load_video gets 0 frame for mp4 file

[yuanyehome]

Hi, when I evaluated on LongVideoBench with the provided command:

python3 -m accelerate.commands.launch \
    --main_process_port 11223 \
    --num_processes=1 -m lmms_eval \
    --model video_llava \
    --tasks longvideobench_val_v \
    --batch_size 1 \
    --log_samples \
    --log_samples_suffix video_llava_lvb_v \
    --output_path ./logs/ \
    --verbosity DEBUG

I got need at least one array to stack error when running lmms_eval/models/model_utils/load_video.py. I think this line may cause this error. For some mp4 files, the metadata doesn't contain the frame information. Is it a bug or is there something wrong with my command?