From 09b24a807ad23b4fec25049775075cc63c0c1fa3 Mon Sep 17 00:00:00 2001 From: Paul B Mahol Date: Wed, 27 Dec 2017 18:51:23 +0100 Subject: avfilter: add entropy filter Signed-off-by: Paul B Mahol --- libavfilter/vf_entropy.c | 206 +++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 206 insertions(+) create mode 100644 libavfilter/vf_entropy.c (limited to 'libavfilter/vf_entropy.c') diff --git a/libavfilter/vf_entropy.c b/libavfilter/vf_entropy.c new file mode 100644 index 0000000000..e6002ce27a --- /dev/null +++ b/libavfilter/vf_entropy.c @@ -0,0 +1,206 @@ +/* + * 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/imgutils.h" +#include "libavutil/opt.h" +#include "libavutil/pixdesc.h" +#include "avfilter.h" +#include "drawutils.h" +#include "formats.h" +#include "internal.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, "mode" }, + { "normal", NULL, 0, AV_OPT_TYPE_CONST, {.i64=0}, 0, 0, FLAGS, "mode" }, + { "diff", NULL, 0, AV_OPT_TYPE_CONST, {.i64=1}, 0, 0, FLAGS, "mode" }, + { NULL } +}; + +AVFILTER_DEFINE_CLASS(entropy); + +static int query_formats(AVFilterContext *ctx) +{ + 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_GRAY16, + AV_PIX_FMT_NONE + }; + + AVFilterFormats *formats = ff_make_format_list(pixfmts); + if (!formats) + return AVERROR(ENOMEM); + return ff_set_common_formats(ctx, formats); +} + +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, + }, + { NULL } +}; + +static const AVFilterPad outputs[] = { + { + .name = "default", + .type = AVMEDIA_TYPE_VIDEO, + }, + { NULL } +}; + +AVFilter ff_vf_entropy = { + .name = "entropy", + .description = NULL_IF_CONFIG_SMALL("Measure video frames entropy."), + .priv_size = sizeof(EntropyContext), + .uninit = uninit, + .query_formats = query_formats, + .inputs = inputs, + .outputs = outputs, + .priv_class = &entropy_class, + .flags = AVFILTER_FLAG_SUPPORT_TIMELINE_GENERIC, +}; -- cgit v1.2.3