[Bug] Streaming Audio takes too long to load and stream

[dsilva-adastra]

Describe the bug

Hello everyone,

I have an issue with streaming audio with Readium. I have an audio file that takes 30 seconds to load the Publication object and another 20 seconds to start streaming after calling the play method.

I don't know if I am doing something wrong.
I attached a sample project that reproduces the issue
I am using Swift 6

Any help is appreciated. Thank you

How to reproduce?

1. Open the Sample project
2. Run it on a simulator or device of your choice (running in the preview also works)
3. You have to wait for 30 seconds until you can play the file
4. You have to wait at least 20 seconds until the playback starts

Readium version

3.2.0

OS version

iOS 17.6+

Testing device

Any device of emulator

Environment

macOS: 15.4
platform: arm64
Xcode 16.3
Build version 16E140

Additional context

ReadiumStreaming.zip

[mickael-menu]

The URL in the project you shared does not seem to be available anymore (the server timed out)

https://davidjares.eu/wp-content/uploads/2025/04/01-Prolog-Cesta-z-ni%CC%81z%CC%8C-neni%CC%81-na%CC%81vratu.mp3

It might be a server issue if your server is too slow to return the bytes. Otherwise I think it might be a duplicate of this other issue: #579

[dsilva-adastra]

@mickael-menu thank you for your reply. I don't know, maybe the server was down at that time, the link works for me, and it's part of a website. It's an audio of more than one hour of playback, which takes a lot of time to start.

I implement my AVPlayer logic, and the playback begins immediately. Strangely, Readium takes so long to load the file and then play it. Even for smaller audio files like this Audio File, it still takes a few seconds to load, whereas when I use the AVPlayer directly, it's instantaneously.

I did a little debugging and the open publication code is stuck for 30 seconds (with the original audio) in this method private func makeReadingOrder(for container: Container) async -> Result<[(AnyURL, Format)], PublicationParseError> after that it's considered loaded, but it still takes several seconds to play.

Thank you again for your reply and I will check the other issue.

[mickael-menu]

Thank you for investigating, that's really helpful. I will try to take a look into the makeReadingOrder code next week.