How to force matlab loading big size v4 .mat file?

For a mysterious reason, eventhough the specification of the v4 version .mat files (according to http://www.mathworks.com/help/matlab/import_export/mat-file-versions.html) states that Maximum Size of Each Variable is 100,000,000 elements per array, and 2^31 bytes per variable, the piscoscope software saves the data of an acquired channel that can reach up to 1 billion samples in v4 .mat files.

When i try to load such files in matlab (R2015b), naturally i get the following error: Error using load Unable to read MAT-file N:\test.mat. File might be corrupt.

Since i need to process this saved data in matlab, i do the following: In python i load the v4 .mat file using the library scipy and then i resave it as a v5 .mat file Now matlab is able to load this latter file.

Is there a way to avoid all this tedious workaround that is very much time consuming (files ~ 4 GB), and have a way to force matlab loading v4 file format even if it is more than 10^8 samples/ variable?

Or can we do this conversion in matlab it self without having to use other programming languages to do the job?

[John D'Errico]

I think you are stuck. MATLAB would actually not read or write that file in -v4 format because of the file size. But you are creating it in that form using a different application. So you will need to convert it to a form that MATLAB will read.

[georges trad]

Thank you John for your answer. Yes, i guess i am stuck. The only way to proceed would be writing a script that would read the .mat file at the binary level following : http://www.mathworks.com/help/pdf_doc/matlab/matfile_format.pdf and then reformatting the file such as matlab is happy...