The VPDMA requires a channel to be setup for each group of transfers. All the channels are described through a Data Transfer Descriptor that has a common format. The client that the channel is mapped to interprets the information in the descriptor to perform the requested data transfer.
Each of the channels has a type of data that it can support based upon the client that it services. The VPDMA supports four types of channels:
- YUV Channel - Clients taking data YUV data
- RGB Channel - Clients taking RGB data
- Miscellaneous Channel - The Miscellaneous channel type is for any data type that is not a normal video type. The Miscellaneous channel type makes no assumptions on data type and just passes the data to the client and supports a single buffer for the client.
- Free Channel - Used in video compositions. The Free channel data type is always ignored as it uses the same data type of the descriptor that first calls the free channel.