Eyevinn / mp4ff / 36469318217

83%

Build Type

push

github

Committed by tobbee

Commit Message

feat(mp4): support saiz versions 1 and 2

ISO/IEC 14496-12:2026 Section 8.7.8 adds saiz version 1 with 16-bit and version 2 with 32-bit default_sample_info_size and sample_info_size fields. mp4ff read every saiz with the version 0 layout, so such boxes failed the size check, and AddSampleInfo rejected sizes above 255 bytes. With Common Encryption subsample patterns that made encryption fail for samples with more than 39 subsamples (16-byte IVs) or 40 subsamples (8-byte IVs).

SaizBox.DefaultSampleInfoSize is now a uint32 and SampleInfo a []uint32, an API change. Both decode paths and encoding follow the version, which is limited to 0, 1 and 2. EncodeSW returns an error if a size does not fit the version or SampleInfo is too short. AddSampleInfo raises the version to the lowest one that holds all sizes, so the output for sizes up to 255 is unchanged.

Version 1 and 2 need the saie brand (Annex E.20). GenerateFtyp adds it when the init segment has such a saiz, or when FragmentFeatures.LargeSampleAuxInfo declares one for the fragments. CheckBrands reports a missing saie. Since CMAF allows only the box versions and flags of iso9 (ISO/IEC 23000-19:2024 7.3.1), both reject saiz version 1 and 2 in CMAF content.

Closes #601

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

Coverage Stats

77 of 78 new or added lines in 3 files covered. (98.72%)

1 existing line in 1 file now uncovered.

22879 of 27745 relevant lines covered (82.46%)

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