video cutter

video_cutter.php

<?php
declare (strict_types = 1);
stream_set_blocking(STDIN, true);
if ($argc >= 2) {
	$in_file = $argv;
	unset($in_file[0]);
	$in_file = implode("", $in_file);
} else {
	echo "choose path to media file: ";
	$in_file = fgets(STDIN);
}
$in_file = trim(strtr($in_file, array('"' => '', "'" => '')));
if (!is_file($in_file)) {
	echo "error: \"{$in_file}\" is not a valid file!\n";
	pause();
	return 1;
}
$in_file = _cygwinify_filepath($in_file);
$in_file = realpath($in_file);
//var_dump($in_file);
echo "filepath parsed: \"{$in_file}\"\n";
$dir = dirname($in_file);
if (!chdir($dir)) {
	die("error: failed to chdir \"{$dir}\"");
}
$in_file_name = basename($in_file);
$total_secs = get_seconds($in_file);
$key_frames = get_key_frames($in_file);
echo "media length is \"{$total_secs}\" seconds (aka \"" . number_format($total_secs / 60, 1) . "\" minutes)\n";
echo "number of keyframes: " . count($key_frames) . "\r\n";
echo "write how many seconds you want each clip to be, and press enter: ";
$clip_sec = fgets(STDIN);
$clip_sec = trim($clip_sec);
if (false === ($clip_sec = filter_var($clip_sec, FILTER_VALIDATE_INT))) {
	die("ERROR: could not parse input as number!");
}
$secs = 0;
$i = 0;
for (;;) {
	++$i;
	$remaining = $total_secs - $secs;
	if ($remaining <= 0) {
		break;
	}
	$next = $secs + $clip_sec;
	if($next<=0){
		break;
	}
	$next=get_next_keyframe($key_frames, $next, $total_secs);
	$cmd = implode(" ", array(
		"ffmpeg",
		"-y",
		"-noaccurate_seek",
		"-i " . escapeshellarg(_uncygwinify_filepath($in_file)),
		"-c:v copy",
		"-c:a copy",
		"-ss " . escapeshellarg((string)($secs-0.1)), // -0.1 is to work around keyframe issues >.<
		"-t " . escapeshellarg((string)($next-$secs)),
		escapeshellarg("clip." . $i . "." . $in_file_name)
	));
	$secs=$next;
	echo "executing: ";
	var_dump($cmd);
	passthru($cmd, $ret);
	if ($ret !== 0) {
		die("FFMPEG ERROR: FFMPEG DID NOT RETURN 0! returned {$ret}.......\n");
	}
	if($next===$total_secs){
		break;
	}
}

function get_next_keyframe(array &$keyframes, float $secs, float $total_secs)
{
	if (0) {
		if (empty($keyframes)) {
			throw new \LogicException("keyframes empty!");
		}
	}
	foreach ($keyframes as $key => $frame) {
		if ($frame >= $secs) {
			return $frame;
		} else {
			unset($keyframes[$key]);
		}
	}
	//..
	return $total_secs;
}

function get_seconds(string $file): float
{
	// -noaccurate_seek
	// ffprobe -print_format json -show_format
	my_exec("ffprobe " . escapeshellarg(_uncygwinify_filepath($file)) . " -print_format json -show_format", "", $stdout, $stderr);
	$parsed = json_decode($stdout, true);
	return ((float)$parsed['format']['duration']);
}
function get_key_frames(string $file): array
{
	// ffprobe -select_streams v -skip_frame nokey -show_frames -show_entries frame=pkt_pts_time -print_format json "file"
	my_exec("ffprobe -select_streams v -skip_frame nokey -show_frames -show_entries frame=pkt_pts_time -print_format json " . escapeshellarg(_uncygwinify_filepath($file)), "", $stdout, $stderr);
	$parsed = json_decode($stdout, true);
	$ret = array();
	foreach ($parsed['frames'] as $keyframe) {
		$ret[] = (double)$keyframe['pkt_pts_time'];
	}
	sort($ret, SORT_NUMERIC);
	return $ret;
}
function pause()
{
	echo "press enter to continue..";
	fgets(STDIN);
	return;
}
function _uncygwinify_filepath(string $path): string
{
	static $is_cygwin_cache = null;
	if ($is_cygwin_cache === null) {
		$is_cygwin_cache = (false !== stripos(PHP_OS, "cygwin"));
	}
	if ($is_cygwin_cache) {
		return trim(shell_exec("cygpath -aw " . escapeshellarg($path)));
	} else {
		return $path;
	}
}
function _cygwinify_filepath(string $path): string
{
	static $is_cygwin_cache = null;
	if ($is_cygwin_cache === null) {
		$is_cygwin_cache = (false !== stripos(PHP_OS, "cygwin"));
	}
	if ($is_cygwin_cache) {
		return trim(shell_exec("cygpath -a " . escapeshellarg($path)));
		//return "/cygdrive/" . strtr($path, array(':' => '', '\\' => '/'));
	} else {
		return $path;
	}
}
function my_exec(string $cmd, string $stdin = "", string &$stdout = null, string &$stderr = null): int
{
	$stdouth = tmpfile();
	$stderrh = tmpfile();
	$descriptorspec = array(
		0 => array("pipe", "rb"),  // stdin
		1 => array("file", stream_get_meta_data($stdouth)['uri'], 'ab'),
		2 => array("file", stream_get_meta_data($stderrh)['uri'], 'ab')
	);
	$pipes = array();
	$proc = proc_open($cmd, $descriptorspec, $pipes);
	while (strlen($stdin) > 0) {
		$written_now = fwrite($pipes[0], $stdin);
		if ($written_now <= 0) {
			//... can add more error checking here, but probably means that target program
			// exited or crashed before consuming all of stdin.
			// (could also have explicitly closed stdin before consuming all)
			break;
		}
		$stdin = substr($stdin, $written_now);
	}
	fclose($pipes[0]);
	unset($stdin, $pipes[0]);
	$proc_ret = proc_close($proc); // this line will stall until the process has exited.
	$stdout = stream_get_contents($stdouth);
	$stderr = stream_get_contents($stderrh);
	fclose($stdouth);
	fclose($stderrh);
	return $proc_ret;
}