Eyevinn / mp4ff / 37463698431

83%

Build Type

push

github

Committed by tobbee

Commit Message

feat(mp4): add experimental ttma box with the maximum period of activation

The paint-model design lets an stpc document or wvtc cues outlive their sample:
they stay active until the next document, bounded by a maximum period of
activation, T_MPA, as in ETSI EN 303 560. The proposal to ISO/IEC 14496-30
carries T_MPA in a TimedTextMaxActivationBox, ttma, which an stpc or wvtc
sample entry shall contain.

TtmaBox is a FullBox with one 32-bit max_activation_period in the media
timescale. StppBox and WvttBox expose it as Ttma after decoding.
SetStpcDescriptor and SetWvtcDescriptor add it with 5 s in the track timescale,
DefaultMaxActivationSeconds, so they now return an error when the track has no
media timescale. mp4ff-subslister prints it as part of the stpc entry.

The 4CC is a placeholder and is not registered with MP4RA.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

Coverage Stats

50 of 56 new or added lines in 6 files covered. (89.29%)

2 existing lines in 2 files now uncovered.

23737 of 28727 relevant lines covered (82.63%)

0.83 hits per line