FFmpeg  2.1.1
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/timestamp.h"
30 #include "libavcodec/dsputil.h"
31 #include "avfilter.h"
32 #include "internal.h"
33 #include "formats.h"
34 #include "video.h"
35 
36 typedef 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  DSPContext dspctx; ///< context providing optimized diff routines
52  AVCodecContext *avctx; ///< codec context required for the DSPContext
54 
55 #define OFFSET(x) offsetof(DecimateContext, x)
56 #define FLAGS AV_OPT_FLAG_VIDEO_PARAM|AV_OPT_FLAG_FILTERING_PARAM
57 
58 static const AVOption mpdecimate_options[] = {
59  { "max", "set the maximum number of consecutive dropped frames (positive), or the minimum interval between dropped frames (negative)",
60  OFFSET(max_drop_count), AV_OPT_TYPE_INT, {.i64=0}, INT_MIN, INT_MAX, FLAGS },
61  { "hi", "set high dropping threshold", OFFSET(hi), AV_OPT_TYPE_INT, {.i64=64*12}, INT_MIN, INT_MAX, FLAGS },
62  { "lo", "set low dropping threshold", OFFSET(lo), AV_OPT_TYPE_INT, {.i64=64*5}, INT_MIN, INT_MAX, FLAGS },
63  { "frac", "set fraction dropping threshold", OFFSET(frac), AV_OPT_TYPE_FLOAT, {.dbl=0.33}, 0, 1, FLAGS },
64  { NULL }
65 };
66 
67 AVFILTER_DEFINE_CLASS(mpdecimate);
68 
69 /**
70  * Return 1 if the two planes are different, 0 otherwise.
71  */
72 static int diff_planes(AVFilterContext *ctx,
73  uint8_t *cur, uint8_t *ref, int linesize,
74  int w, int h)
75 {
76  DecimateContext *decimate = ctx->priv;
77  DSPContext *dspctx = &decimate->dspctx;
78 
79  int x, y;
80  int d, c = 0;
81  int t = (w/16)*(h/16)*decimate->frac;
82  int16_t block[8*8];
83 
84  /* compute difference for blocks of 8x8 bytes */
85  for (y = 0; y < h-7; y += 4) {
86  for (x = 8; x < w-7; x += 4) {
87  dspctx->diff_pixels(block,
88  cur+x+y*linesize,
89  ref+x+y*linesize, linesize);
90  d = dspctx->sum_abs_dctelem(block);
91  if (d > decimate->hi)
92  return 1;
93  if (d > decimate->lo) {
94  c++;
95  if (c > t)
96  return 1;
97  }
98  }
99  }
100  return 0;
101 }
102 
103 /**
104  * Tell if the frame should be decimated, for example if it is no much
105  * different with respect to the reference frame ref.
106  */
108  AVFrame *cur, AVFrame *ref)
109 {
110  DecimateContext *decimate = ctx->priv;
111  int plane;
112 
113  if (decimate->max_drop_count > 0 &&
114  decimate->drop_count >= decimate->max_drop_count)
115  return 0;
116  if (decimate->max_drop_count < 0 &&
117  (decimate->drop_count-1) > decimate->max_drop_count)
118  return 0;
119 
120  for (plane = 0; ref->data[plane] && ref->linesize[plane]; plane++) {
121  int vsub = plane == 1 || plane == 2 ? decimate->vsub : 0;
122  int hsub = plane == 1 || plane == 2 ? decimate->hsub : 0;
123  if (diff_planes(ctx,
124  cur->data[plane], ref->data[plane], ref->linesize[plane],
125  FF_CEIL_RSHIFT(ref->width, hsub),
126  FF_CEIL_RSHIFT(ref->height, vsub)))
127  return 0;
128  }
129 
130  return 1;
131 }
132 
133 static av_cold int init(AVFilterContext *ctx)
134 {
135  DecimateContext *decimate = ctx->priv;
136 
137  av_log(ctx, AV_LOG_VERBOSE, "max_drop_count:%d hi:%d lo:%d frac:%f\n",
138  decimate->max_drop_count, decimate->hi, decimate->lo, decimate->frac);
139 
140  decimate->avctx = avcodec_alloc_context3(NULL);
141  if (!decimate->avctx)
142  return AVERROR(ENOMEM);
143  avpriv_dsputil_init(&decimate->dspctx, decimate->avctx);
144 
145  return 0;
146 }
147 
148 static av_cold void uninit(AVFilterContext *ctx)
149 {
150  DecimateContext *decimate = ctx->priv;
151  av_frame_free(&decimate->ref);
152  if (decimate->avctx) {
153  avcodec_close(decimate->avctx);
154  av_freep(&decimate->avctx);
155  }
156 }
157 
159 {
160  static const enum AVPixelFormat pix_fmts[] = {
168  };
169 
171 
172  return 0;
173 }
174 
175 static int config_input(AVFilterLink *inlink)
176 {
177  AVFilterContext *ctx = inlink->dst;
178  DecimateContext *decimate = ctx->priv;
179  const AVPixFmtDescriptor *pix_desc = av_pix_fmt_desc_get(inlink->format);
180  decimate->hsub = pix_desc->log2_chroma_w;
181  decimate->vsub = pix_desc->log2_chroma_h;
182 
183  return 0;
184 }
185 
186 static int filter_frame(AVFilterLink *inlink, AVFrame *cur)
187 {
188  DecimateContext *decimate = inlink->dst->priv;
189  AVFilterLink *outlink = inlink->dst->outputs[0];
190  int ret;
191 
192  if (decimate->ref && decimate_frame(inlink->dst, cur, decimate->ref)) {
193  decimate->drop_count = FFMAX(1, decimate->drop_count+1);
194  } else {
195  av_frame_free(&decimate->ref);
196  decimate->ref = cur;
197  decimate->drop_count = FFMIN(-1, decimate->drop_count-1);
198 
199  if (ret = ff_filter_frame(outlink, av_frame_clone(cur)) < 0)
200  return ret;
201  }
202 
203  av_log(inlink->dst, AV_LOG_DEBUG,
204  "%s pts:%s pts_time:%s drop_count:%d\n",
205  decimate->drop_count > 0 ? "drop" : "keep",
206  av_ts2str(cur->pts), av_ts2timestr(cur->pts, &inlink->time_base),
207  decimate->drop_count);
208 
209  if (decimate->drop_count > 0)
210  av_frame_free(&cur);
211 
212  return 0;
213 }
214 
215 static int request_frame(AVFilterLink *outlink)
216 {
217  DecimateContext *decimate = outlink->src->priv;
218  AVFilterLink *inlink = outlink->src->inputs[0];
219  int ret;
220 
221  do {
222  ret = ff_request_frame(inlink);
223  } while (decimate->drop_count > 0 && ret >= 0);
224 
225  return ret;
226 }
227 
228 static const AVFilterPad mpdecimate_inputs[] = {
229  {
230  .name = "default",
231  .type = AVMEDIA_TYPE_VIDEO,
232  .config_props = config_input,
233  .filter_frame = filter_frame,
234  },
235  { NULL }
236 };
237 
238 static const AVFilterPad mpdecimate_outputs[] = {
239  {
240  .name = "default",
241  .type = AVMEDIA_TYPE_VIDEO,
242  .request_frame = request_frame,
243  },
244  { NULL }
245 };
246 
248  .name = "mpdecimate",
249  .description = NULL_IF_CONFIG_SMALL("Remove near-duplicate frames."),
250  .init = init,
251  .uninit = uninit,
252  .priv_size = sizeof(DecimateContext),
253  .priv_class = &mpdecimate_class,
255  .inputs = mpdecimate_inputs,
256  .outputs = mpdecimate_outputs,
257 };
AVFrame * ref
reference picture
Definition: vf_mpdecimate.c:50
static const AVFilterPad mpdecimate_inputs[]
This structure describes decoded (raw) audio or video data.
Definition: frame.h:96
AVOption.
Definition: opt.h:253
const char * name
Filter name.
Definition: avfilter.h:468
void * priv
private data for use by the filter
Definition: avfilter.h:648
static const AVFilterPad outputs[]
Definition: af_ashowinfo.c:111
#define av_ts2timestr(ts, tb)
Convenience macro, the return value should be used only directly in function arguments but never stan...
Definition: timestamp.h:72
int(* sum_abs_dctelem)(int16_t *block)
Definition: dsputil.h:132
static int filter_frame(AVFilterLink *inlink, AVFrame *cur)
planar YUV 4:2:2, 16bpp, (1 Cr &amp; Cb sample per 2x1 Y samples)
Definition: avcodec.h:4538
void av_log(void *avcl, int level, const char *fmt,...) av_printf_format(3
Send the specified message to the log if the level is less than or equal to the current av_log_level...
float frac
threshold of changed pixels over the total fraction
Definition: vf_mpdecimate.c:41
Pixel format.
Definition: avcodec.h:4533
#define av_cold
Definition: avcodec.h:653
uint8_t log2_chroma_w
Amount to shift the luma width right to find the chroma width.
Definition: pixdesc.h:68
void av_freep(void *ptr)
Free a memory block which has been allocated with av_malloc(z)() or av_realloc() and set the pointer ...
Definition: mem.c:234
AVFilterFormats * ff_make_format_list(const int *fmts)
Create a list of supported formats.
Definition: formats.c:294
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
const char * name
Pad name.
Definition: internal.h:66
int hi
lower and higher threshold number of differences values for 8x8 blocks
Definition: vf_mpdecimate.c:38
int ff_filter_frame(AVFilterLink *link, AVFrame *frame)
Send a frame of data to the next filter.
Definition: avfilter.c:1118
uint8_t
static const AVOption mpdecimate_options[]
Definition: vf_mpdecimate.c:58
int64_t pts
Presentation timestamp in time_base units (time when frame should be shown to user).
Definition: frame.h:182
#define FF_CEIL_RSHIFT(a, b)
Definition: avcodec.h:916
AVCodecContext * avcodec_alloc_context3(const AVCodec *codec)
Allocate an AVCodecContext and set its fields to default values.
Definition: options.c:151
#define AV_LOG_VERBOSE
Detailed information.
Definition: avcodec.h:4163
planar YUV 4:2:0, 20bpp, (1 Cr &amp; Cb sample per 2x2 Y &amp; A samples)
Definition: avcodec.h:4571
void ff_set_common_formats(AVFilterContext *ctx, AVFilterFormats *formats)
A helper for query_formats() which sets all links to the same list of formats.
Definition: formats.c:531
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...
A filter pad used for either input or output.
Definition: internal.h:60
int avcodec_close(AVCodecContext *avctx)
Close a given AVCodecContext and free all the data associated with it (but not the AVCodecContext its...
Definition: utils.c:2505
int width
width and height of the video frame
Definition: frame.h:145
uint8_t log2_chroma_h
Amount to shift the luma height right to find the chroma height.
Definition: pixdesc.h:77
planar YUV 4:4:4, 24bpp, full scale (JPEG), deprecated in favor of PIX_FMT_YUV444P and setting color_...
Definition: avcodec.h:4548
#define NULL_IF_CONFIG_SMALL(x)
Return NULL if CONFIG_SMALL is true, otherwise the argument without modification. ...
Definition: internal.h:151
planar YUV 4:4:0 full scale (JPEG), deprecated in favor of PIX_FMT_YUV440P and setting color_range ...
Definition: avcodec.h:4570
#define AV_LOG_DEBUG
Stuff which is only useful for libav* developers.
Definition: avcodec.h:4168
planar YUV 4:1:1, 12bpp, (1 Cr &amp; Cb sample per 4x1 Y samples)
Definition: avcodec.h:4541
void av_frame_free(AVFrame **frame)
Free the frame and any dynamically allocated objects in it, e.g.
Definition: frame.c:123
#define OFFSET(x)
Definition: vf_mpdecimate.c:55
AVPixelFormat
Pixel format.
Definition: pixfmt.h:66
float y
ret
Definition: avfilter.c:961
#define FFMIN(a, b)
Definition: avcodec.h:925
AVFilter avfilter_vf_mpdecimate
Main libavfilter public API header.
const AVPixFmtDescriptor * av_pix_fmt_desc_get(enum AVPixelFormat pix_fmt)
Definition: pixdesc.c:1938
planar YUV 4:2:0, 12bpp, full scale (JPEG), deprecated in favor of PIX_FMT_YUV420P and setting color_...
Definition: avcodec.h:4546
AVFilterLink ** outputs
array of pointers to output links
Definition: avfilter.h:642
planar YUV 4:2:0, 12bpp, (1 Cr &amp; Cb sample per 2x2 Y samples)
Definition: avcodec.h:4534
planar YUV 4:4:0 (1 Cr &amp; Cb sample per 1x2 Y samples)
Definition: avcodec.h:4569
static av_cold void uninit(AVFilterContext *ctx)
#define FFMAX(a, b)
Definition: avcodec.h:923
AVCodecContext * avctx
codec context required for the DSPContext
Definition: vf_mpdecimate.c:52
Descriptor that unambiguously describes how the bits of a pixel are stored in the up to 4 data planes...
Definition: pixdesc.h:57
main external API structure.
Definition: avcodec.h:1146
void(* diff_pixels)(int16_t *block, const uint8_t *s1, const uint8_t *s2, int stride)
Definition: dsputil.h:127
Describe the class of an AVClass context structure.
Definition: log.h:50
Filter definition.
Definition: avfilter.h:464
static int query_formats(AVFilterContext *ctx)
static const AVFilterPad inputs[]
Definition: af_ashowinfo.c:102
AVFilterLink ** inputs
array of pointers to input links
Definition: avfilter.h:635
int vsub
chroma subsampling values
Definition: vf_decimate.c:47
static int request_frame(AVFilterLink *outlink)
planar YUV 4:4:4, 24bpp, (1 Cr &amp; Cb sample per 1x1 Y samples)
Definition: avcodec.h:4539
int linesize[AV_NUM_DATA_POINTERS]
For video, size in bytes of each picture line.
Definition: frame.h:124
static const AVFilterPad mpdecimate_outputs[]
int drop_count
if positive: number of frames sequentially dropped if negative: number of sequential frames which wer...
Definition: vf_mpdecimate.c:46
AVFrame * av_frame_clone(AVFrame *src)
Create a new frame that references the same data as src.
Definition: frame.c:338
static float t
Definition: muxing.c:123
static av_cold int init(AVFilterContext *ctx)
static double c[64]
DSP utils.
#define FLAGS
Definition: vf_mpdecimate.c:56
#define AVFILTER_DEFINE_CLASS(fname)
Definition: internal.h:301
static int config_input(AVFilterLink *inlink)
#define AVERROR(e)
An instance of a filter.
Definition: avfilter.h:627
DSPContext dspctx
context providing optimized diff routines
Definition: vf_mpdecimate.c:51
int height
Definition: frame.h:145
av_cold void avpriv_dsputil_init(DSPContext *c, AVCodecContext *avctx)
Definition: dsputil.c:2947
int ff_request_frame(AVFilterLink *link)
Request an input frame from the filter at the other end of the link.
Definition: avfilter.c:335
internal API functions
planar YUV 4:2:2, 16bpp, full scale (JPEG), deprecated in favor of PIX_FMT_YUV422P and setting color_...
Definition: avcodec.h:4547
uint8_t * data[AV_NUM_DATA_POINTERS]
pointer to the picture/channel planes.
Definition: frame.h:107
#define av_ts2str(ts)
Convenience macro, the return value should be used only directly in function arguments but never stan...
Definition: timestamp.h:50
planar YUV 4:1:0, 9bpp, (1 Cr &amp; Cb sample per 4x4 Y samples)
Definition: avcodec.h:4540
static int diff_planes(AVFilterContext *ctx, uint8_t *cur, uint8_t *ref, int linesize, int w, int h)
Return 1 if the two planes are different, 0 otherwise.
Definition: vf_mpdecimate.c:72
DSPContext.
Definition: dsputil.h:124
static int16_t block[64]
Definition: dct-test.c:198