private string UnscrambleDashManifestUrl(
SignatureScrambler signatureScrambler,
string dashManifestUrl)
{
var signature = Regex.Match(dashManifestUrl, "/s/(.*?)(?:/|$)").Groups[1].Value;
if (string.IsNullOrWhiteSpace(signature))
{
return(dashManifestUrl);
}
return(Url.SetRouteParameter(
dashManifestUrl,
"signature",
signatureScrambler.Unscramble(signature)
));
}
private string UnscrambleStreamUrl(
SignatureScrambler signatureScrambler,
string streamUrl,
string?signature,
string?signatureParameter)
{
if (string.IsNullOrWhiteSpace(signature))
{
return(streamUrl);
}
return(Url.SetQueryParameter(
streamUrl,
signatureParameter ?? "signature",
signatureScrambler.Unscramble(signature)
));
}
private async ValueTask PopulateStreamInfosAsync(
ICollection <IStreamInfo> streamInfos,
IEnumerable <IStreamInfoExtractor> streamInfoExtractors,
SignatureScrambler signatureScrambler,
CancellationToken cancellationToken = default)
{
foreach (var streamInfoExtractor in streamInfoExtractors)
{
var itag =
streamInfoExtractor.TryGetItag() ??
throw new YoutubeExplodeException("Could not extract stream itag.");
var urlRaw =
streamInfoExtractor.TryGetUrl() ??
throw new YoutubeExplodeException("Could not extract stream URL.");
// Unscramble URL
var signature = streamInfoExtractor.TryGetSignature();
var signatureParameter = streamInfoExtractor.TryGetSignatureParameter();
var url = UnscrambleStreamUrl(signatureScrambler, urlRaw, signature, signatureParameter);
// Get content length
var contentLength =
streamInfoExtractor.TryGetContentLength() ??
await _httpClient.TryGetContentLengthAsync(url, false, cancellationToken) ??
0;
if (contentLength <= 0)
{
continue; // broken stream URL?
}
var fileSize = new FileSize(contentLength);
var container =
streamInfoExtractor.TryGetContainer()?.Pipe(s => new Container(s)) ??
throw new YoutubeExplodeException("Could not extract stream container.");
var bitrate =
streamInfoExtractor.TryGetBitrate()?.Pipe(s => new Bitrate(s)) ??
throw new YoutubeExplodeException("Could not extract stream bitrate.");
var audioCodec = streamInfoExtractor.TryGetAudioCodec();
var videoCodec = streamInfoExtractor.TryGetVideoCodec();
// Muxed or video-only stream
if (!string.IsNullOrWhiteSpace(videoCodec))
{
var framerate = streamInfoExtractor.TryGetFramerate() ?? 24;
var videoQualityLabel = streamInfoExtractor.TryGetVideoQualityLabel();
var videoQuality = !string.IsNullOrWhiteSpace(videoQualityLabel)
? VideoQuality.FromLabel(videoQualityLabel, framerate)
: VideoQuality.FromItag(itag, framerate);
var videoWidth = streamInfoExtractor.TryGetVideoWidth();
var videoHeight = streamInfoExtractor.TryGetVideoHeight();
var videoResolution = videoWidth is not null && videoHeight is not null
? new Resolution(videoWidth.Value, videoHeight.Value)
: videoQuality.GetDefaultVideoResolution();
// Muxed
if (!string.IsNullOrWhiteSpace(audioCodec))
{
var streamInfo = new MuxedStreamInfo(
url,
container,
fileSize,
bitrate,
audioCodec,
videoCodec,
videoQuality,
videoResolution
);
streamInfos.Add(streamInfo);
}
// Video-only
else
{
var streamInfo = new VideoOnlyStreamInfo(
url,
container,
fileSize,
bitrate,
videoCodec,
videoQuality,
videoResolution
);
streamInfos.Add(streamInfo);
}
}
// Audio-only
else if (!string.IsNullOrWhiteSpace(audioCodec))
{
var streamInfo = new AudioOnlyStreamInfo(
url,
container,
fileSize,
bitrate,
audioCodec
);
streamInfos.Add(streamInfo);
}
else
{
Debug.Fail("Stream doesn't contain neither audio nor video codec information.");
}
}
}
