GStreamer Use Examples

The following code block provides an example of capturing video content from camera/sensor and display over HDMI.

gst-launch-1.0 v4l2src device=/dev/video1 ! video/x-raw,format=NV12,width=1920,height=1080 ! kmssink driver-name=starfive force-modesetting=1

The following diagram shows the video capturing workflow.

The following code block provides an example of playing back an MP4 video file, in this case, the H.264 video stream is decoded via the gst-omx plug-in.

gst-launch-1.0 -v filesrc location=1080p_h264_aac.mp4  ! qtdemux name=demux demux.audio_0 ! queue ! avdec_aac ! audioconvert ! alsasink device=hw:0,2 demux.video_0 ! queue ! h264parse ! omxh264dec  ! video convert ! video/x-raw,width=1920,height=1080 ! kmssink driver-name=starfive force-modesetting=1

The following diagram shows the MP4 playback workflow.

The following code block provides an example of encoding video stream content from camera/sensor into H.264 and encapsulating it to AVI format.

gst-launch-1.0 v4l2src device=/dev/video1 ! video/x-raw,width=640,height=480,format=NV12 !  omxh264enc ! avimux ! filesink location=11.avi

The following diagram shows the video recording workflow.

The following code blocks provide some examples of creating pipelines automatically by using the decodebin or uridecodebin plug-in.

• The following code block provides an example of using the 3 plug-ins filesrc, decodebin, and kmssink together.

  gst-launch-1.0 filesrc location=4K_h265_hevc_30FPS.mkv ! decodebin ! kmssink driver-name=starfive force-modesetting=1

• The following code block provides an example of using the 2 plug-ins uridecodebin and kmssink together. The location of the media file is recorded as value of the URI property of uridecodebin.

  gst-launch-1.0 uridecodebin uri=file:///media/root/4K_h265_hevc_30FPS.mkv ! kmssink driver-name=starfive force-modesetting=1

• The following code block provides an example of using the 2 plug-ins uridecodebin and kmssink together. The location of the media file is recorded as value of the URI property of uridecodebin and output is forced to the MIPI device.

  gst-launch-1.0 uridecodebin uri=file:///media/root/640_360_h265_aac.mkv ! kmssink driver-name=starfive force-modesetting=1 plane-id=74 connector-id=118

• The following code block provides an example of using the plug-in uridecodebin to decode a media file, but only play audio from the decoded file.

  gst-launch-1.0 uridecodebin uri=file:///media/root/640_360_h265_aac.mkv ! audioconvert ! alsasink device=hw:0,1

Follow the steps below to enable the screen to play real-time camera recordings in the Debian operating system.

1. Install the v4l2-ctl tool to detect the recordings and list the resolutions supported by the current camera.

2. Select one of the resolutions for display. The following code blocks provide some examples.

   • Set the resolution to 800×600:

     gst-launch-1.0 v4l2src device=/dev/video4 ! video/x-raw,width=800,height=600 ! videoconvert ! xvimagesink

   • Set the resolution to 1280×720:

     gst-launch-1.0 v4l2src device=/dev/video4 ! video/x-raw,width=1280,height=720 ! videoconvert ! xvimagesink

   • Set the resolution to 1280×900:

     gst-launch-1.0 v4l2src device=/dev/video4 ! video/x-raw,width=1280,height=960 ! videoconvert ! xvimagesink

The following code block provides an example of playing a video with audio output disabled.

gst-play-1.0 -v 1080p_h264_aac.mp4 --audiosink=fakesink --videosink='kmssink driver-name=starfive force-modesetting=1'

gst-play-1.0 1080p_h264_aac.mp4 --audiosink='alsasink device=hw:0,1' --videosink='kmssink driver-name=starfive force-modesetting=1'

gst-play-1.0 1080p_h264_aac.mp4 --audiosink='alsasink device=hw:0,2' --videosink='kmssink driver-name=starfive force-modesetting=1'