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subsurface/core/videoframeextractor.cpp
Berthold Stoeger 91e4fb4769 cleanup: more Coverity silencing
Mostly irrelevant std::move() stuff of copy-on-write Qt objects,
a few real bugs, a timestamp_t downconversion and some codingsyle
adaptation.

Signed-off-by: Berthold Stoeger <bstoeger@mail.tuwien.ac.at>
2024-01-17 14:23:19 -08:00

118 lines
4 KiB
C++

// SPDX-License-Identifier: GPL-2.0
#include "videoframeextractor.h"
#include "imagedownloader.h"
#include "core/pref.h"
#include "core/errorhelper.h"
#include <QtConcurrent>
#include <QProcess>
// Note: this is a global instead of a function-local variable on purpose.
// We don't want this to be generated in a different thread context if
// VideoFrameExtractor::instance() is called from a worker thread.
static VideoFrameExtractor frameExtractor;
VideoFrameExtractor *VideoFrameExtractor::instance()
{
return &frameExtractor;
}
VideoFrameExtractor::VideoFrameExtractor()
{
// Currently, we only process one video at a time.
// Eventually, we might want to increase this value.
pool.setMaxThreadCount(1);
}
void VideoFrameExtractor::extract(QString originalFilename, QString filename, duration_t duration)
{
QMutexLocker l(&lock);
if (!workingOn.contains(originalFilename)) {
// We are not currently extracting this video - add it to the list.
workingOn.insert(originalFilename, QtConcurrent::run(&pool, [this, originalFilename, filename, duration]()
{ processItem(originalFilename, filename, duration); }));
}
}
void VideoFrameExtractor::fail(const QString &originalFilename, duration_t duration, bool isInvalid)
{
if (isInvalid)
emit invalid(originalFilename, duration);
else
emit failed(originalFilename, duration);
QMutexLocker l(&lock);
workingOn.remove(originalFilename);
}
void VideoFrameExtractor::clearWorkQueue()
{
QMutexLocker l(&lock);
for (auto it = workingOn.begin(); it != workingOn.end(); ++it)
it->cancel();
workingOn.clear();
}
// Trivial helper: bring value into given range
template <typename T>
T clamp(T v, T lo, T hi)
{
return v < lo ? lo : v > hi ? hi : v;
}
void VideoFrameExtractor::processItem(QString originalFilename, QString filename, duration_t duration)
{
// If video frame extraction is turned off (e.g. because we failed to start ffmpeg),
// abort immediately.
if (!prefs.extract_video_thumbnails) {
QMutexLocker l(&lock);
workingOn.remove(originalFilename);
return;
}
// Determine the time where we want to extract the image.
// If the duration is < 10 sec, just snap the first frame
duration_t position = { 0 };
if (duration.seconds > 10) {
// We round to second-precision. To be sure that we don't attempt reading past the
// video's end, round down by one second.
--duration.seconds;
position.seconds = clamp(duration.seconds * prefs.extract_video_thumbnails_position / 100,
0, duration.seconds);
}
QString posString = QString("%1:%2:%3").arg(position.seconds / 3600, 2, 10, QChar('0'))
.arg((position.seconds % 3600) / 60, 2, 10, QChar('0'))
.arg(position.seconds % 60, 2, 10, QChar('0'));
QProcess ffmpeg;
ffmpeg.start(prefs.ffmpeg_executable, QStringList {
"-ss", posString, "-i", filename, "-vframes", "1", "-q:v", "2", "-f", "image2", "-"
});
if (!ffmpeg.waitForStarted()) {
// Since we couldn't sart ffmpeg, turn off thumbnailing
// TODO: call the proper preferences-functions
prefs.extract_video_thumbnails = false;
report_error(qPrintable(tr("ffmpeg failed to start - video thumbnail creation suspended. To enable video thumbnailing, set working executable in preferences.")));
return fail(originalFilename, duration, false);
}
if (!ffmpeg.waitForFinished()) {
report_error(qPrintable(tr("Failed waiting for ffmpeg - video thumbnail creation suspended. To enable video thumbnailing, set working executable in preferences.")));
return fail(originalFilename, duration, false);
}
QByteArray data = ffmpeg.readAll();
QImage img;
img.loadFromData(data);
if (img.isNull()) {
qInfo() << "Failed reading ffmpeg output";
// For debugging:
//qInfo() << "stdout: " << QString::fromUtf8(data);
ffmpeg.setReadChannel(QProcess::StandardError);
// For debugging:
//QByteArray stderr_output = ffmpeg.readAll();
//qInfo() << "stderr: " << QString::fromUtf8(stderr_output);
return fail(originalFilename, duration, true);
}
emit extracted(originalFilename, std::move(img), duration, position);
QMutexLocker l(&lock);
workingOn.remove(originalFilename);
}