/* * Copyright (c) 2017 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 "libavutil/mem.h" #include "libavutil/opt.h" #include "libavutil/pixdesc.h" #include "avfilter.h" #include "drawutils.h" #include "filters.h" #include "video.h" typedef struct EntropyContext { const AVClass *class; int mode; int nb_planes; int planeheight[4]; int planewidth[4]; int depth; int is_rgb; uint8_t rgba_map[4]; char planenames[4]; int64_t *histogram; } EntropyContext; #define OFFSET(x) offsetof(EntropyContext, x) #define FLAGS AV_OPT_FLAG_FILTERING_PARAM|AV_OPT_FLAG_VIDEO_PARAM static const AVOption entropy_options[] = { { "mode", "set kind of histogram entropy measurement", OFFSET(mode), AV_OPT_TYPE_INT, {.i64=0}, 0, 1, FLAGS, .unit = "mode" }, { "normal", NULL, 0, AV_OPT_TYPE_CONST, {.i64=0}, 0, 0, FLAGS, .unit = "mode" }, { "diff", NULL, 0, AV_OPT_TYPE_CONST, {.i64=1}, 0, 0, FLAGS, .unit = "mode" }, { NULL } }; AVFILTER_DEFINE_CLASS(entropy); static const enum AVPixelFormat pixfmts[] = { AV_PIX_FMT_YUV444P, AV_PIX_FMT_YUV422P, AV_PIX_FMT_YUV420P, AV_PIX_FMT_YUV411P, AV_PIX_FMT_YUV440P, AV_PIX_FMT_YUVJ422P, AV_PIX_FMT_YUVJ444P, AV_PIX_FMT_YUVJ420P, AV_PIX_FMT_YUVJ411P, AV_PIX_FMT_YUVJ440P, AV_PIX_FMT_YUV444P9, AV_PIX_FMT_YUV422P9, AV_PIX_FMT_YUV420P9, AV_PIX_FMT_YUV444P10, AV_PIX_FMT_YUV422P10, AV_PIX_FMT_YUV420P10, AV_PIX_FMT_YUV440P10, AV_PIX_FMT_YUV444P12, AV_PIX_FMT_YUV422P12, AV_PIX_FMT_YUV420P12, AV_PIX_FMT_YUV440P12, AV_PIX_FMT_YUV444P14, AV_PIX_FMT_YUV422P14, AV_PIX_FMT_YUV420P14, AV_PIX_FMT_YUV444P16, AV_PIX_FMT_YUV422P16, AV_PIX_FMT_YUV420P16, AV_PIX_FMT_GBRP, AV_PIX_FMT_GBRP9, AV_PIX_FMT_GBRP10, AV_PIX_FMT_GBRP12, AV_PIX_FMT_GBRP14, AV_PIX_FMT_GBRP16, AV_PIX_FMT_GRAY8, AV_PIX_FMT_GRAY9, AV_PIX_FMT_GRAY10, AV_PIX_FMT_GRAY12, AV_PIX_FMT_GRAY14, AV_PIX_FMT_GRAY16, AV_PIX_FMT_NONE }; static int config_input(AVFilterLink *inlink) { const AVPixFmtDescriptor *desc = av_pix_fmt_desc_get(inlink->format); AVFilterContext *ctx = inlink->dst; EntropyContext *s = ctx->priv; s->nb_planes = desc->nb_components; s->planeheight[1] = s->planeheight[2] = AV_CEIL_RSHIFT(inlink->h, desc->log2_chroma_h); s->planeheight[0] = s->planeheight[3] = inlink->h; s->planewidth[1] = s->planewidth[2] = AV_CEIL_RSHIFT(inlink->w, desc->log2_chroma_w); s->planewidth[0] = s->planewidth[3] = inlink->w; s->depth = desc->comp[0].depth; s->is_rgb = ff_fill_rgba_map(s->rgba_map, inlink->format) >= 0; s->planenames[0] = s->is_rgb ? 'R' : 'Y'; s->planenames[1] = s->is_rgb ? 'G' : 'U'; s->planenames[2] = s->is_rgb ? 'B' : 'V'; s->planenames[3] = 'A'; s->histogram = av_malloc_array(1 << s->depth, sizeof(*s->histogram)); if (!s->histogram) return AVERROR(ENOMEM); return 0; } static int filter_frame(AVFilterLink *inlink, AVFrame *in) { AVFilterContext *ctx = inlink->dst; AVFilterLink *outlink = ctx->outputs[0]; EntropyContext *s = ctx->priv; int plane, y, x; for (plane = 0; plane < s->nb_planes; plane++) { int cidx = s->is_rgb ? s->rgba_map[plane] : plane; const uint8_t *src8 = in->data[plane]; const uint16_t *src16 = (const uint16_t *)in->data[plane]; float total = s->planewidth[plane] * s->planeheight[plane]; float entropy = 0; char metabuf[128]; char key[128]; memset(s->histogram, 0, (1 << s->depth) * sizeof(*s->histogram)); if (s->depth <= 8) { for (y = 0; y < s->planeheight[plane]; y++) { for (x = 0; x < s->planewidth[plane]; x++) { s->histogram[src8[x]]++; } src8 += in->linesize[plane]; } } else { for (y = 0; y < s->planeheight[plane]; y++) { for (x = 0; x < s->planewidth[plane]; x++) { s->histogram[src16[x]]++; } src16 += in->linesize[plane] / 2; } } for (y = 0; y < 1 << s->depth; y++) { if (s->mode == 0) { if (s->histogram[y]) { float p = s->histogram[y] / total; entropy += -log2(p) * p; } } else if (s->mode == 1) { if (y && (s->histogram[y] - s->histogram[y - 1]) != 0) { float p = FFABS(s->histogram[y] - s->histogram[y - 1]) / total; entropy += -log2(p) * p; } } } snprintf(key, sizeof(key), "lavfi.entropy.entropy.%s.%c", s->mode ? "diff" : "normal", s->planenames[cidx]); snprintf(metabuf, sizeof(metabuf), "%f", entropy); av_dict_set(&in->metadata, key, metabuf, 0); snprintf(key, sizeof(key), "lavfi.entropy.normalized_entropy.%s.%c", s->mode ? "diff" : "normal", s->planenames[cidx]); snprintf(metabuf, sizeof(metabuf), "%f", entropy / log2(1 << s->depth)); av_dict_set(&in->metadata, key, metabuf, 0); } return ff_filter_frame(outlink, in); } static av_cold void uninit(AVFilterContext *ctx) { EntropyContext *s = ctx->priv; av_freep(&s->histogram); } static const AVFilterPad inputs[] = { { .name = "default", .type = AVMEDIA_TYPE_VIDEO, .filter_frame = filter_frame, .config_props = config_input, }, }; const AVFilter ff_vf_entropy = { .name = "entropy", .description = NULL_IF_CONFIG_SMALL("Measure video frames entropy."), .priv_size = sizeof(EntropyContext), .uninit = uninit, FILTER_INPUTS(inputs), FILTER_OUTPUTS(ff_video_default_filterpad), FILTER_PIXFMTS_ARRAY(pixfmts), .priv_class = &entropy_class, .flags = AVFILTER_FLAG_SUPPORT_TIMELINE_GENERIC | AVFILTER_FLAG_METADATA_ONLY, };