When the video resolution is higher, CABAC is commonly used since the compression efficiency is better than CAVLC
is less complex than CABAC, it is still much more efficient than other techniques used in coefficient encoding, such as that used in MPEG-4 encoding.
Evaluation and decision on modes contribute to CAVLC
, CABAC, and EXP-GOLOMB in a simplified way to address the data-handling constraints.
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.
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).
Briefly, with entropy coding, CAVLC is your only option with the Baseline Profile.
Table 6--Recommended Parameters When Optimizing for Quality or Display Rate Resolution SD HD Focus High Quality Simple to Decode Profile Main Baseline Level Resolution dependent Resolution dependent Entropy Encoding CABAC CAVLC B-Frames Yes--2-4 No Reference frames 3 3 Deblocking Filter Yes Yes
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.
264 files, GSpot again falls behind MediaInfo, failing to provide profile and level, or whether the file was produced with CABAC or CAVLC encoding.