Online feature pipeline keeps mfcc features forever

[rosun82]

It seems that the kaldi::OnlineNnet2FeaturePipeline keeps the extracted features forever. Is there any possibilities to add interfaces to release the memory occupied by old features? In such case, the frames ready would become a range.

[danpovey]

That was addressed in #3038. I believe if you put, say, --max-feature-vectors=500 in your mfcc.conf (or whatever type of feature config you have, in that online config directory), it should activate.
Caution: I am not sure if this has been tested with i-vectors + silence-weighting, it's possible that could crash.