Zynq UltraScale+ MPSoC VCU TRD 2019.1 - HDMI Video Capture and HDMI Display With SDSoC

Zynq UltraScale+ MPSoC VCU TRD 2019.1 - HDMI Video Capture and HDMI Display With SDSoC



Table of Contents

1 Overview

This design-module demonstrates how to add a data-copy (also known as By-Pass) accelerator between HDMI Video Capture (HDMI-Rx) and HDMI Display (HDMI-Tx) pipelines in PL using SDSoC tool. The accelerator function (which simply copy the input data to output) is translated to RTL using the Vivado HLS compiler (which is part of SDSoC tool).

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.

Streaming Interfaces:

  • 1G Ethernet on PS

Video format:

  • NV12

Supported Resolution:

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

Resolution
Command Line
Single StreamMulti-stream
4kp60NA
4kp30NA
1080p60NA
1080p30NA


√ - Supported
NA – Not applicable
x – Not supported



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

Pipeline

Input source

Output Type

Resolution

VCU codec

Capture --> bypass --> Display (Passthrough pipeline) 

With and without bypass plugin

HDMI-Rx

HDMI-Tx

4KP/1080p

None

Stream-Out pipeline with and without bypass plugin

HDMI-Rx

Stream-Out

4K/1080p

HEVC/AVC

File/Streaming Playback pipeline with and without bypass plugin

File Source/ Stream-In

HDMI-Tx

4K/1080p

HEVC/AVC

Capture--> Encode--> Decode--> Display without bypass plugin

HDMI-RxHDMI-Tx4K/1080pHEVC/AVC

Record pipeline without bypass plugin

HDMI-RxFile Sink4K/1080pHEVC/AVC



For the overview, software tools, system requirements, and design files follow the link below:

The below figure shows the VCU TRD SDSoC design hardware block diagram.


The below figure shows the HDMI Video Capture and HDMI Display with SDSoC support design software block diagram.

1.1 Board Setup


1.2 Run Flow

The TRD package has ready-to-test SD-card images that enable the user to run the demo. 

  • Copy all the files from the $TRD_HOME/images/vcu_sdx/ to a FAT formatted SD card.

Refer below link 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_sdx/ to FAT32 formatted SD card directory.

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

Configuration files(input.cfg) for various resolutions are placed in the following 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) which is a plain text file.

To execute the application, run the following command:


Example:

4kp60 Passthrough pipeline execution with a bypass filter

4kp60 HEVC_HIGH Display Pipeline execution

4kp60 HEVC_HIGH Stream-out Pipeline execution

4kp60 HEVC_HIGH Stream-in Pipeline execution

NOTE: 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 Build Flow tutorial of  VCU PetaLinux BSP:

By Pass Sample and GStreamer Plugin

This tutorial shows how to build the By-Pass accelerator sample with/without HW acceleration based on the VCU TRD SDSoC platform.

  • Set the build environment variables. This requires that you have previously completed the PetaLinux SDK installation step from Zynq UltraScale+ MPSoC VCU TRD 2019.1 - Run and Build Flow.
    Note 1: Make sure you set the env variables in the same shell that is used to launch SDx. Also make sure the env variables are set before starting SDx, otherwise close and re-start SDx.
    Note 2: The below command might ask you to execute unset LD_LIBRARY_PATH and then re-execute the command. Go ahead and follow those steps.
  • Create a new workspace for the bypass sdsoc and GStreamer plugin projects.

  • Click 'Import Project' from the welcome screen, select Import Type as "Eclipse workspace or zip file", click Next. Browse to the current working directory and make sure all projects are selected as shown in the figure. De-select "Copy projects into workspace". Click Finish.


  • Click 'File -> New → SDx Library Project'. Enter bypass as project name and click 'Next'.


  • Select Accelerated Library Type as "Shared Library" and click Next.
  • Click symbol to add Custom Platform', browse to the $TRD_HOME/apu/vcu_sdx folder and click OK. Select the "vcu_sdx [custom]" platform from the list and click 'Next'.

  • Click Next in System Configuration window.
  • Select "By-Pass" from the template list and click 'Finish'.

  • For Acceleration in HW following steps to be executed:
    • With HW Acceleration, in the "SDx Application Project Settings" panel, keep the active build configuration to "Release" which will have the pre-selected Hardware Function marked for acceleration. Make sure the 'Generate SD card image' box is checked

  • Right-click the "bypass" project in the explorer panel and select 'Build Project'.  Copy the generated SD card image.
  • When the build is finished, right-click the "gstsdxbypass" project and select "Build Project". Copy the generated libraries and the plugin.
    Note: This project has a dependency on "bypass" and the build will fail if "bypass" was not built previously.




2 Other Information

2.1 Known Issues


  • Observed frame drops

    • Frequency: Always
    • Workaround: None
    • Note: Observed frame drops with 4kp60 and 4kp30 for file play back and streaming use cases and with 1080p60 streaming use cases.


2.2 Limitations

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 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.

Common Configuration:
It is the starting point of common configuration.

Num of Input:
Provide the number of input. It is always 1 for this design.

Output:
Select the video interface.
Options: HDMI or DP

Out Type:
Options: display 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

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:///run/media/sda/abc.ts (for file path), udp://192.168.26.89:5004/ (for Network streaming, Here 192.168.26.89 is IP address and 5004 is port no)

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

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

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


Accelerator Filter:
Enable/disable SDx accelerator. In this release, the accelerator will work as a bypass filter.
Options: True, False


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

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

Profile:
Name of the profile.
Options: baseline, main or high for AVC. 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

Format:
The format of input data.
Options: NV12

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

Out-File Name:
Record file path.
Options: /run/media/sda/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

Host IP:
The host to send the packets to
Options: 192.168.26.89 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 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

  • To check the link status, resolution and video node of HDMI input source, run below xmedia-ctl command.

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

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

When the HDMI source is not connected, it shows:

NOTE: Here "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).

  • Follow the below steps to switch the HDMI-Rx resolution from 1080p60 to 4kp60.
    • Check current HDMI Input Source Resolution (1080p60) by following the above-mentioned steps.
    • Run vcu_gst_app for current HDMI resolution (1080p60) by executing the following command.

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

    • 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:
  • Run the following gst-launch-1.0 command to display raw HDMI video using GStreamer pipeline.
  • Run the following gst-launch-1.0 command for file playback using GStreamer pipeline.

NOTE: File location should be SATA SSD(ext4 format) to avoid the read-write bandwidth issue.

  • Run the following gst-launch-1.0 command for cbr stream-out HDMI video using GStreamer pipeline.

NOTE: Here 192.168.25.89 is host/client IP address and 5004 is port no.

  • Run the following gst-launch-1.0 command to display cbr stream-in on HDMI-Tx video using Gstreamer pipeline where 5004 is port no.
  • Run the following gst-launch-1.0 command for low-latency stream-out HDMI video using GStreamer pipeline.

NOTE: Here 192.168.25.89 is host/client IP address and 5004 is port no.

  • Run the following gst-launch-1.0 command to display low-latency stream-in on HDMI-Tx video using Gstreamer pipeline where 5004 is port no.

NOTE: Low latency stream-in pipeline is not supported in vcu_gst_app.

Notes for gst-launch-1.0 commands:

  • Make sure HDMI-Rx media pipeline is configured for 4kp60 resolution and source/sink have the same color format. Run below xmedia-ctl commands to set resolution and format of HDMI scaler node.

When HDMI Input Source is NVIDIA SHIELD

NOTE: Make sure NVIDIA SHIELD is configured for 4kp resolution and RGB888 color format.

When HDMI Input Source is ABOX

NOTE: Make sure ABOX is configured for 4kp resolution and VYYUYY8 color format.