第1年6月15日 h264/acc硬编码

1.

https://www.jianshu.com/p/0f0fc1ec311a

-(aw_flv_audio_tag *)encodePCMDataToFlvTag:(NSData *)pcmData{
    self.curFramePcmData = pcmData;
    
    //构造输出结构体，编码器需要
    AudioBufferList outAudioBufferList = {0};
    outAudioBufferList.mNumberBuffers = 1;
    outAudioBufferList.mBuffers[0].mNumberChannels = (uint32_t)self.audioConfig.channelCount;
    outAudioBufferList.mBuffers[0].mDataByteSize = self.aMaxOutputFrameSize;
    outAudioBufferList.mBuffers[0].mData = malloc(self.aMaxOutputFrameSize);
    
    uint32_t outputDataPacketSize = 1;
    
    //执行编码，此处需要传一个回调函数aacEncodeInputDataProc，以同步的方式，在回调中填充pcm数据。
    OSStatus status = AudioConverterFillComplexBuffer(_aConverter, aacEncodeInputDataProc, (__bridge void * _Nullable)(self), &outputDataPacketSize, &outAudioBufferList, NULL);
    if (status == noErr) {
        //编码成功，获取数据
        NSData *rawAAC = [NSData dataWithBytes: outAudioBufferList.mBuffers[0].mData length:outAudioBufferList.mBuffers[0].mDataByteSize];
        //时间戳(ms) = 1000 * 每秒采样数 / 采样率;
        self.manager.timestamp += 1024 * 1000 / self.audioConfig.sampleRate;
        //获取到aac数据，转成flv audio tag，发送给服务端。
        return aw_encoder_create_audio_tag((int8_t *)rawAAC.bytes, rawAAC.length, (uint32_t)self.manager.timestamp, &_faacConfig);
    }else{
        //编码错误
        [self onErrorWithCode:AWEncoderErrorCodeAudioEncoderFailed des:@"aac 编码错误"];
    }
    
    return NULL;
}

//回调函数，系统指定格式
static OSStatus aacEncodeInputDataProc(AudioConverterRef inAudioConverter, UInt32 *ioNumberDataPackets, AudioBufferList *ioData, AudioStreamPacketDescription **outDataPacketDescription, void *inUserData){
    AWHWAACEncoder *hwAacEncoder = (__bridge AWHWAACEncoder *)inUserData;
    //将pcm数据交给编码器
    if (hwAacEncoder.curFramePcmData) {
        ioData->mBuffers[0].mData = (void *)hwAacEncoder.curFramePcmData.bytes;
        ioData->mBuffers[0].mDataByteSize = (uint32_t)hwAacEncoder.curFramePcmData.length;
        ioData->mNumberBuffers = 1;
        ioData->mBuffers[0].mNumberChannels = (uint32_t)hwAacEncoder.audioConfig.channelCount;
        
        return noErr;
    }
    
    return -1;
}

2.ios利用mic采集Pcm转为AAC，AudioQueue、AudioUnit(流式)

https://www.jianshu.com/p/e2d072b9e4d8

3.

41.FFmpeg学习笔记 - iOS硬编码pcm到aac

https://blog.csdn.net/whoyouare888/article/details/100034182

二、ffplay播放pcm命令

ffplay -f f32le -ac 2 -ar 48000 ./sintel.pcm

其中f32le是pcm格式，2是声道数，48000是采样率。