How to download data without video? Just IMU and keystep annotated.

[qingxinxia]

Hello

Thank you very much for your excellent work.

Could you give me advice about how to download the IMU data that has keystep annotated?

It seems the download tool does not offer such a command to filter video.

Thanks very much for your help!

Best
Cassie

[miguelmartin75]

Hi @qingxinxia

To access IMU stream, you can download the VRS files without image streams (video data). Unfortunately we do not have the IMU pre-extracted, so you will have to use aria data tools Python API to extract it yourself.

You can filter the takes by benchmark via the --benchmarks flag, i.e. --benchmarks keystep

For example here is what your command would look like:

egoexo -o <out-dir> --parts take_vrs_noimagestream --benchmarks keystep

The size of this set is 434.0GiB. Does this work for your use-case?

You can see other file size breakdowns and CLI flag options here: https://docs.ego-exo4d-data.org/download/

Kind regards,
Miguel.

[qingxinxia]

Thank you very much!

I'm waiting for the access key to download.

Hopefully, everything goes well.

[qingxinxia]

Hi @qingxinxia

To access IMU stream, you can download the VRS files without image streams (video data). Unfortunately we do not have the IMU pre-extracted, so you will have to use aria data tools Python API to extract it yourself.

You can filter the takes by benchmark via the --benchmarks flag, i.e. --benchmarks keystep

For example here is what your command would look like:

egoexo -o <out-dir> --parts take_vrs_noimagestream --benchmarks keystep

The size of this set is 434.0GiB. Does this work for your use-case?

You can see other file size breakdowns and CLI flag options here: https://docs.ego-exo4d-data.org/download/

Kind regards, Miguel.

Hello Miguel

Thanks very much for your reply. I recently downloaded the data.

However, after extracting the IMU from vrs file, I found the IMU data really strange.

Could you help me have a look at the data extraction?

Thank you very much.

Here's my code;

import numpy as np
import matplotlib.pyplot as plt
from projectaria_tools.core import data_provider
from projectaria_tools.core.sensor_data import TimeDomain, TimeQueryOptions
from projectaria_tools.core.stream_id import RecordableTypeId, StreamId

vrsfile = r"F:\takes\cmu_bike01_2\aria01_noimagestreams.vrs"
provider = data_provider.create_vrs_data_provider(vrsfile)
assert provider is not None, "Cannot open file"
timestamp, acc, gyro = [], [], []
for data in provider.deliver_queued_sensor_data():
# timestamp, acc, gyro are available
>>if data.sensor_data_type().name == 'IMU':
>>>> acc.append(data.imu_data().accel_msec2)
>>>>timestamp.append(data.imu_data().capture_timestamp_ns)
>>>>gyro.append(data.imu_data().gyro_radsec)`

accnp = np.array(acc)

plt.plot(accnp[:100])
plt.show()