FFmpeg
vf_mpdecimate.c
Go to the documentation of this file.
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 
36 typedef struct DecimateContext {
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
53 
54 #define OFFSET(x) offsetof(DecimateContext, x)
55 #define FLAGS AV_OPT_FLAG_VIDEO_PARAM|AV_OPT_FLAG_FILTERING_PARAM
56 
57 static 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 
66 AVFILTER_DEFINE_CLASS(mpdecimate);
67 
68 /**
69  * Return 1 if the two planes are different, 0 otherwise.
70  */
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  */
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 
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 
159 {
160  DecimateContext *decimate = ctx->priv;
161  av_frame_free(&decimate->ref);
162 }
163 
164 static const enum AVPixelFormat pix_fmts[] = {
171 
173 
176 
178 };
179 
181 {
182  AVFilterContext *ctx = inlink->dst;
183  DecimateContext *decimate = ctx->priv;
184  const AVPixFmtDescriptor *pix_desc = av_pix_fmt_desc_get(inlink->format);
185  decimate->hsub = pix_desc->log2_chroma_w;
186  decimate->vsub = pix_desc->log2_chroma_h;
187 
188  return 0;
189 }
190 
192 {
193  DecimateContext *decimate = inlink->dst->priv;
194  AVFilterLink *outlink = inlink->dst->outputs[0];
195  int ret;
196 
197  if (decimate->ref && decimate_frame(inlink->dst, cur, decimate->ref)) {
198  decimate->drop_count = FFMAX(1, decimate->drop_count+1);
199  } else {
200  av_frame_free(&decimate->ref);
201  decimate->ref = cur;
202  decimate->drop_count = FFMIN(-1, decimate->drop_count-1);
203 
204  if ((ret = ff_filter_frame(outlink, av_frame_clone(cur))) < 0)
205  return ret;
206  }
207 
208  av_log(inlink->dst, AV_LOG_DEBUG,
209  "%s pts:%s pts_time:%s drop_count:%d\n",
210  decimate->drop_count > 0 ? "drop" : "keep",
211  av_ts2str(cur->pts), av_ts2timestr(cur->pts, &inlink->time_base),
212  decimate->drop_count);
213 
214  if (decimate->drop_count > 0)
215  av_frame_free(&cur);
216 
217  return 0;
218 }
219 
220 static const AVFilterPad mpdecimate_inputs[] = {
221  {
222  .name = "default",
223  .type = AVMEDIA_TYPE_VIDEO,
224  .config_props = config_input,
225  .filter_frame = filter_frame,
226  },
227 };
228 
229 static const AVFilterPad mpdecimate_outputs[] = {
230  {
231  .name = "default",
232  .type = AVMEDIA_TYPE_VIDEO,
233  },
234 };
235 
237  .name = "mpdecimate",
238  .description = NULL_IF_CONFIG_SMALL("Remove near-duplicate frames."),
239  .init = init,
240  .uninit = uninit,
241  .priv_size = sizeof(DecimateContext),
242  .priv_class = &mpdecimate_class,
246 };
DecimateContext::lo
int lo
Definition: vf_mpdecimate.c:38
AVPixelFormat
AVPixelFormat
Pixel format.
Definition: pixfmt.h:64
AVERROR
Filter the word “frame” indicates either a video frame or a group of audio as stored in an AVFrame structure Format for each input and each output the list of supported formats For video that means pixel format For audio that means channel sample they are references to shared objects When the negotiation mechanism computes the intersection of the formats supported at each end of a all references to both lists are replaced with a reference to the intersection And when a single format is eventually chosen for a link amongst the remaining all references to the list are updated That means that if a filter requires that its input and output have the same format amongst a supported all it has to do is use a reference to the same list of formats query_formats can leave some formats unset and return AVERROR(EAGAIN) to cause the negotiation mechanism toagain later. That can be used by filters with complex requirements to use the format negotiated on one link to set the formats supported on another. Frame references ownership and permissions
opt.h
ff_filter_frame
int ff_filter_frame(AVFilterLink *link, AVFrame *frame)
Send a frame of data to the next filter.
Definition: avfilter.c:1018
av_pix_fmt_desc_get
const AVPixFmtDescriptor * av_pix_fmt_desc_get(enum AVPixelFormat pix_fmt)
Definition: pixdesc.c:2564
FILTER_PIXFMTS_ARRAY
#define FILTER_PIXFMTS_ARRAY(array)
Definition: internal.h:171
inlink
The exact code depends on how similar the blocks are and how related they are to the and needs to apply these operations to the correct inlink or outlink if there are several Macros are available to factor that when no extra processing is inlink
Definition: filter_design.txt:212
av_frame_free
void av_frame_free(AVFrame **frame)
Free the frame and any dynamically allocated objects in it, e.g.
Definition: frame.c:112
av_pixelutils_sad_fn
int(* av_pixelutils_sad_fn)(const uint8_t *src1, ptrdiff_t stride1, const uint8_t *src2, ptrdiff_t stride2)
Sum of abs(src1[x] - src2[x])
Definition: pixelutils.h:29
AVFrame
This structure describes decoded (raw) audio or video data.
Definition: frame.h:303
pixdesc.h
AVFrame::pts
int64_t pts
Presentation timestamp in time_base units (time when frame should be shown to user).
Definition: frame.h:396
w
uint8_t w
Definition: llviddspenc.c:38
AVOption
AVOption.
Definition: opt.h:247
AV_LOG_VERBOSE
#define AV_LOG_VERBOSE
Detailed information.
Definition: log.h:196
DecimateContext::vsub
int vsub
chroma subsampling values
Definition: vf_decimate.c:50
AV_PIX_FMT_YUV440P
@ AV_PIX_FMT_YUV440P
planar YUV 4:4:0 (1 Cr & Cb sample per 1x2 Y samples)
Definition: pixfmt.h:99
FFMAX
#define FFMAX(a, b)
Definition: macros.h:47
AVFilter::name
const char * name
Filter name.
Definition: avfilter.h:153
video.h
DecimateContext::hsub
int hsub
Definition: vf_decimate.c:50
AVFrame::data
uint8_t * data[AV_NUM_DATA_POINTERS]
pointer to the picture/channel planes.
Definition: frame.h:317
hsub
static void hsub(htype *dst, const htype *src, int bins)
Definition: vf_median.c:74
formats.h
DecimateContext::drop_count
int drop_count
if positive: number of frames sequentially dropped if negative: number of sequential frames which wer...
Definition: vf_mpdecimate.c:46
config_input
static int config_input(AVFilterLink *inlink)
Definition: vf_mpdecimate.c:180
AVFilterPad
A filter pad used for either input or output.
Definition: internal.h:50
av_cold
#define av_cold
Definition: attributes.h:90
filter_frame
static int filter_frame(AVFilterLink *inlink, AVFrame *cur)
Definition: vf_mpdecimate.c:191
AV_PIX_FMT_YUVJ422P
@ AV_PIX_FMT_YUVJ422P
planar YUV 4:2:2, 16bpp, full scale (JPEG), deprecated in favor of AV_PIX_FMT_YUV422P and setting col...
Definition: pixfmt.h:79
AV_PIX_FMT_YUVA420P
@ AV_PIX_FMT_YUVA420P
planar YUV 4:2:0, 20bpp, (1 Cr & Cb sample per 2x2 Y & A samples)
Definition: pixfmt.h:101
AV_CEIL_RSHIFT
#define AV_CEIL_RSHIFT(a, b)
Definition: common.h:51
AV_LOG_DEBUG
#define AV_LOG_DEBUG
Stuff which is only useful for libav* developers.
Definition: log.h:201
FLAGS
#define FLAGS
Definition: vf_mpdecimate.c:55
ctx
AVFormatContext * ctx
Definition: movenc.c:48
pix_fmts
static enum AVPixelFormat pix_fmts[]
Definition: vf_mpdecimate.c:164
av_frame_clone
AVFrame * av_frame_clone(const AVFrame *src)
Create a new frame that references the same data as src.
Definition: frame.c:424
AVPixFmtDescriptor::log2_chroma_w
uint8_t log2_chroma_w
Amount to shift the luma width right to find the chroma width.
Definition: pixdesc.h:80
AV_PIX_FMT_YUV420P
@ AV_PIX_FMT_YUV420P
planar YUV 4:2:0, 12bpp, (1 Cr & Cb sample per 2x2 Y samples)
Definition: pixfmt.h:66
FILTER_INPUTS
#define FILTER_INPUTS(array)
Definition: internal.h:191
AV_PIX_FMT_YUVJ444P
@ AV_PIX_FMT_YUVJ444P
planar YUV 4:4:4, 24bpp, full scale (JPEG), deprecated in favor of AV_PIX_FMT_YUV444P and setting col...
Definition: pixfmt.h:80
AVClass
Describe the class of an AVClass context structure.
Definition: log.h:66
NULL
#define NULL
Definition: coverity.c:32
ff_vf_mpdecimate
const AVFilter ff_vf_mpdecimate
Definition: vf_mpdecimate.c:236
OFFSET
#define OFFSET(x)
Definition: vf_mpdecimate.c:54
AV_PIX_FMT_YUVJ420P
@ AV_PIX_FMT_YUVJ420P
planar YUV 4:2:0, 12bpp, full scale (JPEG), deprecated in favor of AV_PIX_FMT_YUV420P and setting col...
Definition: pixfmt.h:78
DecimateContext::ref
AVFrame * ref
reference picture
Definition: vf_mpdecimate.c:50
c
Undefined Behavior In the C some operations are like signed integer dereferencing freed accessing outside allocated Undefined Behavior must not occur in a C it is not safe even if the output of undefined operations is unused The unsafety may seem nit picking but Optimizing compilers have in fact optimized code on the assumption that no undefined Behavior occurs Optimizing code based on wrong assumptions can and has in some cases lead to effects beyond the output of computations The signed integer overflow problem in speed critical code Code which is highly optimized and works with signed integers sometimes has the problem that often the output of the computation does not c
Definition: undefined.txt:32
av_ts2timestr
#define av_ts2timestr(ts, tb)
Convenience macro, the return value should be used only directly in function arguments but never stan...
Definition: timestamp.h:76
NULL_IF_CONFIG_SMALL
#define NULL_IF_CONFIG_SMALL(x)
Return NULL if CONFIG_SMALL is true, otherwise the argument without modification.
Definition: internal.h:117
mpdecimate_options
static const AVOption mpdecimate_options[]
Definition: vf_mpdecimate.c:57
pixelutils.h
init
static av_cold int init(AVFilterContext *ctx)
Definition: vf_mpdecimate.c:144
AV_PIX_FMT_YUVA444P
@ AV_PIX_FMT_YUVA444P
planar YUV 4:4:4 32bpp, (1 Cr & Cb sample per 1x1 Y & A samples)
Definition: pixfmt.h:167
internal.h
AV_OPT_TYPE_FLOAT
@ AV_OPT_TYPE_FLOAT
Definition: opt.h:227
DecimateContext::sad
av_pixelutils_sad_fn sad
sum of absolute difference function
Definition: vf_mpdecimate.c:51
DecimateContext::max_drop_count
int max_drop_count
if positive: maximum number of sequential frames to drop if negative: minimum number of frames betwee...
Definition: vf_mpdecimate.c:43
DecimateContext::frac
float frac
threshold of changed pixels over the total fraction
Definition: vf_mpdecimate.c:41
FFMIN
#define FFMIN(a, b)
Definition: macros.h:49
AV_PIX_FMT_YUVJ440P
@ AV_PIX_FMT_YUVJ440P
planar YUV 4:4:0 full scale (JPEG), deprecated in favor of AV_PIX_FMT_YUV440P and setting color_range
Definition: pixfmt.h:100
AVFilterPad::name
const char * name
Pad name.
Definition: internal.h:56
AVFilter
Filter definition.
Definition: avfilter.h:149
mpdecimate_outputs
static const AVFilterPad mpdecimate_outputs[]
Definition: vf_mpdecimate.c:229
DecimateContext::hi
int hi
lower and higher threshold number of differences values for 8x8 blocks
Definition: vf_mpdecimate.c:38
ret
ret
Definition: filter_design.txt:187
AVFILTER_DEFINE_CLASS
AVFILTER_DEFINE_CLASS(mpdecimate)
AV_PIX_FMT_NONE
@ AV_PIX_FMT_NONE
Definition: pixfmt.h:65
AV_OPT_TYPE_INT
@ AV_OPT_TYPE_INT
Definition: opt.h:224
avfilter.h
av_pixelutils_get_sad_fn
av_pixelutils_sad_fn av_pixelutils_get_sad_fn(int w_bits, int h_bits, int aligned, void *log_ctx)
Get a potentially optimized pointer to a Sum-of-absolute-differences function (see the av_pixelutils_...
Definition: pixelutils.c:66
ref
static int ref[MAX_W *MAX_W]
Definition: jpeg2000dwt.c:107
AV_PIX_FMT_YUV444P
@ AV_PIX_FMT_YUV444P
planar YUV 4:4:4, 24bpp, (1 Cr & Cb sample per 1x1 Y samples)
Definition: pixfmt.h:71
AVFilterContext
An instance of a filter.
Definition: avfilter.h:386
AV_PIX_FMT_GBRP
@ AV_PIX_FMT_GBRP
planar GBR 4:4:4 24bpp
Definition: pixfmt.h:158
AVMEDIA_TYPE_VIDEO
@ AVMEDIA_TYPE_VIDEO
Definition: avutil.h:201
AV_PIX_FMT_YUV422P
@ AV_PIX_FMT_YUV422P
planar YUV 4:2:2, 16bpp, (1 Cr & Cb sample per 2x1 Y samples)
Definition: pixfmt.h:70
AVPixFmtDescriptor
Descriptor that unambiguously describes how the bits of a pixel are stored in the up to 4 data planes...
Definition: pixdesc.h:69
FILTER_OUTPUTS
#define FILTER_OUTPUTS(array)
Definition: internal.h:192
AV_PIX_FMT_YUV411P
@ AV_PIX_FMT_YUV411P
planar YUV 4:1:1, 12bpp, (1 Cr & Cb sample per 4x1 Y samples)
Definition: pixfmt.h:73
DecimateContext
Definition: vf_decimate.c:38
mpdecimate_inputs
static const AVFilterPad mpdecimate_inputs[]
Definition: vf_mpdecimate.c:220
uninit
static av_cold void uninit(AVFilterContext *ctx)
Definition: vf_mpdecimate.c:158
d
d
Definition: ffmpeg_filter.c:156
timestamp.h
AVFrame::linesize
int linesize[AV_NUM_DATA_POINTERS]
For video, size in bytes of each picture line.
Definition: frame.h:334
AV_PIX_FMT_YUV410P
@ AV_PIX_FMT_YUV410P
planar YUV 4:1:0, 9bpp, (1 Cr & Cb sample per 4x4 Y samples)
Definition: pixfmt.h:72
av_log
#define av_log(a,...)
Definition: tableprint_vlc.h:28
av_ts2str
#define av_ts2str(ts)
Convenience macro, the return value should be used only directly in function arguments but never stan...
Definition: timestamp.h:54
h
h
Definition: vp9dsp_template.c:2038
decimate_frame
static int decimate_frame(AVFilterContext *ctx, AVFrame *cur, AVFrame *ref)
Tell if the frame should be decimated, for example if it is no much different with respect to the ref...
Definition: vf_mpdecimate.c:109
AVPixFmtDescriptor::log2_chroma_h
uint8_t log2_chroma_h
Amount to shift the luma height right to find the chroma height.
Definition: pixdesc.h:89
AV_PIX_FMT_YUVA422P
@ AV_PIX_FMT_YUVA422P
planar YUV 4:2:2 24bpp, (1 Cr & Cb sample per 2x1 Y & A samples)
Definition: pixfmt.h:166
diff_planes
static int diff_planes(AVFilterContext *ctx, uint8_t *cur, int cur_linesize, uint8_t *ref, int ref_linesize, int w, int h)
Return 1 if the two planes are different, 0 otherwise.
Definition: vf_mpdecimate.c:71