public async Task ExecuteAsync() {
context.OnProgresStateChanged(YoutubeStage.StartingDownload);
if (context.VideoInfo == null) throw new InvalidOperationException("Cant extract audio when no VideoInfo is selected.");
HttpResponseMessage response;
var rpf = new RetryableProcessFailed("Video Downloader") {Tag=context};
retry:try {
response = await _httpClient.GetAsync(context.VideoInfo.DownloadUrl);
} catch (Exception e) {
rpf.Defaultize(e);
context.OnDownloadFailed(rpf);
if (rpf.ShouldRetry)
goto retry;
return;
}
if (!response.IsSuccessStatusCode)
throw new Exception();
context.VideoPath = new FileInfo(context.VideoPath?.FullName ?? context.VideoSaveableFilename);
using (var downloadStream = await response.Content.ReadAsStreamAsync())
using (var fileStream = File.Open(context.VideoPath.FullName, FileMode.Create, FileAccess.Write)) {
var buffer = new byte[0x4000]; //16KB buffer
var cancelRequest = false;
int bytes;
double bytesDownloaded = 0;
while (!cancelRequest && (bytes = await downloadStream.ReadAsync(buffer, 0, buffer.Length)) > 0) {
await fileStream.WriteAsync(buffer, 0, bytes);
bytesDownloaded += bytes;
var e = context.OnProgresStateChanged(YoutubeStage.Downloading, ((bytesDownloaded / downloadStream.Length) * 100));
if (e.Cancel)
cancelRequest = true;
}
}
context.OnProgresStateChanged(YoutubeStage.DownloadFinished);
}
/// <summary>
/// Occurs when the downlaod progress of the video file has changed.
/// </summary>
/// <summary>
/// Starts the video download.
/// </summary>
/// <exception cref="IOException">The video file could not be saved.</exception>
/// <exception cref="WebException">An error occured while downloading the video.</exception>
public override void Execute() {
context.OnProgresStateChanged(YoutubeStage.StartingDownload);
if (context.VideoInfo==null) throw new InvalidOperationException("Cant extract audio when no VideoInfo is selected.");
HttpWebRequest request;
var rpf = new RetryableProcessFailed("Video Downloader") { Tag = context };
retry:try {
request = (HttpWebRequest)WebRequest.Create(context.VideoInfo.DownloadUrl);
} catch (Exception e) {
rpf.Defaultize(e);
context.OnDownloadFailed(rpf);
if (rpf.ShouldRetry)
goto retry;
return;
}
if (context.BytesToDownload.HasValue)
request.AddRange(0, context.BytesToDownload.Value - 1);
context.VideoPath = new FileInfo(context.VideoPath?.FullName ?? context.VideoSaveableFilename);
using (var response = request.GetResponse())
using (var source = response.GetResponseStream())
using (var target = File.Open(context.VideoPath.FullName, FileMode.Create, FileAccess.Write)) {
var buffer = new byte[1024];
var cancel = false;
int bytes;
var copiedBytes = 0;
while (!cancel && (bytes = source.Read(buffer, 0, buffer.Length)) > 0) {
target.Write(buffer, 0, bytes);
copiedBytes += bytes;
var e = context.OnProgresStateChanged(YoutubeStage.Downloading, (copiedBytes * 1.0 / response.ContentLength) * 100f);
if (e.Cancel)
cancel = true;
}
}
context.OnProgresStateChanged(YoutubeStage.DownloadFinished);
}
/// <summary>
/// Gets a list of <see cref="VideoInfo" />s for the specified URL.
/// </summary>
/// <param name="context">The context, must contain a url to the video in the Url property</param>
/// <param name="decryptSignature">
/// A value indicating whether the video signatures should be decrypted or not. Decrypting
/// consists of a HTTP request for each <see cref="VideoInfo" />, so you may want to set
/// this to false and call <see cref="DecryptDownloadUrl" /> on your selected
/// <see
/// cref="VideoInfo" />
/// later.
/// </param>
/// <returns>A list of <see cref="VideoInfo" />s that can be used to download the video.</returns>
/// <exception cref="VideoNotAvailableException">The video is not available.</exception>
/// <exception cref="WebException">
/// An error occurred while downloading the YouTube page html.
/// </exception>
/// <exception cref="YoutubeParseException">The Youtube page could not be parsed.</exception>
public static IEnumerable<VideoInfo> GetDownloadUrls(YoutubeContext context, bool decryptSignature = true) {
if (context == null)
throw new ArgumentNullException(nameof(context));
if (context.Url == null)
throw new ArgumentNullException(nameof(context.Url));
context.OnProgresStateChanged(YoutubeStage.ProcessingUrls);
string ytb;
var isYoutubeUrl = TryNormalizeYoutubeUrl(context.Url, out ytb);
context.Url = ytb;
if (!isYoutubeUrl)
throw new ArgumentException("URL is not a valid youtube URL!");
_retry:
try {
var rpf = new RetryableProcessFailed("ParseHtml5Version") {Tag = context.Url};
_redownload:
var json = LoadJson(context.Url);
var videoTitle = GetVideoTitle(json);
var n = 0;
var downloadUrls = ExtractDownloadUrls(json);
var infos = GetVideoInfos(downloadUrls, videoTitle, context.Url).ToArray();
try {
var htmlPlayerVersion = GetHtml5PlayerVersion(json);
foreach (var info in infos) {
info.HtmlPlayerVersion = htmlPlayerVersion;
if (decryptSignature && info.RequiresDecryption)
DecryptDownloadUrl(info);
}
return infos;
} catch (Exception e) {
rpf.Defaultize(e);
context.OnDownloadFailed(rpf);
Console.WriteLine(e);
if (rpf.ShouldRetry)
goto _redownload;
return null;
}
} catch (Exception ex) when (ex.Message == "Result cannot be called on a failed Match.") {
goto _retry;
} catch (Exception ex) {
if (ex is WebException || ex is VideoNotAvailableException)
throw;
ThrowYoutubeParseException(ex, context.Url);
} //Message
return null; // Will never happen, but the compiler requires it
}
/// <summary>
/// Extracts the playlist from the url, wether its on a playlist page or a side playlist when playing a video.
/// Will return the urls of the songs
/// </summary>
public static async Task<List<string>> ExtractPlaylistAsync(string url) {
url = NormalizeYoutubePlaylistUrl(url);
if (string.IsNullOrEmpty(url))
throw new ArgumentNullException(nameof(url));
string pageSource;
var rpf = new RetryableProcessFailed("LoadUrls") {Tag = url};
retry:
try {
pageSource = await _httpClient.DownloadStringTaskAsync(url);
} catch (Exception e) {
rpf.Defaultize(e);
//TODO FailedDownload?.Invoke(rpf);
if (rpf.ShouldRetry)
goto retry;
return null;
}
var doc = new HtmlDocument();
doc.LoadHtml(pageSource);
return _extractPlaylistUrls(url, doc);
}
private static async Task<JObject> LoadJsonAsync(string url) {
string pageSource;
var rpf = new RetryableProcessFailed("LoadUrls") {Tag = url};
retry:
try {
pageSource = await _httpClient.DownloadStringTaskAsync(url);
} catch (Exception e) {
rpf.Defaultize(e);
//TODO FailedDownload?.Invoke(rpf);
if (rpf.ShouldRetry)
goto retry;
return null;
}
if (IsVideoUnavailable(pageSource))
throw new VideoNotAvailableException();
var dataRegex = new Regex(@"ytplayer\.config\s*=\s*(\{.+?\});", RegexOptions.Multiline);
var extractedJson = dataRegex.Match(pageSource).Result("$1");
return JObject.Parse(extractedJson);
}
private static JObject LoadJson(string url) {
string pageSource;
var rpf = new RetryableProcessFailed("LoadUrls") {Tag = url};
var timeout = 1500u;
retry:
try {
pageSource = HttpHelper.DownloadString(url, timeout);
} catch (Exception e) {
rpf.Defaultize(e);
//TODO FailedDownload?.Invoke(rpf);
if (rpf.ShouldRetry) {
timeout += 500;
goto retry;
}
return null;
}
if (IsVideoUnavailable(pageSource))
throw new VideoNotAvailableException();
var dataRegex = new Regex(@"ytplayer\.config\s*=\s*(\{.+?\});", RegexOptions.Multiline);
var extractedJson = dataRegex.Match(pageSource).Result("$1");
return JObject.Parse(extractedJson);
}
/// <summary>
/// Gets a list of <see cref="VideoInfo" />s for the specified URL.
/// </summary>
/// <param name="context">The context, must contain a url to the video in the Url property</param>
/// <param name="decryptSignature">
/// A value indicating whether the video signatures should be decrypted or not. Decrypting
/// consists of a HTTP request for each <see cref="VideoInfo" />, so you may want to set
/// this to false and call <see cref="DecryptDownloadUrl" /> on your selected
/// <see
/// cref="VideoInfo" />
/// later.
/// </param>
/// <returns>A list of <see cref="VideoInfo" />s that can be used to download the video.</returns>
/// <exception cref="VideoNotAvailableException">The video is not available.</exception>
/// <exception cref="WebException">
/// An error occurred while downloading the YouTube page html.
/// </exception>
/// <exception cref="YoutubeParseException">The Youtube page could not be parsed.</exception>
public static async Task<IEnumerable<VideoInfo>> GetDownloadUrlsAsync(YoutubeContext context, bool decryptSignature = true) {
if (context == null)
throw new ArgumentNullException(nameof(context));
if (context.Url == null)
throw new ArgumentNullException(nameof(context.Url));
context.OnProgresStateChanged(YoutubeStage.ProcessingUrls);
string ytb;
var isYoutubeUrl = TryNormalizeYoutubeUrl(context.Url, out ytb);
context.Url = ytb;
if (!isYoutubeUrl)
throw new ArgumentException("URL is not a valid youtube URL!");
try {
var rpf = new RetryableProcessFailed("ParseHtml5Version") {Tag = context.Url };
_redownload:
var json = await LoadJsonAsync(context.Url);
var videoTitle = GetVideoTitle(json);
int n = 0;
var downloadUrls = ExtractDownloadUrls(json);
var infos = GetVideoInfos(downloadUrls, videoTitle, context.Url);
string htmlPlayerVersion;
try {
htmlPlayerVersion = GetHtml5PlayerVersion(json);
} catch (Exception e) {
rpf.Defaultize(e);
context.OnDownloadFailed(rpf);
if (rpf.ShouldRetry)
goto _redownload;
return null;
}
foreach (var info in infos) {
info.HtmlPlayerVersion = htmlPlayerVersion;
if (decryptSignature && info.RequiresDecryption)
await DecryptDownloadUrlAsync(info);
}
return infos;
} catch (Exception ex) {
if (ex is WebException || ex is VideoNotAvailableException)
throw;
ThrowYoutubeParseException(ex, context.Url);
}
return null; // Will never happen, but the compiler requires it
}
internal void OnDownloadFailed(RetryableProcessFailed e)
{
DownloadFailed?.Invoke(this, e);
}
public static async Task<string> DecipherWithVersionAsync(VideoInfo vidinfo, string cipher, string cipherVersion) {
var jsUrl = $"http://s.ytimg.com/yts/jsbin/player-{cipherVersion}.js";
string js;
var rpf = new RetryableProcessFailed("LoadUrls") {Tag = vidinfo};
var timeout = 1500u;
retry:
try {
js = await HttpHelper.DownloadStringAsync(jsUrl, timeout);
} catch (Exception e) {
rpf.Defaultize(e);
if (rpf.ShouldRetry && rpf.NumberOfTries <= 10) {
timeout += 500;
goto retry;
}
return null;
}
//Find "C" in this: var A = B.sig||C (B.s)
var functNamePattern = @"\.sig\s*\|\|([a-zA-Z0-9\$]+)\("; //Regex Formed To Find Word or DollarSign
var funcName = Regex.Match(js, functNamePattern).Groups[1].Value;
if (funcName.Contains("$"))
funcName = "\\" + funcName; //Due To Dollar Sign Introduction, Need To Escape
var funcBodyPattern = @"(?<brace>{([^{}]| ?(brace))*})"; //Match nested angle braces
var funcPattern = @"var " + @funcName + @"=function\(\w+\)\{.*?\};"; //Escape funcName string
var funcBody = Regex.Match(js, funcPattern).Value; //Entire sig function
var lines = funcBody.Split(';'); //Each line in sig function
string idReverse = "", idSlice = "", idCharSwap = ""; //Hold name for each cipher method
var functionIdentifier = "";
var operations = "";
foreach (var line in lines.Skip(1).Take(lines.Length - 2)) //Matches the funcBody with each cipher method. Only runs till all three are defined.
{
if (!string.IsNullOrEmpty(idReverse) && !string.IsNullOrEmpty(idSlice) &&
!string.IsNullOrEmpty(idCharSwap))
break; //Break loop if all three cipher methods are defined
functionIdentifier = GetFunctionFromLine(line);
var reReverse = $@"{functionIdentifier}:\bfunction\b\(\w+\)"; //Regex for reverse (one parameter)
var reSlice = $@"{functionIdentifier}:\bfunction\b\([a],b\).(\breturn\b)?.?\w+\."; //Regex for slice (return or not)
var reSwap = $@"{functionIdentifier}:\bfunction\b\(\w+\,\w\).\bvar\b.\bc=a\b"; //Regex for the char swap.
if (Regex.Match(js, reReverse).Success)
idReverse = functionIdentifier; //If def matched the regex for reverse then the current function is a defined as the reverse
if (Regex.Match(js, reSlice).Success)
idSlice = functionIdentifier; //If def matched the regex for slice then the current function is defined as the slice.
if (Regex.Match(js, reSwap).Success)
idCharSwap = functionIdentifier; //If def matched the regex for charSwap then the current function is defined as swap.
}
foreach (var line in lines.Skip(1).Take(lines.Length - 2)) {
Match m;
functionIdentifier = GetFunctionFromLine(line);
if ((m = Regex.Match(line, @"\(\w+,(?<index>\d+)\)")).Success && functionIdentifier == idCharSwap)
operations += "w" + m.Groups["index"].Value + " "; //operation is a swap (w)
if ((m = Regex.Match(line, @"\(\w+,(?<index>\d+)\)")).Success && functionIdentifier == idSlice)
operations += "s" + m.Groups["index"].Value + " "; //operation is a slice
if (functionIdentifier == idReverse) //No regex required for reverse (reverse method has no parameters)
operations += "r "; //operation is a reverse
}
operations = operations.Trim();
return DecipherWithOperations(cipher, operations);
}
