Loading AIST++ data

[Jhc-china]

When training the CrossCondGPT2 using cc_motion_gpt.yaml config and loading the AIST++ data using load_data_aist[line 538] in ./utils/functional.py, I'm confusing to the for loop in line 572.
Because of 8 downsample rate, the np_music feature current read is at 7.5fps, while the np_dance is at 60fps. However, in the for loop, the seq_len is associate with np_music, and the step for range(...) is move(which is 8 in the config yaml), the step for np_music is i/music_sample_rate (the music_sample_rate I think is also 8), the step for np_dance is 8. As a result, the music training sample is actually step by 1 frame in the range(...) loop. If the music sample step by 1 frame, we should get len(np_music) training sample. But the step in range(....) is 8, len(np_music) - len(np_music)//8 training sample is left behind.
In a nutshell, I think the split function in for loop doesn't match.