THUMOS features frame counts

[thematrixduo]

Hi, I am looking into your uploaded THUMOS features, and it seems it has one less frame than the original video. For example, in your h5 file ,'video_validation_0000051' has 5090 frames, while the original video has 5091 frames. Could you please let me know what causes the difference? I understand that flow features should have 1 less frame, but how is the rgb frames then aligned? Thanks!

[frostinassiky]

Hi @thematrixduo , this is a good catch!

On THUMOS, we extract frames for the video, then extract the feature with stride=1 frame. There can be one frame missing in the process.

As suggested from @Phoenix1327 last year, a better alignment can give us a better representation. (Discussion here) However, 1 frame difference causes less than 0.05-second misalignment, which seems to be acceptable?

[thematrixduo]

I see, Thanks!