P800 Testitem processing

For the P800 testitem processing, we need to process the items of different categories individually, i.e. in individual runs (separate concatenation/processing per category).

I would propose to set up for this

• different config-files per category, allowing e.g. for different background noise files, SNR, sample-names
• different output (input?) folders per category, in order to avoid issues with processing
• a caller script per experiment, which then calls the item processing per category, and copies all resulting files into a common output directory, which is then ready to be used in the subjective tests