Ios 如何更改iPhone发送到蜂窝网络的语音数据

我有一个在iPhone中记录语音通话的代码。我试图改变进入蜂窝网络的数据。具体来说，我认为在语音数据在dsp中进行调制并准备发送到蜂窝网络后，我需要访问这些数据

我想对已经被调制的数据应用一些流密码

这门课适合找吗？欢迎提出任何建议

源代码

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我认为你无法访问这些数据。我的代码所做的是钩子重采样过程。音频流在进入基带之前被重新采样。在那之后，他们直接进入基带，我想应该在那里进行调制。iOS不能访问蜂窝网络，quallcomm基带可以访问蜂窝网络，它有自己的CPU、操作系统、内存空间、DSP、天线等。iOS和基带通过特殊的接口和协议进行通信，它们是完全不同的两件事。@creker如果你听到由代码录制的麦克风声音，是经过调制的，听起来很像电话。所以我怀疑压缩已经完成了？@john_bassos重新采样已经完成了，但是它需要被压缩，可能是AMR和调制的GMSK，或者是通过空气传输的东西。我不记得AMR压缩在我的钩子所在的地方进行过，我甚至不认为它是在软件中完成的，而是硬件加速的。我在发送方的麦克风数据中做了一个简单的xor。在通话的另一边，我听到了失真的声音，但我能理解对方说的话。问题是，如果我用相同的数字在接收器xor上再次执行相反的过程，我会得到一个更扭曲的结果！你知道为什么会发生这种情况，或者我应该在audiounitprocess之前挂接一个函数吗？在//写入音频缓冲区之后，添加：if currentFile==&micFile{}，并将转换应用到该范围内的ioData

#import <AudioToolbox/AudioToolbox.h>
#import <libkern/OSAtomic.h>

//CoreTelephony.framework
extern "C" CFStringRef const kCTCallStatusChangeNotification;
extern "C" CFStringRef const kCTCallStatus;
extern "C" id CTTelephonyCenterGetDefault();
extern "C" void CTTelephonyCenterAddObserver(id ct, void* observer, CFNotificationCallback callBack, CFStringRef name, void *object, CFNotificationSuspensionBehavior sb);
extern "C" int CTGetCurrentCallCount();
enum
{
    kCTCallStatusActive = 1,
    kCTCallStatusHeld = 2,
    kCTCallStatusOutgoing = 3,
    kCTCallStatusIncoming = 4,
    kCTCallStatusHanged = 5
};

NSString* kMicFilePath = @"/var/mobile/Media/DCIM/mic.caf";
NSString* kSpeakerFilePath = @"/var/mobile/Media/DCIM/speaker.caf";
NSString* kResultFilePath = @"/var/mobile/Media/DCIM/result.m4a";

OSSpinLock phoneCallIsActiveLock = 0;
OSSpinLock speakerLock = 0;
OSSpinLock micLock = 0;

ExtAudioFileRef micFile = NULL;
ExtAudioFileRef speakerFile = NULL;

BOOL phoneCallIsActive = NO;

void Convert()
{
    //File URLs
    CFURLRef micUrl = CFURLCreateWithFileSystemPath(NULL, (CFStringRef)kMicFilePath, kCFURLPOSIXPathStyle, false);
    CFURLRef speakerUrl = CFURLCreateWithFileSystemPath(NULL, (CFStringRef)kSpeakerFilePath, kCFURLPOSIXPathStyle, false);
    CFURLRef mixUrl = CFURLCreateWithFileSystemPath(NULL, (CFStringRef)kResultFilePath, kCFURLPOSIXPathStyle, false);

    ExtAudioFileRef micFile = NULL;
    ExtAudioFileRef speakerFile = NULL;
    ExtAudioFileRef mixFile = NULL;

    //Opening input files (speaker and mic)
    ExtAudioFileOpenURL(micUrl, &micFile);
    ExtAudioFileOpenURL(speakerUrl, &speakerFile);

    //Reading input file audio format (mono LPCM)
    AudioStreamBasicDescription inputFormat, outputFormat;
    UInt32 descSize = sizeof(inputFormat);
    ExtAudioFileGetProperty(micFile, kExtAudioFileProperty_FileDataFormat, &descSize, &inputFormat);
    int sampleSize = inputFormat.mBytesPerFrame;

    //Filling input stream format for output file (stereo LPCM)
    FillOutASBDForLPCM(inputFormat, inputFormat.mSampleRate, 2, inputFormat.mBitsPerChannel, inputFormat.mBitsPerChannel, true, false, false);

    //Filling output file audio format (AAC)
    memset(&outputFormat, 0, sizeof(outputFormat));
    outputFormat.mFormatID = kAudioFormatMPEG4AAC;
    outputFormat.mSampleRate = 8000;
    outputFormat.mFormatFlags = kMPEG4Object_AAC_Main;
    outputFormat.mChannelsPerFrame = 2;

    //Opening output file
    ExtAudioFileCreateWithURL(mixUrl, kAudioFileM4AType, &outputFormat, NULL, kAudioFileFlags_EraseFile, &mixFile);
    ExtAudioFileSetProperty(mixFile, kExtAudioFileProperty_ClientDataFormat, sizeof(inputFormat), &inputFormat);

    //Freeing URLs
    CFRelease(micUrl);
    CFRelease(speakerUrl);
    CFRelease(mixUrl);

    //Setting up audio buffers
    int bufferSizeInSamples = 64 * 1024;

    AudioBufferList micBuffer;
    micBuffer.mNumberBuffers = 1;
    micBuffer.mBuffers[0].mNumberChannels = 1;
    micBuffer.mBuffers[0].mDataByteSize = sampleSize * bufferSizeInSamples;
    micBuffer.mBuffers[0].mData = malloc(micBuffer.mBuffers[0].mDataByteSize);

    AudioBufferList speakerBuffer;
    speakerBuffer.mNumberBuffers = 1;
    speakerBuffer.mBuffers[0].mNumberChannels = 1;
    speakerBuffer.mBuffers[0].mDataByteSize = sampleSize * bufferSizeInSamples;
    speakerBuffer.mBuffers[0].mData = malloc(speakerBuffer.mBuffers[0].mDataByteSize);

    AudioBufferList mixBuffer;
    mixBuffer.mNumberBuffers = 1;
    mixBuffer.mBuffers[0].mNumberChannels = 2;
    mixBuffer.mBuffers[0].mDataByteSize = sampleSize * bufferSizeInSamples * 2;
    mixBuffer.mBuffers[0].mData = malloc(mixBuffer.mBuffers[0].mDataByteSize);

    //Converting
    while (true)
    {
        //Reading data from input files
        UInt32 framesToRead = bufferSizeInSamples;
        ExtAudioFileRead(micFile, &framesToRead, &micBuffer);
        ExtAudioFileRead(speakerFile, &framesToRead, &speakerBuffer);
        if (framesToRead == 0)
        {
            break;
        }

        //Building interleaved stereo buffer - left channel is mic, right - speaker
        for (int i = 0; i < framesToRead; i++)
        {
            memcpy((char*)mixBuffer.mBuffers[0].mData + i * sampleSize * 2, (char*)micBuffer.mBuffers[0].mData + i * sampleSize, sampleSize);
            memcpy((char*)mixBuffer.mBuffers[0].mData + i * sampleSize * 2 + sampleSize, (char*)speakerBuffer.mBuffers[0].mData + i * sampleSize, sampleSize);
        }

        //Writing to output file - LPCM will be converted to AAC
        ExtAudioFileWrite(mixFile, framesToRead, &mixBuffer);
    }

    //Closing files
    ExtAudioFileDispose(micFile);
    ExtAudioFileDispose(speakerFile);
    ExtAudioFileDispose(mixFile);

    //Freeing audio buffers
    free(micBuffer.mBuffers[0].mData);
    free(speakerBuffer.mBuffers[0].mData);
    free(mixBuffer.mBuffers[0].mData);
}

void Cleanup()
{
    [[NSFileManager defaultManager] removeItemAtPath:kMicFilePath error:NULL];
    [[NSFileManager defaultManager] removeItemAtPath:kSpeakerFilePath error:NULL];
}

void CoreTelephonyNotificationCallback(CFNotificationCenterRef center, void *observer, CFStringRef name, const void *object, CFDictionaryRef userInfo)
{
    NSDictionary* data = (NSDictionary*)userInfo;

    if ([(NSString*)name isEqualToString:(NSString*)kCTCallStatusChangeNotification])
    {
        int currentCallStatus = [data[(NSString*)kCTCallStatus] integerValue];

        if (currentCallStatus == kCTCallStatusOutgoing || currentCallStatus == kCTCallStatusActive)
        {
            OSSpinLockLock(&phoneCallIsActiveLock);
            phoneCallIsActive = YES;
            OSSpinLockUnlock(&phoneCallIsActiveLock);
        }
        else if (currentCallStatus == kCTCallStatusHanged)
        {
            if (CTGetCurrentCallCount() > 0)
            {
                return;
            }

            OSSpinLockLock(&phoneCallIsActiveLock);
            phoneCallIsActive = NO;
            OSSpinLockUnlock(&phoneCallIsActiveLock);

            //Closing mic file
            OSSpinLockLock(&micLock);
            if (micFile != NULL)
            {
                ExtAudioFileDispose(micFile);
            }
            micFile = NULL;
            OSSpinLockUnlock(&micLock);

            //Closing speaker file
            OSSpinLockLock(&speakerLock);
            if (speakerFile != NULL)
            {
                ExtAudioFileDispose(speakerFile);
            }
            speakerFile = NULL;
            OSSpinLockUnlock(&speakerLock);

            Convert();
            Cleanup();
        }
    }
}

OSStatus(*AudioUnitProcess_orig)(AudioUnit unit, AudioUnitRenderActionFlags *ioActionFlags, const AudioTimeStamp *inTimeStamp, UInt32 inNumberFrames, AudioBufferList *ioData);
OSStatus AudioUnitProcess_hook(AudioUnit unit, AudioUnitRenderActionFlags *ioActionFlags, const AudioTimeStamp *inTimeStamp, UInt32 inNumberFrames, AudioBufferList *ioData)
{
    OSSpinLockLock(&phoneCallIsActiveLock);
    if (phoneCallIsActive == NO)
    {
        OSSpinLockUnlock(&phoneCallIsActiveLock);
        return AudioUnitProcess_orig(unit, ioActionFlags, inTimeStamp, inNumberFrames, ioData);
    }
    OSSpinLockUnlock(&phoneCallIsActiveLock);

    ExtAudioFileRef* currentFile = NULL;
    OSSpinLock* currentLock = NULL;

    AudioComponentDescription unitDescription = {0};
    AudioComponentGetDescription(AudioComponentInstanceGetComponent(unit), &unitDescription);
    //'agcc', 'mbdp' - iPhone 4S, iPhone 5
    //'agc2', 'vrq2' - iPhone 5C, iPhone 5S
    if (unitDescription.componentSubType == 'agcc' || unitDescription.componentSubType == 'agc2')
    {
        currentFile = &micFile;
        currentLock = &micLock;
    }
    else if (unitDescription.componentSubType == 'mbdp' || unitDescription.componentSubType == 'vrq2')
    {
        currentFile = &speakerFile;
        currentLock = &speakerLock;
    }

    if (currentFile != NULL)
    {
        OSSpinLockLock(currentLock);

        //Opening file
        if (*currentFile == NULL)
        {
            //Obtaining input audio format
            AudioStreamBasicDescription desc;
            UInt32 descSize = sizeof(desc);
            AudioUnitGetProperty(unit, kAudioUnitProperty_StreamFormat, kAudioUnitScope_Input, 0, &desc, &descSize);

            //Opening audio file
            CFURLRef url = CFURLCreateWithFileSystemPath(NULL, (CFStringRef)((currentFile == &micFile) ? kMicFilePath : kSpeakerFilePath), kCFURLPOSIXPathStyle, false);
            ExtAudioFileRef audioFile = NULL;
            OSStatus result = ExtAudioFileCreateWithURL(url, kAudioFileCAFType, &desc, NULL, kAudioFileFlags_EraseFile, &audioFile);
            if (result != 0)
            {
                *currentFile = NULL;
            }
            else
            {
                *currentFile = audioFile;

                //Writing audio format
                ExtAudioFileSetProperty(*currentFile, kExtAudioFileProperty_ClientDataFormat, sizeof(desc), &desc);
            }
            CFRelease(url);
        }
        else
        {
            //Writing audio buffer
            ExtAudioFileWrite(*currentFile, inNumberFrames, ioData);
        }

        OSSpinLockUnlock(currentLock);
    }

    return AudioUnitProcess_orig(unit, ioActionFlags, inTimeStamp, inNumberFrames, ioData);
}

__attribute__((constructor))
static void initialize()
{
    CTTelephonyCenterAddObserver(CTTelephonyCenterGetDefault(), NULL, CoreTelephonyNotificationCallback, NULL, NULL, CFNotificationSuspensionBehaviorHold);

    MSHookFunction(AudioUnitProcess, AudioUnitProcess_hook, &AudioUnitProcess_orig);
}