/// <summary>
/// Accepts <paramref name="cipher"/> as a URI-encoded string in the following form:
/// <para>sp=sig&s=wggj6zg7m-...&url=https%3A%2F%2Fr5---sn-5hnekn7k.googlevideo.com%2Fvideoplayback...</para>
/// Extracts its useful encoded parameters and puts them into the specified <paramref name="streamInfo"/>.
/// </summary>
protected virtual void UpdateStreamCipherInfo(YouTubeStreamInfo streamInfo, string cipher)
{
if (string.IsNullOrEmpty(cipher))
{
throw new ArgumentNullException(nameof(cipher));
}
var map = YouTubeUtils.ExtractUrlEncodedParamMap(cipher);
streamInfo.Url = map.GetOrDefault("url") ?? throw new GrabParseException("Failed to extract URL from cipher.");
streamInfo.Signature = map.GetOrDefault("s") ?? throw new GrabParseException("Failed to extract signature from cipher.");
}
/// <summary>
/// Appends the specified <paramref name="stream"/> to the specified <paramref name="result"/>.
/// </summary>
protected virtual void AppendStreamToResult(GrabResult result, YouTubeStreamInfo stream)
{
MediaChannels channels;
// get iTag info
var itagInfo = stream.iTag == null ? null : YouTubeTags.For(stream.iTag.Value);
// extract extension from mime
var extension = stream.Extension ?? stream.Mime?.Split('/')?.Last();
// decide according to stream type - adaptive, or muxed
if (stream is YouTubeMuxedStream muxedStream)
{
// Muxed stream
channels = MediaChannels.Both;
}
else if (stream is YouTubeAdaptiveStream adaptiveStream)
{
// Adaptive stream
var hasVideo = itagInfo?.HasVideo ?? stream.Mime.StartsWith("video");
channels = hasVideo ? MediaChannels.Video : MediaChannels.Audio;
}
else
{
throw new NotSupportedException($"YouTube stream of type {stream.GetType()} is not implemented in {nameof(YouTubeGrabber)}.{nameof(AppendStreamToResult)}.");
}
var format = new MediaFormat(stream.Mime, extension);
var grabbed = new GrabbedMedia(new Uri(stream.Url), null, format, channels);
result.Resources.Add(grabbed);
// update grabbed media iTag info
if (itagInfo != null)
{
UpdateStreamITagInfo(grabbed, itagInfo.Value);
}
}
