Difference between revisions of "H.264"

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== Tutorials ==
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*[http://www.vcodex.com/files/h264_interpred.pdf "H.264 / MPEG-4 Part 10 White Paper:
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Prediction of Inter Macroblocks in P-slices"]
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== Trading power for PSNR ==
 
== Trading power for PSNR ==
 
=== Modifying the Encoder ===
 
=== Modifying the Encoder ===

Revision as of 17:40, 14 March 2008

Tutorials

Prediction of Inter Macroblocks in P-slices"]

Trading power for PSNR

Modifying the Encoder

  • JM12.4
  • In contrast to the original proposal, we would like to look at modifying the encoder in order to make decisions about which blocks to drop. In this case, the decoder need only decide how many blocks to drop. The encoder would categorize and arrange the blocks in the stream so that the "important" blocks are sent first, enabling the decoder to drop the last n blocks without even decoding them.
  • One issue to be addressed in the encoder: how do we decide which blocks are more important? Currently the idea is to look at blocks with smaller motion vectors and consider those less important. An important issue which arises is that this might prevent large slow moving objects from moving at all in the image. This might be avoided if the encoder looks at the average vector size, or vector statistics in order to avoid this situation.

Modifying the Decoder

  • Enabling energy reduction functionality in the decoder without the benefit of a specialized encoder to first analyze the data poses some problems in terms of energy conservation. We want to reduce the amount of computation in order to throttle the processor, but the overhead required to make block dropping decisions might alleviate the advantage.

Benchmarks

Players and PSNR calcualtors

  • VideoMeter, command line tool developed at ASU with PSNR calculations for 3 simultaneous yuv steams
-download videometer

Applicability to Bistable Displays

Articles

Survey

-OHSU, Beaverton, OR
-National University of Singapore
-Good block diagram for h.264
-Good workload breakdown for decoder (pie-chart)

DVFS

-Beijing
  • >Hyekseong Kweon, Younggu Do, Jaejeong Lee, Byoungchul Ahn, [ "An Efficient Power-Aware Scheduling Algorithm in Real Time System"], IEEE PACRIM, 2007
-Seoul
-Good discussion on dynamic and static leakage and dependence on operating voltage

Corruption Model

-Powerpoint Presentation

Profiling/Component Breakdown

General

-Distortion Control and Estimation

Code

-Documentation

Reference Software

-No linux support yet?