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FFmpeg/libavfilter/vf_thumbnail.c
Andreas Rheinhardt 790f793844 avutil/common: Don't auto-include mem.h
There are lots of files that don't need it: The number of object
files that actually need it went down from 2011 to 884 here.

Keep it for external users in order to not cause breakages.

Also improve the other headers a bit while just at it.

Signed-off-by: Andreas Rheinhardt <andreas.rheinhardt@outlook.com>
2024-03-31 00:08:43 +01:00

340 lines
11 KiB
C

/*
* Copyright (c) 2011 Smartjog S.A.S, Clément Bœsch <clement.boesch@smartjog.com>
*
* 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
*/
/**
* @file
* Potential thumbnail lookup filter to reduce the risk of an inappropriate
* selection (such as a black frame) we could get with an absolute seek.
*
* Simplified version of algorithm by Vadim Zaliva <lord@crocodile.org>.
* @see http://notbrainsurgery.livejournal.com/29773.html
*/
#include "libavutil/mem.h"
#include "libavutil/opt.h"
#include "libavutil/pixdesc.h"
#include "avfilter.h"
#include "internal.h"
#define HIST_SIZE (3*256)
struct thumb_frame {
AVFrame *buf; ///< cached frame
int histogram[HIST_SIZE]; ///< RGB color distribution histogram of the frame
};
typedef struct ThumbContext {
const AVClass *class;
int n; ///< current frame
int loglevel;
int n_frames; ///< number of frames for analysis
struct thumb_frame *frames; ///< the n_frames frames
AVRational tb; ///< copy of the input timebase to ease access
int nb_threads;
int *thread_histogram;
int planewidth[4];
int planeheight[4];
} ThumbContext;
#define OFFSET(x) offsetof(ThumbContext, x)
#define FLAGS AV_OPT_FLAG_VIDEO_PARAM|AV_OPT_FLAG_FILTERING_PARAM
static const AVOption thumbnail_options[] = {
{ "n", "set the frames batch size", OFFSET(n_frames), AV_OPT_TYPE_INT, {.i64=100}, 2, INT_MAX, FLAGS },
{ "log", "force stats logging level", OFFSET(loglevel), AV_OPT_TYPE_INT, {.i64 = AV_LOG_INFO}, INT_MIN, INT_MAX, FLAGS, .unit = "level" },
{ "quiet", "logging disabled", 0, AV_OPT_TYPE_CONST, {.i64 = AV_LOG_QUIET}, 0, 0, FLAGS, .unit = "level" },
{ "info", "information logging level", 0, AV_OPT_TYPE_CONST, {.i64 = AV_LOG_INFO}, 0, 0, FLAGS, .unit = "level" },
{ "verbose", "verbose logging level", 0, AV_OPT_TYPE_CONST, {.i64 = AV_LOG_VERBOSE}, 0, 0, FLAGS, .unit = "level" },
{ NULL }
};
AVFILTER_DEFINE_CLASS(thumbnail);
static av_cold int init(AVFilterContext *ctx)
{
ThumbContext *s = ctx->priv;
s->frames = av_calloc(s->n_frames, sizeof(*s->frames));
if (!s->frames) {
av_log(ctx, AV_LOG_ERROR,
"Allocation failure, try to lower the number of frames\n");
return AVERROR(ENOMEM);
}
av_log(ctx, AV_LOG_VERBOSE, "batch size: %d frames\n", s->n_frames);
return 0;
}
/**
* @brief Compute Sum-square deviation to estimate "closeness".
* @param hist color distribution histogram
* @param median average color distribution histogram
* @return sum of squared errors
*/
static double frame_sum_square_err(const int *hist, const double *median)
{
int i;
double err, sum_sq_err = 0;
for (i = 0; i < HIST_SIZE; i++) {
err = median[i] - (double)hist[i];
sum_sq_err += err*err;
}
return sum_sq_err;
}
static AVFrame *get_best_frame(AVFilterContext *ctx)
{
AVFrame *picref;
ThumbContext *s = ctx->priv;
int i, j, best_frame_idx = 0;
int nb_frames = s->n;
double avg_hist[HIST_SIZE] = {0}, sq_err, min_sq_err = -1;
// average histogram of the N frames
for (j = 0; j < FF_ARRAY_ELEMS(avg_hist); j++) {
for (i = 0; i < nb_frames; i++)
avg_hist[j] += (double)s->frames[i].histogram[j];
avg_hist[j] /= nb_frames;
}
// find the frame closer to the average using the sum of squared errors
for (i = 0; i < nb_frames; i++) {
sq_err = frame_sum_square_err(s->frames[i].histogram, avg_hist);
if (i == 0 || sq_err < min_sq_err)
best_frame_idx = i, min_sq_err = sq_err;
}
// free and reset everything (except the best frame buffer)
for (i = 0; i < nb_frames; i++) {
memset(s->frames[i].histogram, 0, sizeof(s->frames[i].histogram));
if (i != best_frame_idx)
av_frame_free(&s->frames[i].buf);
}
s->n = 0;
// raise the chosen one
picref = s->frames[best_frame_idx].buf;
if (s->loglevel != AV_LOG_QUIET)
av_log(ctx, s->loglevel, "frame id #%d (pts_time=%f) selected "
"from a set of %d images\n", best_frame_idx,
picref->pts * av_q2d(s->tb), nb_frames);
s->frames[best_frame_idx].buf = NULL;
return picref;
}
static int do_slice(AVFilterContext *ctx, void *arg, int jobnr, int nb_jobs)
{
ThumbContext *s = ctx->priv;
AVFrame *frame = arg;
int *hist = s->thread_histogram + HIST_SIZE * jobnr;
const int h = frame->height;
const int w = frame->width;
const int slice_start = (h * jobnr) / nb_jobs;
const int slice_end = (h * (jobnr+1)) / nb_jobs;
const uint8_t *p = frame->data[0] + slice_start * frame->linesize[0];
memset(hist, 0, sizeof(*hist) * HIST_SIZE);
switch (frame->format) {
case AV_PIX_FMT_RGB24:
case AV_PIX_FMT_BGR24:
for (int j = slice_start; j < slice_end; j++) {
for (int i = 0; i < w; i++) {
hist[0*256 + p[i*3 ]]++;
hist[1*256 + p[i*3 + 1]]++;
hist[2*256 + p[i*3 + 2]]++;
}
p += frame->linesize[0];
}
break;
case AV_PIX_FMT_RGB0:
case AV_PIX_FMT_BGR0:
case AV_PIX_FMT_RGBA:
case AV_PIX_FMT_BGRA:
for (int j = slice_start; j < slice_end; j++) {
for (int i = 0; i < w; i++) {
hist[0*256 + p[i*4 ]]++;
hist[1*256 + p[i*4 + 1]]++;
hist[2*256 + p[i*4 + 2]]++;
}
p += frame->linesize[0];
}
break;
case AV_PIX_FMT_0RGB:
case AV_PIX_FMT_0BGR:
case AV_PIX_FMT_ARGB:
case AV_PIX_FMT_ABGR:
for (int j = slice_start; j < slice_end; j++) {
for (int i = 0; i < w; i++) {
hist[0*256 + p[i*4 + 1]]++;
hist[1*256 + p[i*4 + 2]]++;
hist[2*256 + p[i*4 + 3]]++;
}
p += frame->linesize[0];
}
break;
default:
for (int plane = 0; plane < 3; plane++) {
const int slice_start = (s->planeheight[plane] * jobnr) / nb_jobs;
const int slice_end = (s->planeheight[plane] * (jobnr+1)) / nb_jobs;
const uint8_t *p = frame->data[plane] + slice_start * frame->linesize[plane];
const ptrdiff_t linesize = frame->linesize[plane];
const int planewidth = s->planewidth[plane];
int *hhist = hist + 256 * plane;
for (int j = slice_start; j < slice_end; j++) {
for (int i = 0; i < planewidth; i++)
hhist[p[i]]++;
p += linesize;
}
}
break;
}
return 0;
}
static int filter_frame(AVFilterLink *inlink, AVFrame *frame)
{
AVFilterContext *ctx = inlink->dst;
ThumbContext *s = ctx->priv;
AVFilterLink *outlink = ctx->outputs[0];
int *hist = s->frames[s->n].histogram;
// keep a reference of each frame
s->frames[s->n].buf = frame;
ff_filter_execute(ctx, do_slice, frame, NULL,
FFMIN(frame->height, s->nb_threads));
// update current frame histogram
for (int j = 0; j < FFMIN(frame->height, s->nb_threads); j++) {
int *thread_histogram = s->thread_histogram + HIST_SIZE * j;
for (int i = 0; i < HIST_SIZE; i++)
hist[i] += thread_histogram[i];
}
// no selection until the buffer of N frames is filled up
s->n++;
if (s->n < s->n_frames)
return 0;
return ff_filter_frame(outlink, get_best_frame(ctx));
}
static av_cold void uninit(AVFilterContext *ctx)
{
int i;
ThumbContext *s = ctx->priv;
for (i = 0; i < s->n_frames && s->frames && s->frames[i].buf; i++)
av_frame_free(&s->frames[i].buf);
av_freep(&s->frames);
av_freep(&s->thread_histogram);
}
static int request_frame(AVFilterLink *link)
{
AVFilterContext *ctx = link->src;
ThumbContext *s = ctx->priv;
int ret = ff_request_frame(ctx->inputs[0]);
if (ret == AVERROR_EOF && s->n) {
ret = ff_filter_frame(link, get_best_frame(ctx));
if (ret < 0)
return ret;
ret = AVERROR_EOF;
}
if (ret < 0)
return ret;
return 0;
}
static int config_props(AVFilterLink *inlink)
{
AVFilterContext *ctx = inlink->dst;
ThumbContext *s = ctx->priv;
const AVPixFmtDescriptor *desc = av_pix_fmt_desc_get(inlink->format);
s->nb_threads = ff_filter_get_nb_threads(ctx);
s->thread_histogram = av_calloc(HIST_SIZE, s->nb_threads * sizeof(*s->thread_histogram));
if (!s->thread_histogram)
return AVERROR(ENOMEM);
s->tb = inlink->time_base;
s->planewidth[1] = s->planewidth[2] = AV_CEIL_RSHIFT(inlink->w, desc->log2_chroma_w);
s->planewidth[0] = s->planewidth[3] = inlink->w;
s->planeheight[1] = s->planeheight[2] = AV_CEIL_RSHIFT(inlink->h, desc->log2_chroma_h);
s->planeheight[0] = s->planeheight[3] = inlink->h;
return 0;
}
static const enum AVPixelFormat pix_fmts[] = {
AV_PIX_FMT_RGB24, AV_PIX_FMT_BGR24,
AV_PIX_FMT_RGBA, AV_PIX_FMT_BGRA,
AV_PIX_FMT_RGB0, AV_PIX_FMT_BGR0,
AV_PIX_FMT_ABGR, AV_PIX_FMT_ARGB,
AV_PIX_FMT_0BGR, AV_PIX_FMT_0RGB,
AV_PIX_FMT_YUV410P, AV_PIX_FMT_YUV411P,
AV_PIX_FMT_YUV420P, AV_PIX_FMT_YUV422P,
AV_PIX_FMT_YUV440P, AV_PIX_FMT_YUV444P,
AV_PIX_FMT_YUVJ420P, AV_PIX_FMT_YUVJ422P,
AV_PIX_FMT_YUVJ440P, AV_PIX_FMT_YUVJ444P,
AV_PIX_FMT_YUVJ411P,
AV_PIX_FMT_YUVA420P, AV_PIX_FMT_YUVA422P, AV_PIX_FMT_YUVA444P,
AV_PIX_FMT_GBRP, AV_PIX_FMT_GBRAP,
AV_PIX_FMT_NONE
};
static const AVFilterPad thumbnail_inputs[] = {
{
.name = "default",
.type = AVMEDIA_TYPE_VIDEO,
.config_props = config_props,
.filter_frame = filter_frame,
},
};
static const AVFilterPad thumbnail_outputs[] = {
{
.name = "default",
.type = AVMEDIA_TYPE_VIDEO,
.request_frame = request_frame,
},
};
const AVFilter ff_vf_thumbnail = {
.name = "thumbnail",
.description = NULL_IF_CONFIG_SMALL("Select the most representative frame in a given sequence of consecutive frames."),
.priv_size = sizeof(ThumbContext),
.init = init,
.uninit = uninit,
FILTER_INPUTS(thumbnail_inputs),
FILTER_OUTPUTS(thumbnail_outputs),
FILTER_PIXFMTS_ARRAY(pix_fmts),
.priv_class = &thumbnail_class,
.flags = AVFILTER_FLAG_SUPPORT_TIMELINE_GENERIC |
AVFILTER_FLAG_SLICE_THREADS,
};