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  ctx->internal->execute(ctx, s->do_slice, frame, NULL,
73  FFMIN(frame->height, ff_filter_get_nb_threads(ctx)));
74 
75  return ff_filter_frame(ctx->outputs[0], frame);
76 }
77 
79 {
80  static const enum AVPixelFormat pixel_fmts[] = {
83  };
84 
86 
87  formats = ff_make_format_list(pixel_fmts);
88  if (!formats)
89  return AVERROR(ENOMEM);
90 
91  return ff_set_common_formats(ctx, formats);
92 }
93 
95 {
96  AVFilterContext *ctx = inlink->dst;
97  ExposureContext *s = ctx->priv;
98 
100 
101  return 0;
102 }
103 
104 static const AVFilterPad exposure_inputs[] = {
105  {
106  .name = "default",
107  .type = AVMEDIA_TYPE_VIDEO,
108  .needs_writable = 1,
109  .filter_frame = filter_frame,
110  .config_props = config_input,
111  },
112  { NULL }
113 };
114 
115 static const AVFilterPad exposure_outputs[] = {
116  {
117  .name = "default",
118  .type = AVMEDIA_TYPE_VIDEO,
119  },
120  { NULL }
121 };
122 
123 #define OFFSET(x) offsetof(ExposureContext, x)
124 #define VF AV_OPT_FLAG_FILTERING_PARAM|AV_OPT_FLAG_VIDEO_PARAM|AV_OPT_FLAG_RUNTIME_PARAM
125 
126 static const AVOption exposure_options[] = {
127  { "exposure", "set the exposure correction", OFFSET(exposure), AV_OPT_TYPE_FLOAT, {.dbl=0}, -3, 3, VF },
128  { "black", "set the black level correction", OFFSET(black), AV_OPT_TYPE_FLOAT, {.dbl=0}, -1, 1, VF },
129  { NULL }
130 };
131 
133 
135  .name = "exposure",
136  .description = NULL_IF_CONFIG_SMALL("Adjust exposure of the video stream."),
137  .priv_size = sizeof(ExposureContext),
138  .priv_class = &exposure_class,
140  .inputs = exposure_inputs,
141  .outputs = exposure_outputs,
144 };
#define VF
Definition: vf_exposure.c:124
#define NULL
Definition: coverity.c:32
This structure describes decoded (raw) audio or video data.
Definition: frame.h:318
AVFilter ff_vf_exposure
Definition: vf_exposure.c:134
AVOption.
Definition: opt.h:248
misc image utilities
Main libavfilter public API header.
AVFilterFormats * ff_make_format_list(const int *fmts)
Create a list of supported formats.
Definition: formats.c:287
#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:126
const char * name
Pad name.
Definition: internal.h:60
int ff_filter_frame(AVFilterLink *link, AVFrame *frame)
Send a frame of data to the next filter.
Definition: avfilter.c:1094
#define av_cold
Definition: attributes.h:88
AVOptions.
#define height
#define OFFSET(x)
Definition: vf_exposure.c:123
A filter pad used for either input or output.
Definition: internal.h:54
static const AVFilterPad exposure_outputs[]
Definition: vf_exposure.c:115
int width
Definition: frame.h:376
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:588
#define NULL_IF_CONFIG_SMALL(x)
Return NULL if CONFIG_SMALL is true, otherwise the argument without modification. ...
Definition: internal.h:117
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:882
void * priv
private data for use by the filter
Definition: avfilter.h:356
#define AVFILTER_FLAG_SLICE_THREADS
The filter supports multithreading by splitting frames into multiple parts and processing them concur...
Definition: avfilter.h:117
const char * arg
Definition: jacosubdec.c:66
static int filter_frame(AVFilterLink *inlink, AVFrame *frame)
Definition: vf_exposure.c:66
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
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:105
static int process_command(AVFilterContext *ctx, const char *cmd, const char *args, char *res, int res_len, int flags)
Definition: af_acrusher.c:336
#define width
AVFormatContext * ctx
Definition: movenc.c:48
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
#define s(width, name)
Definition: cbs_vp9.c:257
int(* do_slice)(AVFilterContext *s, void *arg, int jobnr, int nb_jobs)
Definition: vf_exposure.c:37
static const AVFilterPad outputs[]
Definition: af_acontrast.c:203
#define exp2f(x)
Definition: libm.h:293
int linesize[AV_NUM_DATA_POINTERS]
For video, size in bytes of each picture line.
Definition: frame.h:349
static const AVFilterPad exposure_inputs[]
Definition: vf_exposure.c:104
Describe the class of an AVClass context structure.
Definition: log.h:67
Filter definition.
Definition: avfilter.h:145
const char * name
Filter name.
Definition: avfilter.h:149
AVFilterLink ** outputs
array of pointers to output links
Definition: avfilter.h:353
static av_cold int query_formats(AVFilterContext *ctx)
Definition: vf_exposure.c:78
#define flags(name, subs,...)
Definition: cbs_av1.c:561
AVFilterInternal * internal
An opaque struct for libavfilter internal use.
Definition: avfilter.h:381
uint8_t * data[AV_NUM_DATA_POINTERS]
pointer to the picture/channel planes.
Definition: frame.h:332
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
#define AV_PIX_FMT_GBRPF32
Definition: pixfmt.h:428
int
#define AV_PIX_FMT_GBRAPF32
Definition: pixfmt.h:429
AVFILTER_DEFINE_CLASS(exposure)
avfilter_execute_func * execute
Definition: internal.h:136
static int slice_end(AVCodecContext *avctx, AVFrame *pict)
Handle slice ends.
Definition: mpeg12dec.c:2033
A list of supported formats for one end of a filter link.
Definition: formats.h:65
static int exposure_slice(AVFilterContext *ctx, void *arg, int jobnr, int nb_jobs)
Definition: vf_exposure.c:41
An instance of a filter.
Definition: avfilter.h:341
int height
Definition: frame.h:376
formats
Definition: signature.h:48
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
static const AVOption exposure_options[]
Definition: vf_exposure.c:126
static av_cold int config_input(AVFilterLink *inlink)
Definition: vf_exposure.c:94
AVPixelFormat
Pixel format.
Definition: pixfmt.h:64
for(j=16;j >0;--j)