Application Report
SPRAAG9A – April 2007
1
Decode Demo for the DVEVM/DVSDK 1.2
Niclas Anderberg SDO Applications
ABSTRACT
The DaVinci Digital Video Evaluation Module (DVEVM) comes with demonstration applications
that illustrate the use of its software and hardware components. This document describes the
design of the “decode” demo application. The decode demo uses the Codec Engine as well as
video, audio, and speech algorithms from Texas Instruments to decode video and sound data
from files on the Linux file system, and outputs them to Linux device drivers controlling the video
and audio peripherals on the DM6446.
Contents
1
Overview ..........................................................................................................................................2
2 Application Design..........................................................................................................................3
2.1 Main Thread ..................................................................................................................4
2.2 Control Thread...............................................................................................................5
2.3 Speech Thread ..............................................................................................................6
2.4 Audio Thread .................................................................................................................8
2.5 Video Thread ...............................................................................................................10
2.5.1 Display Thread ............................................................................................................11
2.5.2 Video Thread Interaction .............................................................................................12
2.6 Encoded Data File Loader...........................................................................................13
3 Adapting the Application..............................................................................................................15
3.1 Speech Only ................................................................................................................15
3.2 Audio Only ...................................................................................................................15
3.3 Video Only ...................................................................................................................15
3.4 Exit Cleanly Without Control Thread............................................................................16
3.5 Replacing the Decode Algorithms with Other Codecs.................................................16
4 More Information...........................................................................................................................18
Figures
Figure 1.
Decode Demo Architecture.........................................................................................2
Figure 2. Decode Demo Threads................................................................................................3
Figure 3. Main Thread Flow ........................................................................................................4
Figure 4. Speech Thread Initialization Flow..............................................................................6
Figure 5. Speech Thread Main Loop Flow.................................................................................7
Figure 6. Audio Thread Initialization Flow.................................................................................8
Figure 7. Audio Thread Main Loop Flow ...................................................................................9
Figure 8. Video Thread Initialization Flow...............................................................................10
Figure 9. Video Thread Interactions.........................................................................................12
Figure 10. File Loader Algorithm ...............................................................................................13