/// <summary>
/// Selects best media streams for the specified video, downloads them, and processes into a single file.
/// </summary>
public static async Task DownloadAsync(
this VideoClient videoClient,
VideoId videoId,
ConversionRequest request,
IProgress <double>?progress = null,
CancellationToken cancellationToken = default)
{
var streamManifest = await videoClient.Streams.GetManifestAsync(videoId);
var streamInfos = GetBestMediaStreamInfos(streamManifest, request.Format).ToArray();
await videoClient.DownloadAsync(
streamInfos,
request,
progress,
cancellationToken
);
}
/// <summary>
/// Downloads specified media streams and processes them into a single file.
/// </summary>
public static async ValueTask DownloadAsync(
this VideoClient videoClient,
IReadOnlyList <IStreamInfo> streamInfos,
ConversionRequest request,
IProgress <double>?progress = null,
CancellationToken cancellationToken = default)
{
Platform.EnsureDesktop();
// Ensure that the provided stream collection is not empty
if (!streamInfos.Any())
{
throw new InvalidOperationException("No streams provided.");
}
// If all streams have the same container as the output format, then transcoding is not required
var isTranscodingRequired = streamInfos.Any(s => IsTranscodingRequired(s.Container, request.Format));
// Progress setup
var progressMixer = progress?.Pipe(p => new ProgressMixer(p));
var downloadProgressPortion = isTranscodingRequired ? 0.15 : 0.99;
var totalStreamSize = streamInfos.Sum(s => s.Size.Bytes);
// Temp files for streams
var streamFilePaths = new List <string>(streamInfos.Count);
try
{
// Download streams
foreach (var streamInfo in streamInfos)
{
var streamIndex = streamFilePaths.Count + 1;
var streamFilePath = $"{request.OutputFilePath}.stream-{streamIndex}.tmp";
streamFilePaths.Add(streamFilePath);
var streamDownloadProgress = progressMixer?.Split(
downloadProgressPortion * streamInfo.Size.Bytes / totalStreamSize
);
await videoClient.Streams.DownloadAsync(
streamInfo,
streamFilePath,
streamDownloadProgress,
cancellationToken
).ConfigureAwait(false);
}
// Mux/convert streams
var conversionProgress = progressMixer?.Split(1 - downloadProgressPortion);
await new FFmpeg(request.FFmpegCliFilePath).ExecuteAsync(
streamFilePaths,
request.OutputFilePath,
request.Format.Name,
request.Preset.ToString().ToLowerInvariant(),
isTranscodingRequired,
conversionProgress,
cancellationToken
).ConfigureAwait(false);
progress?.Report(1);
}
finally
{
// Delete temp files
foreach (var streamFilePath in streamFilePaths)
{
try
{
File.Delete(streamFilePath);
}
catch
{
// Try our best but don't crash
}
}
}
}