LSA-T: The first continuous LSA dataset

LSA-T is the first continuous Argentinian Sign Language (LSA) dataset. It contains ~22 hs of video extracted from the CN Sordos YouTube channel with spanish subtitles, joints for each signer and the infered signer if there is more than one person in a clip. Videos are in 30 FPS full HD (1920x1080). We’ve also developed Seni.ar, a platform for exploring, validating and augmenting LSA-T.

Files and format

meta.csv

This file contains labels and extra metadata for the 8459 clips. It contains the following columns:

id: id of the clip. It’s used as the name of the mp4 file and the key for its keypoints.
label: the spanish translation of the clip.
video: title of the video which the clip belongs to.
playlist: title of the playlist which the clip belongs to.
start: time in seconds where the clip starts (respect to the video).
end: time in seconds where the clip ends (respect to the video).
duration: duration of the clip in seconds.
splits: clips are cropped according to sentences. Sentences might be split into many pieces of subtitles, so data of this splits is kept as a list of tuples containing (piece_of_subtitle, start, end). start and end are stored as time in seconds respect to the whole video.
prev_delta: as sometimes cropping clips according to the subtitles timestamp resulted in cropping signs, a time delta was added. By default is of 0.5 secs, unless there is another clip that ends nearer the video, in that case, the distance of the ending time of the previous clip and current clip’s starting time it’s used as delta.
post_delta: same as prev_delta but at the end of each clip.
signers_amount: amount of people (potential signers) present in the clip (detected by YOLOv8).
infered_signer: id of the person infered to be the signer (used to identify it’s keypoints in the keypoints file).
infered_signer_confidence: confidence of the semi automatic signer inference (from 0 to 1).
movement_per_signer: amount of movement computed for each signer.

clips.7z

Contains the clips in mp4, full HD 30 FPS. Their name matches their id in the labels.csv file.

joints.h5

Contains the joints for each person in each clip and their bounding boxes. The hdf5 dataset contains a group for each clip (accesed by the clip’s id) and then a group for each signer (ids as signer_i).

Each keypoint is represented as x,y,z,confidence.

Statistics and comparison with other DBs (original paper version)

	LSA-T	PHOENIX*	SIGNUM	CSL	GSL	KETI
language	Spanish	German	German	Chinese	Greek	Korean
sign language	LSA	GSL	GSL	CSL	GSL	KLS
real life	Yes	Yes	No	No	No	No
signers	103	9	25	50	7	14
duration (h)	21.78	10.71	55.3	100+	9.51	28
# samples	14,880	7096	33,210	25,000	10,295	14,672
# unique sentences	14,254	5672	780	100	331	105
% unique sentences	95.79%	79.93%	2.35%	0.4%	3.21%	0.71%
vocab. size (w)	14,239	2887	N/A	178	N/A	419
# singletons (w)	7150	1077	0	0	0	0
% singletons (w)	50.21%	37.3%	0%	0%	0%	0%
vocab. size (gl)	-	1066	450	-	310	524
# singletons (gl)	-	337	0	-	0	0
# singletons (gl)	-	31.61%	0%	-	0%	0%
resolution	1920x1080	210x260	776x578	1920x1080	848x480	1920x1080
fps	30	25	30	30	30	30

Usage

Deprecated, working in a new version of the loader

This repository can be installed via pip and contains the LSA_Dataset class (in lsat.dataset.LSA_Dataset module). This class inherits from the Pytorch dataset class and implements all necessary methods for using it with a Pytorch dataloader. It also manages the downloading and extraction of the database.

Also, useful transforms for the clips and keypoints are provided in lsat.dataset.transforms

Citation

@inproceedings{dal2022lsa,
    title={Lsa-t: The first continuous argentinian sign language dataset for sign language translation},
    author={Dal Bianco, Pedro and R{\'\i}os, Gast{\'o}n and Ronchetti, Franco and Quiroga, Facundo and Stanchi, Oscar and Hasperu{\'e}, Waldo and Rosete, Alejandro},
    booktitle={Ibero-American Conference on Artificial Intelligence},
    pages={293--304},
    year={2022},
    organization={Springer}
}