Difference between revisions of "Using gstreamer"
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| + | Gstreamer has made a lot of progress lately and some say it already outperforms Mplayer because of its focus on speed and hardware acceleration like using OpenGL, etc. | ||
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| + | Gstreamer is a modular node based player as well as encoder in a single application. It is possible to create chains of so called elements with a wide range of different plugins. | ||
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= Gstreamer and live video processing over the network = | = Gstreamer and live video processing over the network = | ||
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= Requirements = | = Requirements = | ||
| − | You will need | + | You will need: |
| − | * a fairly recent gstreamer distribution, with the rtpjpegdepay plugin | + | * a fairly recent gstreamer distribution ("gstreamer0.10" as ubuntu package for example), with the rtpjpegdepay plugin |
| − | |||
= Limitations = | = Limitations = | ||
| − | You will not (at this time) be able to decode the | + | You will not (at this time) be able to decode the video streams from Elphel 353 cameras on resolutions higher than 1920x1088, because of the RTP payloading limits. |
| − | + | To bypass this limitation you can build it yourself (see [http://www.pitivi.org/wiki/GStreamer_CVS_Setup_Page this guide from PiTiVi]). | |
= Tips = | = Tips = | ||
Revision as of 06:10, 8 August 2009
Gstreamer has made a lot of progress lately and some say it already outperforms Mplayer because of its focus on speed and hardware acceleration like using OpenGL, etc.
Gstreamer is a modular node based player as well as encoder in a single application. It is possible to create chains of so called elements with a wide range of different plugins.
Contents
Gstreamer and live video processing over the network
Gstreamer is very suited to live video and audio processing, notably for live decoding/encoding, audio muxing.
Requirements
You will need:
- a fairly recent gstreamer distribution ("gstreamer0.10" as ubuntu package for example), with the rtpjpegdepay plugin
Limitations
You will not (at this time) be able to decode the video streams from Elphel 353 cameras on resolutions higher than 1920x1088, because of the RTP payloading limits.
To bypass this limitation you can build it yourself (see this guide from PiTiVi).
Tips
You won't get 25 fps if autoexposure is on and local brightness not high enough: the camera will automatically lower framerate for keeping clear picture. Either lighten up, or play with image settings (notably, gain).
Command line experiments
(Note: replace width and height accordingly to your camera setup and your computer's horsepower :p).
Displaying
gst-launch -v rtspsrc location=rtsp://elphel:554 ! queue ! rtpjpegdepay ! queue ! jpegdec ! queue ! xvimagesink sync=false
Dumping
mjpeg dumping
gst-launch -v rtspsrc location=rtsp://elphel:554 ! queue ! rtpjpegdepay ! videorate ! capsfilter caps = "image/jpeg, framerate=(fraction)25/1, width=1024, height=768" ! queue ! matroskamux ! filesink location=/tmp/test.mkv
YUV Dumping
gst-launch -v rtspsrc location=rtsp://elphel:554 ! queue ! rtpjpegdepay ! queue ! jpegdec ! queue ! videorate ! capsfilter caps="video/x-raw-yuv, format=(fourcc)I420, width=(int)1024, height=(int)768, framerate=(fraction)25/1" ! queue ! avimux ! filesink location=/tmp/test.avi
Dump transcoding example
gst-launch filesrc location=test.mkv ! matroskademux ! queue ! jpegdec ! queue ! theoraenc bitrate=4000 ! queue ! oggmux ! filesink location=test.ogg
Live encoding
gst-launch -v rtspsrc location=rtsp://elphel:554 ! queue ! rtpjpegdepay ! queue ! jpegdec ! queue ! videorate ! capsfilter caps="video/x-raw-yuv, format=(fourcc)I420, width=(int)1024, height=(int)768, framerate=(fraction)25/1" ! queue ! theoraenc bitrate=4000 ! queue ! oggmux ! filesink location=/tmp/test1024.ogg
I did some benchmarks; a Core 2 Quad Q6600 (2.4 Ghz) is not powerful enough for h264 encoding @fullHD resolution (using 4 treads).
