[wp-trac] [WordPress Trac] #26845: MP3 ID3 Tag Metadata Malformed

[WordPress Trac]

#26845: MP3 ID3 Tag Metadata Malformed
--------------------------+-----------------------------
 Reporter:  chipbennett   |      Owner:
     Type:  defect (bug)  |     Status:  new
 Priority:  normal        |  Milestone:  Awaiting Review
Component:  Media         |    Version:  3.8
 Severity:  normal        |   Keywords:
--------------------------+-----------------------------
 = Issue: =

 Retrieving audio/mp3 attachment metadata returns malformed serialized data
 for metadata generated from ID3 tags.

 = To reproduce: =

 1. Upload/attach mp3 file containing valid ID3 tags to a post
 2. Query attached audio files:
 {{{
 $tracks = get_children( array(
         'post_parent' => $post->ID,
         'post_type' => 'attachment',
         'post_mime_type' => 'audio',
 ) );
 // Loop through them
 foreach ( $tracks as $track ) {}
 }}}
 3. Attempt to retrieve metadata using either method:
 {{{
 $metadata = get_post_meta( $track->ID, '_wp_attachment_metadata', true );
 // or
 $metadata = wp_get_attachment_metadata( $track->ID );
 }}}

 = Example =

 Above procedure performed on a small mp3 file with valid ID3 tags produces
 the following output:

 {{{
 a:29:{s:10:"dataformat";s:3:"mp3";s:8:"channels";i:2;s:11:"sample_rate";i:44100;s:7:"bitrate";d:237594.2401960784;s:11:"channelmode";s:12:"joint
 stereo";s:12:"bitrate_mode";s:3:"abr";s:5:"codec";s:4:"LAME";s:7:"encoder";s:15:"LAME3.98
 (beta)";s:8:"lossless";b:0;s:15:"encoder_options";s:3:"ABR";s:17:"compression_ratio";d:0.16836326544506688;s:10:"fileformat";s:3:"mp3";s:8:"filesize";i:531738;s:9:"mime_type";s:10:"audio/mpeg";s:6:"length";i:10;s:16:"length_formatted";s:4:"0:09";s:5:"title";s:5:"There";s:6:"artist";s:20:"They
 Might Be Giants";s:5:"album";s:8:"Nanobots";s:5:"genre";s:16:"Alternative
 Rock";s:8:"composer";s:14:"Not Documented";s:9:"conductor";s:2:""
 }}}

 And dumping it:
 {{{
 var_dump( $metadata );
 }}}

 Results in:
 {{{
 bool(false)
 }}}

 Attempting to correct malformed syntax like so:
 {{{
 a:22:{s:10:"dataformat";s:3:"mp3";s:8:"channels";i:2;s:11:"sample_rate";i:44100;s:7:"bitrate";d:237594.2401960784;s:11:"channelmode";s:12:"joint
 stereo";s:12:"bitrate_mode";s:3:"abr";s:5:"codec";s:4:"LAME";s:7:"encoder";s:15:"LAME3.98
 (beta)";s:8:"lossless";b:0;s:15:"encoder_options";s:3:"ABR";s:17:"compression_ratio";d:0.16836326544506688;s:10:"fileformat";s:3:"mp3";s:8:"filesize";i:531738;s:9:"mime_type";s:10:"audio/mpeg";s:6:"length";i:10;s:16:"length_formatted";s:4:"0:09";s:5:"title";s:5:"There";s:6:"artist";s:20:"They
 Might Be Giants";s:5:"album";s:8:"Nanobots";s:5:"genre";s:16:"Alternative
 Rock";s:8:"composer";s:14:"Not Documented";s:9:"conductor";s:2:"na";}
 }}}

 And dumping it:
 {{{
 var_dump( $metadata );
 }}}

 Results in:
 {{{
 array(22) { ["dataformat"]=> string(3) "mp3" ["channels"]=> int(2)
 ["sample_rate"]=> int(44100) ["bitrate"]=> float(237594.24019608)
 ["channelmode"]=> string(12) "joint stereo" ["bitrate_mode"]=> string(3)
 "abr" ["codec"]=> string(4) "LAME" ["encoder"]=> string(15) "LAME3.98
 (beta)" ["lossless"]=> bool(false) ["encoder_options"]=> string(3) "ABR"
 ["compression_ratio"]=> float(0.16836326544507) ["fileformat"]=> string(3)
 "mp3" ["filesize"]=> int(531738) ["mime_type"]=> string(10) "audio/mpeg"
 ["length"]=> int(10) ["length_formatted"]=> string(4) "0:09" ["title"]=>
 string(5) "There" ["artist"]=> string(20) "They Might Be Giants"
 ["album"]=> string(8) "Nanobots" ["genre"]=> string(16) "Alternative Rock"
 ["composer"]=> string(14) "Not Documented" ["conductor"]=> string(2) "na"
 }
 }}}

 = Reproducibility =

 I repeated the process with four different MP3 files from the same album.
 I then repeated the process with three different MP3 files from a
 different album.

 All appear to have a serialization issue at/after "conductor". The
 serialization halts, resulting in only 22 of the 29 array keys being added
 to the serialized string, and the 22nd ("conductor") being malformed.

--
Ticket URL: <https://core.trac.wordpress.org/ticket/26845>
WordPress Trac <https://core.trac.wordpress.org/>
WordPress publishing platform