static void fill_audiodata(AudioData *out, uint8_t *in_arg [SWR_CH_MAX]){
    int i;
    if(!in_arg){
        memset(out->ch, 0, sizeof(out->ch));
    }else if(out->planar){
        for(i=0; i<out->ch_count; i++)
            out->ch[i]= in_arg[i];
    }else{
        for(i=0; i<out->ch_count; i++)
            out->ch[i]= in_arg[0] + i*out->bps;
    }
}