https://www.kecl.ntt.co.jp/icl/lirg/jparacrawl/
ct2-fairseq-converter --model_path big.pretrain.pt --data_dir . --source_lang en --target_lang ja --quantization float16 --output_dir ../converted/jparacrawl-v3-big-ct2-float16/en-ja
ct2-fairseq-converter --model_path ./big/big.pretrain.pt --data_dir ./big --source_lang ja --target_lang en --quantization float16 --output_dir ../converted/jparacrawl-v3-big-ct2-float16/ja-en