function Get_iOS_ChunkedSound()
{
// detect the first request after a new sound icon click, and clear any stored data
// to avoid reusing the same sound endlessly within a session
// javascript player adds a timestamp querystring param ("&d=..."), so it can be detected by it
$isJavaScriptPlayerRequest = array_key_exists('d', $_GET) && LBD_StringHelper::HasValue($_GET['d']);
if ($isJavaScriptPlayerRequest) {
// when javascript is enabled, we can detect the first request because the timestamp changed
$soundClickId = LBD_StringHelper::Normalize($_GET['d']);
$prevSoundClickId = LBD_Persistence_Load('prevSoundClickId');
if (0 != strcasecmp($soundClickId, $prevSoundClickId)) {
Clear_iOS_SoundData();
LBD_Persistence_Save('prevSoundClickId', $soundClickId);
// on first request, save for future checks
}
}
// sound byte subset
$range = GetSoundByteRange();
$rangeStart = $range['start'];
$rangeEnd = $range['end'];
$rangeSize = $rangeEnd - $rangeStart;
// full sound bytes
$soundBytes = Get_iOS_SoundData();
if (is_null($soundBytes)) {
return;
}
$totalSize = strlen($soundBytes) - 1;
// initial iOS 6.0.1 testing; leaving as fallback since we can't be sure it won't happen again:
// we depend on observed behavior of invalid range requests to detect
// end of sound playback, cleanup and tell AppleCoreMedia to stop requesting
// invalid "bytes=rangeEnd-rangeEnd" ranges in an infinite(?) loop
if ($rangeStart == $rangeEnd || $rangeEnd > $totalSize) {
Clear_iOS_SoundData();
LBD_HttpHelper::BadRequest('invalid byte range');
}
while (ob_get_length()) {
ob_end_clean();
}
ob_start();
try {
// partial content response with the requested byte range
header('HTTP/1.1 206 Partial Content');
$mimeType = $captcha->SoundMimeType;
header("Content-Type: {$mimeType}");
header('Content-Transfer-Encoding: binary');
header('X-Robots-Tag: noindex, nofollow, noarchive, nosnippet');
header('Accept-Ranges: bytes');
header("Content-Length: {$rangeSize}");
header("Content-Range: bytes {$rangeStart}-{$rangeEnd}/{$totalSize}");
if (!array_key_exists('d', $_GET)) {
// javascript player not used, we send the file directly as a download
$downloadId = LBD_CryptoHelper::GenerateGuid();
header("Content-Disposition: attachment; filename=captcha_{$downloadId}.wav");
}
LBD_HttpHelper::SmartDisallowCache();
$rangeBytes = substr($soundBytes, $rangeStart, $rangeSize);
echo $rangeBytes;
} catch (Exception $e) {
header('Content-Type: text/plain');
echo $e->getMessage();
}
ob_end_flush();
exit;
}
function GetSound()
{
$captcha = GetCaptchaObject();
if (is_null($captcha)) {
LBD_HttpHelper::BadRequest('Captcha doesn\'t exist');
}
if (!$captcha->SoundEnabled) {
// sound requests can be disabled with this config switch / instance property
LBD_HttpHelper::BadRequest('Sound disabled');
}
$instanceId = GetInstanceId();
if (is_null($instanceId)) {
LBD_HttpHelper::BadRequest('Instance doesn\'t exist');
}
$soundBytes = GetSoundData($captcha, $instanceId);
session_write_close();
if (is_null($soundBytes)) {
LBD_HttpHelper::BadRequest('Please reload the form page before requesting another Captcha sound');
exit;
}
$totalSize = strlen($soundBytes);
// response headers
LBD_HttpHelper::SmartDisallowCache();
$mimeType = $captcha->SoundMimeType;
header("Content-Type: {$mimeType}");
header('Content-Transfer-Encoding: binary');
if (!array_key_exists('d', $_GET)) {
// javascript player not used, we send the file directly as a download
$downloadId = LBD_CryptoHelper::GenerateGuid();
header("Content-Disposition: attachment; filename=captcha_{$downloadId}.wav");
}
if (DetectIosRangeRequest()) {
// iPhone/iPad sound issues workaround: chunked response for iOS clients
// sound byte subset
$range = GetSoundByteRange();
$rangeStart = $range['start'];
$rangeEnd = $range['end'];
$rangeSize = $rangeEnd - $rangeStart + 1;
// initial iOS 6.0.1 testing; leaving as fallback since we can't be sure it won't happen again:
// we depend on observed behavior of invalid range requests to detect
// end of sound playback, cleanup and tell AppleCoreMedia to stop requesting
// invalid "bytes=rangeEnd-rangeEnd" ranges in an infinite(?) loop
if ($rangeStart == $rangeEnd || $rangeEnd > $totalSize) {
LBD_HttpHelper::BadRequest('invalid byte range');
}
$rangeBytes = substr($soundBytes, $rangeStart, $rangeSize);
// partial content response with the requested byte range
header('HTTP/1.1 206 Partial Content');
header('Accept-Ranges: bytes');
header("Content-Length: {$rangeSize}");
header("Content-Range: bytes {$rangeStart}-{$rangeEnd}/{$totalSize}");
echo $rangeBytes;
// chrome needs this kind of response to be able to replay Html5 audio
} else {
if (DetectFakeRangeRequest()) {
header('Accept-Ranges: bytes');
header("Content-Length: {$totalSize}");
$end = $totalSize - 1;
header("Content-Range: bytes 0-{$end}/{$totalSize}");
echo $soundBytes;
} else {
// regular sound request
header('Accept-Ranges: none');
header("Content-Length: {$totalSize}");
echo $soundBytes;
}
}
}
