Eyevinn / mp4ff / 36387831180

83%

Build Type

push

github

Committed by tobbee

Commit Message

fix(mp4): make the defragmenter's ftyp from the progressive output

The defragmenter kept the input ftyp minus a list of fragment-format brands, always added isom, and kept the input's minor version. That could claim brands the output no longer conforms to: isom next to a rebuilt ctts version 1 (which needs iso4), iso5/iso6 that only the fragments needed, and brands unknown to mp4ff, which ISO/IEC 14496-12:2026 Annex B.4.2 says a rewriter ought to remove.

The ftyp is now made after the moov is rebuilt: major brand mp42 with minor version 0, the lowest structural brand of Annex E that the rebuilt moov needs, the codec brands av01, iamf and dby1, and the ISO/IEC 14496-15 brands of the input (nras, hvci and the other L-HEVC and tile brands), which describe the bitstreams and still hold. isoBrandFor is factored out of GenerateFtyp for the shared mapping of avc1 to iso2.

Refs #540

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_017q3eYmMQXKrP3iY8UCS48r

Coverage Stats

14 of 14 new or added lines in 2 files covered. (100.0%)

1 existing line in 1 file now uncovered.

22643 of 27502 relevant lines covered (82.33%)

0.82 hits per line