current encode audio

    //Get the data and encode
    while (true)
    {
        pkt.data = NULL; // packet data will be allocated by the encoder
        pkt.size = 0;

        ret = avcodec_fill_audio_frame(frame, c->channels, c->sample_fmt, (const uint8_t*)samples, buffer_size, 0);

        /* encode the samples */
        ret = avcodec_encode_audio2(c, &pkt, frame, &got_output);
        if (ret < 0)
        {
            fprintf(stderr, "error encoding audio frame\n");
            exit(1);
        }

        if (got_output) {
            fwrite(pkt.data, 1, pkt.size, f);
            av_free_packet(&pkt);
        }

        //Refill the sample buffer
        if((audio->size() - vectorPosition) < buffer_size)
        {
            memcpy(samples, &audio->at(vectorPosition), (audio->size() - vectorPosition));
            vectorPosition += (audio->size() - vectorPosition);
        }
        else
        {
            memcpy(samples, &audio->at(vectorPosition), buffer_size);
            vectorPosition += buffer_size;
        }
    }