Eyevinn / mp4ff / 32614221306

82%

master: 82%

Pull #560

github

feat(mp4): resolve overlapping fragments during defragmentation

A fragment whose tfdt re-declares an earlier decode time supersedes the
earlier samples of its track (a retransmission): the fragment appearing
later in the file wins, whole re-sent fragments disappear, superseded
tails are trimmed at sample granularity, and the timeline continues
from the declaring fragment, whether or not the re-sent bytes are
identical. Non-overlapping input converts byte-identically to before.

Ambiguous overlaps keep failing closed instead of being guessed at: an
overlap that starts inside a sample (unless it only shrinks earlier
tfdt-gap padding), any abandoned time range that no surviving later
fragment declares again (whether the superseded fragment was trimmed or
dropped whole, and with voided declarations not counting as coverage),
and overlapping files whose fragments use absolute base data offsets
are rejected, so no declared content is ever silently dropped. The
payload size bound now applies to the surviving samples, so re-sent
declarations larger than the input file no longer reject a file that
resolves cleanly.

642 of 765 new or added lines in 2 files covered. (83.92%)

21469 of 26300 relevant lines covered (81.63%)

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