diff options
author | Paul B Mahol <onemda@gmail.com> | 2021-02-07 18:42:12 +0100 |
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committer | Paul B Mahol <onemda@gmail.com> | 2021-02-10 19:23:48 +0100 |
commit | 4390573c44a47e0bed4790a45934006df7ee1e2f (patch) | |
tree | 8cdb12355da6379977f9f82c7c1d5ae8eb805532 /libavfilter/vf_exposure.c | |
parent | 579e4e57a2c4ab8d98bf2e18413dc73ce02353f9 (diff) |
avfilter: add exposure video filter
Diffstat (limited to 'libavfilter/vf_exposure.c')
-rw-r--r-- | libavfilter/vf_exposure.c | 144 |
1 files changed, 144 insertions, 0 deletions
diff --git a/libavfilter/vf_exposure.c b/libavfilter/vf_exposure.c new file mode 100644 index 0000000000..b7ad075630 --- /dev/null +++ b/libavfilter/vf_exposure.c @@ -0,0 +1,144 @@ +/* + * Copyright (c) 2021 Paul B Mahol + * + * This file is part of FFmpeg. + * + * FFmpeg is free software; you can redistribute it and/or + * modify it under the terms of the GNU Lesser General Public + * License as published by the Free Software Foundation; either + * version 2.1 of the License, or (at your option) any later version. + * + * FFmpeg is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + * Lesser General Public License for more details. + * + * You should have received a copy of the GNU Lesser General Public + * License along with FFmpeg; if not, write to the Free Software + * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA + */ + +#include <float.h> + +#include "libavutil/opt.h" +#include "libavutil/imgutils.h" +#include "avfilter.h" +#include "formats.h" +#include "internal.h" +#include "video.h" + +typedef struct ExposureContext { + const AVClass *class; + + float exposure; + float black; + + float scale; + int (*do_slice)(AVFilterContext *s, void *arg, + int jobnr, int nb_jobs); +} ExposureContext; + +static int exposure_slice(AVFilterContext *ctx, void *arg, int jobnr, int nb_jobs) +{ + ExposureContext *s = ctx->priv; + AVFrame *frame = arg; + const int width = frame->width; + const int height = frame->height; + const int slice_start = (height * jobnr) / nb_jobs; + const int slice_end = (height * (jobnr + 1)) / nb_jobs; + const float black = s->black; + const float scale = s->scale; + + for (int p = 0; p < 3; p++) { + const int linesize = frame->linesize[p] / 4; + float *ptr = (float *)frame->data[p] + slice_start * linesize; + for (int y = slice_start; y < slice_end; y++) { + for (int x = 0; x < width; x++) + ptr[x] = (ptr[x] - black) * scale; + + ptr += linesize; + } + } + + return 0; +} + +static int filter_frame(AVFilterLink *inlink, AVFrame *frame) +{ + AVFilterContext *ctx = inlink->dst; + ExposureContext *s = ctx->priv; + + s->scale = 1.f / (exp2f(-s->exposure) - s->black); + ctx->internal->execute(ctx, s->do_slice, frame, NULL, + FFMIN(frame->height, ff_filter_get_nb_threads(ctx))); + + return ff_filter_frame(ctx->outputs[0], frame); +} + +static av_cold int query_formats(AVFilterContext *ctx) +{ + static const enum AVPixelFormat pixel_fmts[] = { + AV_PIX_FMT_GBRPF32, AV_PIX_FMT_GBRAPF32, + AV_PIX_FMT_NONE + }; + + AVFilterFormats *formats = NULL; + + formats = ff_make_format_list(pixel_fmts); + if (!formats) + return AVERROR(ENOMEM); + + return ff_set_common_formats(ctx, formats); +} + +static av_cold int config_input(AVFilterLink *inlink) +{ + AVFilterContext *ctx = inlink->dst; + ExposureContext *s = ctx->priv; + + s->do_slice = exposure_slice; + + return 0; +} + +static const AVFilterPad exposure_inputs[] = { + { + .name = "default", + .type = AVMEDIA_TYPE_VIDEO, + .needs_writable = 1, + .filter_frame = filter_frame, + .config_props = config_input, + }, + { NULL } +}; + +static const AVFilterPad exposure_outputs[] = { + { + .name = "default", + .type = AVMEDIA_TYPE_VIDEO, + }, + { NULL } +}; + +#define OFFSET(x) offsetof(ExposureContext, x) +#define VF AV_OPT_FLAG_FILTERING_PARAM|AV_OPT_FLAG_VIDEO_PARAM|AV_OPT_FLAG_RUNTIME_PARAM + +static const AVOption exposure_options[] = { + { "exposure", "set the exposure correction", OFFSET(exposure), AV_OPT_TYPE_FLOAT, {.dbl=0}, -3, 3, VF }, + { "black", "set the black level correction", OFFSET(black), AV_OPT_TYPE_FLOAT, {.dbl=0}, -1, 1, VF }, + { NULL } +}; + +AVFILTER_DEFINE_CLASS(exposure); + +AVFilter ff_vf_exposure = { + .name = "exposure", + .description = NULL_IF_CONFIG_SMALL("Adjust exposure of the video stream."), + .priv_size = sizeof(ExposureContext), + .priv_class = &exposure_class, + .query_formats = query_formats, + .inputs = exposure_inputs, + .outputs = exposure_outputs, + .flags = AVFILTER_FLAG_SUPPORT_TIMELINE_GENERIC | AVFILTER_FLAG_SLICE_THREADS, + .process_command = ff_filter_process_command, +}; |