Question

是否可以将音频输出重定向到手机扬声器并仍然使用麦克风耳机输入？

如果我将音频路线重定向到手机扬声器而不是耳机，它也会重定向麦克风。这是有道理的，但我似乎只能重新定向麦克风输入？有什么想法吗？

以下是我用来将音频重定向到发言人的代码：

UInt32 doChangeDefaultRoute = true;        
propertySetError = AudioSessionSetProperty(kAudioSessionProperty_OverrideCategoryDefaultToSpeaker, sizeof(doChangeDefaultRoute), &doChangeDefaultRoute);
NSAssert(propertySetError == 0, @"Failed to set audio session property: OverrideCategoryDefaultToSpeaker");
UInt32 audioRouteOverride = kAudioSessionOverrideAudioRoute_Speaker;
AudioSessionSetProperty (kAudioSessionProperty_OverrideAudioRoute,sizeof (audioRouteOverride),&audioRouteOverride);

Answer 1

这是可能的，但是如何设置它是很挑剔的。

[[AVAudioSession sharedInstance] setCategory:AVAudioSessionCategoryPlayAndRecord error:nil];
UInt32 audioRouteOverride = kAudioSessionOverrideAudioRoute_Speaker;
AudioSessionSetProperty(kAudioSessionProperty_OverrideAudioRoute, sizeof(audioRouteOverride), &audioRouteOverride);

使用AVAudioSessionCategoryPlayAndRecord非常重要，否则路线将无法转到演讲者。一旦为音频会话设置了覆盖路由，就可以使用AVAudioPlayer实例并将一些输出发送给扬声器。

希望对我这样的人有用。关于此的文档是分散的，但Skype应用证明它是可能的。坚持不懈，我的朋友们！：）

这里有一些Apple文档：http://developer.apple.com/library/ios/#documentation/AudioToolbox/Reference/AudioSessionServicesReference/Reference/reference.html

在页面上搜索kAudioSessionProperty_OverrideAudioRoute

Answer 2

它看起来不可能，我很害怕。

来自Audio Session Programming Guide - kAudioSessionProperty_OverrideAudioRoute

如果在设置此属性的值时已插入耳机到kAudioSessionOverrideAudioRoute_Speaker，系统改变了输入和输出的音频路由：输入来自内置麦克风;输出到内置扬声器。

this question

可能重复

Answer 3

您可以做的是在任何情况下强制音频输出到扬声器：

来自UI Hacker - iOS: Force audio output to speakers while headphones are plugged in

@interface AudioRouter : NSObject

+ (void) initAudioSessionRouting;
+ (void) switchToDefaultHardware;
+ (void) forceOutputToBuiltInSpeakers;

@end

和

#import "AudioRouter.h"
#import <AudioToolbox/AudioToolbox.h>
#import <AVFoundation/AVFoundation.h>

@implementation AudioRouter

#define IS_DEBUGGING NO
#define IS_DEBUGGING_EXTRA_INFO NO

+ (void) initAudioSessionRouting {

    // Called once to route all audio through speakers, even if something's plugged into the headphone jack
    static BOOL audioSessionSetup = NO;
    if (audioSessionSetup == NO) {

        // set category to accept properties assigned below
        NSError *sessionError = nil;
        [[AVAudioSession sharedInstance] setCategory:AVAudioSessionCategoryPlayAndRecord withOptions:AVAudioSessionCategoryOptionDefaultToSpeaker error: &sessionError];

        // Doubly force audio to come out of speaker
        UInt32 audioRouteOverride = kAudioSessionOverrideAudioRoute_Speaker;
        AudioSessionSetProperty (kAudioSessionProperty_OverrideAudioRoute, sizeof(audioRouteOverride), &audioRouteOverride);

        // fix issue with audio interrupting video recording - allow audio to mix on top of other media
        UInt32 doSetProperty = 1;
        AudioSessionSetProperty (kAudioSessionProperty_OverrideCategoryMixWithOthers, sizeof(doSetProperty), &doSetProperty);

        // set active
        [[AVAudioSession sharedInstance] setDelegate:self];
        [[AVAudioSession sharedInstance] setActive: YES error: nil];

        // add listener for audio input changes
        AudioSessionAddPropertyListener (kAudioSessionProperty_AudioRouteChange, onAudioRouteChange, nil );
        AudioSessionAddPropertyListener (kAudioSessionProperty_AudioInputAvailable, onAudioRouteChange, nil );

    }

    // Force audio to come out of speaker
    [[AVAudioSession sharedInstance] overrideOutputAudioPort:AVAudioSessionPortOverrideSpeaker error:nil];


    // set flag
    audioSessionSetup = YES;
}

+ (void) switchToDefaultHardware {
    // Remove forcing to built-in speaker
    UInt32 audioRouteOverride = kAudioSessionOverrideAudioRoute_None;
    AudioSessionSetProperty (kAudioSessionProperty_OverrideAudioRoute, sizeof(audioRouteOverride), &audioRouteOverride);
}

+ (void) forceOutputToBuiltInSpeakers {
    // Re-force audio to come out of speaker
    UInt32 audioRouteOverride = kAudioSessionOverrideAudioRoute_Speaker;
    AudioSessionSetProperty (kAudioSessionProperty_OverrideAudioRoute, sizeof(audioRouteOverride), &audioRouteOverride);


}

void onAudioRouteChange (void* clientData, AudioSessionPropertyID inID, UInt32 dataSize, const void* inData) {

    if( IS_DEBUGGING == YES ) {
        NSLog(@"==== Audio Harware Status ====");
        NSLog(@"Current Input:  %@", [AudioRouter getAudioSessionInput]);
        NSLog(@"Current Output: %@", [AudioRouter getAudioSessionOutput]);
        NSLog(@"Current hardware route: %@", [AudioRouter getAudioSessionRoute]);
        NSLog(@"==============================");
    }

    if( IS_DEBUGGING_EXTRA_INFO == YES ) {
        NSLog(@"==== Audio Harware Status (EXTENDED) ====");
        CFDictionaryRef dict = (CFDictionaryRef)inData;
        CFNumberRef reason = CFDictionaryGetValue(dict, kAudioSession_RouteChangeKey_Reason);
        CFDictionaryRef oldRoute = CFDictionaryGetValue(dict, kAudioSession_AudioRouteChangeKey_PreviousRouteDescription);
        CFDictionaryRef newRoute = CFDictionaryGetValue(dict, kAudioSession_AudioRouteChangeKey_CurrentRouteDescription);
        NSLog(@"Audio old route: %@", oldRoute);
        NSLog(@"Audio new route: %@", newRoute);
        NSLog(@"=========================================");
    }



}

+ (NSString*) getAudioSessionInput {
    UInt32 routeSize;
    AudioSessionGetPropertySize(kAudioSessionProperty_AudioRouteDescription, &routeSize);
    CFDictionaryRef desc; // this is the dictionary to contain descriptions

    // make the call to get the audio description and populate the desc dictionary
    AudioSessionGetProperty (kAudioSessionProperty_AudioRouteDescription, &routeSize, &desc);

    // the dictionary contains 2 keys, for input and output. Get output array
    CFArrayRef outputs = CFDictionaryGetValue(desc, kAudioSession_AudioRouteKey_Inputs);

    // the output array contains 1 element - a dictionary
    CFDictionaryRef diction = CFArrayGetValueAtIndex(outputs, 0);

    // get the output description from the dictionary
    CFStringRef input = CFDictionaryGetValue(diction, kAudioSession_AudioRouteKey_Type);
    return [NSString stringWithFormat:@"%@", input];
}

+ (NSString*) getAudioSessionOutput {
    UInt32 routeSize;
    AudioSessionGetPropertySize(kAudioSessionProperty_AudioRouteDescription, &routeSize);
    CFDictionaryRef desc; // this is the dictionary to contain descriptions

    // make the call to get the audio description and populate the desc dictionary
    AudioSessionGetProperty (kAudioSessionProperty_AudioRouteDescription, &routeSize, &desc);

    // the dictionary contains 2 keys, for input and output. Get output array
    CFArrayRef outputs = CFDictionaryGetValue(desc, kAudioSession_AudioRouteKey_Outputs);

    // the output array contains 1 element - a dictionary
    CFDictionaryRef diction = CFArrayGetValueAtIndex(outputs, 0);

    // get the output description from the dictionary
    CFStringRef output = CFDictionaryGetValue(diction, kAudioSession_AudioRouteKey_Type);
    return [NSString stringWithFormat:@"%@", output];
}

+ (NSString*) getAudioSessionRoute {
    /*
     returns the current session route:
     * ReceiverAndMicrophone
     * HeadsetInOut
     * Headset
     * HeadphonesAndMicrophone
     * Headphone
     * SpeakerAndMicrophone
     * Speaker
     * HeadsetBT
     * LineInOut
     * Lineout
     * Default
    */

    UInt32 rSize = sizeof (CFStringRef);
    CFStringRef route;
    AudioSessionGetProperty (kAudioSessionProperty_AudioRoute, &rSize, &route);

    if (route == NULL) {
        NSLog(@"Silent switch is currently on");
        return @"None";
    }
    return [NSString stringWithFormat:@"%@", route];
}

@end

将音频输出重定向到手机扬声器和麦克风输入到耳机

3 个答案: