Metadata

You can access, add, and edit metadata in media files.

The main metadata features include the following:

• Metadata editing (Deprecated since API Level 12)

  You can edit the metadata of several popular audio formats using the metadata editor. You can add and remove album art, or update the information for the audio file.

  The metadata editor supports editing the metadata of audio files in the MP3 and MP4 file formats. Image and video file editing is not supported.

• Metadata extraction

  Media files, such as MP3 and MP4 files, contain extractable metadata. You can retrieve metadata from such media files with the metadata extractor.

  The metadata extractor can be used with video and audio files only. It is not supported for image files.

• MIME type handling

  You can get the MIME type for a file extension and get a list of file extensions associated, for example, with an image or the JPEG MIME type.

Prerequisites

To enable your application to use the metadata functionality, proceed as follows:

1. To access media files on the device, the application has to request permission by adding the following privileges to the tizen-manifest.xml file:

   
                   
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   <privileges>
      <!--To access media storage-->
      <privilege>http://tizen.org/privilege/mediastorage</privilege>
      <!--To access external storage-->
      <privilege>http://tizen.org/privilege/externalstorage</privilege>
   </privileges>
   

2. To use the methods and properties of the Tizen.Multimedia.MetadataEditor and Tizen.Multimedia.MetadataExtractor classes, include the Tizen.Multimedia namespace in your application:

   
                   
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   using Tizen.Multimedia;
   

Edit metadata and artwork (Deprecated since API Level 12)

To add and edit metadata in an audio file, proceed as follows:

1. Create an instance of the Tizen.Multimedia.MetadataEditor class with the path of the file to be edited. Make sure you have access to the file whose metadata and artwork you want to edit:

   
                   
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   var metadataEditor = new MetadataEditor(mediaPath);
   

2. Edit the metadata by using various properties of the Tizen.Multimedia.MetadataEditor class:

   
                   
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   /// Set the title of the audio file
   metadataEditor.Title = "My Song";
   
   /// Set the artist of the audio file
   metadataEditor.Artist = "Artist";
   

3. To add images to the audio file:

   • Add an image to the audio file using the AddPicture() method of the Tizen.Multimedia.MetadataEditor class with an image path containing the artwork:

     The image to be added must be in JPEG or PNG format. The image is added to the first free index position. You can add multiple image files to the same audio file.

     
                     
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     metadataEditor.AddPicture(artworkpath);
     

   • To remove an image from the file, use the RemovePicture() method with the index number of image file to be removed:

     
                     
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     int index = 5;
     metadataEditor.RemovePicture(index);
     

   • To retrieve the number of images added to the file, use the PictureCount property of the Tizen.Multimedia.MetadataEditor class and to retrieve a specific image, use the GetPicture() method with the index number of the desired image:

     
                     
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     /// Get the number of images associated with the file
     int pictureCount = metadataEditor.PictureCount;
     
     /// Retrieve a specific image
     Artwork artwork = metadataEditor.GetPicture(pictureCount - 1);
     

4. Apply the metadata and artwork changes to the audio file using the Commit() method:

   
                   
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   metadataEditor.Commit();
   

Retrieve metadata

To retrieve metadata from a file, proceed as follows:

1. Create an instance of the Tizen.Multimedia.MetadataExtractor class and pass the path of the file or buffer whose metadata you want to retrieve as a parameter:

   • Create a Tizen.Multimedia.MetadataExtractor instance with a file path parameter:

     
                     
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     var metadataExtractor = new MetadataExtractor(mediaPath);
     

   • Create a Tizen.Multimedia.MetadataExtractor instance with a buffer parameter:

     
                     
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     var buffer = File.ReadAllBytes(mediaPath);
     var metadataExtractor = new MetadataExtractor(buffer);
     

2. Retrieve the metadata:

   • Retrieve the metadata from the file by using the GetMetadata() method of the Tizen.Multimedia.MetadataExtractor class, which returns an instance of the Tizen.Multimedia.Metadata class containing all the metadata of the file.

     The following example retrieves the artist and title of the media file:

     
                     
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     /// Get Artist and Title metadata of the file
     Metadata metadata = metadataExtractor.GetMetadata();
     
     Tizen.Log.Info(LogTag, "Artist: " + metadata.Artist);
     Tizen.Log.Info(LogTag, "Title: " + metadata.Title);
     

     You can retrieve other metadata in the same way.

   • For an audio file, retrieve the artwork from the file using the GetArtwork() method, which returns an instance of the Tizen.Multimedia.Artwork class containing the encoded artwork image and the MIME type of the artwork:

     
                     
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     var artWork = metadataExtractor.GetArtwork();
     

   • For an audio file, retrieve the synchronized lyrics from the file using the GetSyncLyrics() method with an index number as a parameter.

     To retrieve the synchronized lyrics index number, use the SyncLyricsCount property of the Tizen.Multimedia.Metadata class.

     The following example code retrieves the synchronized lyrics from index number 1 and prints the time information and lyrics:

     
                     
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     /// Retrieve the synchronized lyrics of the file
     Metadata metadata = metadataExtractor.GetMetadata();
     
     SyncLyrics syncLyrics = metadataExtractor.GetSyncLyrics(1);
     
     Tizen.Log.Info(LogTag, $"Lyrics = {syncLyrics.Lyrics}, Timestamp = {syncLyrics.Timestamp}");
     

   • For a video file, retrieve frames from the file in one of the following ways:

     • To retrieve a frame without specifying the time when the frame appears, use the GetVideoThumbnail() method:

       
                       
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       byte[] thumbnail = metadataExtractor.GetVideoThumbnail();
       

     • To retrieve a frame with a timestamp, use the GetFrameAt() method with the timestamp in milliseconds. To capture the exact frame desired, the second parameter must be set to true, otherwise, the method returns the I-frame nearest to the desired timestamp:

       
                       
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       byte[] videoFrame = metadataExtractor.GetFrameAt(100, true);
       

Retrieve the MIME type for a file extension

To retrieve the MIME type for a given file extension, use the GetMimeType() method of the Tizen.Content.MimeType.MimeUtil class.

If the given file extension is not associated with any specific file format, the MIME type is application/octet-stream:

                
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string mimeType = MimeUtil.GetMimeType("png");

Retrieve file extensions for a MIME type

To retrieve the file extensions for a given MIME type, use GetFileExtension() method of the Tizen.Content.MimeType.MimeUtil class:

                
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/// Retrieve a list of file extensions for a given MIME type
IEnumerable<string> ext = MimeUtil.GetFileExtension("video/mpeg");
foreach(string ex in ext)
{
    Tizen.Log.Info(LogTag, "Extension = " + ex);
}

Editable metadata attributes

The following table lists the metadata you can edit.

Table: Editable metadata attributes

Extractable metadata attributes

The following table lists the extractable metadata.

The metadata is available with the properties and methods of the Tizen.Multimedia.AudioMetadata, Tizen.Multimedia.Metadata, Tizen.Multimedia.MetadataExtractor, Tizen.Multimedia.SyncLyrics, and Tizen.Multimedia.VideoMetadata classes.

Table: Metadata extractor attributes

Related information

• Dependencies
  • Tizen 4.0 and Higher