Zynq UltraScale+ MPSoC VCU TRD 2019.2 - HDMI Video Capture

Zynq UltraScale+ MPSoC VCU TRD 2019.2 - HDMI Video Capture


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. The TRD will serve as a platform to tune the performance parameters of VCU and arrive at optimal configurations for encoder and decoder blocks. 

This design supports the following video interfaces:

Sources:

  • HDMI-Rx capture pipeline implemented in the PL.

Sink:

  • Stream-out from network or internet.
  • File sink (SD card, USB storage, SATA hard disk).

VCU Codec:

  • Video Encode/Decode capability using VCU hard block in PL 
    • AVC/HEVC encoding.
    • Encoder/decoder parameter configuration.

Streaming Interfaces:

  • 1G Ethernet PS GEM 

Video Format:

  • NV12

Supported Resolution:

The table below provides the supported resolution from GUI and command-line app in this design.

Resolution
GUICommand Line
Single StreamSingle Stream
4kp60X
4kp30X
1080p60X

√ - 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

Single Stream: Record/Stream-Out pipeline

HDMI-Rx

File Sink/ Stream-Out

4K/1080p

HEVC/AVC

The below figure shows the HDMI Video Capture design hardware block diagram.


The below figure shows the HDMI Video Capture 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.

Refer below link to download all TRD contents.


TRD package contents specific to HDMI Video Capture design is placed in the following directory structure. The user needs to copy all the files from the $TRD_HOME/images/vcu_hdmi_rx/ to FAT32 formatted SD card directory.

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

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) to be provided in plain text.

Execution of the application is shown below:


Example:

4kp60 HEVC_HIGH Record Pipeline execution

4kp60 HEVC_HIGH Stream-out 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




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.

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 a common configuration.

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

Output:
Select the video interface.
Options: DP

Out Type:
Options: 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

Input Type:
Input source type.
Options: HDMI

Uri:
File path. Applicable for file playback only. Supported file formats for playback are ts, mp4, and mkv.
Options: file:///media/usb/abc.ts

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

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: /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.

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

  • 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 the key on remote).


Notes for gst-launch-1.0 commands:

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


  • 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 modetest followed by 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 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 desired HDMI Input Source Resolution (4kp60) by following the above-mentioned steps.
  • Run the following gst-launch-1.0 command to record HDMI video using the GStreamer pipeline.

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

  • Run the following gst-launch-1.0 command for the CBR stream-out pipeline. Where "videoX" indicates a video node for the input source.

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

  • Run the following gst-launch-1.0 command for low-latency(LLP1) stream-out pipeline. Where "videoX" indicates a video node for the input source and 192.168.25.89 is host/client IP address and 5004 is port no.

NOTE: The low latency(LLP1) stream-out pipeline is supported with tsmux in vcu_gst_app.