Eyevinn / moqlivemock / 31078528651

48%

Build Type

push

github

Committed by tobbee

Commit Message

feat(cc608): add roll-up modes to -cc608mode

Completes the -cc608mode set with the third CTA-608 presentation style:
roll-up2, roll-up3 and roll-up4, plus bare roll-up for roll-up2 (matching
go-608's own go608-clock, whose window size defaults to 2).

Roll-up shares paint-on's animation - it writes to the displayed screen,
so the one-pair-per-frame drain types the text out - and differs in what
happens between lines: a CR scrolls the window instead of the screen being
cleared. Measured at 25 fps it finishes two frames after paint-on, on
frames 5 and 19 against paint-on's 4 and 17, which is the extra CR per
line. It fits the pair budget at every broadcast rate from 23.976 to
60 fps, checked across all three window sizes.

The window size is carried by the Mode value itself (ModeRollUp2/3/4 with
rollUpRows) rather than a separate rows field, so an out-of-range window
is unrepresentable and the zero value stays paint-on.

Groups stay independent, which needed one more omission than pop-on did:
go-608's WithRollUpCarry would leave a group's upper rows holding its
predecessor's lines, so the default per-unit window reset is used instead.
Carry is deliberately not exposed - it would break the property the mode
set is built around. A consequence worth documenting: with one cue per
group and the window reset each group, only the two rows a group writes
for itself are ever filled, so the three window sizes differ in the
RU2/RU3/RU4 code on the wire but display identically. That is what makes
them useful for exercising a decoder rather than redundant.

The mode-parameterised tests now iterate an allModes slice, so the
round-trip, display-timing and self-containment properties are asserted
for all five modes and a mode added later is covered by construction.

Coverage Stats

25 of 27 new or added lines in 3 files covered. (92.59%)

56 existing lines in 2 files now uncovered.

2392 of 5031 relevant lines covered (47.55%)

2049.09 hits per line