GStreamer Compositor Application

Introduction

The /opt/xilinx/vvas/bin/vvas_xcompositor application is a command line utility which implements the GStreamer video transcoding pipeline described in the diagram below. This application expects four input video files 60(mp4 with H.264/H.265 or H.264/H.265 elementary stream). The resolution of each input cannot exceed 1080p. The application creates an output stream by first composing the four inputs in a 2x2 grid, then by adding an optional logo and lastly by inserting a time stamp.

This application is installed through the xilinx-alveo-u30-gstreamer package. If this package is not present on your system, install it by following the steps described in the package feed page.

GStreamer pipeline of the vvas_xcompositor application

Host System Requirement

  • Xilinx Video SDK

  • GStreamer 1.16.2

  • gst-plugins-good

  • gst-plugins-base

  • gst-plugins-bad

  • gst-libav

  • Opensource GStreamer plugins to be verified after installation of above packages:

    • compositor

    • gdkpixbufoverlay

    • timeoverlay

    • h264parse

    • qtdemux

    • qtmux

Usage

Parameter

Description

-f
mp4/elementary-stream file path. Resolutions up to 1080p are supported.
Type: string
Range: NA
Default: NA
Option: Mandatory

-l
png/jpg logo file path. No logo will be overlayed if this option is not specified.
Type: string
Range: NA
Default: Null
Option: Optional

-b
Max bitrate for encoder in Kbps
Type: int
Range: 0 to 4294967295
Default: 5000
Option: Optional

-i
device index
Type: int
Range: 0 to 31
Default: 0
Option: Optional

-h
Horizontal offset of overlay logo in fractions of video image width, from top-left corner of video image (in relative positioning)
Type: double
Range: 0 to 1
Default: 0.9
Option: Optional

-v
Vertical offset of overlay logo in fractions of video image height, from top-left corner of video image (in relative positioning)
Type: double
Range: 0 to 1
Default: 0
Option: Optional

-n
Number of input buffers
Type: integer
Range: 20 to 2147483647
Default: 2000
Option: Optional

-o
Output file name and path
Type: String
Range: NA
Default: ./result.mp4
Option: Optional

Examples

  1. Composition along with logo on top right of video:

    vvas_xcompositor -f ./video1.mp4 -f ./video2.mp4 -f ./video3.h264 -f ./video4.h265 -l ./logo.png

  2. Composition with logo on top left of video:

    vvas_xcompositor -f ./video1.mp4 -f ./video2.mp4 -f ./video3.h264 -f ./video4.h265 -l ./logo.png -h 0 -v 0

  3. Composition with logo on center of video:

    vvas_xcompositor -f ./video1.mp4 -f ./video2.mp4 -f ./video3.h264 -f ./video4.h265 -l ./logo.png -h 0.5 -v 0.5

  4. Composition without logo layer:

    vvas_xcompositor -f ./video1.mp4 -f ./video2.mp4 -f ./video3.h264 -f ./video4.h265

  5. Composition on device with index 2:

    vvas_xcompositor -f ./video1.mp4 -f ./video2.mp4 -f ./video3.h264 -f ./video4.h265 -i 2

  6. Composition on decoder soft kernel start index at 8:

    vvas_xcompositor -f ./video1.mp4 -f ./video2.mp4 -f ./video3.h264 -f ./video4.h265