multimedia

多媒体处理

音频

音频会话配置

import AVFoundation

func configureAudioSession(category: AVAudioSession.Category = .playAndRecord) {
    let session = AVAudioSession.sharedInstance()
    do {
        try session.setCategory(category, mode: .default, options: [.defaultToSpeaker, .allowBluetooth])
        try session.setActive(true)
    } catch {
        Logger.error("音频会话配置失败: \(error)")
    }
}

场景与 Category 对照

场景	Category	Mode	Options
录音	.playAndRecord	.default	.defaultToSpeaker
播放音乐	.playback	.default	-
语音通话	.playAndRecord	.voiceChat	.allowBluetooth
后台播放	.playback	.default	需 Background Modes → Audio
静音开关跟随	.ambient	.default	-

音频录制

final class AudioRecorder: NSObject {
    private var recorder: AVAudioRecorder?
    private var recordingURL: URL?

    func startRecording(to url: URL) throws {
        configureAudioSession(category: .playAndRecord)
        let settings: [String: Any] = [
            AVFormatIDKey: Int(kAudioFormatMPEG4AAC),
            AVSampleRateKey: 44100.0,
            AVNumberOfChannelsKey: 1,
            AVEncoderAudioQualityKey: AVAudioQuality.high.rawValue
        ]
        recorder = try AVAudioRecorder(url: url, settings: settings)
        recorder?.record()
        recordingURL = url
    }

    func stopRecording() -> URL? {
        recorder?.stop()
        return recordingURL
    }

    var isRecording: Bool { recorder?.isRecording ?? false }

    var currentTime: TimeInterval { recorder?.currentTime ?? 0 }
}

音频播放

final class AudioPlayer {
    private var player: AVAudioPlayer?

    func play(url: URL) {
        configureAudioSession(category: .playback)
        do {
            player = try AVAudioPlayer(contentsOf: url)
            player?.play()
        } catch {
            Logger.error("音频播放失败: \(error)")
        }
    }

    func stop() {
        player?.stop()
        player = nil
    }

    var isPlaying: Bool { player?.isPlaying ?? false }

    var duration: TimeInterval { player?.duration ?? 0 }

    var currentTime: TimeInterval { player?.currentTime ?? 0 }
}