Sporadic 403 errors in the middle of reading a stream

[Tyrrrz]

Version

v6.2.13 / master

Details

Trying to download a media stream can sometimes result in a 403 error. This happens sporadically and can sometimes happen in the middle of the stream. Once that happens, the stream URL becomes unusable, as all further attempts also result in a 403 error.

First reported here: Tyrrrz/YoutubeDownloader#333

Steps to reproduce

• Use the DemoWpf project
• Resolve stream manifest for youtube.com/watch?v=6XM7BgoQdhU
• Download the first video-only stream
• Get an error at some point during the process
• If there's no error, try downloading the same stream again (it usually fails every other time)

[Tyrrrz]

Looks like my initial analysis was a bit inaccurate. The error always happens at the beginning of the stream (on the call to MediaStream.InitializeAsync()), but only if that stream (or any other stream from the same manifest) has been read in full.

The original issue (Tyrrrz/YoutubeDownloader#333) suggested that the streams were failing in the middle because the app downloads two streams one after another (audio then video) and only the second one fails.

The error seems to only happen with the ANDROID client, but not the TVHTML5_SIMPLY_EMBEDDED_PLAYER client. We can just switch to using the latter for all requests, but it's a bit heavier and yields a different set of streams (most notably, much fewer muxed streams).

Note that using TVHTML5_SIMPLY_EMBEDDED_PLAYER is also not a very good option because occasionally it returns streams with the n parameter, and we don't support n-signature deciphering yet: #706.

[Tyrrrz]

I found that using ANDROID_TESTSUITE instead of the ANDROID client appears to work, at least for now. Going to use that as the solution.