The quad sensor MIPI CSI-2 receiver capture pipeline is shown in the
following figure.
Figure 1. Quad MIPI CSI Video Capture Pipeline
- The Avnet Multicamera FMC module bundles fours ON Semi image sensors (AR0231) with GMSL (Gigabit Multimedia Serial Link) serializers (MAX96705) and deserialzer (MAX9286).
- The MIPI CSI-2 subsystem, see the MIPI CSI-2 Receiver Subsystem Product Guide (PG232), captures images from the deserializer in RAW12 format on four lanes and outputs AXI4-Stream video data.
- The AXI subset converter converts the raw 12-bit (RAW12) AXI4-Stream input data to raw 8-bit (RAW8) AXI4-Stream output data by truncating the four least significant bits (LSB) of each data word. The AXIS switch splits the incoming data into four streams using the destination id.
- The ISP IP receives the RAW AXI4-Stream input data and interpolates the missing color components for every pixel to generate a 24-bit, 8 bits per pixel (8 bpc) RGB output image transported via AXI4-Stream.
- The VPSS takes AXI4-Stream input data in 24-bit RGB format and converts it to a 16-bit, 8 bpc YUV 4:2:2 output format.
- The video frame buffer takes YUV 4:2:2 sub-sampled AXI4-Stream input data and converts it to AXI4-MM format which is written to memory as 16-bit packed YUYV.
All of the IPs in this pipeline are configured to transport 2 ppc @ 150
MHz, enabling up to 1920x1080 resolution at 120 fps, or 30 fps per stream.
- Time to transfer one frame: (1920 + 280) x (1080 + 45) / (150 MHz * 2 ppc) = 0.00825 ms
- Number of frames transferred per second = 1/0.00825 = 120 frames
Note: The
AR0231 sensor is limited to 1080p30
applications.