4030 - HLS_COULD_NOT_PARSE_SEGMENT_START_TIME with live content

[alexandercerutti]

Have you read the FAQ and checked for duplicate open issues?

Yes

What version of Shaka Player are you using?

2.5.6

Can you reproduce the issue with our latest release version?

Yes

Can you reproduce the issue with the latest code from master?

Didn't tried.

Are you using the demo app or your own custom app?

Both

If custom app, can you reproduce the issue using our demo app?

https://devstreaming-cdn.apple.com/videos/streaming/examples/img_bipbop_adv_example_ts/master.m3u8

What browser and OS are you using?

Chrome on macOS 10.15.1

What are the manifest and license server URIs?

(explained below the form)

What did you do?

• (explained below the form)

What did you expect to happen?

HLS Content to being reproduced correctly.

What actually happened?

Error messages

===

So, I'm testing for some live HLS streams. I tried with some from our content server and we received this error, along with error 4030 (HLS_COULD_NOT_PARSE_SEGMENT_START_TIME)

So we told ourselves, "okay, so our content server seems to not support like "range" requests (I suppose?), so fallbacks but CORS fail. We have to tell the ones who handle requests. Well, okay...

So we tried to play a sample HLS (VOD) from Apple in your Demo:

https://devstreaming-cdn.apple.com/videos/streaming/examples/img_bipbop_adv_example_ts/master.m3u8

It works perfectly in Safari on its own, but both on Demo and our implemented Player, it fails with the above error 4030.

https://shaka-player-demo.appspot.com/demo/#audiolang=it-IT;textlang=it-IT;asset=https://devstreaming-cdn.apple.com/videos/streaming/examples/img_bipbop_adv_example_ts/master.m3u8;panel=CUSTOM%20CONTENT;build=uncompiled;nativecontrols

We also tried to install mux.js (but we are using webpack, I don't know if, in the final bundle, it got imported before or after Shaka).

We think there might be some kind of problem with Shaka (or it could be something in common with Apple and our stream?).

Thank you.

[alexandercerutti]

So, through the URL above, I went in debug step-by-step in Shaka and discovered that it has an audio track with mimeType audio/aac (which seems to be unsupported yet - see #1083 (comment)).

---

For what concerns our LIVE contents, we found that our streams seems to fail on this line: https://github.com/google/shaka-player/blob/64896d70b0b916e379070b1e99f76efc9b118d71/lib/hls/hls_parser.js#L1793

Any clues on how could this be possible in the streams from our content providers? Do they have to add, edit or do something specific, in your knowledge?

---

Anyway, I looked better at our webpack output bundle and found that mux.js wasn't being imported in it. So, I have fixed that through issue #1927, and I've tested with a known-to-be-working TS stream, that wasn't working without mux.js.

[joeyparrish]

Is it possible that the mime type audio/aac means it's not in a TS container? If that's the case, that would explain why the TS parser fails.

[alexandercerutti]

I actually don't know. I'm not that into these topics 😅. Do you mean TS parser in mux.js?

[joeyparrish]

No, the failure point you linked to in hls_parser.js is in Shaka Player. It's a minimal TS parser that just extracts timestamps from TS segments. That is what seems to be failing.

[TheModMaker]

What's happening is we don't support raw AAC. We can't parse it, so you get a COULD_NOT_PARSE_SEGMENT_START_TIME error. You didn't provide the stream that produces the second error, so I can't be sure; but my guess is the stream has a .ts extension so we assume it is TS, but it may be AAC or another format. If you provided the stream that produced that error, we could diagnose more.

[alexandercerutti]

I'll try to provide you something via email, but I'm not sure I'll be able to provide you something valid since our content (as you can see from the screenshot), passes through akamai and has an expiration time. Meanwhile, thank you.

[alexandercerutti]

@TheModMaker @joeyparrish Okay, I'm going to send you an email a live stream that fails due to PESPacket missing.

Thank you very much!

[joeyparrish]

I was unable to access the stream just now. I got an HTTP 403 error. We can work this out via email, and then resume here. Thanks!

[joeyparrish]

I am able to access your content using an Italian VPN to work around the geo-restriction. I was able to fetch the TS files that we failed to parse, and I can confirm that they look valid in an independent parser.

So this seems to be a bug in the HLS parser's timestamp extraction code for TS segments.

[joeyparrish]

It's not a regression, at least. This content fails in Shaka Player all the way back to v2.3.0, the first HLS-enabled release. There must be something about the structure of the TS segment that our parser has never been able to handle.

[joeyparrish]

This is working now in the nightly build. It was fixed by 1ee3284, which will be cherry-picked to v2.5.9.