# Audio-video playback
Source: [https://docs.qualcomm.com/doc/80-70020-50/topic/gst-audio-video-playback.html](https://docs.qualcomm.com/doc/80-70020-50/topic/gst-audio-video-playback.html)
The **gst-audio-video-playback** application supports simultaneous audio and video
decoding and playback of FLAC/MP3 audio and AVC/HEVC video.
The following are the applicable scenarios to use the gst-audio-video-playback
application:
- Media player applications
- Streaming services
- Video conferencing
- Surveillance systems
- Educational platforms
- Entertainment platforms that can play back audio and video files in various
formats
As shown in the following figure, the pipeline involves several elements for audio and
video playback. For more information about these elements, see [Pipeline flow](https://docs.qualcomm.com/doc/80-70020-50/topic/gst-audio-video-playback.html#gst-audio-video-playback__section_g4v_31g_4bc).
Figure : gst-audio-video-playback pipeline
## Prerequisites
- [Get started with the Qualcomm IM SDK](https://docs.qualcomm.com/bundle/publicresource/topics/80-70020-51/install-sdk.html)
for your Qualcomm Linux 1.5 or Ubuntu Server.
- Activate SSH on your Qualcomm Linux or Ubuntu to sign in with SSH and connect to
the target device. For instructions see:
- [Sign in using SSH](https://docs.qualcomm.com/bundle/publicresource/topics/80-70020-254/how_to.html#use-ssh) for Qualcomm
Linux
- [Sign in using SSH](https://docs.qualcomm.com/bundle/publicresource/topics/80-90441-1/Use_Ubuntu_on_RB3_Gen2_3.html#sign-in-to-the-rb3-gen-2-console-using-ssh) for Ubuntu
Server
Note: If SSH is already set up and Wi-Fi is
connected, skip this step.
- Use the HDMI port to connect the display to the device. For instructions, see
[Set up HDMI display](https://docs.qualcomm.com/bundle/publicresource/topics/80-70020-18/samples.html).
- Sign in to the target device using SSH.
- In the terminal of the target device, run the following commands from the SSH
shell of the target device to activate the display on the host computer:
- For
Linux:
export XDG_RUNTIME_DIR=/dev/socket/weston && export WAYLAND_DISPLAY=wayland-1Copy to clipboard
- For Ubuntu Server:
export XDG_RUNTIME_DIR=/run/user/$(id -u ubuntu)/ && export WAYLAND_DISPLAY=wayland-1 Copy to clipboard
- Connect the speaker to activate the audio on the target device. For
instructions, see [Set up audio hardware](https://docs.qualcomm.com/bundle/publicresource/topics/80-70020-16/enable-audio.html).
If you face
issues in recording the audio, run the following command in the terminal of
the target
device:
pactl set-default-source pal_source_speaker_micCopy to clipboard
- If you face issues with the camera or display, see [Camera troubleshooting](https://docs.qualcomm.com/bundle/publicresource/topics/80-70020-17/troubleshooting.html) and [Display troubleshooting](https://docs.qualcomm.com/bundle/publicresource/topics/80-70020-18/debug.html).
## Run the application
1. Ensure that you input `.mp4`,
`.mp4`,
`.mp4`,
`.mp4` video files on the target
device.
2. In the terminal of the target device, run the use
case:
gst-audio-video-playback -v 1 -a 1 -i /etc/media/.mp4Copy to clipboard
The following table provides a description of the command-line
parameters: | Command-line parameter | Description |
| --- | --- |
| `-v` | Specifies the video codec.
1 = AVC (H.264)
2 = HEVC (H.265)
|
| `-a` | Specifies the audio codec.
1 = FLAC
2 = MP3
|
| `-i` | Specifies the absolute path to the MP4 input file |
For example, run the commands in the following list for different
audio and video formats:
- AVC video with FLAC
audio:
gst-audio-video-playback -v 1 -a 1 -i /etc/media/.mp4 Copy to clipboard
- AVC video with MP3
audio:
gst-audio-video-playback -v 1 -a 2 -i /etc/media/.mp4Copy to clipboard
- HEVC video with FLAC
audio:
gst-audio-video-playback -v 2 -a 1 -i /etc/media/.mp4Copy to clipboard
- HEVC video with MP3
audio:
gst-audio-video-playback -v 2 -a 2 -i /etc/media/.mp4Copy to clipboard
3. To stop the use case, use CTRL +
C.
4. In the terminal of the target device, run the following command in the SSH shell
to display the available help
options:
gst-audio-video-playback --helpCopy to clipboard
## Expected output
- The AVC/HEVC video is displayed on the screen.
- The audio plays through the device speaker.
Figure : Expected output for gst-audio-video-playback application
## Pipeline flow
The following table lists the plugins used to run the audio-video playback
pipeline:| Plugin | Description |
| --- | --- |
| filesrc | Reads the video data. |
| qtdemux | Demultiplexes the video data into separate audio and video streams. |
| h264parse | Parses the H.264 video stream. |
| h265parse | Parses the H.265 video stream. |
| [v4l2h264dec](https://docs.qualcomm.com/doc/80-70020-50/topic/v4l2h264dec.html) | Decodes the H.264 video streams. |
| [v4l2h265dec](https://docs.qualcomm.com/doc/80-70020-50/topic/v4l2h265dec.html) | Decodes the H.265 video stream. |
| [Waylandsink](https://docs.qualcomm.com/doc/80-70020-50/topic/waylandsink.html) | Displays the video stream on Wayland display. |
| flacparse or mpegaudioparse | Parses the audio stream. |
| flacdec or mpg123audiodec | Decodes the audio stream. |
| [pulsesink](https://docs.qualcomm.com/doc/80-70020-50/topic/pulsesink.html) | Allows playback of the audio stream. |
## Related information
[Audio-video use cases](https://docs.qualcomm.com/doc/80-70020-50/topic/audio-video-use-cases.html)
**Parent Topic:** [Run sample applications for video and audio](https://docs.qualcomm.com/doc/80-70020-50/topic/audio-sample-applications.html)
Last Published: Jan 30, 2026
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