Issue using SGDMA to frame buffer

Since it's a single channel DMA the easiest way would be to have multiple DMAs assuming all the video feeds are concurrent. If you only need to write one video frame at a time to memory then a single DMA should be sufficient along with a streaming mux that selects the appropriate input.

If the video streams are concurrent and you wanted to use a single DMA then you would need to break each frame down into smaller transfers and constantly feed descriptors into the DMA cycling through each video input a portion of a frame at a time. Of course you'll need a large enough buffer for each video input to hold the incoming data while other video inputs are being written out to memory.