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 
34  uint8_t colorkey_rgba[4];
35  float similarity;
36  float blend;
37 
38  int (*do_slice)(AVFilterContext *ctx, void *arg,
39  int jobnr, int nb_jobs);
40 } ColorkeyContext;
41 
42 static uint8_t do_colorkey_pixel(ColorkeyContext *ctx, uint8_t r, uint8_t g, uint8_t b)
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]] =
73  do_colorkey_pixel(ctx,
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 
119 static av_cold int init_filter(AVFilterContext *avctx)
120 {
121  ColorkeyContext *ctx = avctx->priv;
122 
123  if (!strcmp(avctx->filter->name, "colorkey")) {
124  ctx->do_slice = do_colorkey_slice;
125  } else {
126  ctx->do_slice = do_colorhold_slice;
127  }
128 
129  return 0;
130 }
131 
132 static int filter_frame(AVFilterLink *link, AVFrame *frame)
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;
151  const AVPixFmtDescriptor *desc = av_pix_fmt_desc_get(outlink->format);
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 
164 static av_cold int query_formats(AVFilterContext *avctx)
165 {
166  static const enum AVPixelFormat pixel_fmts[] = {
167  AV_PIX_FMT_ARGB,
168  AV_PIX_FMT_RGBA,
169  AV_PIX_FMT_ABGR,
170  AV_PIX_FMT_BGRA,
171  AV_PIX_FMT_NONE
172  };
173 
174  AVFilterFormats *formats = NULL;
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 
215 AVFilter ff_vf_colorkey = {
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,
220  .query_formats = query_formats,
221  .init = init_filter,
222  .inputs = colorkey_inputs,
223  .outputs = colorkey_outputs,
224  .flags = AVFILTER_FLAG_SUPPORT_TIMELINE_GENERIC | AVFILTER_FLAG_SLICE_THREADS,
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 
239 AVFilter ff_vf_colorhold = {
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,
244  .query_formats = query_formats,
245  .init = init_filter,
246  .inputs = colorkey_inputs,
247  .outputs = colorkey_outputs,
248  .flags = AVFILTER_FLAG_SUPPORT_TIMELINE_GENERIC | AVFILTER_FLAG_SLICE_THREADS,
249 };
250 
251 #endif /* CONFIG_COLORHOLD_FILTER */
formats
formats
Definition: signature.h:48
init_filter
static av_cold int init_filter(AVFilterContext *avctx)
Definition: vf_colorkey.c:119
AVPixelFormat
AVPixelFormat
Pixel format.
Definition: pixfmt.h:64
init
static av_cold int init(AVCodecContext *avctx)
Definition: avrndec.c:35
r
const char * r
Definition: vf_curves.c:114
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_make_format_list
AVFilterFormats * ff_make_format_list(const int *fmts)
Create a list of supported formats.
Definition: formats.c:283
colorkey_outputs
static const AVFilterPad colorkey_outputs[]
Definition: vf_colorkey.c:192
ff_filter_frame
int ff_filter_frame(AVFilterLink *link, AVFrame *frame)
Send a frame of data to the next filter.
Definition: avfilter.c:1080
av_pix_fmt_desc_get
const AVPixFmtDescriptor * av_pix_fmt_desc_get(enum AVPixelFormat pix_fmt)
Definition: pixdesc.c:2522
query_formats
static av_cold int query_formats(AVFilterContext *avctx)
Definition: vf_colorkey.c:164
AVFrame
This structure describes decoded (raw) audio or video data.
Definition: frame.h:295
av_frame_make_writable
int av_frame_make_writable(AVFrame *frame)
Ensure that the frame data is writable, avoiding data copy if possible.
Definition: frame.c:611
AVOption
AVOption.
Definition: opt.h:246
b
#define b
Definition: input.c:41
AV_PIX_FMT_BGRA
@ AV_PIX_FMT_BGRA
packed BGRA 8:8:8:8, 32bpp, BGRABGRA...
Definition: pixfmt.h:95
AVFilter::name
const char * name
Filter name.
Definition: avfilter.h:148
video.h
AVFilterFormats
A list of supported formats for one end of a filter link.
Definition: formats.h:64
formats.h
AVFilterContext::priv
void * priv
private data for use by the filter
Definition: avfilter.h:353
ColorkeyContext::blend
float blend
Definition: vf_colorkey.c:36
AVFilterPad
A filter pad used for either input or output.
Definition: internal.h:54
ColorkeyContext::do_slice
int(* do_slice)(AVFilterContext *ctx, void *arg, int jobnr, int nb_jobs)
Definition: vf_colorkey.c:38
av_cold
#define av_cold
Definition: attributes.h:84
ff_set_common_formats
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:568
filter_frame
static int filter_frame(AVFilterLink *link, AVFrame *frame)
Definition: vf_colorkey.c:132
do_colorkey_slice
static int do_colorkey_slice(AVFilterContext *avctx, void *arg, int jobnr, int nb_jobs)
Definition: vf_colorkey.c:57
g
const char * g
Definition: vf_curves.c:115
slice_end
static int slice_end(AVCodecContext *avctx, AVFrame *pict)
Handle slice ends.
Definition: mpeg12dec.c:2026
outputs
static const AVFilterPad outputs[]
Definition: af_acontrast.c:203
ctx
AVFormatContext * ctx
Definition: movenc.c:48
do_colorkey_pixel
static uint8_t do_colorkey_pixel(ColorkeyContext *ctx, uint8_t r, uint8_t g, uint8_t b)
Definition: vf_colorkey.c:42
ColorkeyContext::colorkey_rgba
uint8_t colorkey_rgba[4]
Definition: vf_colorkey.c:34
link
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
Definition: filter_design.txt:23
AV_PIX_FMT_RGBA
@ AV_PIX_FMT_RGBA
packed RGBA 8:8:8:8, 32bpp, RGBARGBA...
Definition: pixfmt.h:93
arg
const char * arg
Definition: jacosubdec.c:66
AVClass
Describe the class of an AVClass context structure.
Definition: log.h:67
NULL
#define NULL
Definition: coverity.c:32
ColorkeyContext
Definition: vf_colorkey.c:28
AV_OPT_TYPE_COLOR
@ AV_OPT_TYPE_COLOR
Definition: opt.h:238
AVFilterContext::inputs
AVFilterLink ** inputs
array of pointers to input links
Definition: avfilter.h:346
inputs
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
Definition: filter_design.txt:243
AV_PIX_FMT_ABGR
@ AV_PIX_FMT_ABGR
packed ABGR 8:8:8:8, 32bpp, ABGRABGR...
Definition: pixfmt.h:94
do_colorhold_slice
static int do_colorhold_slice(AVFilterContext *avctx, void *arg, int jobnr, int nb_jobs)
Definition: vf_colorkey.c:83
desc
const char * desc
Definition: nvenc.c:68
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:188
ff_vf_colorkey
AVFilter ff_vf_colorkey
FFMIN
#define FFMIN(a, b)
Definition: common.h:96
a
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:41
ff_vf_colorhold
AVFilter ff_vf_colorhold
ColorkeyContext::co
int co[4]
Definition: vf_colorkey.c:32
ColorkeyContext::similarity
float similarity
Definition: vf_colorkey.c:35
colorkey_inputs
static const AVFilterPad colorkey_inputs[]
Definition: vf_colorkey.c:183
internal.h
AVFILTER_FLAG_SUPPORT_TIMELINE_GENERIC
#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
AVFILTER_DEFINE_CLASS
#define AVFILTER_DEFINE_CLASS(fname)
Definition: internal.h:334
AV_PIX_FMT_ARGB
@ AV_PIX_FMT_ARGB
packed ARGB 8:8:8:8, 32bpp, ARGBARGB...
Definition: pixfmt.h:92
AV_OPT_TYPE_FLOAT
@ AV_OPT_TYPE_FLOAT
Definition: opt.h:226
i
#define i(width, name, range_min, range_max)
Definition: cbs_h2645.c:259
FLAGS
#define FLAGS
Definition: vf_colorkey.c:202
ff_filter_get_nb_threads
int ff_filter_get_nb_threads(AVFilterContext *ctx)
Get number of threads for current filter instance.
Definition: avfilter.c:802
uint8_t
uint8_t
Definition: audio_convert.c:194
AVFilterPad::name
const char * name
Pad name.
Definition: internal.h:60
AVFilter
Filter definition.
Definition: avfilter.h:144
frame
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
Definition: filter_design.txt:264
AVFilterInternal::execute
avfilter_execute_func * execute
Definition: internal.h:155
AV_PIX_FMT_NONE
@ AV_PIX_FMT_NONE
Definition: pixfmt.h:65
avfilter.h
AVFilterContext::internal
AVFilterInternal * internal
An opaque struct for libavfilter internal use.
Definition: avfilter.h:378
AVFilterContext
An instance of a filter.
Definition: avfilter.h:338
AVFILTER_FLAG_SLICE_THREADS
#define AVFILTER_FLAG_SLICE_THREADS
The filter supports multithreading by splitting frames into multiple parts and processing them concur...
Definition: avfilter.h:116
AVMEDIA_TYPE_VIDEO
@ AVMEDIA_TYPE_VIDEO
Definition: avutil.h:201
AVPixFmtDescriptor
Descriptor that unambiguously describes how the bits of a pixel are stored in the up to 4 data planes...
Definition: pixdesc.h:81
diff
static av_always_inline int diff(const uint32_t a, const uint32_t b)
Definition: vf_palettegen.c:136
OFFSET
#define OFFSET(x)
Definition: vf_colorkey.c:201
imgutils.h
flags
#define flags(name, subs,...)
Definition: cbs_av1.c:565
AVFilterContext::filter
const AVFilter * filter
the AVFilter of which this is an instance
Definition: avfilter.h:341
int
int
Definition: ffmpeg_filter.c:191
config_output
static av_cold int config_output(AVFilterLink *outlink)
Definition: vf_colorkey.c:147
AVFilterContext::outputs
AVFilterLink ** outputs
array of pointers to output links
Definition: avfilter.h:350
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