如何确定录音源

Posted 2023-02-25

【中文标题】如何确定录音源

【英文标题】：How to determine sound recording source

【发布时间】：2011-05-25 12:39:47

【问题描述】：

在使用我的 iPad 应用录制声音时，我如何知道声音的来源是来自内置麦克风还是耳机麦克风？

附加信息：ios 4.2 及更高版本。

【参考方案1】：

确定的方法是轮询硬件，查询当前音频路由。

使用AudioSessionGetProperty 对象获取音频的路由。

这个example by @TPoschel 应该会让你走上正轨。

- (void)playSound:(id) sender

    if(player)

        CFStringRef route;
        UInt32 propertySize = sizeof(CFStringRef);
        AudioSessionInitialize(NULL, NULL, NULL, NULL);
        AudioSessionGetProperty(kAudioSessionProperty_AudioRoute, &propertySize, &route);

        if((route == NULL) || (CFStringGetLength(route) == 0))
            // Silent Mode
            NSLog(@"AudioRoute: SILENT");
         else 
            NSString* routeStr = (NSString*)route;
            NSLog(@"AudioRoute: %@", routeStr);

            /* Known values of route:
             * "Headset"
             * "Headphone"
             * "Speaker"
             * "SpeakerAndMicrophone"
             * "HeadphonesAndMicrophone"
             * "HeadsetInOut"
             * "ReceiverAndMicrophone"
             * "Lineout"
             */

            NSRange headphoneRange = [routeStr rangeOfString : @"Headphone"];
            NSRange headsetRange = [routeStr rangeOfString : @"Headset"];
            NSRange receiverRange = [routeStr rangeOfString : @"Receiver"];
            NSRange speakerRange = [routeStr rangeOfString : @"Speaker"];
            NSRange lineoutRange = [routeStr rangeOfString : @"Lineout"];

            if (headphoneRange.location != NSNotFound) 
                // Don't change the route if the headphone is plugged in.
             else if(headsetRange.location != NSNotFound) 
                // Don't change the route if the headset is plugged in.
             else if (receiverRange.location != NSNotFound) 
                // Change to play on the speaker
                UInt32 audioRouteOverride = kAudioSessionOverrideAudioRoute_Speaker;
                AudioSessionSetProperty (kAudioSessionProperty_OverrideAudioRoute,sizeof (audioRouteOverride),&audioRouteOverride);
             else if (speakerRange.location != NSNotFound) 
                // Don't change the route if the speaker is currently playing.
             else if (lineoutRange.location != NSNotFound) 
                // Don't change the route if the lineout is plugged in.
             else 
                NSLog(@"Unknown audio route.");
            
        

        [player play];