# Video transformation
Source: [https://docs.qualcomm.com/doc/80-70023-50/topic/gst-transform-example.html](https://docs.qualcomm.com/doc/80-70023-50/topic/gst-transform-example.html)
The **gst-transform-example** application supports rotation, flipping, and scaling
operations.
You can use this application for a security camera. Adjust the orientation of the
displayed image using the flip and mirror operations on the CCTV camera. For more
information about the transformation properties, see qtivtransform.
The following figure shows the pipeline, which takes the captured video stream,
transforms it, and either displays it or saves it to a file. For information about the
plugins used in the pipeline, see Pipeline flow.
Figure : gst-transform-example pipeline
## Run the application
1. Ensure that you complete the Prerequisites.
2. In the terminal of the target device, run the following use cases to rotate,
downscale, or flip the video:
- Use camera source and save output to a file.
- Perform operations such as rotate, flip, upscale/downscale
simultaneously:
gst-transform-example -r 90 -f 2 --output_width 1920 --output_height 1080 -o /etc/media/video_transform.mp4 -i .mp4Copy to clipboard
- Rotate:
gst-transform-example -r 90 --input_width 3840 --input_height 2160 -o .mp4Copy to clipboard
- Downscale/upscale:
gst-transform-example --input_width 3840 --input_height 2160 --output_width 1920 --output_height 1080 -o .mp4Copy to clipboard
- Flip:
gst-transform-example -f 2 --input_width 3840 --input_height 2160 -o .mp4Copy to clipboard
- Use file source and save output to a file.
- Perform operations such as rotate, flip, upscale/downscale
simultaneously:
gst-transform-example -r 90 -f 2 –i .mp4 --output_width 1920 --output_height 1080 -o .mp4Copy to clipboard
- Rotate:
gst-transform-example -r 90 -i .mp4 -o .mp4Copy to clipboard
- Downscale/upscale:
gst-transform-example -i .mp4 --output_width 1920 --output_height 1080 -o .mp4Copy to clipboard
- Flip:
gst-transform-example -f 2 -i .mp4 -o .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-transform-example --helpCopy to clipboard
5. In the terminal of the host computer, run the following command to pull the
files from the target
device:
scp root@:/etc/media/Copy to clipboard
The following table provides a description of the command-line
parameters:| Command-line parameter | Description |
| --- | --- |
| `-h, --help` | Help |
| `--output_width` | Downscale/upscale width.
The default value is 1920.
You can scale from 1080 to 720 or from 720 to 1080.
|
| `--output_height` | Downscale/upscale height. The default value is 1080. |
| `-o` | Absolute path to generate the file. |
| `-r` | Image rotate. The values are 0, 90, 180, 270. |
| `--input_width` | Camera width. The default value is 1920. |
| `--input_height` | Camera height. The default value is 1080. |
| `-f` | Flip the image. The values are:
0: Don't flip (Default).
1: Flip horizontally.
2: Flip vertically.
3: Flip both horizontally and vertically.
|
| `-I`, `--input_file` | Absolute path of the input file. For example, `-I /etc/media/inputfileh264.mp4` |
| `-o`,`--output_file` | Absolute path to generate the output file. For example, `-o /etc/media/video_transform.mp4` |
## Expected output
This pipeline supports simultaneous live preview and recording of the transformed
video stream.
It provides two outputs:
- A video recording that's stored as an MP4 file in the specified path.
- A preview on a display device.
Figure : Expected output for gst-transform-example application–Preview
## Pipeline flow
The following table lists the plugins used to run the video transforming
pipeline:| Plugin | Description |
| --- | --- |
| qtiqmmfsrc and filesrc | Captures the video data. |
| capsfilter | Enforces constraints on the raw video data. |
| qtivtransform | Transforms the video data. After transformation, capsfilter is applied again. |
| tee | Splits the transformed video data in two output paths:
Live preview
Save to file
|
| Waylandsink | Displays the video in live preview. |
| h264parse | Parses the encoded H.264 video stream. |
| mp4mux | Multiplexes the stream into an MP4 container. |
| filesink | Writes the video data to a file. |
## Related information
Transform and Transcode use cases
**Parent Topic:** Run sample applications for video and audio
Last Published: Mar 27, 2026
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