area Detector and GStreamer Similarities and Differences Tom
- Slides: 9
area. Detector and GStreamer Similarities and Differences Tom Cobb
What is GStreamer • Streaming media framework – audio and video • Many plugins available for data formats / data manipulation • Higher level than just input / filters / output – Networking, audio/video mixed streams, auto data handling – Various options utilizing hardware accelerators • Has been extended for use in some scientific communities • Written in C with Python (and other language) bindings
What is area. Detector • I hope I don’t need to say anything here. . .
What does GStreamer do that area. Detector does? • Chains plugins for data processing • Options to run any plugin in its own thread • Image transformations and conversion (rotate, scale and offset, ROI, debayer, overlay, color convert) • File and network I/O in various datatypes • Some stats functions • Rewirable chain on the fly • Gig. E cameras • Windows, Linux, MAC OS X
What does GStreamer do that area. Detector doesn’t? • Some data formats (YUV is about the only one that is immediately useful) • Some file formats (MJPEG, H 264 multicast streaming) • Autoplugging chain based on data formats • A lot of plugins that we could make use of (opencv functions, • Synchronization of different clock sources • V 4 L cameras • Could make use of audio processing for ADC data
What does area. Detector do that GStreamer doesn’t? • • • Some data formats (Int 32, Float 64) Some file formats (HDF 5, net. CDF) Some stats functions Most of our detectors EPICS integration vx. Works
Who else is using GStreamer? • LIGO: gravitational-wave data analysis tools for 1 D data (see tutorial) • Military: various 2 D sources, mainly Camera Link and Coa. XPress framegrabbers from Active Silicaon, NI, DALSA, Matrox, EDT (see presentation) • Software Radio: FFTs and other 1 D data functions • Lots of A/V people. . .
What neat ideas does it have? • GObject based, so written in C but get Python wrapper for free • Message passing on bus • Video format (Caps) negotiation • Bins for groups of plugins with a bit of logic • Multiple clock sources (e. g. for stream synchronisation) • Connections can be run in push or pull mode (e. g. For limited rate outputs, or attribute readers)
Demo • EPICS V 4 monitor on NTNDArray producing data to a pipeline of GStreamer plugins
