Support for Transcript

[AlmightyLks]

Simple question:

Can you fetch a video's transcription through YoutubeExplode?
If not, why not?

[Tyrrrz]

You mean closed captions?

[AlmightyLks]

Never thought it through tbh, but the transcript should be the captions and its timestamps, yeah

[AlmightyLks]

"Closed Captions" was a good keyword, found my way around :)
Thank you

[AlmightyLks]

@Tyrrrz
Any reason why captions can't be fetched for https://www.youtube.com/watch?v=1VKIIw05JnE ?
"Could not extract caption duration" is the only information given to me by the exception, looking at the captions / transcript on the site manually works

[AlmightyLks]

You're parsing the p-tag's attributes of a caption here:

YoutubeExplode/YoutubeExplode/Bridge/ClosedCaptionExtractor.cs

Lines 24 to 26 in 0ae2b0c

	public TimeSpan? TryGetDuration() => Memo.Cache(this, () =>
	((double?) _content.Attribute("d"))?.Pipe(TimeSpan.FromMilliseconds)
	);

When it doesn't find it however, it throws, here:

YoutubeExplode/YoutubeExplode/Videos/ClosedCaptions/ClosedCaptionClient.cs

Lines 85 to 87 in 46d47b5

	var duration =
	c.TryGetDuration() ??
	throw new YoutubeExplodeException("Could not extract caption duration.");

Looking at https://js-jrod.medium.com/the-first-complete-guide-to-youtube-captions-f886e06f7d9d#6aa6
It states that the d-attribute is mandatory. However, I come across the case that it is missing

Which is where it ends up breaking for me.
Have you come upon this before and/or what is your opinion on how things are?

Not sure whether you don't care about this feature at all or you'd be interested in a change

[Tyrrrz]

Hmm, I could've sworn we skipped captions with no duration 🤔
Can you please submit a PR to change the code you linked ClosedCaptionClient.cs to continue instead of throwing? And also please add your video to the test suite for regression purposes.

[AlmightyLks]

Mind elaborating on "add your video to the test suite"?
Would you like me to add a new test for "download and skip borked auto-generated captions"?

[AlmightyLks]

@Tyrrrz

[Tyrrrz]

Similar to

YoutubeExplode/YoutubeExplode.Tests/ClosedCaptionSpecs.cs

Lines 49 to 63 in 4ef7d50

	[Fact]
	public async Task User_can_get_a_specific_closed_caption_track_from_a_video()
	{
	// Arrange
	var youtube = new YoutubeClient();
	// Act
	var manifest = await youtube.Videos.ClosedCaptions.GetManifestAsync(VideoIds.ContainsClosedCaptions);
	var trackInfo = manifest.GetByLanguage("en-US");
	var track = await youtube.Videos.ClosedCaptions.GetAsync(trackInfo);
	// Assert
	track.Captions.Should().HaveCountGreaterOrEqualTo(500);
	}

except something like User_can_get_a_specific_closed_caption_track_from_a_video_with_broken_autogenerated_captions