FFmpeg
vf_exposure.c
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1 /*
2  * Copyright (c) 2021 Paul B Mahol
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 <float.h>
22 
23 #include "libavutil/opt.h"
24 #include "libavutil/imgutils.h"
25 #include "avfilter.h"
26 #include "formats.h"
27 #include "internal.h"
28 #include "video.h"
29 
30 typedef struct ExposureContext {
31  const AVClass *class;
32 
33  float exposure;
34  float black;
35 
36  float scale;
38  int jobnr, int nb_jobs);
40 
41 static int exposure_slice(AVFilterContext *ctx, void *arg, int jobnr, int nb_jobs)
42 {
43  ExposureContext *s = ctx->priv;
44  AVFrame *frame = arg;
45  const int width = frame->width;
46  const int height = frame->height;
47  const int slice_start = (height * jobnr) / nb_jobs;
48  const int slice_end = (height * (jobnr + 1)) / nb_jobs;
49  const float black = s->black;
50  const float scale = s->scale;
51 
52  for (int p = 0; p < 3; p++) {
53  const int linesize = frame->linesize[p] / 4;
54  float *ptr = (float *)frame->data[p] + slice_start * linesize;
55  for (int y = slice_start; y < slice_end; y++) {
56  for (int x = 0; x < width; x++)
57  ptr[x] = (ptr[x] - black) * scale;
58 
59  ptr += linesize;
60  }
61  }
62 
63  return 0;
64 }
65 
67 {
68  AVFilterContext *ctx = inlink->dst;
69  ExposureContext *s = ctx->priv;
70 
71  s->scale = 1.f / (exp2f(-s->exposure) - s->black);
72  ff_filter_execute(ctx, s->do_slice, frame, NULL,
74 
75  return ff_filter_frame(ctx->outputs[0], frame);
76 }
77 
79 {
80  static const enum AVPixelFormat pixel_fmts[] = {
83  };
84 
85  return ff_set_common_formats_from_list(ctx, pixel_fmts);
86 }
87 
89 {
90  AVFilterContext *ctx = inlink->dst;
91  ExposureContext *s = ctx->priv;
92 
93  s->do_slice = exposure_slice;
94 
95  return 0;
96 }
97 
98 static const AVFilterPad exposure_inputs[] = {
99  {
100  .name = "default",
101  .type = AVMEDIA_TYPE_VIDEO,
103  .filter_frame = filter_frame,
104  .config_props = config_input,
105  },
106 };
107 
108 static const AVFilterPad exposure_outputs[] = {
109  {
110  .name = "default",
111  .type = AVMEDIA_TYPE_VIDEO,
112  },
113 };
114 
115 #define OFFSET(x) offsetof(ExposureContext, x)
116 #define VF AV_OPT_FLAG_FILTERING_PARAM|AV_OPT_FLAG_VIDEO_PARAM|AV_OPT_FLAG_RUNTIME_PARAM
117 
118 static const AVOption exposure_options[] = {
119  { "exposure", "set the exposure correction", OFFSET(exposure), AV_OPT_TYPE_FLOAT, {.dbl=0}, -3, 3, VF },
120  { "black", "set the black level correction", OFFSET(black), AV_OPT_TYPE_FLOAT, {.dbl=0}, -1, 1, VF },
121  { NULL }
122 };
123 
124 AVFILTER_DEFINE_CLASS(exposure);
125 
127  .name = "exposure",
128  .description = NULL_IF_CONFIG_SMALL("Adjust exposure of the video stream."),
129  .priv_size = sizeof(ExposureContext),
130  .priv_class = &exposure_class,
135  .process_command = ff_filter_process_command,
136 };
AVPixelFormat
AVPixelFormat
Pixel format.
Definition: pixfmt.h:64
opt.h
OFFSET
#define OFFSET(x)
Definition: vf_exposure.c:115
ff_vf_exposure
const AVFilter ff_vf_exposure
Definition: vf_exposure.c:126
ff_filter_frame
int ff_filter_frame(AVFilterLink *link, AVFrame *frame)
Send a frame of data to the next filter.
Definition: avfilter.c:1019
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
AVFrame
This structure describes decoded (raw) audio or video data.
Definition: frame.h:303
ExposureContext::exposure
float exposure
Definition: vf_exposure.c:33
exposure_slice
static int exposure_slice(AVFilterContext *ctx, void *arg, int jobnr, int nb_jobs)
Definition: vf_exposure.c:41
AVOption
AVOption.
Definition: opt.h:247
float.h
AVFilter::name
const char * name
Filter name.
Definition: avfilter.h:153
video.h
formats.h
filter_frame
static int filter_frame(AVFilterLink *inlink, AVFrame *frame)
Definition: vf_exposure.c:66
AVFilterPad
A filter pad used for either input or output.
Definition: internal.h:50
exposure_outputs
static const AVFilterPad exposure_outputs[]
Definition: vf_exposure.c:108
av_cold
#define av_cold
Definition: attributes.h:90
width
#define width
s
#define s(width, name)
Definition: cbs_vp9.c:257
slice_end
static int slice_end(AVCodecContext *avctx, AVFrame *pict)
Handle slice ends.
Definition: mpeg12dec.c:2041
ff_set_common_formats_from_list
int ff_set_common_formats_from_list(AVFilterContext *ctx, const int *fmts)
Equivalent to ff_set_common_formats(ctx, ff_make_format_list(fmts))
Definition: formats.c:703
ctx
AVFormatContext * ctx
Definition: movenc.c:48
exp2f
#define exp2f(x)
Definition: libm.h:293
FILTER_INPUTS
#define FILTER_INPUTS(array)
Definition: internal.h:152
arg
const char * arg
Definition: jacosubdec.c:67
ExposureContext::black
float black
Definition: vf_exposure.c:34
AVClass
Describe the class of an AVClass context structure.
Definition: log.h:66
NULL
#define NULL
Definition: coverity.c:32
ExposureContext::do_slice
int(* do_slice)(AVFilterContext *s, void *arg, int jobnr, int nb_jobs)
Definition: vf_exposure.c:37
exposure_options
static const AVOption exposure_options[]
Definition: vf_exposure.c:118
for
for(j=16;j >0;--j)
Definition: h264pred_template.c:469
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
AV_PIX_FMT_GBRPF32
#define AV_PIX_FMT_GBRPF32
Definition: pixfmt.h:418
ExposureContext
Definition: vf_exposure.c:30
ff_filter_process_command
int ff_filter_process_command(AVFilterContext *ctx, const char *cmd, const char *arg, char *res, int res_len, int flags)
Generic processing of user supplied commands that are set in the same way as the filter options.
Definition: avfilter.c:883
height
#define height
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:130
AV_OPT_TYPE_FLOAT
@ AV_OPT_TYPE_FLOAT
Definition: opt.h:227
ExposureContext::scale
float scale
Definition: vf_exposure.c:36
ff_filter_get_nb_threads
int ff_filter_get_nb_threads(AVFilterContext *ctx)
Get number of threads for current filter instance.
Definition: avfilter.c:804
FFMIN
#define FFMIN(a, b)
Definition: macros.h:49
AVFilterPad::name
const char * name
Pad name.
Definition: internal.h:56
AVFilter
Filter definition.
Definition: avfilter.h:149
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
AVFILTER_DEFINE_CLASS
AVFILTER_DEFINE_CLASS(exposure)
query_formats
static av_cold int query_formats(AVFilterContext *ctx)
Definition: vf_exposure.c:78
VF
#define VF
Definition: vf_exposure.c:116
AV_PIX_FMT_NONE
@ AV_PIX_FMT_NONE
Definition: pixfmt.h:65
avfilter.h
AV_PIX_FMT_GBRAPF32
#define AV_PIX_FMT_GBRAPF32
Definition: pixfmt.h:419
AVFilterContext
An instance of a filter.
Definition: avfilter.h:346
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:121
AVMEDIA_TYPE_VIDEO
@ AVMEDIA_TYPE_VIDEO
Definition: avutil.h:201
exposure_inputs
static const AVFilterPad exposure_inputs[]
Definition: vf_exposure.c:98
FILTER_OUTPUTS
#define FILTER_OUTPUTS(array)
Definition: internal.h:153
imgutils.h
ff_filter_execute
static av_always_inline int ff_filter_execute(AVFilterContext *ctx, avfilter_action_func *func, void *arg, int *ret, int nb_jobs)
Definition: internal.h:143
int
int
Definition: ffmpeg_filter.c:156
AVFILTERPAD_FLAG_NEEDS_WRITABLE
#define AVFILTERPAD_FLAG_NEEDS_WRITABLE
The filter expects writable frames from its input link, duplicating data buffers if needed.
Definition: internal.h:69
config_input
static av_cold int config_input(AVFilterLink *inlink)
Definition: vf_exposure.c:88