Commercial support for spdifrx?

I can successfully receive data from spdifrx via dma with my stm32f769. Unfortunally, the received data are very strange arranged and that is not documented in the specification that manner: Only every 8th word contains a spdif subframe. The meaning of the other 7 words is unknown. You can define a buffer with max 256 words for dma. That means, if you run in a circular dma mode you can only process 16 samples per callback. That isn't much.

I would be glad if ST would take a position as to whether this observed behavior is correct or not. If it is correct please adapt the documentation, and if not, please document, how to read the data from spdifrx per dma without the multiplier of 8.

Thank you.