In this frame for speed of encoding CAVLC
was used in the base layer and CABAC was used in the three enhancement layers.
When the video resolution is higher, CABAC is commonly used since the compression efficiency is better than CAVLC. However, entropy decoding based on CABAC takes more time.
Entropy coding in H.264/AVC employs either CAVLC or CABAC.
Data is compressed much more efficiently with CABAC than CAVLC
; but CABAC encoding needs much more processing power to drive it.
We introduced the loop partition technology to divide the whole pipeline into four steps (ME, intracoding, CAVLC
, and deblocking filter) in terms of frame.
Evaluation and decision on modes contribute to CAVLC
, CABAC, and EXP-GOLOMB in a simplified way to address the data-handling constraints.
The entropy coding uses Exp-golomb code, context-adaptive variable-length coding (CAVLC
), and the CABAC; therefore, the novel fast mode-decision method is highly effective in reducing computational processing time.
In my tests comparing similarly configured files (720p at 800Kbps video data rate) encoded with CAVLC
and CABAC, the quality difference was noticeable in some hard-to-compress scenes, and I've seen some experts claim that CABAC delivers similar quality at 12%-15% lower data rates.
Episode provides access to a good range of H.264 encoding parameters, including the Baseline, Main, and High profiles; entropy encoding (CABAC and CAVLC
); and the number of B-frames and reference frames.
However, you probably don't have the expertise to choose a codec (H.264, VP6, or VC-1), select a player (Flash, QuickTime, Windows Media, or Silverlight), or specify general encoding parameters such as resolution, data rate, or frame rate, not to mention advanced parameters such as variable bitrate encoding, B-frame interface, and CABAC versus CAVLC
Since I've selected the Baseline Profile, Telestream disables the "Entropy coding" mode, forcing me to use CAVLC
(contextadaptive variable-length coding) with no access to CABAC (context-adaptive binary arithmetic coding).
If you experiment with lots of encoding parameters, you'd probably like to know the B-frame interval and whether CABAC or CAVLC
was utilized, since both affect the horsepower required to play the file.