media: venus: implementing multi-stream support
This is implementing multi-stream decoder support. The multi-stream will be used to enable/disable the primary/secondary decoder outputs. Depending on formats on both decoder outputs we could implement downscale, dithering and supporting UBWC (universal bandwidth compression) formats. The UBWC compressed raw format is used to optimize interconnect bandwidth for bigger resolutions like 4K and hence we will get some power-saving benefits as well. Both decoder outputs are distinguished by buffer_type field in the HFI packets. For example HFI_BUFFER_OUTPUT is the buffer type for primary decoder output and HFI_BUFFER_OUTPUT2 is for secondary decoder output. Starting from Venus 4xx the DPB buffers format must be UBWC, so the multi-stream becomes mandatory for this Venus version. That means that we need to allocate internally in the driver a set of DPB buffers (with UBWC NV12 format) and give them to the firmware. The other decoder output (we called it OPB) format will be NV12 linear format and with the same resolution (or smaller in case the user wants to downscale). The DPB buffers are used for decoder reference frames and those have to be in a specific format (UBWC). So one decoder output is used to fill those reference buffers while the other output is used to fill the userspace buffers with the user requested format. Signed-off-by: Stanimir Varbanov <stanimir.varbanov@linaro.org> Reviewed-by: Tomasz Figa <tfiga@chromium.org> Reviewed-by: Alexandre Courbot <acourbot@chromium.org> Tested-by: Alexandre Courbot <acourbot@chromium.org> Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com> Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>
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