| /* |
| * 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 "avfilter.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; |
| |
| typedef struct ThreadData { |
| AVFrame *out, *in; |
| } ThreadData; |
| |
| static int exposure_slice(AVFilterContext *ctx, void *arg, int jobnr, int nb_jobs) |
| { |
| ExposureContext *s = ctx->priv; |
| ThreadData *td = arg; |
| const int width = td->out->width; |
| const int height = td->out->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 slinesize = td->in->linesize[p] / 4; |
| const int dlinesize = td->out->linesize[p] / 4; |
| const float *src = (const float *)td->in->data[p] + slice_start * slinesize; |
| float *ptr = (float *)td->out->data[p] + slice_start * dlinesize; |
| for (int y = slice_start; y < slice_end; y++) { |
| for (int x = 0; x < width; x++) |
| ptr[x] = (src[x] - black) * scale; |
| |
| ptr += dlinesize; |
| src += slinesize; |
| } |
| } |
| |
| if (td->in->data[3] && td->in->linesize[3] && td->in != td->out) { |
| const int slinesize = td->in->linesize[3] / 4; |
| const int dlinesize = td->out->linesize[3] / 4; |
| const float *src = (const float *)td->in->data[3] + slice_start * slinesize; |
| float *ptr = (float *)td->out->data[3] + slice_start * dlinesize; |
| for (int y = slice_start; y < slice_end; y++) { |
| memcpy(ptr, src, width * sizeof(*ptr)); |
| ptr += dlinesize; |
| src += slinesize; |
| } |
| } |
| |
| return 0; |
| } |
| |
| static int filter_frame(AVFilterLink *inlink, AVFrame *in) |
| { |
| AVFilterContext *ctx = inlink->dst; |
| AVFilterLink *outlink = ctx->outputs[0]; |
| ExposureContext *s = ctx->priv; |
| float diff = fabsf(exp2f(-s->exposure) - s->black); |
| ThreadData td; |
| AVFrame *out; |
| |
| if (av_frame_is_writable(in)) { |
| out = in; |
| } else { |
| out = ff_get_video_buffer(outlink, outlink->w, outlink->h); |
| if (!out) { |
| av_frame_free(&in); |
| return AVERROR(ENOMEM); |
| } |
| av_frame_copy_props(out, in); |
| } |
| |
| diff = diff > 0.f ? diff : 1.f / 1024.f; |
| s->scale = 1.f / diff; |
| td.out = out; |
| td.in = in; |
| ff_filter_execute(ctx, s->do_slice, &td, NULL, |
| FFMIN(out->height, ff_filter_get_nb_threads(ctx))); |
| |
| if (out != in) |
| av_frame_free(&in); |
| return ff_filter_frame(outlink, out); |
| } |
| |
| 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, |
| .filter_frame = filter_frame, |
| .config_props = config_input, |
| }, |
| }; |
| |
| #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); |
| |
| const 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, |
| FILTER_INPUTS(exposure_inputs), |
| FILTER_OUTPUTS(ff_video_default_filterpad), |
| FILTER_PIXFMTS(AV_PIX_FMT_GBRPF32, AV_PIX_FMT_GBRAPF32), |
| .flags = AVFILTER_FLAG_SUPPORT_TIMELINE_GENERIC | AVFILTER_FLAG_SLICE_THREADS, |
| .process_command = ff_filter_process_command, |
| }; |