bug fix audio codec

zhangmeng

2019-09-26 1f005df2f3ff78458f332f9bf1cf2e78b6a8e8e4

 csrc/worker/decoder.cpp

@@ -92,7 +92,7 @@
    int decoder::SetFrame(std::shared_ptr<ffwrapper::CodedData> data, int64_t &id){

        if (!data) return -1;
        if (decRef_->isAudioPkt(&data->getAVPacket())) return -2;
        if (!decRef_->isVideoPkt(&data->getAVPacket())) return -2;
        
        if (!conv_){
            if (initDecoder() != 0) return -3;