How to extract all elements of sequential numpy file?

[noamsgl]

Describe the question.

Hi,

I am using fn.readers.numpy(files=file_names) to read a list of .npy files. Each file includes a chunk of frames. Each file has a 3D layout 'FCH' (frame, channel, height) where C and H are constant but F might differ between files.

I would like to instruct DALI that each CH slice should be an individual sample on the output.

I have tried to use nvidia.dali.fn.element_extract however this requires me to determine element_map in advance and request specific indices. How can I instead extract all the elements of each file, essentially dechunking and then rebatching with the intended training batch size?

Check for duplicates

• [X] I have searched the open bugs/issues and have found no duplicates for this bug report