/**
* If the first frame is orange, use the orage to detect the viewport
* and re-number the remaining frames
*
* @param mixed $videoDir
* @param mixed $viewport
*/
function FindAVIViewport($videoDir, $startOffset, &$viewport)
{
$files = glob("{$videoDir}/video-*.png");
if ($files && count($files)) {
if (IsOrangeAVIFrame($files[0])) {
// load the image and figure out the viewport area (orange)
$im = imagecreatefrompng($files[0]);
if ($im) {
$width = imagesx($im);
$height = imagesy($im);
$x = floor($width / 2);
$y = floor($height / 2);
$orange = imagecolorat($im, $x, $y);
$left = null;
while (!isset($left) && $x >= 0) {
if (!PixelColorsClose(imagecolorat($im, $x, $y), $orange)) {
$left = $x + 1;
} else {
$x--;
}
}
if (!isset($left)) {
$left = 0;
}
$x = floor($width / 2);
$right = null;
while (!isset($right) && $x < $width) {
if (!PixelColorsClose(imagecolorat($im, $x, $y), $orange)) {
$right = $x - 1;
} else {
$x++;
}
}
if (!isset($right)) {
$right = $width;
}
$x = floor($width / 2);
$top = null;
while (!isset($top) && $y >= 0) {
if (!PixelColorsClose(imagecolorat($im, $x, $y), $orange)) {
$top = $y + 1;
} else {
$y--;
}
}
if (!isset($top)) {
$top = 0;
}
$y = floor($height / 2);
$bottom = null;
while (!isset($bottom) && $y < $height) {
if (!PixelColorsClose(imagecolorat($im, $x, $y), $orange)) {
$bottom = $y - 1;
} else {
$y++;
}
}
if (!isset($bottom)) {
$bottom = $height;
}
if ($left || $top || $right != $width || $bottom != $height) {
$viewport = array('x' => $left, 'y' => $top, 'width' => $right - $left, 'height' => $bottom - $top);
}
}
// Remove all of the orange video frames.
do {
$file = array_shift($files);
unlink($file);
} while (count($files) && IsOrangeAVIFrame($files[0]));
}
$fileCount = count($files);
$firstFrame = null;
for ($i = 0; $i < $fileCount; $i++) {
$file = $files[$i];
if (preg_match('/video-(?P<frame>[0-9]+).png$/', $file, $matches)) {
$currentFrame = intval($matches['frame']);
if (!isset($firstFrame)) {
$firstFrame = $currentFrame;
}
$frameTime = $currentFrame - $firstFrame;
if ($startOffset) {
$frameTime = max($frameTime - $startOffset, 0);
}
$dest = "{$videoDir}/image-" . sprintf('%06d', $frameTime) . ".png";
if (is_file($dest)) {
unlink($dest);
}
rename($file, $dest);
}
}
}
}
/**
* See if we can find the viewport from the first frame of the video and crop down to that
*
* @param mixed $videoFile
* @param mixed $videoDir
*/
function FindVideoCrop($videoFile, $videoDir)
{
$crop = '';
$image = "{$videoDir}/viewport.png";
if (is_file($image)) {
unlink($image);
}
$command = "ffmpeg -i \"{$videoFile}\" -frames:v 1 \"{$image}\" 2>&1";
$result;
exec($command, $output, $result);
if (is_file($image)) {
if (IsOrangeAVIFrame($image) || IsBlankAVIFrame($image)) {
$viewport = GetImageViewport($image);
if (isset($viewport)) {
$crop = "crop={$viewport['width']}:{$viewport['height']}:{$viewport['x']}:{$viewport['y']},";
}
}
unlink($image);
}
return $crop;
}
