Some streams can return 404

[Tyrrrz]

Version

master

Platform

.NET 8

Steps to reproduce

var streamManifest = await _youtube.Videos.Streams.GetManifestAsync("JQgKhZZyBYg");
var streamInfo = streamManifest.GetMuxedStreams().MaxBy(s => s.VideoQuality);

// This fails
await _youtube.Videos.Streams.DownloadAsync(streamInfo, "video.mp4");

Details

Looks like one of the muxed streams (720p mp4) returns 404 when accessed.

Originally reported at Tyrrrz/YoutubeDownloader#406

Checklist

• I have looked through existing issues to make sure that this bug has not been reported before
• I have provided a descriptive title for this issue
• I have made sure that this bug is reproducible on the latest version of the package
• I have provided all the information needed to reproduce this bug as efficiently as possible
• I have sponsored this project

[Tyrrrz]

A bit more detail into what's happening. The stream does not immediately return 404, which is why it's not filtered out by this check in the StreamClient:

YoutubeExplode/YoutubeExplode/Videos/Streams/StreamClient.cs

Lines 85 to 87 in 49ce828

	// Stream cannot be accessed
	if (contentLength <= 0)
	continue;

Instead, what actually happens is that the stream initially serves data, up to a certain point:

Then, at some point, the underlying ContentLengthReadStream class throws an exception, indicating that the stream has mismatched content length:

After that, MediaStream attempts to re-initialize the last segment, on the off chance that this is a transient error. This time, the stream returns 404 instead, most likely because the new values of the range parameter are out of bounds.

Worth noting that even Chrome fails to read this stream, due to content length mismatch:

The bottom line is that this stream is broken, but it's currently not filtered out because the issue appears later on in the stream's lifecycle.

[QINGCHARLES]

Wow, what a weird error. I can only guess YouTube's encoder failed for some reason and pushed out a broken file that none of their systems are set up to check for.

There is not much for you to do in your code. The best you could do is indicate to the user somehow that they should try the stream again but select a different stream type to download and it might work.

[Tyrrrz]

Looks like I found a way to filter them out. I'll release a new update on Thursday.

[QINGCHARLES]

You're a star, thank you.