Supported input
Progressive and fragmented MP4, M4A, and QuickTime .mov files, with moov first or last. Nothing is decoded or re-encoded, so the codecs must already suit the protocol:
| Supported | |
|---|---|
| Video | H.264, HEVC (hvc1/hev1), VP9, AV1 |
| Audio | AAC-LC, HE-AAC and HE-AACv2 (explicit signaling), AC-3, E-AC-3, Opus, FLAC |
| Layout | one video track and any number of audio tracks, or audio only; edit lists of one edit, optionally after one empty edit |
| Skipped | tracks that are not audio or video (timecode, metadata, subtitles) |
| Rejected | encrypted media, samples in moov mixed with fragments, external data references, more than one sample description per track, other codecs (each error names what was found) |
Whether a player can decode a codec is a separate question: HEVC and the Dolby codecs need Safari or a platform decoder, for instance. See TDD 0004 for what was verified where.