# Audio-video playback
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/80-80021-50/topic/gst-audio-video-playback.html#section-g4v-31g-4bc).
**Figure : gst-audio-video-playback pipeline**
## Run the application
1. Ensure that you complete the [Prerequisites](https://docs.qualcomm.com/doc/80-80021-50/topic/mm_sample_apps_prerequisites.html).
2. Input `.mp4`, `.mp4`, `.mp4`, `.mp4` video files on the target device.
3. In the terminal of the target device, run the use case:
gst-audio-video-playback -v 1 -a 1 -i /etc/media/.mp4
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| 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:
``` {#codeblock_kl3_yl3_y1c}
gst-audio-video-playback -v 1 -a 1 -i /etc/media/.mp4
```
- AVC video with MP3 audio:
``` {#codeblock_rmp_yl3_y1c}
gst-audio-video-playback -v 1 -a 2 -i /etc/media/.mp4
```
- HEVC video with FLAC audio:
``` {#codeblock_h3w_yl3_y1c}
gst-audio-video-playback -v 2 -a 1 -i /etc/media/.mp4
```
- HEVC video with MP3 audio:
``` {#codeblock_n32_zl3_y1c}
gst-audio-video-playback -v 2 -a 2 -i /etc/media/.mp4
```
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4. To stop the use case, use **CTRL + C**.
5. 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 --help
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## 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
| 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/80-80021-50/topic/v4l2h264dec.html) | Decodes the H.264 video streams. |
| [v4l2h265dec](https://docs.qualcomm.com/doc/80-80021-50/topic/v4l2h265dec.html) | Decodes the H.265 video stream. |
| [Waylandsink](https://docs.qualcomm.com/doc/80-80021-50/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/80-80021-50/topic/pulsesink.html) | Allows playback of the audio stream. |
## Known issue
Audio and video playback may not work if the sink isn't selected using wpctl.
## Related information
[Audio-video use cases](https://docs.qualcomm.com/doc/80-80021-50/topic/audio-video-use-cases.html)
Last Published: Mar 26, 2026
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