count videogame fps by inspecting video stream frame-by-frame - suggested tolerance: 0.4

fps_counter.php

<?php
// TODO: investigate -enc_time_base -1 / AndreKR's comment here: https://superuser.com/questions/1512575/why-total-frame-count-is-different-in-ffmpeg-than-ffprobe/1512583?noredirect=1#comment2288790_1512583
declare (strict_types = 1);
//require_once('hhb_.inc.php');
const EXT = "png"; //jpg gives unreliable results (but significantly less disk space usage =/ )
init();
global $input_file, $tolerance;
// ffmpeg -i test_30.mp4 thumb%01d.png -hide_banner
$cmd = implode(" ", array(
    escapeshellarg('ffmpeg'),
    // All FFmpeg tools will normally show a copyright notice, build options and library versions.
    // This option can be used to suppress printing this information.
    '-hide_banner',
    // Print encoding progress/statistics. It is on by default, to explicitly disable it you need to specify -nostats.
    '-nostats',
    // input file
    "-i " . escapeshellarg(_uncygwinify_filepath($input_file)),
    // Each frame is passed with its timestamp from the demuxer to the muxer.
    '-vsync passthrough',
    // As an input option, blocks all audio streams of a file from being filtered or being automatically selected or mapped for any output. See -discard option to disable streams individually.
    // As an output option, disables audio recording i.e. automatic selection or mapping of any audio stream. For full manual control see the -map option.
    '-an',
    // Show a line containing various information for each input video frame
    '-vf showinfo',
    escapeshellarg("frame%01d." . EXT),
));
echo "cmd: ";
var_dump($cmd);
my_exec2($cmd, "", $stdout, $stderr);
//var_dump(strlen($stdout), strlen($stderr));
$lines = array_values(array_filter(array_map("trim", explode("\n", $stderr)), 'strlen'));
$frames = array();
foreach ($lines as $line) {
    // [Parsed_showinfo_0 @ 000000000253fc80] n:   2 pts:    400 pts_time:0.0333667 pos:    80974 fmt:yuv420p sar:1/1 s:1280x720 i:P iskey:0 type:P checksum:9AEB549C plane_checksum:[8A1C9BC4 E8699C52 5AD21C77] mean:[39 135 119] stdev:[28.3 8.3 7.2]
    $rex_ret = preg_match('/n\\:\\s*(?<frame_num>\\d+)\\s*pts\\:\\s*\\d+\\s*pts_time\\:\\s*(?<pts_time>\\d+(?:\\.\\d+)?)/', $line, $matches);
    //var_dump($rex_ret, $matches);
    if (!$rex_ret) {
        continue;
    }
    // why +1? because ffmpeg image name output starts at 1..
    $frames[((int)$matches['frame_num']) + 1] = (float)$matches['pts_time'];
}
//var_dump($frames);
//var_dump(count($frames) , count(glob("*")));
assert(count($frames) === count(glob("*")));
unset($lines, $line, $rex_ret, $matches);
echo "total frames: " . count($frames) . "\n";
echo "WARNING, SLOW OPERATION: now removing duplicate frames, tolerance: {$tolerance}%\n";
$i = 0;
$duplicates = 0;
uglyhack:
//
$keys = array_keys($frames);
for (; $i < (count($keys) - 1); ++$i) {
    $frame1 = "frame" . $keys[$i] . "." . EXT;
    $frame2 = "frame" . $keys[$i + 1] . "." . EXT;
    $similarity = image_compare($frame1, $frame2);
    if ($similarity >= (100 - $tolerance)) {
        ++$duplicates;
        echo "deleting " . $frame2 . " because it's a duplicate of " . $frame1 . " (similarity: {$similarity}%)\n";
        unlink($frame2);
        unset($frames[$keys[$i + 1]]);
        // goto uglyhack;
        $keys = array_keys($frames);
        --$i;
    } else {
        echo "{$similarity}% - ";
    }
}
echo "total duplicates: {$duplicates} - remaining non-duplicate frames: " . count($frames) . "\n";
echo "creating FPS summary..";
$summary = array();
foreach ($frames as $frame => $time) {
    $time = (int)floor($time);
    $summary[$time] = ($summary[$time] ?? 0) + 1;
}
register_shutdown_function(function () use ($summary) {
    echo "<summary>\n";
    foreach ($summary as $time => $counter) {
        echo "at second #{$time}: {$counter} FPS.\n";
    }
    echo "</summary>\n";
});

function init()
{
    global $argc, $argv, $input_file, $tolerance;
    //hhb_init(); //better error reporting.
    stream_set_blocking(STDIN, true);
    if (!is_executable_pathenv('ffmpeg')) {
        die("error: ffmpeg not installed");
    }
    if (!is_executable_pathenv('compare')) {
        die("error: imagemagick compare not installed");
    }
    if (0) {
        $input_file = "";
        $tolerance = 0.4;
    } else {
        if ($argc !== 3) {
            die("usage: {$argv[0]} \"input_file\" tolerance  (tolerance is a float, i suggest 0.4)");
        } else {
            $input_file = trim($argv[1]);
            $tolerance = trim($argv[2]);
            if (false === ($tolerance = filter_var($tolerance, FILTER_VALIDATE_FLOAT, array(
                'options' => array(
                    'min_range' => 0,
                    'max_range' => 100,
                    'default' => false
                )
            )))) {
                die("error: cannot parse tolerance ({$argv[2]}) as float between 0-100! pick a number between 0-100");
            }
        }
    }
    $input_file = _cygwinify_filepath($input_file);
    if (!is_file($input_file) || !is_readable($input_file)) {
        die("input file \"{$input_file}\" not readable!");
    }
    $input_file = realpath($input_file);
    if (!is_dir("fps_counter_workdir")) {
        if (!mkdir("fps_counter_workdir")) {
            die("error: cannot create folder fps_counter_workdir");
        }
    }
    if (!chdir("fps_counter_workdir")) {
        die("error: cannot chdir(fps_counter_workdir)");
    }
    $pid = (string)getmypid();
    if (is_dir($pid)) {
        delTree($pid);
    }
    mkdir($pid);
    chdir($pid);
    echo "working dir: \"" . getcwd() . "\"\n";
    echo "input file: \"" . $input_file . "\"\n";
    register_shutdown_function(function () {
        echo "shutting down, cleaning up.\n";
        chdir("..");
        delTree((string)getmypid());
        echo "\n";
    });
}
/**
 * return how similar 2 images are, in percentage
 *
 * @param string $image1_path comparison image filepath
 * @param string $image2_path comparison image filepath
 * @return float similarity percentage
 */
function image_compare(string $image1_path, string $image2_path): float
{
    // compare -metric MAE testrealNEW.png testrealNEW1px.png JSON:-
    my_exec("compare -metric MAE " . escapeshellarg($image1_path) . " " . escapeshellarg($image2_path) . " JSON:-", "", $stdout, $stderr);
    if (empty($stdout)) {
        throw new \RuntimeException("imagemagick compare errors: {$stderr}");
    }
    $parsed = filter_var(json_decode($stdout, true)[0]['image']['properties']['distortion'], FILTER_VALIDATE_FLOAT);
    if (false === ($parsed)) {
        var_dump($stdout, $stderr);
        throw new \LogicException("could not parse distortion from imagemagic stdout json!");
    }
    $parsed = 100 - ($parsed * 100);
    assert($parsed > (-1) && $parsed < 101);
    // hhb_var_dump($parsed, $stdout, $stderr);
    return $parsed;
}


function is_executable_pathenv(string $filename): bool
{
    if (is_executable($filename)) {
        return true;
    }
    if ($filename !== basename($filename)) {
        return false;
    }
    $separator = (stripos(PHP_OS_FAMILY, "win") === false ? ":" : ";");
    $paths = explode($separator, getenv("PATH"));
    foreach ($paths as $path) {
        if (is_executable($path . DIRECTORY_SEPARATOR . $filename)) {
            return true;
        }
    }
    return false;
}

function delTree($dir)
{
    $dir = realpath($dir);
    echo "deleting dir \"{$dir}\"\n";
    $files = array_diff(scandir($dir, SCANDIR_SORT_NONE), array('.', '..'));
    foreach ($files as $file) {
        $path = $dir . DIRECTORY_SEPARATOR . $file;
        if (is_dir($path)) {
            delTree($path);
        } else {
            //echo "deleting file \"{$path}\"\n";
            unlink($path);
        }
    }
    return rmdir($dir);
}


function ask(string $question, string $default): string
{
    $shown_default = (empty($default) ? "emptystring" : "\"{$default}\"");
    echo "enter \"{$question}\" and press enter (or just press enter and it will default to {$shown_default} )\n";
    echo "{$question}: ";
    $ret = fgets(STDIN);
    $ret = trim($ret);
    if (!strlen($ret)) {
        $ret = $default;
    }
    echo "set to \"{$ret}\".\n";
    return $ret;
}

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;
}
function my_exec2(string $cmd, string $stdin = "", string &$stdout = null, string &$stderr = null): int
{
    $stdout = "";
    $stderr = "";
    $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]);
    $fetch_and_print = function () use (&$stderrh, &$stdouth, &$stderr, &$stdout) {
        // feof() LIES!! TODO: BUGREPORT
        if (true || !feof($stdouth)) {
            $new = stream_get_contents($stdouth);
            if ($new !== false && strlen($new) > 0) {
                echo $new;
                $stdout .= $new;
            }
        }
        if (true || !feof($stderrh)) {
            $new = stream_get_contents($stderrh);
            if ($new !== false && strlen($new) > 0) {
                echo $new;
                $stderr .= $new;
            }
        }
        return;
    };
    while (($status = proc_get_status($proc))['running']) {
        $fetch_and_print();
        msleep(0.1);
    }
    proc_close($proc);
    $fetch_and_print();
    fclose($stdouth);
    fclose($stderrh);
    return $status['exitcode'];
}
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 $path;
    }
}
function msleep($time)
{
    usleep((int)($time * 1000000));
}