Using Qt Mobility to get metadata from media files

Comments

Swarit - In Qt 5.0 how to get metadata info of a song in Qt 5.0

in Qt 5.0 following code is not working. QtMediaServices is not there,it seems.please someone help me how to get metadata info of a song in Qt 5.0

void MediaMetaDataExample::GetMetaData()

 {
   // Get the list of keys there is metadata available for
   QList<QtMediaServices::MetaData> metadatalist = player->availableMetaData();

   // Get the size of the list
   int list_size = metadatalist.size();

   // Define variables to store metadata key and value    
   QtMediaServices::MetaData metadata_key;
   QVariant var_data;

   for (int indx = 0; indx < list_size; indx++) {
     // Get the key from the list
     metadata_key = metadatalist.at(indx);

     // Get the value for the key
     var_data = player->metaData(metadata_key);

     switch(metadata_key) {
       case QtMediaServices::Title:
         // Retrieve title (using var_data.toString())
         break;
       case QtMediaServices::SubTitle:
         // Retrieve subtitle
         break;
       case QtMediaServices::Author:
         // Retrieve author
         break;

       // ... see QtMediaServices for rest of the values

       default:
         break;
     }
   }

}

swarit 19:21, 18 November 2012 (EET)

Hamishwillee - No idea

Nokia devices use Qt 4.x so I don't think there will many people who will know the answer to this. I've updated the Qt compatibility to Qt 4.x above. You might want to check out the new module QMultimedia

hamishwillee 06:05, 20 November 2012 (EET)

Log in or Join to leave comments.

Article Metadata

---

Tested with

Devices(s): Tested on: Nokia 5800 XpressMusic

---

Compatibility

Platform(s): Qt 4.x

---

Article

Keywords: QMediaPlayer, QMediaObject

Created: User:Kbwiki (29 Jun 2010)

Last edited: hamishwillee (20 Nov 2012)

Description

With the QMediaObject::availableMetaData() and QMediaObject::metaData() functions we can retrieve the metadata in a media file (audio/video). The metadata information can be only retrieved while the file is playing.

Qt Mobility APIs are included in the Qt SDK.

Solution

Define the QtMobility/Multimedia configuration in the .pro file:

  CONFIG += mobility
  MOBILITY = multimedia

Header files:

  #include <QMediaPlayer>
  #include <qtmedianamespace.h>

Implementation:

  // Use QMediaPlayer as a class member
  QMediaPlayer *player;
 
  // create the player and start playback
  player = new QMediaPlayer(this);
  player->setMedia(QUrl::fromLocalFile("C:\\Data\\sample.mp3"));
  player->setVolume( 25 );
  player->play();

A method to get the metadata of the media file:

  void MediaMetaDataExample::GetMetaData()
  {
    // Get the list of keys there is metadata available for
    QList<QtMediaServices::MetaData> metadatalist = player->availableMetaData();
 
    // Get the size of the list
    int list_size = metadatalist.size();
 
    // Define variables to store metadata key and value    
    QtMediaServices::MetaData metadata_key;
    QVariant var_data;
 
    for (int indx = 0; indx < list_size; indx++) {
      // Get the key from the list
      metadata_key = metadatalist.at(indx);
 
      // Get the value for the key
      var_data = player->metaData(metadata_key);
 
      switch(metadata_key) {
        case QtMediaServices::Title:
          // Retrieve title (using var_data.toString())
          break;
        case QtMediaServices::SubTitle:
          // Retrieve subtitle
          break;
        case QtMediaServices::Author:
          // Retrieve author
          break;
 
        // ... see QtMediaServices for rest of the values
 
        default:
          break;
      }
    }
  }

A method to get the extended metadata of the media file:

  void MediaMetaDataExample::GetExtendedMetaData()
  {
    // Retrieve extended metadata key list
    QStringList extn_metadata = player->availableExtendedMetaData();
    int count_extn = extn_metadata.count();
    QString extn_metadata_key;
    QVariant extn_metadata_value;
    for( int indx = 0; indx < count_extn; indx++ )
      {
      extn_metadata_key = extn_metadata.at(indx);
      extn_metadata_value = player->extendedMetaData(extn_metadata_key);
 
      // Process extended metadata here
      // Need to convert QVariant into proper type
      }
  }