This page provides all the information related to Design Module 3 - VCU TRD Multi stream Audio-Video design.
Table of Contents
|Table of Contents|
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.
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
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.
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
└── rdf0428-zcu106-vcu-trd-2020.-1 ├── apu │ └── vcu_petalinux_bsp │ └── xilinx-vcu-zcu106-v2020.1-final.bsp ├── images │ ├── vcu_audio │ │ ├── autostart.sh │ │ ├── bin │ │ ├── BOOT.BIN │ │ ├── boot.scr │ │ ├── config │ │ ├── image.ub │ │ ├── system.dtb │ │ └── vcu ├── pcie_host_package ├── pl │ ├── constrs │ ├── designs │ │ ├── zcu106_audio │ ├── prebuild │ │ ├── zcu106_audio │ ├── README.md │ └── srcs │ ├── hdl │ └── ip └── README.txt
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)
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.
1.3 Build Flow
Refer below link for Build Flow
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: PetaLinux 2020.1 - Product Update Release Notes and Known Issues
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 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: PetaLinux 2020.1 - Product Update Release Notes and Known Issues
2.3 Optimum VCU Encoder parameters for use-cases:
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
qp-mode=autofor 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
For more detail please refer: https://gstreamer.freedesktop.org/documentation/application-development/advanced/clocks.html?gi-language=c
3 Appendix A - Input Configuration File (input.cfg)
The example configuration files are stored at
It indicates to the application that the configuration is over.
The mount locations for various devices can be found in the below table.
The mount locations can vary. Users can use
mount to find the location of the mounted devices.
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.