# Video wall
Source: [https://docs.qualcomm.com/doc/80-70014-50/topic/gst-concurrent-videoplay-composition.html](https://docs.qualcomm.com/doc/80-70014-50/topic/gst-concurrent-videoplay-composition.html)
The **gst-concurrent-videoplay-composition** application supports concurrent video
playback for MP4 AVC (H.264) videos and performs composition on a video wall display.
In the concurrent video playback and composition pipeline, four decode and composition
pipelines run concurrently. For more information, see [Pipeline flow](https://docs.qualcomm.com/doc/80-70014-50/topic/gst-concurrent-videoplay-composition.html#gst-concurrent-videoplay-composition__section_s22_qsf_4bc).
Figure : gst-concurrent-videoplay-composition pipeline with 4 streams
This video shows you how to stream from multiple cameras simultaneously, display the
feeds side-by-side, or encode for storage.
## Prerequisites
- Enable SSH in Permissive mode to securely access your host device. For
instructions, see [How to SSH?](https://docs.qualcomm.com/bundle/publicresource/topics/80-70014-254/how_to.html#how-to-ssh-)
- Use the following command to enter the SSH shell and execute the use
cases:
ssh root@Copy to clipboard
- Run the following command to enable the Permissive
mode:
setenforce 0Copy to clipboard
- Run the following command to enable the
display:
export XDG_RUNTIME_DIR=/dev/socket/weston && export WAYLAND_DISPLAY=wayland-1Copy to clipboard
- Run the following command to push the files from host
machine:
scp root@:/opt/Copy to clipboard
## Use cases
The application requires at least one input video file. The input file should be a
MP4 AVC (H.264) file.
The table lists the use cases that are supported through the
gst-concurrent-videoplay-composition application:| Use case | Description |
| --- | --- |
| Video conferencing |
Simultaneously decodes the video streams of multiple participants.
This is beneficial in a multi-party video conference scenario where the application manages multiple video streams.
|
| Surveillance systems | Concurrently decodes video feeds from two separate cameras. |
| Digital signage | Enables simultaneous changes or updates to centrally managed information that is electronically displayed across multiple locations. |
To execute the use cases, do the following:
1. Load the AVC-encoded MP4 (H.264) files onto the device.
2. Use the following syntax command to run the application for your use
case:
gst-concurrent-videoplay-composition -c -i .mp4 -i .mp4Copy to clipboard
The table provides a description of the command-line
parameters: | Command-line parameter | Description |
| --- | --- |
| `-c` |
Number of streams to decode for composition.
Supported values are 2, 4, 8.
|
| `-i` | Specifies the absolute path to the input video file |
Use the following commands to execute the concurrent playback use
cases:
- Concurrent playback of two
sessions:
gst-concurrent-videoplay-composition -c 2 -i .mp4 -i .mp4Copy to clipboard
If
one video is provided as input, the same file is played
concurrently.
- Concurrent playback of four
sessions:
gst-concurrent-videoplay-composition -c 4 -i .mp4 -i .mp4 -i .mp4 -i .mp4Copy to clipboard
To stop the use case, press CTRL + C.
## Expected output
The individual composed
streams are tiled together to display as unified stream.
## Pipeline flow
The table lists the plugins used to execute the video wall pipeline:| Plugin | Description |
| --- | --- |
| filesrc | Reads the video data. |
| qtdemux | Demultiplexes the video data. |
| h264parse | Parses the H.264 video streams. |
| [v4l2h264dec](https://docs.qualcomm.com/doc/80-70014-50/topic/v4l2h264dec.html) | Decodes the H.264 video streams. |
| [qtivcomposer](https://docs.qualcomm.com/doc/80-70014-50/topic/qtivcomposer.html) | Composes the decoded streams and sends them over the display. |
| [Waylandsink](https://docs.qualcomm.com/doc/80-70014-50/topic/waylandsink.html) | Displays the composed video streams on Wayland display. |
**Known issues**: Video playback is closing or freezing. After an hour
(approximately), it continues running with 16 H264 720p concurrent video playback
sessions.
**Parent Topic:** [Sample applications for video and audio](https://docs.qualcomm.com/doc/80-70014-50/topic/audio-sample-applications.html)
Last Published: Oct 27, 2025
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