getid3_midi::Analyze()

Complexity

Conditions	47
Paths	> 20000

Size

Total Lines	296
Code Lines	161

Duplication

Lines	0
Ratio	0 %

Importance

Changes	1
Bugs	0	Features	0

<?php
    public function Analyze()
    {
        $getid3 = $this->getid3;

        $getid3->info['midi']['raw'] = [];
        $info_midi                   = &$getid3->info['midi'];
        $info_midi_raw               = &$info_midi['raw'];

        $getid3->info['fileformat']          = 'midi';
        $getid3->info['audio']['dataformat'] = 'midi';

        fseek($getid3->fp, $getid3->info['avdataoffset'], SEEK_SET);
        $midi_data = fread($getid3->fp, getid3::FREAD_BUFFER_SIZE);

        // Magic bytes: 'MThd'

        getid3_lib::ReadSequence(
            'BigEndian2Int',
            $info_midi_raw,
            $midi_data,
            4,
            [
                'headersize'    => 4,
                'fileformat'    => 2,
                'tracks'        => 2,
                'ticksperqnote' => 2
            ]
        );

        $offset = 14;

        for ($i = 0; $i < $info_midi_raw['tracks']; $i++) {
            if ((strlen($midi_data) - $offset) < 8) {
                $midi_data .= fread($getid3->fp, getid3::FREAD_BUFFER_SIZE);
            }

            $track_id = substr($midi_data, $offset, 4);
            $offset   += 4;

            if ('MTrk' != $track_id) {
                throw new getid3_exception('Expecting "MTrk" at ' . $offset . ', found ' . $track_id . ' instead');
            }

            $track_size = getid3_lib::BigEndian2Int(substr($midi_data, $offset, 4));
            $offset     += 4;

            $track_data_array[$i] = substr($midi_data, $offset, $track_size);
            $offset               += $track_size;
        }

        if (!isset($track_data_array) || !is_array($track_data_array)) {

The variable $track_data_array does not seem to be defined for all execution paths leading up to this point.

            throw new getid3_exception('Cannot find MIDI track information');
        }

        $info_midi['totalticks']          = 0;
        $getid3->info['playtime_seconds'] = 0;
        $current_ms_per_beat              = 500000; // 120 beats per minute;  60,000,000 microseconds per minute -> 500,000 microseconds per beat

The assignment to $current_ms_per_beat is dead and can be removed.

        $current_beats_per_min            = 120;    // 120 beats per minute;  60,000,000 microseconds per minute -> 500,000 microseconds per beat

The assignment to $current_beats_per_min is dead and can be removed.

        $ms_per_quarter_note_after        = [];

        foreach ($track_data_array as $track_number => $track_data) {
            $events_offset = $last_issued_midi_command = $last_issued_midi_channel = $cumulative_delta_time = $ticks_at_current_bpm = 0;

            while ($events_offset < strlen($track_data)) {
                $event_id = 0;
                if (isset($midi_events[$track_number]) && is_array($midi_events[$track_number])) {
                    $event_id = count($midi_events[$track_number]);
                }
                $delta_time = 0;
                for ($i = 0; $i < 4; $i++) {
                    $delta_time_byte = ord($track_data{$events_offset++});
                    $delta_time      = ($delta_time << 7) + ($delta_time_byte & 0x7F);
                    if ($delta_time_byte & 0x80) {
                        // another byte follows
                    } else {
                        break;
                    }
                }

                $cumulative_delta_time += $delta_time;
                $ticks_at_current_bpm  += $delta_time;

                $midi_events[$track_number][$event_id]['deltatime'] = $delta_time;

                $midi_event_channel = ord($track_data{$events_offset++});

                // OK, normal event - MIDI command has MSB set
                if ($midi_event_channel & 0x80) {
                    $last_issued_midi_command = $midi_event_channel >> 4;
                    $last_issued_midi_channel = $midi_event_channel & 0x0F;
                } // Running event - assume last command
                else {
                    $events_offset--;
                }

                $midi_events[$track_number][$event_id]['eventid'] = $last_issued_midi_command;
                $midi_events[$track_number][$event_id]['channel'] = $last_issued_midi_channel;

                switch ($midi_events[$track_number][$event_id]['eventid']) {
                    case 0x8:       // Note off (key is released)
                    case 0x9:       // Note on (key is pressed)
                    case 0xA:       // Key after-touch

                        //$notenumber = ord($track_data{$events_offset++});
                        //$velocity   = ord($track_data{$events_offset++});
                        $events_offset += 2;
                        break;

                    case 0xB:       // Control Change

                        //$controllernum = ord($track_data{$events_offset++});
                        //$newvalue      = ord($track_data{$events_offset++});
                        $events_offset += 2;
                        break;

                    case 0xC:       // Program (patch) change

                        $new_program_num = ord($track_data{$events_offset++});

                        $info_midi_raw['track'][$track_number]['instrumentid'] = $new_program_num;
                        $info_midi_raw['track'][$track_number]['instrument']   = 10 == $track_number ? getid3_midi::GeneralMIDIpercussionLookup($new_program_num) : getid3_midi::GeneralMIDIinstrumentLookup($new_program_num);
                        break;

                    case 0xD:       // Channel after-touch

                        //$channelnumber = ord($track_data{$events_offset++});
                        break;

                    case 0xE:       // Pitch wheel change (2000H is normal or no change)

                        //$changeLSB = ord($track_data{$events_offset++});
                        //$changeMSB = ord($track_data{$events_offset++});
                        //$pitchwheelchange = (($changeMSB & 0x7F) << 7) & ($changeLSB & 0x7F);
                        $events_offset += 2;
                        break;

                    case 0xF:

                        if (0xF == $midi_events[$track_number][$event_id]['channel']) {
                            $meta_event_command = ord($track_data{$events_offset++});
                            $meta_event_length  = ord($track_data{$events_offset++});
                            $meta_event_data    = substr($track_data, $events_offset, $meta_event_length);
                            $events_offset      += $meta_event_length;

                            switch ($meta_event_command) {
                                case 0x00: // Set track sequence number

                                    //$track_sequence_number = getid3_lib::BigEndian2Int(substr($meta_event_data, 0, $meta_event_length));
                                    //$info_midi_raw['events'][$track_number][$event_id]['seqno'] = $track_sequence_number;
                                    break;

                                case 0x01: // Text: generic

                                    $text_generic = substr($meta_event_data, 0, $meta_event_length);
                                    //$info_midi_raw['events'][$track_number][$event_id]['text'] = $text_generic;
                                    $info_midi['comments']['comment'][] = $text_generic;
                                    break;

                                case 0x02: // Text: copyright

                                    $text_copyright = substr($meta_event_data, 0, $meta_event_length);
                                    //$info_midi_raw['events'][$track_number][$event_id]['copyright'] = $text_copyright;
                                    $info_midi['comments']['copyright'][] = $text_copyright;
                                    break;

                                case 0x03: // Text: track name

                                    $text_trackname                                = substr($meta_event_data, 0, $meta_event_length);
                                    $info_midi_raw['track'][$track_number]['name'] = $text_trackname;
                                    break;

                                case 0x04: // Text: track instrument name

                                    //$text_instrument = substr($meta_event_data, 0, $meta_event_length);
                                    //$info_midi_raw['events'][$track_number][$event_id]['instrument'] = $text_instrument;
                                    break;

                                case 0x05: // Text: lyrics

                                    $text_lyrics = substr($meta_event_data, 0, $meta_event_length);
                                    //$info_midi_raw['events'][$track_number][$event_id]['lyrics'] = $text_lyrics;
                                    if (!isset($info_midi['lyrics'])) {
                                        $info_midi['lyrics'] = '';
                                    }
                                    $info_midi['lyrics'] .= $text_lyrics . "\n";
                                    break;

                                case 0x06: // Text: marker

                                    //$text_marker = substr($meta_event_data, 0, $meta_event_length);
                                    //$info_midi_raw['events'][$track_number][$event_id]['marker'] = $text_marker;
                                    break;

                                case 0x07: // Text: cue point

                                    //$text_cuepoint = substr($meta_event_data, 0, $meta_event_length);
                                    //$info_midi_raw['events'][$track_number][$event_id]['cuepoint'] = $text_cuepoint;
                                    break;

                                case 0x2F: // End Of Track

                                    //$info_midi_raw['events'][$track_number][$event_id]['EOT'] = $cumulative_delta_time;
                                    break;

                                case 0x51: // Tempo: microseconds / quarter note

                                    $current_ms_per_beat                                                        = getid3_lib::BigEndian2Int(substr($meta_event_data, 0, $meta_event_length));
                                    $info_midi_raw['events'][$track_number][$cumulative_delta_time]['us_qnote'] = $current_ms_per_beat;
                                    $current_beats_per_min                                                      = (1000000 / $current_ms_per_beat) * 60;
                                    $ms_per_quarter_note_after[$cumulative_delta_time]                          = $current_ms_per_beat;
                                    $ticks_at_current_bpm                                                       = 0;
                                    break;

                                case 0x58: // Time signature
                                    $timesig_numerator   = getid3_lib::BigEndian2Int($meta_event_data[0]);
                                    $timesig_denominator = pow(2, getid3_lib::BigEndian2Int($meta_event_data[1])); // $02 -> x/4, $03 -> x/8, etc
                                    //$timesig_32inqnote   = getid3_lib::BigEndian2Int($meta_event_data[2]);         // number of 32nd notes to the quarter note
                                    //$info_midi_raw['events'][$track_number][$event_id]['timesig_32inqnote']   = $timesig_32inqnote;
                                    //$info_midi_raw['events'][$track_number][$event_id]['timesig_numerator']   = $timesig_numerator;
                                    //$info_midi_raw['events'][$track_number][$event_id]['timesig_denominator'] = $timesig_denominator;
                                    //$info_midi_raw['events'][$track_number][$event_id]['timesig_text']        = $timesig_numerator.'/'.$timesig_denominator;
                                    $info_midi['timesignature'][] = $timesig_numerator . '/' . $timesig_denominator;
                                    break;

                                case 0x59: // Keysignature

                                    $keysig_sharpsflats = getid3_lib::BigEndian2Int($meta_event_data{0});
                                    if ($keysig_sharpsflats & 0x80) {
                                        // (-7 -> 7 flats, 0 ->key of C, 7 -> 7 sharps)
                                        $keysig_sharpsflats -= 256;
                                    }

                                    $keysig_majorminor = getid3_lib::BigEndian2Int($meta_event_data{1}); // 0 -> major, 1 -> minor
                                    $keysigs           = [-7 => 'Cb', -6 => 'Gb', -5 => 'Db', -4 => 'Ab', -3 => 'Eb', -2 => 'Bb', -1 => 'F', 0 => 'C', 1 => 'G', 2 => 'D', 3 => 'A', 4 => 'E', 5 => 'B', 6 => 'F#', 7 => 'C#'];
                                    //$info_midi_raw['events'][$track_number][$event_id]['keysig_sharps'] = (($keysig_sharpsflats > 0) ? abs($keysig_sharpsflats) : 0);
                                    //$info_midi_raw['events'][$track_number][$event_id]['keysig_flats']  = (($keysig_sharpsflats < 0) ? abs($keysig_sharpsflats) : 0);
                                    //$info_midi_raw['events'][$track_number][$event_id]['keysig_minor']  = (bool)$keysig_majorminor;
                                    //$info_midi_raw['events'][$track_number][$event_id]['keysig_text']   = $keysigs[$keysig_sharpsflats].' '.($info_midi_raw['events'][$track_number][$event_id]['keysig_minor'] ? 'minor' : 'major');

                                    // $keysigs[$keysig_sharpsflats] gets an int key (correct) - $keysigs["$keysig_sharpsflats"] gets a string key (incorrect)
                                    $info_midi['keysignature'][] = $keysigs[$keysig_sharpsflats] . ' ' . ((bool)$keysig_majorminor ? 'minor' : 'major');
                                    break;

                                case 0x7F: // Sequencer specific information

                                    $custom_data = substr($meta_event_data, 0, $meta_event_length);

The assignment to $custom_data is dead and can be removed.

                                    break;

                                default:

                                    $getid3->warning('Unhandled META Event Command: ' . $meta_event_command);
                            }
                        }
                        break;

                    default:
                        $getid3->warning('Unhandled MIDI Event ID: ' . $midi_events[$track_number][$event_id]['eventid']);
                }
            }

            if (($track_number > 0) || (1 == count($track_data_array))) {
                $info_midi['totalticks'] = max($info_midi['totalticks'], $cumulative_delta_time);
            }
        }

        $previous_tick_offset = null;

        ksort($ms_per_quarter_note_after);
        foreach ($ms_per_quarter_note_after as $tick_offset => $ms_per_beat) {
            if (is_null($previous_tick_offset)) {
                $prev_ms_per_beat     = $ms_per_beat;
                $previous_tick_offset = $tick_offset;
                continue;
            }

            if ($info_midi['totalticks'] > $tick_offset) {
                $getid3->info['playtime_seconds'] += (($tick_offset - $previous_tick_offset) / $info_midi_raw['ticksperqnote']) * ($prev_ms_per_beat / 1000000);

The variable $prev_ms_per_beat seems to be defined later in this foreach loop on line 297. Are you sure it is defined here?

                $prev_ms_per_beat     = $ms_per_beat;
                $previous_tick_offset = $tick_offset;
            }
        }

        if ($info_midi['totalticks'] > $previous_tick_offset) {
            $getid3->info['playtime_seconds'] += (($info_midi['totalticks'] - $previous_tick_offset) / $info_midi_raw['ticksperqnote']) * ($ms_per_beat / 1000000);

The variable $ms_per_beat seems to be defined by a foreach iteration on line 295. Are you sure the iterator is never empty, otherwise this variable is not defined?

        }

        if (@$getid3->info['playtime_seconds'] > 0) {
            $getid3->info['bitrate'] = (($getid3->info['avdataend'] - $getid3->info['avdataoffset']) * 8) / $getid3->info['playtime_seconds'];
        }

        if (!empty($info_midi['lyrics'])) {
            $info_midi['comments']['lyrics'][] = $info_midi['lyrics'];
        }

        return true;
    }