public function testCreateAndDestroy()
{
$fs = new Tempdir();
$dir = $fs->getPath();
$this->assertTrue(is_dir($dir));
unset($fs);
$this->assertTrue(!file_exists($dir));
}
/**
* Generates sprite and WebVTT for selected video
*
* @throws \Exception
*/
public function generate()
{
// create temporay directory
$tempDir = new Tempdir('sprite');
$tempDir->addPlugin(new ListFiles());
// get basic info about video
$ffprobe = FFProbe::create()->format($this->getSource());
$duration = floatval($ffprobe->get('duration'));
// check if sample rate is high enough to reach desired minimum amount of thumbnails
if ($duration <= $this->getMinThumbs()) {
// we only have a 1 second resolution, so we can't get lower than 1 obviously
$this->setRate(1);
} else {
if ($duration / $this->getRate() < $this->getMinThumbs()) {
// sample rate too high, let's adjust rate a little
$this->setRate(floor($duration / $this->getMinThumbs()));
}
}
// capture images to tempdir
for ($i = 0; $i <= $duration; $i += $this->getRate()) {
$cmd = sprintf('ffmpeg -y -ss %d -i %s -frames:v 1 -filter:v scale=%d:-1 %s/%04d.jpg', $i, $this->getSource(), $this->getWidth(), $tempDir->getPath(), floor($i / $this->getRate()));
$proc = new Process($cmd);
$proc->setTimeout(null);
$proc->run();
if (!$proc->isSuccessful()) {
throw new \RuntimeException($cmd . ":" . $proc->getErrorOutput());
}
}
// combine all images to one sprite with quadratic tiling
$gridSize = ceil(sqrt(count($tempDir->listFiles())));
$firstImage = Image::make(sprintf('%s/0001.jpg', $tempDir->getPath()));
$spriteFile = sprintf('%s/%s.jpg', $this->getOutputDirectory(), $this->getPrefix());
$spriteUrl = empty($this->getUrlPrefix()) ? basename($spriteFile) : sprintf('%s/%s', $this->getUrlPrefix(), basename($spriteFile));
$cmd = sprintf('montage %1$s/*.jpg -tile %2$dx -geometry %3$dx%4$d+0+0 %5$s', $tempDir->getPath(), $gridSize, $firstImage->width(), $firstImage->height(), $spriteFile);
$proc = new Process($cmd);
$proc->run();
if (!$proc->isSuccessful()) {
throw new RuntimeException($proc->getErrorOutput());
}
// create WebVTT output
$vttFile = sprintf('%s/%s.vtt', $this->getOutputDirectory(), $this->getPrefix());
$vtt = new WebvttFile();
for ($i = 0; $i < count($tempDir->listFiles()); $i++) {
$start = $i * $this->getRate();
$end = ($i + 1) * $this->getRate();
$x = $i % $gridSize * $firstImage->width();
$y = floor($i / $gridSize) * $firstImage->height();
$vtt->addCue(new WebvttCue($this->secondsToCue($start), $this->secondsToCue($end), sprintf('%s#xywh=%d,%d,%d,%d', $spriteUrl, $x, $y, $firstImage->width(), $firstImage->height())));
}
$vtt->build();
$vtt->save($vttFile);
}
