`This This page provides all the information related to Design Module 3 - VCU TRD Multi stream Audio-Video design.

Table of Contents

1 Overview

The primary goal of this Design is to demonstrate the capabilities of VCU hard block present in Zynq UltraScale+ EV devices with soft audio codec. The TRD will serve as a platform to tune the performance parameters of VCU and arrive at optimal configurations for encoder and decoder blocks with audio-video synchronization.

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The below figure shows the HDMI, MIPI Video Capture  along with HDMI, I2S Audio Capture and HDMI Display with Audio design software block diagram.

                                                         

1.1 Board Setup

Refer below link for Board Setup

• Zynq UltraScale+ MPSoC VCU TRD 2020.1 Board Setup

• I2S Audio. signals from MPSoC PL fabric are connected to PMOD0 GPIO Header (J55 - right angle female connector )

• PMOD I2S2 Add on card connects to J55 connector and its Master/Slave select jumper (JP1) should be placed into the Slave (SLV) position

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 2020.1 wiki page to download all TRD contents.

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rdf0428-zcu106-vcu-trd-2020.-1
    ├── apu
    │   └── vcu_petalinux_bsp
    ├── images
    │   ├── vcu_10g
    │   ├── vcu_audio
    │   ├── vcu_hdmi_multistream_xv20
    │   ├── vcu_hdmi_rx
    │   ├── vcu_hdmi_tx
    │   ├── vcu_llp2_hdmi_nv12
    │   ├── vcu_llp2_hdmi_nv16
    │   ├── vcu_llp2_hdmi_xv20
    │   ├── vcu_llp2_sdi_xv20
    │   ├── vcu_multistream_nv12
    │   ├── vcu_pcie
    │   ├── vcu_sdirx
    │   ├── vcu_sditx
    │   └── vcu_sdi_xv20
    ├── pcie_host_package
    │   ├── COPYING
    │   ├── include
    │   ├── libxdma
    │   ├── LICENSE
    │   ├── readme.txt
    │   ├── RELEASE
    │   ├── tests
    │   ├── tools
    │   └── xdma
    ├── pl
    │   ├── constrs
    │   ├── designs
    │   ├── prebuild
    │   ├── README.md
    │   └── srcs
    └── README.txt

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config
├── 1-4kp60
│   ├── Display
│   ├── Record
│   ├── Stream-in
│   └── Stream-out
├── 2-1080p60
│   ├── Display
│   ├── Record
│   ├── Stream-in
│   └── Stream-out
├── 2-4kp30
│   ├── Display
│   ├── Record
│   ├── Stream-in
│   └── Stream-out
└── input.cfg

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.

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• Zynq UltraScale+ MPSoC VCU TRD 2020.1 - Run Flow

1.3 Build Flow

Refer below link for Build Flow

• Zynq UltraScale+ MPSoC VCU TRD 2020.1 - Build Flow

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2 Other Information

2.1 Known Issues

• Block Noise is observed in AVC_MEDIUM and AVC_LOW in 4Kp60 pipelines

• The digilent PMOD card cannot support the passive source like MICROPHONES. Only active sources are to be connected. Here the source is from the Aux cable which is connected in between the source (laptop) and PMOD card.

• For Petalinux related known issues please refer AR# 72950: PetaLinux 2020.1 - Product Update Release Notes and Known Issues Link will be added <June-05>.

• For VCU related known issues please refer (Link will be added <June-05>) AR# 66763: LogiCORE H.264/H.265 Video Codec Unit (VCU) - Release Notes and Known Issues and Xilinx Zynq UltraScale+ MPSoC Video Codec Unit.

2.2 Limitations

• For playback in DP, video input resolution should match to DP's native resolution. This constraint is due to the support of the GUI. In the GUI case if we allow video source other than native resolution(by setting fullscreen full screen overlay) then the graphics layer will disappear. To recover back GUI user need to kill and relaunch the GUI app. To avoid such condition TRD only supports video input resolution which is equal to DP's native resolution.

• For Petalinux related limitations please refer AR# 72950: PetaLinux 2020.1 - Product Update Release Notes and Known Issues Link will be added <June-05>.

• For VCU related limitations please refer (Link will be added <June-05>) 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 Link will be added <June-05>.

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, 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

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• 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 bitrate

2.4 Audio-Video Synchronization

Clocks and synchronization in GStreamer

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For more detail please refer: https://gstreamer.freedesktop.org/documentation/application-development/advanced/clocks.html?gi-language=c

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

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

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Slice:
The number of slices produced for each frame. Each slice contains one or more complete macroblock/CTU row(s). Slices are distributed over the frame as regularly as possible. If slice-size is defined as well more slices may be produced to fit the slice-size requirement.
Options:
4-22 4K 4Kp resolution with HEVC codec
4-32 4K 4Kp resolution with AVC codec
4-32 1080p resolution with HEVC codec
4-32 1080p resolution with AVC codec

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Exit
It indicates to the application that the configuration is over.

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.

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

This section covers configuration of HDMI-Rx using media-ctl utility and HDMI-Tx using modetest utility, along with demonstrating HDMI-Rx/Tx link-up issues and steps to switch HDMI-Rx resolution. It also contains sample GStreamer HDMI Audio+Video (also I2S Audio + MIPI CSI Video pipelines for Display, Record & Playback, Stream-in and Stream-out use-cases.

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• Run the following command to check the current resolution of SCD nodesnode (here media1 have combined SCD node with Video0).

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• Display RAW use case for HDMI: Run the following gst-launch-1.0 command to capture and display passthrough pass-through HDMI video and Audio using the GStreamer pipeline.

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