thekid
commented
1 year ago POC
<?php
use io\File;
use util\cmd\Console;
function atom($f) {
$atom= unpack('Nlength/a4name', $f->read(8));
if (0 === $atom['length']) {
$atom['length']= $f->size() - $f->tell();
} else if (1 === $atom['length']) {
$atom['length']= unpack('J', $f->read(8))[1];
}
return $atom;
}
function atoms($f) {
static $CONTAINERS= ['moov' => 1, 'udta' => 1, 'ilst' => 1];
while (($offset= $f->tell()) < $f->size()) {
yield $offset => $atom= atom($f);
$end= $offset + $atom['length'];
if (isset($CONTAINERS[$atom['name']])) {
while (($offset= $f->tell()) < $end) {
yield $offset => ['parent' => $atom['name']] + $child= atom($f, false);
$f->seek($offset + $child['length'], SEEK_SET);
}
}
$f->seek($end, SEEK_SET);
}
}
$f= new File($argv[1]);
$f->open(File::READ);
try {
foreach (atoms($f) as $offset => $atom) {
Console::writeLinef(
'@%012d %s%s: %d bytes',
$offset,
isset($atom['parent']) ? $atom['parent'].'.' : '',
$atom['name'],
$atom['length']
);
}
} finally {
$f->close();
}Results for a video filmed on iOS
$ xp atoms.script.php Albums/4.5_islands-2019/horikawacho_2019-05-24/20190524_112729000_iOS.MOV
@000000000000 ftyp: 20 bytes
@000000000020 wide: 8 bytes
@000000000028 mdat: 26162772 bytes
@000026162800 moov: 21092 bytes
@000026162808 moov.mvhd: 108 bytes
@000026162916 moov.trak: 12382 bytes
@000026175298 moov.trak: 5848 bytes
@000026181146 moov.trak: 1678 bytes
@000026182824 moov.trak: 629 bytes
@000026183453 moov.meta: 439 bytesResults for a Windows phone video
$ xp atoms.script.php Albums/sudamerica-2018/rumbling_through_the_night-2018-12-14/WP_20181214_23_23_30_Pro.mp4
@000000000000 ftyp: 24 bytes
@000000000024 uuid: 40 bytes
@000000000064 mdat: 70401394 bytes
@000070401458 moov: 34089 bytes
@000070401466 moov.mvhd: 108 bytes
@000070401574 moov.trak: 15807 bytes
@000070417381 moov.trak: 18069 bytes
@000070435450 moov.udta: 97 bytesWe can now use the mvhd atom to extract duration and creation time, see here and the meta and udta atoms to extract further information as described here and here
See also: