/// <summary>
/// Extracts the media descriptions via reflection on a <see cref="Type"/>.
/// </summary>
/// <returns>
/// It returns a <see cref="Dictionary{TMediaFormat,MediaFormatAttribute}"/> mapping all known media formats with the relative
/// <see cref="MediaFormatAttribute"/>.
/// </returns>
/// <exception cref="ArgumentNullException">
/// Exception thrown if <paramref name="type"/> is null.
/// </exception>
protected void ExtractDescriptions(Type type)
{
if (type == null)
{
throw new ArgumentNullException("type");
}
Dictionary <string, MediaFormatAttribute> formatDescriptions = new Dictionary <string, MediaFormatAttribute>();
FieldInfo[] mediaFormatMembers = type.GetFields(BindingFlags.Public | BindingFlags.Static);
foreach (FieldInfo mediaFormatField in mediaFormatMembers)
{
MediaFormatAttribute mediaFormatAttribute = (MediaFormatAttribute)Attribute.GetCustomAttribute(mediaFormatField, typeof(MediaFormatAttribute));
if ((mediaFormatAttribute != null) && (mediaFormatAttribute.Abstract == false))
{
formatDescriptions[(string)mediaFormatField.GetValue(null)] = mediaFormatAttribute;
}
}
foreach (KeyValuePair <string, MediaFormatAttribute> pair in formatDescriptions)
{
if (mCodecDescriptions.ContainsKey(pair.Key))
{
_Log.Warn("The type {0} define media {1}, but it is ignored because it is already defined elsewhere.", type, pair.Key);
continue;
}
mCodecDescriptions.Add(pair.Key, pair.Value);
}
}
/// <summary>
/// Gets the possible media formats from URL.
/// </summary>
/// <param name="url">
/// A <see cref="String"/> that specify the URL where media is located.
/// </param>
/// <returns>
/// A <see cref="IEnumerable{TMediaFormat}"/> enumerating all possible media formats given <paramref name="url"/>. This
/// method could return an empty enumeration.
/// </returns>
/// <exception cref='ArgumentNullException'>
/// Is thrown when an argument passed to a method is invalid because it is <see langword="null" /> .
/// </exception>
public IEnumerable <string> GetFormatsFromUrl(string url)
{
if (url == null)
{
throw new ArgumentNullException("url");
}
List <string> mediaFormats = new List <string>();
foreach (KeyValuePair <string, MediaFormatAttribute> pair in mCodecDescriptions)
{
MediaFormatAttribute mediaFormat = pair.Value;
if (mediaFormat.MatchPattern(url))
{
mediaFormats.Add(pair.Key);
}
}
return(mediaFormats);
}