1. Igor Jánoš

2. Goal of This Project Decode and process a full-HD video clip using only software resources Dimension – 1920 x 1080 pixels

3. Motivation High computational power demands for HD video Latest trend – integrate more CPU cores in one chip Systems without powerful GPU GPU is busy with another job

4. Video Filters Deinterlace Noise reduction Color controls No dependencies among resulting pixels Very good for thread-parallel processing

5. Deinterlace Filter Produces frames at doubled rate – higher memory demands Combines odd and even lines from successive frames Half-pixel shift to reduce comb effect Reads 2 frames Writes 2 frames

8. Previous FrameCurrent Frame Generated Interlaced Frame Output Frame 2 Output Frame 1

9. Denoise Filter Gradual noise reduction Threshold – reduces temporal noise Weighted averaging More difficult to compute Reads 2 frames Writes 1 frame

10. Two successive frames in a stationary scene

12. Without Denoise Filter

13. With Denoise Filter

14. Color Controls Filter Reads 1 frame Writes 1 frame Easy to compute in Y-U-V color space

15. Color Controls Filter

16. Basic algorithm idea “Divide & Conquer” approach Assign a part of a larger job for each CPU core

17. Experiment Use processing filters with live video and offline content Standard Definition High Definition

19. Results

20. SD (720x576) HD (1920x1080) Decoding only (no color conversion) 304.0 FPS74.8 FPS Decoding with color conversion 262.8 FPS61.4 FPS Full processing in 1 thread (original) 98.4 FPS17.57 FPS Full processing multi- threaded 142.6 FPS25.87 FPS Performance gain44.9 %47.7 %

22. Conclusion Software-only thread-parallel processing is possible in real-time Memory performance is the bottleneck DI performance drop after exceeding memory page size Latest Quad-Core CPUs from Intel with enlarged L2 cache - 40% faster

23. Future Work Different frame buffer structure Hybrid encoder/decoder (GPU + Multi-core CPU) GPU – motion estimation & compensation, color space conversion, deblocking CPU – VLC, transformations, intra predictions

24. Thank you