/// <inheritdoc />
public async Task DownloadAndProcessMediaStreamsAsync(IReadOnlyList <MediaStreamInfo> mediaStreamInfos,
string filePath, string format,
IProgress <double> progress = null,
CancellationToken cancellationToken = default(CancellationToken))
{
mediaStreamInfos.GuardNotNull(nameof(mediaStreamInfos));
filePath.GuardNotNull(nameof(filePath));
format.GuardNotNull(nameof(format));
// Determine if transcoding is required for at least one of the streams
var transcode = mediaStreamInfos.Any(s => IsTranscodingRequired(s.Container, format));
// Set up progress-related stuff
var progressMixer = progress != null ? new ProgressMixer(progress) : null;
var downloadProgressPortion = transcode ? 0.15 : 0.99;
var ffmpegProgressPortion = 1 - downloadProgressPortion;
var totalContentLength = mediaStreamInfos.Sum(s => s.Size);
// Keep track of the downloaded streams
var streamFilePaths = new List <string>();
try
{
// Download all streams
foreach (var streamInfo in mediaStreamInfos)
{
// Generate file path
var streamIndex = streamFilePaths.Count + 1;
var streamFilePath = $"{filePath}.stream-{streamIndex}.tmp";
// Add file path to list
streamFilePaths.Add(streamFilePath);
// Set up download progress handler
var streamDownloadProgress =
progressMixer?.Split(downloadProgressPortion * streamInfo.Size / totalContentLength);
// Download stream
await _youtubeClient.DownloadMediaStreamAsync(streamInfo, streamFilePath, streamDownloadProgress, cancellationToken);
}
// Set up process progress handler
var ffmpegProgress = progressMixer?.Split(ffmpegProgressPortion);
// Process streams (mux/transcode/etc)
await _ffmpeg.ProcessAsync(streamFilePaths, filePath, format, transcode, ffmpegProgress, cancellationToken);
// Report completion in case there are rounding issues in progress reporting
progress?.Report(1);
}
finally
{
// Delete all stream files
foreach (var streamFilePath in streamFilePaths)
{
FileEx.TryDelete(streamFilePath);
}
}
}
