/// <summary>
/// Download all segments for the closed caption starting in specified <paramref name="position"/>.
/// </summary>
/// <param name="subtitle">Subtitle rendition of the closed caption to download.</param>
/// <param name="position">Starting position for the download.</param>
/// <returns>Async task.</returns>
private async Task DownloadAllSegmentsAsync(IHLSSubtitleRendition subtitle, TimeSpan position)
{
if (null == this._Controller || !this._Controller.IsValid || null == this._Controller.Playlist)
{
return;
}
uint segmentCount = await subtitle.RefreshAsync();
if (0 == segmentCount)
{
return;
}
var locators = subtitle.GetSubtitleLocators();
List <Tuple <uint, string> > toFetch = null;
if (this._Controller.Playlist.IsLive && !(null == this._WebVTTLocators || 0 == this._WebVTTLocators.Count))
{
var locdata = locators.Where(l => l.StartPosition >= position.TotalSeconds).Select(l => new Tuple <uint, string>(l.Index, l.Location)).ToList();
toFetch = locdata.Except(_WebVTTLocators, new LocatorEqualityComparer()).ToList();
this._WebVTTLocators = locdata;
}
else
{
this._WebVTTLocators = locators.Where(l => l.StartPosition >= position.TotalSeconds).Select(l => new Tuple <uint, string>(l.Index, l.Location)).ToList();
toFetch = this._WebVTTLocators;
}
await Task.Run(async() =>
{
using (System.Net.Http.HttpClient client = new System.Net.Http.HttpClient())
{
foreach (var loc in toFetch)
{
if (this._Cancel)
{
break;
}
Uri uri;
if (Uri.TryCreate(loc.Item2, UriKind.RelativeOrAbsolute, out uri))
{
await this.DownloadSegmentAsync(client, loc.Item1, uri);
}
}
}
});
}
/// <summary>
/// Download all segments for the closed caption starting in specified <paramref name="position"/>.
/// </summary>
/// <param name="id">ID of the closed caption to download.</param>
/// <param name="position">Starting position for the download.</param>
public async Task DownloadAllSegmentsAsync(string id, TimeSpan position)
{
try
{
IHLSSubtitleRendition subtitle = this.FindRendition(id);
if (null != subtitle)
{
this.CurrentSubtitleId = id;
await this.DownloadAllSegmentsAsync(subtitle, position);
}
}
catch (NullReferenceException)
{
// Swallow exceptions here as 404s and other errors can cause the SDK code being accessed above to throw
}
}
