two7bitblocks

Two7bitblocks is a term used in discussions of digital data encoding to describe a unit formed by pairing two consecutive 7-bit blocks. In this view, each 7-bit block encodes a value from 0 to 127, and a pair yields a 14-bit value that can be treated as a single symbol for storage or transmission.

Technical description: If block A has value a and block B has value b, both in [0,127], the combined 14-bit value is (a << 7) | b. This 14-bit unit can be stored in various ways, for example as two 8-bit bytes with the high bits carrying a and b, or as a compact 14-bit field within a larger bitstream using bit-packing schemes.

Encoding variants: To send data over channels that restrict characters to 7-bit ASCII, two7bitblocks may be encoded using a base128-like scheme or split into 8-bit bytes with additional framing bits. The exact layout depends on the protocol; there is no single standard.

Applications and limitations: The approach is primarily discussed in pedagogical or legacy contexts to illustrate packing efficiency. It is most relevant where bandwidth conservation or compatibility with 7-bit channels is important, but adds complexity in encoding and decoding.

Relation to other concepts: It relates to bit-packing, 7-bit data streams, base128 encodings, and MIDI-style data handling, where 7-bit boundaries govern data organization.

Notes: The term is informal and may appear in code comments or design documents rather than formal specifications. See also 7-bit encoding, bit packing, base128.