swift - 当默认模式兼容所有类别时，AVAudioSession 中其他模式的用途是什么？

Question

// Access the shared, singleton audio session instance
let session = AVAudioSession.sharedInstance()
do {
    // Configure the audio session for movie playback
    try session.setCategory(AVAudioSessionCategoryPlayback,
                            mode: AVAudioSessionModeMoviePlayback,
                            options: [])
} catch let error as NSError {
    print("Failed to set the audio session category and mode: \(error.localizedDescription)")
}

无法理解 Audio Session 中模式的使用。

modes here

Answer 1

其他模式针对特定用途进行了优化。 “兼容”与“最佳”不同。例如，当使用 video chat mode :

the device’s tonal equalization is optimized for voice and the set of allowable audio routes is reduced to only those appropriate for video chat.