This page provides all the information related to Design Module 11 - VCU Quad Sensor MIPI CSI Video Capture and HDMI Display design.

Table of Contents

1 Overview

This module enables video capture from the quad sensor connected through MIPI CSI-2 Rx implemented in the PL. The Avnet Multi-Camera FMC module is used to capture four video streams through a MIPI CSI-2 interface. The video can be displayed using HDMI Tx through the PL, and can be recorded in SD cards or USB/SATA drives. The module can stream-in or stream-out encoded data through an Ethernet interface. This module supports four video streams using AXI switch at capture side and mixer at display side for NV12 pixel format.

This design supports the following video interfaces:

Sources:

• MIPI CSI-2 Rx capture pipeline implemented in the PL

• File source (SD card, USB storage, SATA hard disk)

• Stream-In from network or internet

Sinks:

• HDMI-Tx display pipeline implemented in the PL

VCU Codec:

• Video Encode/Decode capability using VCU hard block in PL

  • AVC/HEVC encoding

  • Encoder/decoder parameter configuration

Streaming Interfaces:

• 1G Ethernet PS GEM 

Video format:

• NV12

Supported Resolution:

The table below provides the supported resolution from the command-line app in this design.

√- Supported
x - Not supported
NA - Not applicable

The below table gives information about the features supported in this design. 

The below figure shows the VCU Quad Sensor MIPI CSI Multi Stream design hardware block diagram.

Open

The below figure shows the VCU Quad Sensor MIPI CSI Multi Stream design software block diagram.

Open

1.1 Board Setup

Refer below link for Board Setup

• Zynq UltraScale+ MPSoC VCU TRD 2020.2 Board Setup

1.2 Run Flow

The TRD package is released with the source code, Vivado project, Petalinux BSP, and SD card image that enables the user to run the demonstration. It also includes the binaries necessary to configure and boot the ZCU106 board. Prior to running the steps mentioned in this wiki page, download the TRD package and extract its contents to a directory referred to as TRD_HOME which is the home directory.

Refer below link to download all TRD contents.

• Refer Section 4.1 : Download the TRD of Zynq UltraScale+ MPSoC VCU TRD 2020.2 wiki page to download all TRD contents.

TRD package contents are placed in the following directory structure. The user needs to copy all the files from the $TRD_HOME/images/vcu_quad_sensor/ to FAT32 formatted SD card directory.

TRD package contents specific to VCU Quad Sensor MIPI CSI Multi Stream design are placed in the following directory structure.

The below snippet shows the configuration files (input.cfg) for running various multistream Display, Record, and Streaming use cases. All these configurations files are placed in the images folder mentioned above. The directory structure in /media/card.

1.2.1 GStreamer Application (vcu_gst_app)

The vcu_gst_app is a command-line multi-threaded Linux application. The command-line application requires an input configuration file (input.cfg) to be provided in the plain text.

Run below modetest command to set CRTC configurations for 4Kp30:

Execution of the application is shown below:

Example:

4-1080p30 HEVC_HIGH Display Pipeline Execution

4-1080p30 HEVC_HIGH Record Pipeline Execution

4-1080p30 HEVC_HIGH Stream-out Pipeline Execution

4-1080p30 HEVC_HIGH Stream-in Pipeline Execution

Latency Measurement: To measure the latency of the pipeline, run the below command. The latency data is huge, so dump it to a file.

Refer below link for detailed run flow steps

• Zynq UltraScale+ MPSoC VCU TRD 2020.2 - Run Flow

1.3 Build Flow

Refer below link for detailed build flow steps

• Zynq UltraScale+ MPSoC VCU TRD 2020.2 - Build Flow

2 Other Information

2.1 Known Issues

• For Petalinux related known issues please refer: PetaLinux 2020.2 - Product Update Release Notes and Known Issues

• For VCU related known issues please refer AR# 66763: LogiCORE H.264/H.265 Video Codec Unit (VCU) - Release Notes and Known Issues and Xilinx Zynq UltraScale+ MPSoC Video Codec Unit.

• For Out of Memory(OOM) killer error on UART console in long run, please refer to AR# 75900: Why do I see out of memory messages in UART console in long run of VCU TRD multi-stream designs?

2.2 Limitations

• For Petalinux related limitations please refer: PetaLinux 2020.2 - Product Update Release Notes and Known Issues

• For VCU related limitations please refer AR# 66763: LogiCORE H.264/H.265 Video Codec Unit (VCU) - Release Notes and Known Issues, Xilinx Zynq UltraScale+ MPSoC Video Codec Unit and PG252

2.3 Optimum VCU Encoder parameters for use-cases:

Video streaming:

• Video streaming use-case requires a very stable bitrate graph for all pictures

• It is good to avoid periodic large Intra pictures during the encoding session

• Low-latency rate control (hardware RC) is the preferred control-rate for video streaming; as it tries to maintain equal amount frame sizes for all pictures.

• Good to avoid periodic Intra frames instead use low-delay-p (IPPPPP…)

• VBR is not a preferred mode of streaming

Performance: AVC Encoder settings:

• It is preferred to use 8 or higher slices for better AVC encoder performance

• AVC standard does not support Tile mode processing, which results in the processing of MB rows sequentially for entropy coding.

Quality: Low bitrate AVC encoding:

• Enable profile=high and use qp-mode=auto for low-bitrate encoding use-cases

• The high profile enables 8x8 transform which results in better video quality at low bitrates

3 Appendix A - Input Configuration File (input.cfg)

The example configuration files are stored at /media/card/config/ folder.

Mount Locations

The mount locations for various devices can be found in the below table.
The mount locations can vary.  Users can use lsblk or mount to find the location of the mounted devices.

Below are some example mount points

4 Appendix B - CSI-2 Rx/HDMI-Tx Link-up and GStreamer Commands

This section covers configuration of CSI-2 Rx using media-ctl utility and HDMI-Tx using modetest utility, along with demonstrating CSI-2 Rx/HDMI-Tx link-up issues. It also contains sample GStreamer MIPI CSI Video pipelines for Display, Record & Playback, Stream-in and Stream-out use-cases.

• Run the below command for media node to print media device topology where "media0" represents media node.

• When MIPI CSI-2 Rx source is connected, it shows as below:

Notes for gst-launch-1.0 commands:

• Video node for MIPI CSI-2 Rx source can be checked using media-ctl command. Run below media-ctl command to check video node for MIPI CSI-2 Rx source where "media0" indicates media node for MIPI CSI input source.

• Make sure MIPI CSI-2 Rx media pipeline is configured for 1080p resolution and source/sink have the same color format. Run below script to set resolution and format of MIPI CSI-2 Rx media pipeline nodes where "media0" indicates media node for MIPI CSI-2 Rx input source.

If HDMI-Tx link-up issue is observed after Linux booting, use the following command:

• Display RAW use case: Run the following gst-launch-1.0 command to display pass-through pipeline.

• Display serial use case: Run the following gst-launch-1.0 command to display processed pipeline (capture → encode → decode → display) on HDMI-Tx.

• Record use case: Run the following gst-launch-1.0 command to record video using GStreamer pipeline.

• File Playback use case: Run the following gst-launch-1.0 command to play the recorded file on HDMI-Tx using the GStreamer pipeline.

• Stream-out use case: Run the following gst-launch-1.0 command for cbr stream-out pipeline.

• Stream-in use case: Run the following gst-launch-1.0 command to display cbr stream-in on HDMI-Tx video using Gstreamer pipeline where 5004, 5008, 5012 and 5016 are port numbers.