This page provides all the information related to Design Module 8 - VCU TRD Xilinx low latency(LLP2) PL DDR NV16 HDMI design.

1 Overview

This module enables capture of video from an HDMI-Rx subsystem implemented in the PL. The video can be displayed through the HDMI-Tx subsystem implemented in the PL. The module can stream-out and stream-in live captured video frames through an Ethernet interface at ultra-low latencies using Sync IP. This module supports four video streams using AXI broadcaster at capture side and mixer at display side for NV16 pixel format. In this design PL_DDR is used for decoding and PS_DDR for encoding so that DDR bandwidth would be enough to support high bandwidth VCU applications requiring simultaneous encoder and decoder operations and transcoding at 4k @60 FPS.

The VCU encoder and decoder operate in slice mode. An input frame is divided into multiple slices (8 or 16) horizontally. The encoder generates a slice_done interrupt at every end of the slice. Generated NAL unit data can be passed to a downstream element immediately without waiting for the frame_done interrupt. The VCU decoder also starts processing data as soon as one slice of data is ready in its circular buffer instead of waiting for complete frame data. The Sync IP does an AXI transaction-level tracking so that the producer and consumer can be synchronized at the granularity of AXI transactions instead of granularity at the video buffer level. Sync IP is responsible for synchronizing buffers between Capture DMA and VCU encoder as both work on same buffer.

The capture element (FB write DMA) writes video buffers in raster-scan order. SyncIP monitors the buffer level while the capture element is writing into DRAM and allows the encoder to read input buffer data if the requested data is already written by DMA, otherwise it blocks the encoder until DMA completes its writes. On the decoder side, the VCU decoder writes decoded video buffer data into DRAM in block-raster scan order and displays reads data in raster-scan order. To avoid display under-run problems, software ensures a phase difference of "~frame_period/2", so that decoder is ahead compare to display.

This design supports the following video interfaces:

Sources:

HDMI-Rx capture pipeline implemented in the PL.
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.

Video format:

NV16

Supported Resolution:

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

Resolution	Command Line
Resolution	Single Stream	Multi-stream
4kp60	√	NA
4kp30	√	√ (Max 2)
1080p60	√	√ (Max 4 for encoder) (Max 2 for decoder)

√ - Supported
NA – Not applicable
x – Not supported

note

When using Low Latency mode (LLP1/LLP2), The encoder and decoder are limited by the number of internal cores. The encoder has a maximum of four streams and the decoder has a maximum of two streams.

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

Pipeline	Input source	Format	Output Type	Resolution	VCU codec
Serial pipeline	HDMI-Rx	NV16	HDMI-Tx	4kp60/4kp30/1080p60	HEVC/AVC
Stream-Out pipeline	HDMI-Rx	NV16	Stream-Out	4kp60/4kp30/1080p60	HEVC/AVC
Stream-in pipeline	Stream-In	NV16	HDMI-Tx	4kp60/4kp30/1080p60	HEVC/AVC

The below figure shows the Xilinx Low Latency PL DDR NV16 HDMI design hardware block diagram.

Xilinx Wiki > Zynq UltraScale+ MPSoC VCU TRD 2020.1 - Xilinx Low Latency PL DDR NV16 HDMI Video Capture and Display > image2020-5-25_15-44-2.png

The below figure shows the Xilinx Low Latency PL DDR NV16 HDMI design software block diagram.

Xilinx Wiki > Zynq UltraScale+ MPSoC VCU TRD 2020.1 - Xilinx Low Latency PL DDR NV16 HDMI Video Capture and Display > NV16(1).png

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 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_llp2_hdmi_nv16/ to FAT32 formatted SD card directory.

rdf0428-zcu106-vcu-trd-2020.2/
├── apu
│   └── vcu_petalinux_bsp
├── images
│   ├── vcu_10g
│   ├── vcu_audio
│   ├── vcu_hdr10_hdmi
│   ├── vcu_llp2_hdmi_nv12
│   ├── vcu_llp2_hdmi_nv16
│   ├── vcu_llp2_hdmi_xv20
│   ├── vcu_llp2_sdi_xv20
│   ├── vcu_multistream_nv12
│   ├── vcu_pcie
│   ├── vcu_quad_sensor
│   └── vcu_sdi_xv20
├── pcie_host_package
│   ├── COPYING
│   ├── include
│   ├── LICENSE
│   ├── readme.txt
│   ├── RELEASE
│   ├── tests
│   ├── tools
│   └── xdma
├── pl
│   ├── constrs
│   ├── designs
│   ├── prebuild
│   ├── README.md
│   └── srcs
└── README.txt

TRD package contents specific to VCU Xilinx Low Latency PL DDR NV16 HDMI design are placed in the following directory structure.

rdf0428-zcu106-vcu-trd-2020-2
├── apu
│   └── vcu_petalinux_bsp
│       └── xilinx-vcu-zcu106-v2020.2-final.bsp
├── images
│   ├── vcu_llp2_hdmi_nv16
│   │   ├── autostart.sh
│   │   ├── BOOT.BIN
│   │   ├── boot.scr
│   │   ├── config
│   │   ├── image.ub
│   │   ├── system.dtb
│   │   └── vcu
├── pcie_host_package
├── pl
│   ├── constrs
│   ├── designs
│   │   ├── zcu106_llp2_nv16
│   ├── prebuild
│   │   ├── zcu106_llp2_nv16
│   ├── README.md
│   └── srcs
│       ├── hdl
│       └── ip
└── README.txt

Configuration files(input.cfg) for various resolutions are placed in the following directory structure in /media/card.

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

Run below modetest command to set CRTC configurations for 4kp60:

$ modetest -D a00c0000.v_mix -s 39:3840x2160-60@BG24

Run below modetest command to set CRTC configurations for 4kp30:

$ modetest -D a00c0000.v_mix -s 39:3840x2160-30@BG24

Execution of the application is shown below:

$ vcu_gst_app < path to *.cfg file>

Example:

note

Make sure HDMI-Rx should be configured to 4kp60 mode, while running below example pipelines.
Low latency(LLP1/LLP2) stream-in pipelines are not supported in vcu_gst_app.

Make sure HDMI-Rx should be configured to 4kp60 mode, while running below example pipelines.
Low latency(LLP1/LLP2) stream-in pipelines are not supported in vcu_gst_app.

4kp60 NV16 HEVC_25Mbps ultra low-latency(LLP2) display pipeline execution.

$ vcu_gst_app /media/card/config/1-4kp60/Display/Single_4kp60_HEVC_25_Mbps.cfg

4kp60 NV16 HEVC_25Mbps ultra low-latency(LLP2) stream-out pipeline execution.

$ vcu_gst_app /media/card/config/1-4kp60/Stream-out/Single_4kp60_HEVC_25_Mbps.cfg

4kp60 NV16 HEVC ultra low-latency(LLP2) stream-in pipeline execution.

$ gst-launch-1.0 udpsrc port=5004 buffer-size=60000000 caps="application/x-rtp, media=video, clock-rate=90000, payload=96, encoding-name=H265" ! rtpjitterbuffer latency=7 ! rtph265depay ! h265parse ! video/x-h265, alignment=nal ! omxh265dec low-latency=1 ! video/x-raw\(memory:XLNXLL\) ! queue max-size-bytes=0 ! fpsdisplaysink name=fpssink text-overlay=false video-sink="kmssink bus-id=a00c0000.v_mix" sync=true -v

For LLP1/LLP2 Multistream HEVC serial and stream-out use-cases (2-4kp30, 2-1080p60, 4-1080p60), use ENC_EXTRA_OP_BUFFERS=10 variable before vcu_gst_app command. Below is the sample pipeline:

$ ENC_EXTRA_OP_BUFFERS=10 vcu_gst_app /media/card/config/2-4kp30/Display/2_4kp30_HEVC_12_5_Mbps.cfg

note

The above variable is recommended to use for LLP1/LLP2 multi-stream HEVC use-cases only.

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

$ GST_DEBUG="GST_TRACER:7" GST_TRACERS="latency" GST_DEBUG_FILE=/run/latency.log vcu_gst_app /media/card/config/< path to *.cfg 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.
To reduce performance issues with llp2 4x serial pipelines, please refer to chapter# 40 of Section VI: Appendices for IRQ Balancing scheme in PG252.
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 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.

Performance: AVC Encoder settings:

It is preferred to use 8 slices only 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.

Configuration Type	Configuration Name	Description	Available Options	Note
Common	Common configuration	It is the starting point of common configuration
	Number of Input		1,2,3,4
	Output	Select the video interface	HDMI
	Out Type		display and stream
	Display Rate	Pipeline frame rate	30 or 60 FPS
	Exit	It indicates to the application that the configuration is over
Input	Input Configuration	It is the starting point of the input configuration
	Input Numbers	Starting N^th input configuration	1, 2, 3, 4
	Input Type	Input Type	HDMI
	Raw	To tell the pipeline is processed or pass-through	FALSE	Raw use-case is not supported for both LLP2 and non-LLP2 use-case as mixer is not connected to PS DDR
	Width	The width of the live source	3840, 1920
	Height	The height of the live source	2160,1080
	Format	The format of input data	NV16
	Enable LLP2	To enable LLP2 configuration.	TRUE, FALSE	Set Enable LLP2 equals to False for non-LLP2 use-case.
	Exit	It indicates to the application that the configuration is over
Encoder	Encoder Configuration	It is the starting point of encoder configuration
	Encoder Number	Starting N^th encoder configuration	1,2,3,4
	Encoder Name	Name of the encoder	AVC/HEVC
	Profile	Name of the profile	high for AVC main for HEVC
	Rate Control	Rate control options	low_latency
	Filler Data	Filler Data NAL units for CBR rate control	False
	QP	QP control mode used by the VCU encoder	Uniform, Auto
	L2 Cache	Enable or Disable L2Cache buffer in encoding process	True, False
	Latency Mode	Encoder latency mode	sub_frame
	Low Bandwidth	If enabled, decrease the vertical search range used for P-frame motion estimation to reduce the bandwidth	True, False
	Gop Mode	Group of Pictures mode.	Basic, low_delay_p, low_delay_b
	Bitrate	Target bitrate in Kbps	1-25000
	B Frames	Number of B-frames between two consecutive P-frames	0
	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.	4-22 4K resolution with HEVC codec 4-32 4K resolution with AVC codec 4-32 1080p resolution with HEVC codec 4-32 1080p resolution with AVC codec	The recommended slice for LLP2 use-case is 8.
	GoP Length	The distance between two consecutive I frames	1-1000
	GDR Mode	It specifies which Gradual Decoder Refresh(GDR) scheme should be used when gop-mode = low_delay_p	Horizontal/Vertical/Disabled	GDR mode is currently supported with LLP1/LLP2 low-delay-p use-cases only
	Entropy Mode	It specifies the entropy mode for H.264 (AVC) encoding process	CAVLC/CABAC/Default
	Max Picture Size	It is used to curtail instantaneous peak in the bit-stream using this parameter. It works in CBR/VBR rate-control only. When it is enabled, max-picture-size value is calculated and set with 10% of AllowedPeakMargin. i.e. `max-picture-size = (TargetBitrate / FrameRate) * 1.1`	TRUE/FALSE
	Preset		Custom
	Exit	It indicates to the application that the configuration is over
Streaming	Streaming Configuration	It is the starting point of streaming configuration
	Streaming Number	Starting N^th Streaming configuration	1, 2, 3, 4
	Host IP	The host to send the packets to	192.168.25.89 or Windows PC IP
	Port	The port to send the packets to	5004, 5008, 5012 and 5016
	Exit	It indicates to the application that the configuration is over
Trace	Trace Configuration	It is the starting point of trace configuration
	FPS Info	To display fps info on the console	True, False
	APM Info	To display APM counter number on the console	True, False
	Pipeline Info	To display pipeline info on console	True, False
	Exit	It indicates to the application that the configuration is over

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 Low-Latency NV16 and Xilinx’s Ultra Low-Latency NV16 Video pipelines for Display, Stream-In and Stream-Out use-cases.

HDMI source can be locked to any resolution. Run the below command for all media nodes to print media device topology where mediaX represents different media nodes. In the topology, log look for the v_hdmi_rx_ss string to identify the HDMI input source media node.

$ media-ctl -p -d /dev/mediaX

To check the link status, resolution and video node of the HDMI input source, run below media-ctl command where mediaX indicates media node for the HDMI input source.

$ media-ctl -p -d /dev/mediaX

When HDMI source is connected to 4KP60 resolution, it shows:

root@zcu106_vcu_llp2_nv16:~# media-ctl -p -d /dev/media0 -----> media node for HDMI input source
Media controller API version 5.4.0

Media device information
------------------------
driver          xilinx-video
model           Xilinx Video Composite Device
serial          
bus info        
hw revision     0x0
driver version  5.4.0

Device topology
- entity 1: vcapaxis_broad_out1hdmi_input_a (1 pad, 1 link)
            type Node subtype V4L flags 0
            device node name /dev/video0      ----> Video node for HDMI-RX source
	pad0: Sink
		<- "amba_pl@0:axis_broadcasterhdmi_":1 [ENABLED]

- entity 5: vcapaxis_broad_out1hdmi_input_a (1 pad, 1 link)
            type Node subtype V4L flags 0
            device node name /dev/video1
	pad0: Sink
		<- "amba_pl@0:axis_broadcasterhdmi_":2 [ENABLED]

- entity 9: vcapaxis_broad_out1hdmi_input_a (1 pad, 1 link)
            type Node subtype V4L flags 0
            device node name /dev/video2
	pad0: Sink
		<- "amba_pl@0:axis_broadcasterhdmi_":3 [ENABLED]

- entity 13: vcapaxis_broad_out1hdmi_input_a (1 pad, 1 link)
             type Node subtype V4L flags 0
             device node name /dev/video3
	pad0: Sink
		<- "amba_pl@0:axis_broadcasterhdmi_":4 [ENABLED]

- entity 17: amba_pl@0:axis_broadcasterhdmi_ (5 pads, 5 links)
             type V4L2 subdev subtype Unknown flags 0
             device node name /dev/v4l-subdev0
	pad0: Sink
		[fmt:UYVY8_1X16/3840x2160 field:none]
		<- "a0040000.v_proc_ss":1 [ENABLED]
	pad1: Source
		[fmt:UYVY8_1X16/3840x2160 field:none]
		-> "vcapaxis_broad_out1hdmi_input_a":0 [ENABLED]
	pad2: Source
		[fmt:UYVY8_1X16/3840x2160 field:none]
		-> "vcapaxis_broad_out1hdmi_input_a":0 [ENABLED]
	pad3: Source
		[fmt:UYVY8_1X16/3840x2160 field:none]
		-> "vcapaxis_broad_out1hdmi_input_a":0 [ENABLED]
	pad4: Source
		[fmt:UYVY8_1X16/3840x2160 field:none]
		-> "vcapaxis_broad_out1hdmi_input_a":0 [ENABLED]

- entity 23: a0040000.v_proc_ss (2 pads, 2 links)
             type V4L2 subdev subtype Unknown flags 0
             device node name /dev/v4l-subdev1
	pad0: Sink
		[fmt:RBG888_1X24/3840x2160 field:none]
		<- "a0000000.v_hdmi_rx_ss":0 [ENABLED]
	pad1: Source
		[fmt:UYVY8_1X16/3840x2160 field:none]
		-> "amba_pl@0:axis_broadcasterhdmi_":0 [ENABLED]

- entity 26: a0000000.v_hdmi_rx_ss (1 pad, 1 link)
             type V4L2 subdev subtype Unknown flags 0
             device node name /dev/v4l-subdev2
	pad0: Source
		[fmt:RBG888_1X24/3840x2160 field:none]
		[dv.caps:BT.656/1120 min:0x0@25000000 max:4096x2160@297000000 stds:CEA-861,DMT,CVT,GTF caps:progressive,reduced-blanking,custom]
		[dv.detect:BT.656/1120 3840x2160p60 (4400x2250) stds:CEA-861 flags:CE-video]
		-> "a0040000.v_proc_ss":0 [ENABLED]

note

Check resolution and frame-rate of dv.detect under v_hdmi_rx_ss node.

When the HDMI source is not connected, it shows:

root@zcu106_vcu_llp2_nv16:~# media-ctl -p -d /dev/media0    -----> media node for HDMI input source
Media controller API version 5.4.0

Media device information
------------------------
driver          xilinx-video
model           Xilinx Video Composite Device
serial          
bus info        
hw revision     0x0
driver version  5.4.0

Device topology
- entity 1: vcapaxis_broad_out1hdmi_input_a (1 pad, 1 link)
            type Node subtype V4L flags 0
            device node name /dev/video0    ----> Video node for HDMI-RX source
	pad0: Sink
		<- "amba_pl@0:axis_broadcasterhdmi_":1 [ENABLED]

- entity 5: vcapaxis_broad_out1hdmi_input_a (1 pad, 1 link)
            type Node subtype V4L flags 0
            device node name /dev/video1
	pad0: Sink
		<- "amba_pl@0:axis_broadcasterhdmi_":2 [ENABLED]

- entity 9: vcapaxis_broad_out1hdmi_input_a (1 pad, 1 link)
            type Node subtype V4L flags 0
            device node name /dev/video2
	pad0: Sink
		<- "amba_pl@0:axis_broadcasterhdmi_":3 [ENABLED]

- entity 13: vcapaxis_broad_out1hdmi_input_a (1 pad, 1 link)
             type Node subtype V4L flags 0
             device node name /dev/video3
	pad0: Sink
		<- "amba_pl@0:axis_broadcasterhdmi_":4 [ENABLED]

- entity 17: amba_pl@0:axis_broadcasterhdmi_ (5 pads, 5 links)
             type V4L2 subdev subtype Unknown flags 0
             device node name /dev/v4l-subdev0
	pad0: Sink
		[fmt:UYVY8_1X16/3840x2160 field:none]
		<- "a0040000.v_proc_ss":1 [ENABLED]
	pad1: Source
		[fmt:UYVY8_1X16/3840x2160 field:none]
		-> "vcapaxis_broad_out1hdmi_input_a":0 [ENABLED]
	pad2: Source
		[fmt:UYVY8_1X16/3840x2160 field:none]
		-> "vcapaxis_broad_out1hdmi_input_a":0 [ENABLED]
	pad3: Source
		[fmt:UYVY8_1X16/3840x2160 field:none]
		-> "vcapaxis_broad_out1hdmi_input_a":0 [ENABLED]
	pad4: Source
		[fmt:UYVY8_1X16/3840x2160 field:none]
		-> "vcapaxis_broad_out1hdmi_input_a":0 [ENABLED]

- entity 23: a0040000.v_proc_ss (2 pads, 2 links)
             type V4L2 subdev subtype Unknown flags 0
             device node name /dev/v4l-subdev1
	pad0: Sink
		[fmt:RBG888_1X24/3840x2160 field:none]
		<- "a0000000.v_hdmi_rx_ss":0 [ENABLED]
	pad1: Source
		[fmt:UYVY8_1X16/3840x2160 field:none]
		-> "amba_pl@0:axis_broadcasterhdmi_":0 [ENABLED]

- entity 26: a0000000.v_hdmi_rx_ss (1 pad, 1 link)
             type V4L2 subdev subtype Unknown flags 0
             device node name /dev/v4l-subdev2
	pad0: Source
		[fmt:RBG888_1X24/3840x2160 field:none]
		[dv.caps:BT.656/1120 min:0x0@25000000 max:4096x2160@297000000 stds:CEA-861,DMT,CVT,GTF caps:progressive,reduced-blanking,custom]
		[dv.query:no-link]		----> HDMI-RX Link status
		-> "a0040000.v_proc_ss":0 [ENABLED]

note

dv.query:no-link under v_hdmi_rx_ss node shows HDMI-Rx source is not connected or HDMI-Rx source is not active (Try waking up the device by pressing a key on remote).

Notes for gst-launch-1.0 commands:

Video node for HDMI-Rx source can be checked using media-ctl command. Run below media-ctl command to check video node for HDMI-Rx source where media3 indicates media node for HDMI input source.

$ media-ctl -p -d /dev/media0

Make sure HDMI-Rx media pipeline is configured for 4kp60 resolution and source/sink have the same color format for connected nodes. For NV16 format, run below media-ctl commands to set resolution and format of HDMI scaler node where media0 indicates media node for HDMI input source.
When HDMI Input Source is NVIDIA SHIELD

$ media-ctl -d /dev/media0 -V "\"a0040000.v_proc_ss\":0 [fmt:RBG888_1X24/3840x2160 field:none]"
$ media-ctl -d /dev/media0 -V "\"a0040000.v_proc_ss\":1 [fmt:UYVY8_1X16/3840x2160 field:none]"

note

Make sure NVIDIA SHIELD is configured for 4kp resolution and RBG888_1X24 format.

Follow the below steps to switch the HDMI-Rx resolution from 1080p60 to 4kp60.
- Check current HDMI input source resolution (1080p60) by following the steps mentioned earlier to check HDMI resolution using media-ctl command
- Run vcu_gst_app for current HDMI resolution (1080p60) by executing the following command.

$ vcu_gst_app /media/card/config/input.cfg

Below configurations needs to be set in input.cfg for non-LLP2 HDMI-1080p60 use-case.

Common Configuration    : START
Num Of Input            : 1
Output                  : HDMI
Out Type                : Display
Frame Rate              : 60
Exit

Input Configuration     : START
Input Num               : 1
Input Type              : hdmi_1
Raw                     : FALSE
Width                   : 1920
Height                  : 1080
Format                  : NV16
Enable LLP2             : FALSE
Exit

Encoder Configuration   : START
Encoder Num             : 1
Encoder Name            : HEVC
Profile                 : Main
Rate Control            : Low_Latency
Filler Data             : False
QP                      : Auto
L2 Cache                : TRUE
Latency Mode            : Sub_Frame
Low Bandwidth           : FALSE
Gop Mode                : Basic
Bitrate                 : 25000
B Frames                : 0
Slice                   : 8
GoP Length              : 60
GDR Mode		: Horizontal
Preset                  : Custom
Exit

Change Resolution of HDMI Input Source from 1080p60 to 4kp60 by following below steps.
- Set the HDMI source resolution to 4kp60 (Homepage → Settings → Display & Sound → Resolution → change to 4kp60).
- Save the configuration to take place the change.
Verify the desired HDMI Input Source Resolution (4kp60) by following the above-mentioned steps.

If HDMI-Tx link-up issue is observed after Linux booting, use the following command to get the blue screen on HDMI-Tx for 4kp60.

$ modetest -D a00c0000.v_mix -s 39:3840x2160-60@BG24

The table below lists the parameters of the pixel format.

Pixel Format	GStreamer Format	Media Bus Format	GStreamer HEVC Profile	GStreamer AVC Profile	Kmssink Plane-id
NV16	NV16	UYVY8_1X16	main-422	high-4:2:2	34 and 35

note

Video0 in the each gst-launch pipelines indicates a video node for the input source.
Make sure HDMI-Rx should be configured to 4kp60 mode, while running below example pipelines.
LLP1/LLP2 stream-in pipelines are not supported using vcu_gst_app.
For LLP1/LLP2 Multi-stream HEVC serial and stream-out use-cases (2-4kp30, 2-1080p60, 4-1080p60), use ENC_EXTRA_OP_BUFFERS=10 variable before gst-launch-1.0 command.
For LLP1/LLP2 Multi-stream serial and stream-in use-cases (2-4kp30, 2-1080p60, 4-1080p60), use internal-entropy-buffers=3 property in decoder.

Video0 in the each gst-launch pipelines indicates a video node for the input source.
Make sure HDMI-Rx should be configured to 4kp60 mode, while running below example pipelines.
LLP1/LLP2 stream-in pipelines are not supported using vcu_gst_app.
For LLP1/LLP2 Multi-stream HEVC serial and stream-out use-cases (2-4kp30, 2-1080p60, 4-1080p60), use ENC_EXTRA_OP_BUFFERS=10 variable before gst-launch-1.0 command.
For LLP1/LLP2 Multi-stream serial and stream-in use-cases (2-4kp30, 2-1080p60, 4-1080p60), use internal-entropy-buffers=3 property in decoder.

Run the following gst-launch-1.0 command to display NV16 video on HDMI-Tx using low-latency (LLP1) GStreamer pipeline..

$ gst-launch-1.0 -v v4l2src io-mode=dmabuf device=/dev/video0 ! video/x-raw, width=3840, height=2160, format=NV16, framerate=60/1 ! omxh265enc num-slices=8 control-rate=low-latency gop-mode=low-delay-p target-bitrate=25000 cpb-size=500 gdr-mode=horizontal initial-delay=250 periodicity-idr=240 filler-data=0 prefetch-buffer=true ! video/x-h265, alignment=nal ! queue max-size-buffers=0 ! omxh265dec low-latency=1 internal-entropy-buffers=5 ! video/x-raw ! queue max-size-bytes=0 ! fpsdisplaysink name=fpssink text-overlay=false 'video-sink=kmssink bus-id=a00c0000.v_mix hold-extra-sample=1 show-preroll-frame=false sync=true' sync=true -v

Run the following gst-launch-1.0 command to display NV16 video on HDMI-Tx using Xilinx's ultra low-latency(LLP2) GStreamer pipeline.

$ gst-launch-1.0 -v v4l2src io-mode=dmabuf device=/dev/video0 ! video/x-raw\(memory:XLNXLL\), width=3840, height=2160, format=NV16, framerate=60/1 ! omxh265enc num-slices=8 control-rate=low-latency gop-mode=low-delay-p target-bitrate=25000 cpb-size=500 gdr-mode=horizontal initial-delay=250 periodicity-idr=240 filler-data=0 prefetch-buffer=true ! video/x-h265, alignment=nal ! queue max-size-buffers=0 ! omxh265dec low-latency=1 internal-entropy-buffers=5 ! video/x-raw\(memory:XLNXLL\) ! queue max-size-bytes=0 ! fpsdisplaysink name=fpssink text-overlay=false 'video-sink=kmssink bus-id=a00c0000.v_mix hold-extra-sample=1 show-preroll-frame=false sync=true' sync=true -v

Run the following gst-launch-1.0 command to stream-out NV16 video using low-latency(LLP1) GStreamer pipeline. where, 192.168.25.89 is host/client IP address and 5004 is port number.

$ gst-launch-1.0 -v v4l2src device=/dev/video0 io-mode=4 ! video/x-raw, format=NV16, width=3840, height=2160, framerate=60/1 ! omxh265enc num-slices=8 periodicity-idr=240 cpb-size=500 gdr-mode=horizontal initial-delay=250 control-rate=low-latency prefetch-buffer=true target-bitrate=25000 gop-mode=low-delay-p ! video/x-h265, alignment=nal ! rtph265pay ! udpsink buffer-size=60000000 host=192.168.25.89 port=5004 async=false max-lateness=-1 qos-dscp=60 max-bitrate=120000000 -v

Run the following gst-launch-1.0 command to display NV16 stream-in video on HDMI-Tx using low-latency(LLP1) GStreamer pipeline. where, 5004 is port number.

$ gst-launch-1.0 udpsrc port=5004 buffer-size=60000000 caps="application/x-rtp, media=video, clock-rate=90000, payload=96, encoding-name=H265" ! rtpjitterbuffer latency=7 ! rtph265depay ! h265parse ! video/x-h265, alignment=nal ! omxh265dec low-latency=1 internal-entropy-buffers=5 ! video/x-raw ! queue max-size-bytes=0 ! fpsdisplaysink name=fpssink text-overlay=false video-sink="kmssink bus-id=a00c0000.v_mix" sync=true -v

Run the following gst-launch-1.0 command to stream-out NV16 video using Xilinx's ultra low-latency(LLP2) GStreamer pipeline. where, 192.168.25.89 is host/client IP address and 5004 is port number.

$ gst-launch-1.0 -v v4l2src device=/dev/video0 io-mode=4 ! video/x-raw\(memory:XLNXLL\), format=NV16, width=3840, height=2160, framerate=60/1 ! omxh265enc num-slices=8 periodicity-idr=240 cpb-size=500 gdr-mode=horizontal initial-delay=250 control-rate=low-latency prefetch-buffer=true target-bitrate=25000 gop-mode=low-delay-p ! video/x-h265, alignment=nal ! rtph265pay ! udpsink buffer-size=60000000 host=192.168.25.89 port=5004 async=false max-lateness=-1 qos-dscp=60 max-bitrate=120000000 -v

Run the following gst-launch-1.0 command to display NV16 stream-in video on HDMI-Tx using Xilinx's ultra low-latency(LLP2) GStreamer pipeline. where, 5004 is port no.

$ gst-launch-1.0 udpsrc port=5004 buffer-size=60000000 caps="application/x-rtp, media=video, clock-rate=90000, payload=96, encoding-name=H265" ! rtpjitterbuffer latency=7 ! rtph265depay ! h265parse ! video/x-h265, alignment=nal ! omxh265dec low-latency=1 internal-entropy-buffers=5 ! video/x-raw\(memory:XLNXLL\) ! queue max-size-bytes=0 ! fpsdisplaysink name=fpssink text-overlay=false video-sink="kmssink bus-id=a00c0000.v_mix" sync=true -v

Table of Contents

1 Overview

1.1 Board Setup

1.2 Run Flow

1.2.1 GStreamer Application (vcu_gst_app)

1.3 Build Flow

2 Other Information

2.1 Known Issues

2.2 Limitations

2.3 Optimum VCU Encoder parameters for use-cases

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

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