const VP8_REFRESH_QUANTIZER: u32 = 2;Expand description
The VP8 quantizer a capped CRF’s refresh codes a block at, at the coarsest, where the session’s
quality index is at or under VP8_FINEST_MATCHED (Codec::refresh_index), where three index
steps move VP8’s quantizer by one or two. Refreshed three steps finer, a 320x240 page of text a
capped session coded bound came out 0.5 dB under the uncapped session at indices 22 to 24, and
a 1280x720 page of text and UI 0.11 under at 22 and 23; at quantizer 2 they came within 0.06 dB
at 22 and 23 and level or past at 24 and 25, at 4% fewer to 8% more bytes. Quantizer 3 came out
under 4 (43.95 dB against 44.40 at 25), and 1 under 2 (44.68 against 44.79, at 4% more bytes);
nine index steps at every index took those past 26 to quantizers 1 to 9, 4 to 17 dB past the
session’s quality at up to twice the bytes.