FFmpeg
vf_colorkey.c
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1 /*
2  * Copyright (c) 2015 Timo Rothenpieler <timo@rothenpieler.org>
3  *
4  * This file is part of FFmpeg.
5  *
6  * FFmpeg is free software; you can redistribute it and/or
7  * modify it under the terms of the GNU Lesser General Public
8  * License as published by the Free Software Foundation; either
9  * version 2.1 of the License, or (at your option) any later version.
10  *
11  * FFmpeg is distributed in the hope that it will be useful,
12  * but WITHOUT ANY WARRANTY; without even the implied warranty of
13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
14  * Lesser General Public License for more details.
15  *
16  * You should have received a copy of the GNU Lesser General Public
17  * License along with FFmpeg; if not, write to the Free Software
18  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
19  */
20 
21 #include "libavutil/opt.h"
22 #include "libavutil/imgutils.h"
23 #include "avfilter.h"
24 #include "formats.h"
25 #include "internal.h"
26 #include "video.h"
27 
28 typedef struct ColorkeyContext {
29  const AVClass *class;
30 
31  /* color offsets rgba */
32  int co[4];
33 
35  float similarity;
36  float blend;
37 
39  int jobnr, int nb_jobs);
41 
43 {
44  int dr = (int)r - ctx->colorkey_rgba[0];
45  int dg = (int)g - ctx->colorkey_rgba[1];
46  int db = (int)b - ctx->colorkey_rgba[2];
47 
48  double diff = sqrt((dr * dr + dg * dg + db * db) / (255.0 * 255.0));
49 
50  if (ctx->blend > 0.0001) {
51  return av_clipd((diff - ctx->similarity) / ctx->blend, 0.0, 1.0) * 255.0;
52  } else {
53  return (diff > ctx->similarity) ? 255 : 0;
54  }
55 }
56 
57 static int do_colorkey_slice(AVFilterContext *avctx, void *arg, int jobnr, int nb_jobs)
58 {
59  AVFrame *frame = arg;
60 
61  const int slice_start = (frame->height * jobnr) / nb_jobs;
62  const int slice_end = (frame->height * (jobnr + 1)) / nb_jobs;
63 
64  ColorkeyContext *ctx = avctx->priv;
65 
66  int o, x, y;
67 
68  for (y = slice_start; y < slice_end; ++y) {
69  for (x = 0; x < frame->width; ++x) {
70  o = frame->linesize[0] * y + x * 4;
71 
72  frame->data[0][o + ctx->co[3]] =
74  frame->data[0][o + ctx->co[0]],
75  frame->data[0][o + ctx->co[1]],
76  frame->data[0][o + ctx->co[2]]);
77  }
78  }
79 
80  return 0;
81 }
82 
83 static int do_colorhold_slice(AVFilterContext *avctx, void *arg, int jobnr, int nb_jobs)
84 {
85  AVFrame *frame = arg;
86 
87  const int slice_start = (frame->height * jobnr) / nb_jobs;
88  const int slice_end = (frame->height * (jobnr + 1)) / nb_jobs;
89 
90  ColorkeyContext *ctx = avctx->priv;
91 
92  int x, y;
93 
94  for (y = slice_start; y < slice_end; ++y) {
95  for (x = 0; x < frame->width; ++x) {
96  int o, t, r, g, b;
97 
98  o = frame->linesize[0] * y + x * 4;
99  r = frame->data[0][o + ctx->co[0]];
100  g = frame->data[0][o + ctx->co[1]];
101  b = frame->data[0][o + ctx->co[2]];
102 
103  t = do_colorkey_pixel(ctx, r, g, b);
104 
105  if (t > 0) {
106  int a = (r + g + b) / 3;
107  int rt = 255 - t;
108 
109  frame->data[0][o + ctx->co[0]] = (a * t + r * rt + 127) >> 8;
110  frame->data[0][o + ctx->co[1]] = (a * t + g * rt + 127) >> 8;
111  frame->data[0][o + ctx->co[2]] = (a * t + b * rt + 127) >> 8;
112  }
113  }
114  }
115 
116  return 0;
117 }
118 
120 {
121  ColorkeyContext *ctx = avctx->priv;
122 
123  if (!strcmp(avctx->filter->name, "colorkey")) {
125  } else {
127  }
128 
129  return 0;
130 }
131 
133 {
134  AVFilterContext *avctx = link->dst;
135  ColorkeyContext *ctx = avctx->priv;
136  int res;
137 
138  if (res = av_frame_make_writable(frame))
139  return res;
140 
141  if (res = avctx->internal->execute(avctx, ctx->do_slice, frame, NULL, FFMIN(frame->height, ff_filter_get_nb_threads(avctx))))
142  return res;
143 
144  return ff_filter_frame(avctx->outputs[0], frame);
145 }
146 
147 static av_cold int config_output(AVFilterLink *outlink)
148 {
149  AVFilterContext *avctx = outlink->src;
150  ColorkeyContext *ctx = avctx->priv;
152  int i;
153 
154  outlink->w = avctx->inputs[0]->w;
155  outlink->h = avctx->inputs[0]->h;
156  outlink->time_base = avctx->inputs[0]->time_base;
157 
158  for (i = 0; i < 4; ++i)
159  ctx->co[i] = desc->comp[i].offset;
160 
161  return 0;
162 }
163 
165 {
166  static const enum AVPixelFormat pixel_fmts[] = {
172  };
173 
175 
176  formats = ff_make_format_list(pixel_fmts);
177  if (!formats)
178  return AVERROR(ENOMEM);
179 
180  return ff_set_common_formats(avctx, formats);
181 }
182 
183 static const AVFilterPad colorkey_inputs[] = {
184  {
185  .name = "default",
186  .type = AVMEDIA_TYPE_VIDEO,
187  .filter_frame = filter_frame,
188  },
189  { NULL }
190 };
191 
192 static const AVFilterPad colorkey_outputs[] = {
193  {
194  .name = "default",
195  .type = AVMEDIA_TYPE_VIDEO,
196  .config_props = config_output,
197  },
198  { NULL }
199 };
200 
201 #define OFFSET(x) offsetof(ColorkeyContext, x)
202 #define FLAGS AV_OPT_FLAG_FILTERING_PARAM|AV_OPT_FLAG_VIDEO_PARAM
203 
204 #if CONFIG_COLORKEY_FILTER
205 
206 static const AVOption colorkey_options[] = {
207  { "color", "set the colorkey key color", OFFSET(colorkey_rgba), AV_OPT_TYPE_COLOR, { .str = "black" }, CHAR_MIN, CHAR_MAX, FLAGS },
208  { "similarity", "set the colorkey similarity value", OFFSET(similarity), AV_OPT_TYPE_FLOAT, { .dbl = 0.01 }, 0.01, 1.0, FLAGS },
209  { "blend", "set the colorkey key blend value", OFFSET(blend), AV_OPT_TYPE_FLOAT, { .dbl = 0.0 }, 0.0, 1.0, FLAGS },
210  { NULL }
211 };
212 
213 AVFILTER_DEFINE_CLASS(colorkey);
214 
216  .name = "colorkey",
217  .description = NULL_IF_CONFIG_SMALL("Turns a certain color into transparency. Operates on RGB colors."),
218  .priv_size = sizeof(ColorkeyContext),
219  .priv_class = &colorkey_class,
221  .init = init_filter,
222  .inputs = colorkey_inputs,
223  .outputs = colorkey_outputs,
225 };
226 
227 #endif /* CONFIG_COLORKEY_FILTER */
228 #if CONFIG_COLORHOLD_FILTER
229 
230 static const AVOption colorhold_options[] = {
231  { "color", "set the colorhold key color", OFFSET(colorkey_rgba), AV_OPT_TYPE_COLOR, { .str = "black" }, CHAR_MIN, CHAR_MAX, FLAGS },
232  { "similarity", "set the colorhold similarity value", OFFSET(similarity), AV_OPT_TYPE_FLOAT, { .dbl = 0.01 }, 0.01, 1.0, FLAGS },
233  { "blend", "set the colorhold blend value", OFFSET(blend), AV_OPT_TYPE_FLOAT, { .dbl = 0.0 }, 0.0, 1.0, FLAGS },
234  { NULL }
235 };
236 
237 AVFILTER_DEFINE_CLASS(colorhold);
238 
240  .name = "colorhold",
241  .description = NULL_IF_CONFIG_SMALL("Turns a certain color range into gray. Operates on RGB colors."),
242  .priv_size = sizeof(ColorkeyContext),
243  .priv_class = &colorhold_class,
245  .init = init_filter,
246  .inputs = colorkey_inputs,
247  .outputs = colorkey_outputs,
249 };
250 
251 #endif /* CONFIG_COLORHOLD_FILTER */
#define NULL
Definition: coverity.c:32
const AVPixFmtDescriptor * av_pix_fmt_desc_get(enum AVPixelFormat pix_fmt)
Definition: pixdesc.c:2522
This structure describes decoded (raw) audio or video data.
Definition: frame.h:295
AVOption.
Definition: opt.h:246
uint8_t colorkey_rgba[4]
Definition: vf_colorkey.c:34
misc image utilities
Main libavfilter public API header.
const char * g
Definition: vf_curves.c:115
const char * desc
Definition: nvenc.c:68
static av_cold int init(AVCodecContext *avctx)
Definition: avrndec.c:35
static const AVFilterPad colorkey_outputs[]
Definition: vf_colorkey.c:192
The reader does not expect b to be semantically here and if the code is changed by maybe adding a a division or other the signedness will almost certainly be mistaken To avoid this confusion a new type was SUINT is the C unsigned type but it holds a signed int to use the same example SUINT a
Definition: undefined.txt:36
AVFilterFormats * ff_make_format_list(const int *fmts)
Create a list of supported formats.
Definition: formats.c:283
static av_cold int config_output(AVFilterLink *outlink)
Definition: vf_colorkey.c:147
#define AVFILTER_FLAG_SUPPORT_TIMELINE_GENERIC
Some filters support a generic "enable" expression option that can be used to enable or disable a fil...
Definition: avfilter.h:125
const char * name
Pad name.
Definition: internal.h:60
AVFilterLink ** inputs
array of pointers to input links
Definition: avfilter.h:346
int ff_filter_frame(AVFilterLink *link, AVFrame *frame)
Send a frame of data to the next filter.
Definition: avfilter.c:1093
AVComponentDescriptor comp[4]
Parameters that describe how pixels are packed.
Definition: pixdesc.h:117
uint8_t
#define av_cold
Definition: attributes.h:82
AVOptions.
static uint8_t do_colorkey_pixel(ColorkeyContext *ctx, uint8_t r, uint8_t g, uint8_t b)
Definition: vf_colorkey.c:42
packed ABGR 8:8:8:8, 32bpp, ABGRABGR...
Definition: pixfmt.h:94
A filter pad used for either input or output.
Definition: internal.h:54
#define i(width, name, range_min, range_max)
Definition: cbs_h2645.c:259
int width
Definition: frame.h:353
int 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:569
#define NULL_IF_CONFIG_SMALL(x)
Return NULL if CONFIG_SMALL is true, otherwise the argument without modification. ...
Definition: internal.h:186
packed BGRA 8:8:8:8, 32bpp, BGRABGRA...
Definition: pixfmt.h:95
const char * r
Definition: vf_curves.c:114
void * priv
private data for use by the filter
Definition: avfilter.h:353
#define AVFILTER_FLAG_SLICE_THREADS
The filter supports multithreading by splitting frames into multiple parts and processing them concur...
Definition: avfilter.h:116
const char * arg
Definition: jacosubdec.c:66
packed ARGB 8:8:8:8, 32bpp, ARGBARGB...
Definition: pixfmt.h:92
static int filter_frame(AVFilterLink *link, AVFrame *frame)
Definition: vf_colorkey.c:132
packed RGBA 8:8:8:8, 32bpp, RGBARGBA...
Definition: pixfmt.h:93
static int do_colorhold_slice(AVFilterContext *avctx, void *arg, int jobnr, int nb_jobs)
Definition: vf_colorkey.c:83
static int do_colorkey_slice(AVFilterContext *avctx, void *arg, int jobnr, int nb_jobs)
Definition: vf_colorkey.c:57
#define b
Definition: input.c:41
int ff_filter_get_nb_threads(AVFilterContext *ctx)
Get number of threads for current filter instance.
Definition: avfilter.c:802
#define FFMIN(a, b)
Definition: common.h:96
AVFormatContext * ctx
Definition: movenc.c:48
static const AVFilterPad colorkey_inputs[]
Definition: vf_colorkey.c:183
these buffered frames must be flushed immediately if a new input produces new the filter must not call request_frame to get more It must just process the frame or queue it The task of requesting more frames is left to the filter s request_frame method or the application If a filter has several the filter must be ready for frames arriving randomly on any input any filter with several inputs will most likely require some kind of queuing mechanism It is perfectly acceptable to have a limited queue and to drop frames when the inputs are too unbalanced request_frame For filters that do not use the this method is called when a frame is wanted on an output For a it should directly call filter_frame on the corresponding output For a if there are queued frames already one of these frames should be pushed If the filter should request a frame on one of its repeatedly until at least one frame has been pushed Return or at least make progress towards producing a frame
static const AVFilterPad outputs[]
Definition: af_acontrast.c:203
AVFilter ff_vf_colorhold
#define FLAGS
Definition: vf_colorkey.c:202
int linesize[AV_NUM_DATA_POINTERS]
For video, size in bytes of each picture line.
Definition: frame.h:326
Descriptor that unambiguously describes how the bits of a pixel are stored in the up to 4 data planes...
Definition: pixdesc.h:81
#define OFFSET(x)
Definition: vf_colorkey.c:201
these buffered frames must be flushed immediately if a new input produces new the filter must not call request_frame to get more It must just process the frame or queue it The task of requesting more frames is left to the filter s request_frame method or the application If a filter has several inputs
Describe the class of an AVClass context structure.
Definition: log.h:67
Filter definition.
Definition: avfilter.h:144
const char * name
Filter name.
Definition: avfilter.h:148
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 link
AVFilterLink ** outputs
array of pointers to output links
Definition: avfilter.h:350
int offset
Number of elements before the component of the first pixel.
Definition: pixdesc.h:47
int av_frame_make_writable(AVFrame *frame)
Ensure that the frame data is writable, avoiding data copy if possible.
Definition: frame.c:611
#define flags(name, subs,...)
Definition: cbs_av1.c:561
AVFilterInternal * internal
An opaque struct for libavfilter internal use.
Definition: avfilter.h:378
uint8_t * data[AV_NUM_DATA_POINTERS]
pointer to the picture/channel planes.
Definition: frame.h:309
int
avfilter_execute_func * execute
Definition: internal.h:155
static int slice_end(AVCodecContext *avctx, AVFrame *pict)
Handle slice ends.
Definition: mpeg12dec.c:2036
static av_always_inline int diff(const uint32_t a, const uint32_t b)
#define AVFILTER_DEFINE_CLASS(fname)
Definition: internal.h:334
static av_cold int init_filter(AVFilterContext *avctx)
Definition: vf_colorkey.c:119
static av_cold int query_formats(AVFilterContext *avctx)
Definition: vf_colorkey.c:164
A list of supported formats for one end of a filter link.
Definition: formats.h:64
An instance of a filter.
Definition: avfilter.h:338
int height
Definition: frame.h:353
formats
Definition: signature.h:48
AVFilter ff_vf_colorkey
int(* do_slice)(AVFilterContext *ctx, void *arg, int jobnr, int nb_jobs)
Definition: vf_colorkey.c:38
internal API functions
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
AVPixelFormat
Pixel format.
Definition: pixfmt.h:64
const AVFilter * filter
the AVFilter of which this is an instance
Definition: avfilter.h:341