/// <summary>
/// Returns whether the local file should be replaced by the YouTube version.
/// </summary>
/// <param name="localFile">A path to the local file.</param>
/// <param name="serverFile">The information of the available server file.</param>
/// <returns>True if the local file should be replaced.</returns>
public async Task<VideoListItemStatusEnum> IsHigherQualityAvailable(string localFile, BestFormatInfo serverFile) {
// If there is no local file, it should be downloaded.
if (!File.Exists(localFile))
return VideoListItemStatusEnum.HigherQualityAvailable;
// If local file is FLV and there's another format available, it should be downloaded.
string LocalFileExt = Path.GetExtension(localFile).ToLower();
if (LocalFileExt == ".flv" && serverFile.BestVideo.VideoType != VideoType.Flash)
return VideoListItemStatusEnum.HigherQualityAvailable;
// Original VCD files and files of unrecognized extensions should not be replaced.
MediaInfoReader InfoReader = new MediaInfoReader();
await InfoReader.LoadInfoAsync(localFile);
if (!DownloadBusiness.DownloadedExtensions.Contains(LocalFileExt) || InfoReader.VideoFormat == "MPEG Video") {
serverFile.StatusText = "Not from YouTube";
return VideoListItemStatusEnum.OK;
}
// For server file size, estimate 10% extra for audio. Estimate 35% advantage for VP9 format. non-DASH WebM is VP8 and doesn't have that bonus.
long ServerFileSize = (long)(serverFile.BestVideo.FileSize * 1.1);
if (serverFile.BestVideo.VideoType == VideoType.WebM && serverFile.BestVideo.AdaptiveType == AdaptiveType.Video)
ServerFileSize = (long)(ServerFileSize * 1.35);
long LocalFileSize = new FileInfo(localFile).Length;
if (InfoReader.VideoFormat == "VP9")
LocalFileSize = (long)(LocalFileSize * 1.35);
// If server resolution is better, download unless local file is bigger.
int LocalFileHeight = InfoReader.Height ?? 0;
if (serverFile.BestVideo.Resolution > LocalFileHeight) {
if (ServerFileSize > LocalFileSize)
return VideoListItemStatusEnum.HigherQualityAvailable;
else if (ServerFileSize != 0) {
// non-DASH videos have no file size specified, and we won't replace local video with non-DASH video.
serverFile.StatusText = "Local file larger";
return VideoListItemStatusEnum.OK;
}
}
// Is estimated server file size is at least 15% larger than local file (for same resolution), download.
if (ServerFileSize > LocalFileSize * 1.15)
return VideoListItemStatusEnum.HigherQualityAvailable;
// download audio and merge with local video. (that didn't work, ffmpeg failed to merge back)
int? LocalAudioBitRate = InfoReader.AudioBitRate;
int ServerAudioBitRate = serverFile.BestAudio != null ? serverFile.BestAudio.AudioBitrate : serverFile.BestVideo.AudioBitrate;
// Fix a bug where MediaInfo returns no bitrate for MKV containers with AAC audio.
if (LocalAudioBitRate != null || LocalFileExt != ".mkv") {
if ((LocalAudioBitRate == null || LocalAudioBitRate < ServerAudioBitRate * .8) && serverFile.BestVideo.Resolution == LocalFileHeight) {
// Only redownload for audio if video file size is similar. Videos with AdaptiveType=None don't have file size.
if (ServerFileSize > LocalFileSize * .9 && serverFile.BestVideo.AdaptiveType == AdaptiveType.Video) {
serverFile.StatusText = "Audio";
return VideoListItemStatusEnum.HigherQualityAvailable;
} else {
serverFile.StatusText = "";
return VideoListItemStatusEnum.BetterAudioAvailable;
}
}
}
return VideoListItemStatusEnum.OK;
}
/// <summary>
/// Returns the best format from the list in this order of availability: WebM, Mp4 or Flash.
/// Mp4 will be chosen if WebM is over 35% smaller.
/// </summary>
/// <param name="list">The list of videos to chose from.</param>
/// <returns>The best format available.</returns>
public static BestFormatInfo SelectBestFormat(IEnumerable<VideoInfo> list) {
var MaxResolutionList = (from v in list
where (Settings.SavedFile.MaxDownloadQuality == 0 || v.Resolution <= Settings.SavedFile.MaxDownloadQuality)
&& v.AdaptiveType != AdaptiveType.Audio
orderby v.Resolution descending
select v).ToList();
MaxResolutionList = MaxResolutionList.Where(v => v.Resolution == MaxResolutionList.First().Resolution).ToList();
// If for the maximum resolution, only some formats have a file size, the other ones must be queried.
if (MaxResolutionList.Any(v => v.FileSize == 0) && MaxResolutionList.Any(v => v.FileSize > 0)) {
foreach (VideoInfo item in MaxResolutionList.Where(v => v.FileSize == 0)) {
DownloadUrlResolver.QueryStreamSize(item);
}
}
VideoInfo BestVideo = (from v in MaxResolutionList
// WebM VP9 encodes ~35% better. non-DASH is VP8 and isn't better than MP4.
let Preference = (int)((v.VideoType == VideoType.WebM && v.AdaptiveType == AdaptiveType.Video) ? v.FileSize * 1.35 : v.FileSize)
where v.Resolution == MaxResolutionList.First().Resolution
orderby Preference descending
select v).FirstOrDefault();
if (BestVideo != null) {
BestFormatInfo Result = new BestFormatInfo();
Result.BestVideo = BestVideo;
// Even for non-DASH videos, we still want to know what audio is available even though it may not be downloaded.
Result.BestAudio = SelectBestAudio(from v in list
where (v.CanExtractAudio || v.AdaptiveType == AdaptiveType.Audio)
orderby v.AudioBitrate descending
select v);
return Result;
} else
return null;
}