Zynq UltraScale+ MPSoC VCU TRD 2020.1 - PL DDR HDMI Video Capture and Display

Owned by Ronak Shah (Unlicensed)
Last updated: Sept 18, 2020 by Sunil Vaghela
17 min read

This page provides all the information related to Design Module 10 - VCU TRD PL DDR HDMI design.

Table of Contents

1 Overview

This module enables the capture of video from an HDMI-Rx Subsystem implemented in the PL. The video can be displayed through HDMI-Tx through the PL and 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 single-stream and multi-stream for XV20 format. It also supports DCI 4k (4096 x 2160) resolution at 60 FPS.

This is the new design approach proposed to use PL_DDR 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. This approach makes the most effective use of limited AXI4 read/write issuance capability in minimizing latency for the decoder. DMA buffer sharing requirements determine how capture, display, and intermediate processing stages should be mapped to the PS or PL DDR.

This design supports the following video interfaces:
Sources:

  • HDMI-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.

Video format:

  • XV20

Supported Resolution:

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

Resolution

Command Line

Single Stream

Multi-stream

DCI-4kp60

√

NA

4kp60

√

NA

4kp30

√

√ (Max 2)

1080p60

√

√ (Max 4)

√ - Supported
NA – Not applicable
x – Not supported

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

Pipeline

Input source

Format

Output Type

Resolution

VCU codec

Pipeline

Input source

Format

Output Type

Resolution

VCU codec

Serial pipeline

HDMI-Rx

XV20

HDMI-Tx

DCI-4kp60/4kp60/4kp30/1080p60

HEVC/AVC

Record/Stream-Out pipeline

HDMI-Rx

XV20

File Sink/ Stream-Out

DCI-4kp60/4kp60/4kp30/1080p60

HEVC/AVC

File/Streaming Playback pipeline

File Source/ Stream-In

XV20

HDMI-Tx

DCI-4kp60/4kp60/4kp30/1080p60

HEVC/AVC


The below figure shows the PL DDR HDMI design hardware block diagram.

 

The below figure shows the PL DDR HDMI design software block diagram.

1.1 Board Setup

Refer below link for 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.

TRD package contents are placed in the following directory structure. The user needs to copy all the files from the $TRD_HOME/images/vcu_hdmi_multistream_xv20/ to FAT32 formatted SD card 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

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

rdf0428-zcu106-vcu-trd-2020-1 ├── apu │   └── vcu_petalinux_bsp │   └── xilinx-vcu-zcu106-v2020.1-final.bsp ├── images │   ├── vcu_hdmi_multistream_xv20 │   │   ├── autostart.sh │   │   ├── BOOT.BIN │   │   ├── boot.scr │   │   ├── config │   │   ├── image.ub │   │   ├── system.dtb │   │   └── vcu ├── pcie_host_package ├── pl │   ├── constrs │   ├── designs │   │   ├── zcu106_plddr_hdmi │   ├── prebuild │   │   ├── zcu106_plddr_hdmi │   ├── 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 ├── 2-4kp30 │   ├── Display │   ├── Record │   ├── Stream-in │   └── Stream-out ├── 4-1080p60 │   ├── Display │   ├── Record │   ├── Stream-in │   └── Stream-out ├── 4kp60 │   ├── Display │   ├── Record │   ├── Stream-in │   └── Stream-out ├── DCI-4kp60 │   ├── 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 plain text.

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

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

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

Execution of the application is shown below:

Example:

4kp60 XV20 HEVC_HIGH Display Pipeline execution

4kp60 XV20 HEVC_HIGH Record Pipeline execution

4kp60 XV20 HEVC_HIGH Stream-out Pipeline execution

4kp60 XV20 HEVC_HIGH Stream-in Pipeline execution

Make sure HDMI-Rx should be configured to 4kp60 mode

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

1.3 Build Flow

Refer below link for detailed build flow steps

2 Other Information

2.1 Known Issues

2.2 Limitations

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.

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.

2.4 Max Bit-rate Benchmarking

The following tables summarize the maximum bit rate achievable for 3840x2610p60 resolution, XV20 pixel format at GStreamer level. The maximum supported target bit rate values vary based on what elements and type of input used in the pipeline.

Maximum Bit Rate support for Record Use case with 4kp60 resolution

The table below provides Encoder Maximum Bit Rate Tests with XV20 format and Variable Rate Control Mode.

Video Recording ( Live video capture → VCU encoder → parser → muxer → filesink )

Format 

Codec

Entropy Mode

Rate Control Mode

B-Frames = 4

DDR Mode

Max Target Bitrate



4:2:2, 10 bit


H.264 (AVC)

CABAC

VBR

IBBBBP

PS-DDR

160 Mb/s

CAVLC

VBR

IBBBBP

PS-DDR

160 Mb/s

H.265 (HEVC)

-

VBR

IBBBBP

PS-DDR

267 Mb/s

Example pipeline used for measurement:

  • Run the following gst-launch-1.0 command to record the XV20 video using the GStreamer pipeline. where, video0 indicates a video node for the input source.

  • It is recommended to store output file in RAM or SATA

  • Achieved target bit rate depends on complexity of video content

  • Above data is captured by recording a file in mp4 container format

Maximum Bit Rate support for Playback Use case with 4kp60 resolution

The table below provides Decoder Maximum Bit Rate Tests with XV20 format and Variable Rate Control Mode.

Playback ( Filesrc → Decoder → Display )

Format 

Codec

Entropy Mode

Rate Control Mode

B-Frames = 4

DDR Mode

Max Target Bitrate



4:2:2, 10 bit


H.264 (AVC)

CABAC

VBR

IBBBBP

PL_DDR

120 Mb/s

CAVLC

VBR

IBBBBP

PL_DDR

160 Mb/s

H.265 (HEVC)

-

VBR

IBBBBP

PL_DDR

267 Mb/s

Example pipeline used for measurement:

  • Run the following gst-launch-1.0 command to play XV20 recorded file on HDMI-Tx using the GStreamer pipeline. where, a00c0000.v_mix indicates bus-id for DRM mixer.

It is recommended to keep input file in RAM or SATA

Maximum Bit Rate support for Streaming Use case with 4kp60 resolution.

The table below provides Encoder/Decoder Maximum Bit Rate Tests with XV20 format (For Streaming).

Video Streaming ( Live video capture → VCU encoder → Parser → rtppay → Stream-out
Stream-in → rtpdepay → Decoder → Display )

Format 

Codec

Rate Control Mode

Latency Mode

B-Frames = 0

DDR Mode

Max Target Bitrate







4:2:2, 10 bit




 


H.264 (AVC)


LOW_LATENCY

Normal







IPPP









Encoder (PS_DDR),
Decoder (PL_DDR)



90 Mb/s

Reduced

90 Mb/s


CBR  + max-picture-size

Normal

90 Mb/s

Reduced

90 Mb/s



H.265 (HEVC)




LOW_LATENCY

Normal

130 Mb/s

Reduced

130 Mb/s


CBR  + max-picture-size

Normal

110 Mb/s

Reduced

110 Mb/s

Example pipeline used for measurement:

H.265 (HEVC) with Low-latency rate control mode and Normal latency-mode

  • Run the following gst-launch-1.0 command to stream-out the XV20 video using the GStreamer pipeline. where, video0 indicates a video node for the input source.

  • Run the following gst-launch-1.0 command to display XV20 stream-in video on HDMI-Tx using the GStreamer pipeline where 5004 is port number.

H.265 (HEVC) with CBR rate control mode and Normal latency mode

  • Run the following gst-launch-1.0 command to stream-out the XV20 video using the GStreamer pipeline. Where video0 indicates a video node for the input source.

  • Run the following gst-launch-1.0 command to display XV20 stream-in video on HDMI-Tx using the GStreamer pipeline where 5004 is port number.

Maximum Bit Rate support for Serial Use case with 4kp60 resolution.

The table below provides Encoder/Decoder Maximum Bit Rate Tests with XV20 format.

Serial ( Live video capture → VCU encoder → VCU decoder → Display )

Format 

Codec

Rate Control Mode

Latency Mode

B-Frames = 0 or 4

DDR Mode

Max Target Bitrate




4:2:2, 10 bit


H.264 (AVC)


CBR  + max-picture-size

Normal

IBBBBP



Encoder (PS_DDR),
Decoder (PL_DDR)

90 Mb/s

Reduced

IPPP

200 Mb/s


H.265 (HEVC)


CBR  + max-picture-size

Normal

IBBBBP

120 Mb/s

Reduced

IPPP

200 Mb/s

Example pipeline used for measurement:

H.265 (HEVC) with CBR rate control mode and Normal latency mode

  • Run the following gst-launch-1.0 command to display the XV20 video on HDMI-Tx using the GStreamer pipeline (capture → encode → decode → display). where, video0 indicates a video node for the input source.

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

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

Common Configuration:
It is the starting point of common configuration.
 
Num of Input:
1,2,3 or 4

Output:
Select the video interface.
Options: HDMI

Out Type:
Options: display, record, and stream

Display Rate:
Pipeline frame rate.
Options: 30 FPS or 60 FPS for each stream

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

Input Configuration:
It is the starting point of the input configuration.

Input Num:
Starting Nth input configuration.
Options: 1, 2, 3, or 4

Input Type:
Input source type.
Options: HDMI, File, Stream

Uri:
File path or Network URL. Applicable for file playback and stream-in pipeline only. Supported file formats for playback are ts, mp4, and mkv.
Options: file:///media/usb/abc.ts (for file path), udp://192.168.25.89:5004/ (for Network streaming, Here 192.168.25.89 is IP address and 5004 is port no)

Raw:
To tell the pipeline is processed or pass-through.
Options: False


Width:
The width of the live source.
Options: 4096, 3840, 1920

Height:
The height of the live source.
Options: 2160, 1080

Format:
The format of input data.
Options: XV20

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

Encoder Configuration:
It is the starting point of encoder configuration.

Encoder Num:
Starting Nth encoder configuration.
Options: 1, 2, 3 or 4

Encoder Name:
Name of the encoder.
Options: AVC, HEVC

Profile:
Name of the profile.
Options: high for AVC and main for HEVC.

Rate Control:
Rate control options.
Options: CBR, VBR, and low-latency.

Filler Data:
Filler Data NAL units for CBR rate control.
Options: True, False

QP:
QP control mode used by the VCU encoder.
Options: Uniform, Auto

L2 Cache:
Enable or Disable L2Cache buffer in encoding process.
Options: True, False

Latency Mode:
Encoder latency mode.
Options: normal, sub_frame

Low Bandwidth:
If enabled, decrease the vertical search range used for P-frame motion estimation to reduce the bandwidth.
Options: True, False

Gop Mode:
Group of Pictures mode.
Options: Basic, low_delay_p, low_delay_b

Bitrate:
Target bitrate in Kbps
Options: 1-60000

B Frames:
Number of B-frames between two consecutive P-frames
Options: 0-4

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 4kp resolution with HEVC codec
4-32 4kp resolution with AVC codec
4-32 1080p resolution with HEVC codec
4-32 1080p resolution with AVC codec

GoP Length:
The distance between two consecutive I frames
Options: 1-1000

GDR Mode:
It specifies which Gradual Decoder Refresh(GDR) scheme should be used when gop-mode = low_delay_p
Options: Horizontal/Vertical/Disabled

Entropy Mode:
It specifies the entropy mode for H.264 (AVC) encoding process
Options: CAVLC/CABAC/Default

Max Picture Size:
It is used to curtail instantaneous peak in the bit-stream. 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
Options: TRUE/FALSE

Preset:
Options: HEVC_HIGH, HEVC_MEDIUM, HEVC_LOW, AVC_HIGH, AVC_MEDIUM, AVC_LOW, Custom

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

Record Configuration:
It is the starting point of record configuration.

Record Num:
Starting Nth record configuration.
Options: 1, 2, 3 or 4

Out-File Name:
Record file path.
Options: /media/usb/abc.ts

Duration:
Duration in minutes.
Options: 1-3

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

Streaming Configuration:
It is the starting point of streaming configuration.

Streaming Num:
Starting Nth streaming configuration.
Options: 1, 2, 3 or 4

Host IP:
The host to send the packets to
Options: 192.168.25.89 or Windows PC IP

Port:
The port to send the packets to
Options: 5004, 5008, 5012 and 5016

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

Trace Configuration:
It is the starting point of trace configuration.

FPS Info:
To display fps info on the console.
Options: True, False

APM Info:
To display the APM counter number on the console.
Options: True, False

Pipeline Info:
To display pipeline info on console.
Options: 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 HDMI video pipelines for Display, Record & Playback, 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.

  • 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.

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

  • When the HDMI source is not connected, it shows:

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.

  • Make sure the HDMI-Rx media pipeline is configured for 4kp60 resolution and source/sink has the same color format for connected nodes. For XV20 format, run below media-ctl commands to set resolution and format of HDMI scaler node where media3 indicates media node for HDMI input source.

When HDMI Input Source is NVIDIA SHIELD

  • 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-Rx resolution using media-ctl command.

    • Run vcu_gst_app for current HDMI-Rx resolution (1080p60) by executing the following command.

Below configurations needs to be set in input.cfg for HDMI-Rx 1080p60 resolution.

  • Change Resolution of HDMI Input Source from 1080p60 to 4kp60 by following the 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 the HDMI-Tx link-up issue is observed after Linux booting, use the following command to get the blue screen on HDMI-Tx for 4kp60.

  • 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

Pixel Format

GStreamer Format

Media Bus Format

GStreamer HEVC Profile

GStreamer AVC Profile

Kmssink Plane-id

XV20

NV16_10LE32

UYVY10_1X20

main-422-10

high-4:2:2

33, 34, 35 and 36

  • Run the following gst-launch-1.0 command to display the XV20 video on HDMI-Tx using the GStreamer pipeline (capture → encode → decode → display). Where "video0" indicates a video node for the input source.

  • Run the following gst-launch-1.0 command to record the XV20 video using the GStreamer pipeline. Where "video0" indicates a video node for the input source.

  • Run the following gst-launch-1.0 command to play XV20 recorded file on HDMI-Tx using the GStreamer pipeline.

  • Run the following gst-launch-1.0 command to stream-out the XV20 video using the GStreamer pipeline. Where "video0" indicates a video node for the input source.

  • Run the following gst-launch-1.0 command to display XV20 stream-in video on HDMI-Tx using the GStreamer pipeline where 5004 is port number.

 

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