public static function MPEGaudioHeaderValid($raw_array, $echo_errors = false, $allow_bitrate_15 = false)
{
if (($raw_array['synch'] & 0xffe) != 0xffe) {
return false;
}
static $mpeg_audio_version_lookup;
static $mpeg_audio_layer_lookup;
static $mpeg_audio_bitrate_lookup;
static $mpeg_audio_frequency_lookup;
static $mpeg_audio_channel_mode_lookup;
static $mpeg_audio_mode_extension_lookup;
static $mpeg_audio_emphasis_lookup;
if (empty($mpeg_audio_version_lookup)) {
$mpeg_audio_version_lookup = getid3_mp3::MPEGaudioVersionarray();
$mpeg_audio_layer_lookup = getid3_mp3::MPEGaudioLayerarray();
$mpeg_audio_bitrate_lookup = getid3_mp3::MPEGaudioBitratearray();
$mpeg_audio_frequency_lookup = getid3_mp3::MPEGaudioFrequencyarray();
$mpeg_audio_channel_mode_lookup = getid3_mp3::MPEGaudioChannelModearray();
$mpeg_audio_mode_extension_lookup = getid3_mp3::MPEGaudioModeExtensionarray();
$mpeg_audio_emphasis_lookup = getid3_mp3::MPEGaudioEmphasisarray();
}
if (isset($mpeg_audio_version_lookup[$raw_array['version']])) {
$decodedVersion = $mpeg_audio_version_lookup[$raw_array['version']];
} else {
echo $echo_errors ? "\n" . 'invalid Version (' . $raw_array['version'] . ')' : '';
return false;
}
if (isset($mpeg_audio_layer_lookup[$raw_array['layer']])) {
$decodedLayer = $mpeg_audio_layer_lookup[$raw_array['layer']];
} else {
echo $echo_errors ? "\n" . 'invalid Layer (' . $raw_array['layer'] . ')' : '';
return false;
}
if (!isset($mpeg_audio_bitrate_lookup[$decodedVersion][$decodedLayer][$raw_array['bitrate']])) {
echo $echo_errors ? "\n" . 'invalid Bitrate (' . $raw_array['bitrate'] . ')' : '';
if ($raw_array['bitrate'] == 15) {
// known issue in LAME 3.90 - 3.93.1 where free-format has bitrate ID of 15 instead of 0
// let it go through here otherwise file will not be identified
if (!$allow_bitrate_15) {
return false;
}
} else {
return false;
}
}
if (!isset($mpeg_audio_frequency_lookup[$decodedVersion][$raw_array['sample_rate']])) {
echo $echo_errors ? "\n" . 'invalid Frequency (' . $raw_array['sample_rate'] . ')' : '';
return false;
}
if (!isset($mpeg_audio_channel_mode_lookup[$raw_array['channelmode']])) {
echo $echo_errors ? "\n" . 'invalid ChannelMode (' . $raw_array['channelmode'] . ')' : '';
return false;
}
if (!isset($mpeg_audio_mode_extension_lookup[$decodedLayer][$raw_array['modeextension']])) {
echo $echo_errors ? "\n" . 'invalid Mode Extension (' . $raw_array['modeextension'] . ')' : '';
return false;
}
if (!isset($mpeg_audio_emphasis_lookup[$raw_array['emphasis']])) {
echo $echo_errors ? "\n" . 'invalid Emphasis (' . $raw_array['emphasis'] . ')' : '';
return false;
}
// These are just either set or not set, you can't mess that up :)
// $raw_array['protection'];
// $raw_array['padding'];
// $raw_array['private'];
// $raw_array['copyright'];
// $raw_array['original'];
return true;
}