGS },
61 { "lo", "set low dropping threshold", OFFSET(lo), AV_OPT_TYPE_INT, {.i64=64*5}, INT_MIN, INT_MAX, FLAGS },
62 { "frac", "set fraction dropping threshold", OFFSET(frac), AV_OPT_TYPE_FLOAT, {.dbl=0.33}, 0, 1, FLAGS },
63 { NULL }
64};
65
66AVFILTER_DEFINE_CLASS(mpdecimate);
67
68/**
69 * Return 1 if the two planes are different, 0 otherwise.
70 */
71static int diff_planes(AVFilterContext *ctx,
72 uint8_t *cur, int cur_linesize,
73 uint8_t *ref, int ref_linesize,
74 int w, int h)
75{
76 DecimateContext *decimate = ctx->priv;
77
78 int x, y;
79 int d, c = 0;
80 int t = (w/16)*(h/16)*decimate->frac;
81
82 /* compute difference for blocks of 8x8 bytes */
83 for (y = 0; y < h-7; y += 4) {
84 for (x = 8; x < w-7; x += 4) {
85 d = decimate->sad(cur + y*cur_linesize + x, cur_linesize,
86 ref + y*ref_linesize + x, ref_linesize);
87 if (d > decimate->hi) {
88 av_log(ctx, AV_LOG_DEBUG, "%d>=hi ", d);
89 return 1;
90 }
91 if (d > decimate->lo) {
92 c++;
93 if (c > t) {
94 av_log(ctx, AV_LOG_DEBUG, "lo:%d>=%d ", c, t);
95 return 1;
96 }
97 }
98 }
99 }
100
101 av_log(ctx, AV_LOG_DEBUG, "lo:%d<%d ", c, t);
102 return 0;
103}
104
105/**
106 * Tell if the frame should be decimated, for example if it is no much
107 * different with respect to the reference frame ref.
108 */
109static int decimate_frame(AVFilterContext *ctx,
110 AVFrame *cur, AVFrame *ref)
111{
112 DecimateContext *decimate = ctx->priv;
113 int plane;
114
115 if (decimate->max_drop_count > 0 &&
116 decimate->drop_count >= decimate->max_drop_count)
117 return 0;
118 if (decimate->max_drop_count < 0 &&
119 (decimate->drop_count-1) > decimate->max_drop_count)
120 return 0;
121
122 for (plane = 0; ref->data[plane] && ref->linesize[plane]; plane++) {
123 /* use 8x8 SAD even on subsampled planes. The blocks won't match up with
124 * luma blocks, but hopefully nobody is depending on this to catch
125 * localized chroma changes that wouldn't exceed the thresholds when
126 * diluted by using what's effectively a larger block size.
127 */
128 int vsub = plane == 1 || plane == 2 ? decimate->vsub : 0;
129 int hsub = plane == 1 || plane == 2 ? decimate->hsub : 0;
130 if (diff_planes(ctx,
131 cur->data[plane], cur->linesize[plane],
132 ref->data[plane], ref->linesize[plane],
133 AV_CEIL_RSHIFT(ref->width, hsub),
134 AV_CEIL_RSHIFT(ref->height, vsub))) {
135 emms_c();
136 return 0;
137 }
138 }
139
140 emms_c();
141 return 1;
142}
143
144static av_cold int init(AVFilterContext *ctx)
145{
146 DecimateContext *decimate = ctx->priv;
147
148 decimate->sad = av_pixelutils_get_sad_fn(3, 3, 0, ctx); // 8x8, not aligned on blocksize
149 if (!decimate->sad)
150 return AVERROR(EINVAL);
151
152 av_log(ctx, AV_LOG_VERBOSE, "max_drop_count:%d hi:%d lo:%d frac:%f\n",
153 decimate->max_drop_count, decimate->hi, decimate->lo, decimate->frac);
154
155 return 0;
156}
157
158static av_cold void uninit(AVFilterContext *ctx)
159{
160 DecimateContext *decimate = ctx->priv;
161 av_frame_free(&decimate->ref);
162}
163
164static int query_formats(AVFilterContext *ctx)
165{
166 static const enum AVPixelFormat pix_fmts[] = {
167 AV_PIX_FMT_YUV444P, AV_PIX_FMT_YUV422P,
168 AV_PIX_FMT_YUV420P, AV_PIX_FMT_YUV411P,
169 AV_PIX_FMT_YUV410P, AV_PIX_FMT_YUV440P,
170 AV_PIX_FMT_YUVJ444P, AV_PIX_FMT_YUVJ422P,
171 AV_PIX_FMT_YUVJ420P, AV_PIX_FMT_YUVJ440P,
172 AV_PIX_FMT_YUVA420P,
173
174 AV_PIX_FMT_GBRP,
175
176 AV_PIX_FMT_YUVA444P,
177 AV_PIX_FMT_YUVA422P,
178
179 AV_PIX_FMT_NONE
180 };
181 AVFilterFormats *fmts_list = ff_make_format_list(pix_fmts);
182 if (!fmts_list)
183 return AVERROR(ENOMEM);
184 return ff_set_common_formats(ctx, fmts_list);
185}
186
187static int config_input(AVFilterLink *inlink)
188{
189 AVFilterContext *ctx = inlink->dst;
190 DecimateContext *decimate = ctx->priv;
191 const AVPixFmtDescriptor *pix_desc = av_pix_fmt_desc_get(inlink->format);
192 decimate->hsub = pix_desc->log2_chroma_w;
193 decimate->vsub = pix_desc->log2_chroma_h;
194
195 return 0;
196}
197
198static int filter_frame(AVFilterLink *inlink, AVFrame *cur)
199{
200 DecimateContext *decimate = inlink->dst->priv;
201 AVFilterLink *outlink = inlink->dst->outputs[0];
202 int ret;
203
204 if (decimate->ref && decimate_frame(inlink->dst, cur, decimate->ref)) {
205 decimate->drop_count = FFMAX(1, decimate->drop_count+1);
206 } else {
207 av_frame_free(&decimate->ref);
208 decimate->ref = cur;
209 decimate->drop_count = FFMIN(-1, decimate->drop_count-1);
210
211 if ((ret = ff_filter_frame(outlink, av_frame_clone(cur))) < 0)
212 return ret;
213 }
214
215 av_log(inlink->dst, AV_LOG_DEBUG,
216 "%s pts:%s pts_time:%s drop_count:%d\n",
217 decimate->drop_count > 0 ? "drop" : "keep",
218 av_ts2str(cur->pts), av_ts2timestr(cur->pts, &inlink->time_base),
219 decimate->drop_count);
220
221 if (decimate->drop_count > 0)
222 av_frame_free(&cur);
223
224 return 0;
225}
226
227static const AVFilterPad mpdecimate_inputs[] = {
228 {
229 .name = "default",
230 .type = AVMEDIA_TYPE_VIDEO,
231 .config_props = config_input,
232 .filter_frame = filter_frame,
233 },
234 { NULL }
235};
236
237static const AVFilterPad mpdecimate_outputs[] = {
238 {
239 .name = "default",
240 .type = AVMEDIA_TYPE_VIDEO,
241 },
242 { NULL }
243};
244
245AVFilter ff_vf_mpdecimate = {
246 .name = "mpdecimate",
247 .description = NULL_IF_CONFIG_SMALL("Remove near-duplicate frames."),
248 .init = init,
249 .uninit = uninit,
250 .priv_size = sizeof(DecimateContext),
251 .priv_class = &mpdecimate_class,
252 .query_formats = query_formats,
253 .inputs = mpdecimate_inputs,
254 .outputs = mpdecimate_outputs,
255};
256
generated by cgit at 2024-05-17 01:49:09 (GMT)