- http://www.webmproject.org/ - http://en.wikipedia.org/wiki/VP8 - VP8 Data Format and Decoding Guide -- https://tools.ietf.org/html/rfc6386 * データ形式 [#format] - http://datatracker.ietf.org/doc/rfc6386/ *. [#s7c89eca] - VP8 Segment, VP8 Partition and H264 Slice -- https://groups.google.com/a/webmproject.org/forum/#!topic/webm-discuss/h6l7Sp1Tpdk * a VP8 segment (up to four such) is a coding feature, that attaches to each macroblock a predefined set of coding parameters (quantization level, filtering strength, ...). Thanks to segment-id, a macroblock can belong to any such feature group and there's no restriction on the ordering. It's pretty much a map. * A VP8 Partition is a bitstream-level feature that tells how the bytes are to be ordered in the bitstream. It's just about the layout of data, but doesn't impact visually the compression. In particular, partitions are not supposed to be independently decodable. More precisely, if partitions are used, every macroblock row is to be decoded from a different partition, in a cyclic fashion. This helps with resiliences to transmission error. * H264 slices relates to grouping of macroblocks in independently-decodable units. Grouping is not necessarily in a row-by-row fashion if FMO is used. Several patterns are possible (spiral, rectangles, etc.) With slices, a little efficiency is lost because one cannot predict across slice boundary. Slice can be transmitted in arbitrary order, note. * 関連 [#rel] - [[WebP]] - [[WebM]] - [[VP9]] - [[VP10]] |