1. Embedded Streaming Media with GStreamer and BeagleBoard ESC-228 Presented by Santiago Nunez santiago.nunez (at) ridgerun.com

2. Agenda Introduction to BeagleBoard multimedia architecture features. GStreamer concepts OMAP GStreamer hands on exercises DMAI and GStreamer Questions

3. Introduction Primary objective for this class is to introduce audience to GStreamer on OMAP3 with hands on exercises This doesn’t class won't cover extensively the APIs available and assumes basic knowledge on C programming, Linux and computer graphics.

4. BeagleBoard and OMAP3 architecture Provides architecture with several multimedia features:  Cortex A8 with Neon  C64x DSP  Video accelerators How to utilize the hardware features with the software stack?

5. BeagleBoard and OMAP3 architecture Provides architecture with several multimedia features:  Cortex A8 with Neon  C64x DSP  Video accelerators How to utilize the hardware features with the software stack?

6. BeagleBoard and OMAP3 architecture Provides architecture with several multimedia features:  Cortex A8 with Neon  C64x DSP  Video accelerators How to utilize the hardware features with the software stack?

7. GStreamer Streaming media framework – audio and video Close to 200 plug-ins available Higher level than just input / filters / output  Networking, audio/video mixed streams, auto data handling  Various options utilizing hardware accelerators

8. GStreamer Overview Elements  Sources, filters, sinks Bins and Pipelines  Containers, pipeline is the overall bin Pads  Element source / sink connection points Caps  Capabilities organized by stream type with a set of properties

9. GStreamer Overview Elements  Sources, filters, sinks Bins and Pipelines  Containers, pipeline is the overall bin Pads  Element source / sink connection points Caps  Capabilities organized by stream type with a set of properties Plugin  Collection of elements

10. Simple MP3 Player Create dynamically using gst-launch Source element reads from a file Filter element converts MP3 to PWM Sink element passes to ALSA output gst-launch filesrc location=a.mp3 ! mad ! alsasink

11. Hands On Exercise 0 Start up Windowing environment with two terminals  cd gst . s Period character to source the file named 's'

12. Hands On Exercise 0 Play audio file  a2  Actual command gst-launch filesrc location=bbb.flac ! flacdec !alsasink  You can see the contents of the script cat a2  There are lots of audio scripts to try  a1, a2, a3

13. Simple Audio Player Source Code Create pipeline, source, filter, sink  Set element properties Build into pipeline  Connect src and sink pads Setup pipeline event handler  End of stream Set pipeline state to play Run

14. Simple PA System Create dynamically using gst-launch Source element ALSA audio in No filters Sink element passes to ALSA output gst-launch alsasrc num-buffers=100 ! alsasink Try it: r

15. Keeping Plug-ins Organized Each known plug-in is added to registry Most aspects of plug-in are tracked in the registry Registry support run-in pipeline creation and dynamic filter selection Use gst-inspect to list plug-ins gst-inspect | less gst-inspect filesrc

16. Hands On Exercise 1 Using gst-inspect, list  All plug-ins  All video plug-ins  Element properties for filesrc plug-in

17. Hands On Exercise 2 GStreamer video pipelines  v1 – script shown below gst-launch videotestsrc ! ffmpegcolorspace ! fbdevsink  Other video scripts  v1, v2, v3, v4  Idea is the same  source data, filter data, send data to sink

18. Performance Data Passing Stream held in buffers with data, timestamp, other info When possible, buffer memory allocated by sink pad Use hardware when data copy is necessary

19. Performance Data Transformation Cortex A8 compiler optimization NEON  Single Instruction Multiple Data C64  Video accelerator DMA and other data movers

20. Davinci Multimedia Application Interface

21. DMAI and GStreamer Davinci Multimedia Application Interface  Exposes OMAP/Davinci hardware using high level of abstraction  Stream audio / video  Graphics display  Hardware optimized frame/data copy

22. OMAP3 Codec Engine Isolates users for audio/video codecs from those implementing the codecs Codec can run in several places without the calling application being aware  Cortex A8, NEON, C64, hardware accelerator  Uses DSPLink and DSPBios conventions to support DSP based algorithms dynamically

23. Video Phone Vision – video phone application can create audio and video GStreamer pipelines for capture / rendering DMAI, Codec engine, DSPLink, C64 algorithms perform heavy lifting OMAP3 hardware capabilities utilized Video phone application focused on call management, not streaming data manipulation

24. GStreamer in 3 Layers