@nxtedition/mime

MIME type lookup and extension resolution with built-in support for broadcast and professional media formats missing from the standard mime package.

Install

npm install @nxtedition/mime

Usage

Lookup MIME type by filename

import { lookup } from '@nxtedition/mime'

lookup('video.mxf') // 'application/mxf'
lookup('video.mp4') // 'video/mp4'
lookup('video.nut') // 'video/x-nut'
lookup('audio.ac3') // 'audio/ac3'
lookup('subs.stl') // 'application/x-ebu-stl'
lookup('subs.scc') // 'text/x-scc'

// Bare extensions work too (like the standard mime package):
lookup('nut') // 'video/x-nut'
lookup('dnxhd') // 'video/x-dnxhd'

Get extension from MIME type

import { extension } from '@nxtedition/mime'

extension('video/mp4') // 'mp4'
extension('video/x-dnxhd') // 'dnxhd'
extension('audio/ac3') // 'ac3'
extension('application/x-ebu-stl') // 'stl'
extension('video/quicktime') // 'mov'

// MIME types are case-insensitive and parameters are ignored:
extension('Video/X-DnxHD; profile=hd') // 'dnxhd'

Broadcast & media types

Types handled beyond (or instead of) the standard mime package:

| Extension | MIME Type | Format | | ---------------------- | ----------------------------- | ------------------------- | | .nut | video/x-nut | NUT container | | .aaf | application/x-aaf | Avid AAF | | .lxf | application/x-lxf | Leitch LXF | | .dnxhd .dnxhr | video/x-dnxhd | Avid DNxHD/DNxHR | | .dv | video/x-dv | DV video | | .h265 .265 .hevc | video/h265 | Raw HEVC stream | | .264 .avc | video/h264 | Raw AVC stream | | .h266 .266 .vvc | video/h266 | Raw VVC stream | | .av1 | video/av1 | Raw AV1 stream | | .ffv1 | video/ffv1 | FFV1 archival codec | | .vc1 | video/vc1 | VC-1 video | | .prores | video/x-prores | Apple ProRes | | .r3d | video/x-red-r3d | RED REDCODE RAW | | .braw | video/x-blackmagic-braw | Blackmagic RAW | | .ari | image/x-arri-ari | ARRIRAW frame | | .ac3 | audio/ac3 | Dolby Digital | | .eac3 .ec3 | audio/eac3 | Dolby Digital Plus | | .opus | audio/opus | Opus audio | | .flac | audio/flac | FLAC lossless | | .pcm-s16le | audio/x-pcm-s16le | Raw 16-bit PCM | | .pcm-s24le | audio/x-pcm-s24le | Raw 24-bit PCM | | .pcm-s32le | audio/x-pcm-s32le | Raw 32-bit PCM | | .bwf | audio/wav | Broadcast Wave | | .w64 | audio/x-w64 | Sony Wave64 | | .rf64 | audio/x-rf64 | EBU RF64 | | .stl | application/x-ebu-stl | EBU STL subtitles | | .scc | text/x-scc | Scenarist Closed Captions | | .cap | application/x-cap | Softel CAP captions | | .890 | application/x-890 | Cavena 890 subtitles | | .pac | application/x-pac | Screen Electronics PAC | | .ass | text/x-ass | Advanced SubStation Alpha | | .ssa | text/x-ssa | SubStation Alpha | | .dfxp .itt | application/ttml+xml | TTML dialects | | .exr | image/x-exr | OpenEXR | | .cin | image/x-cin | Cineon | | .ism | application/vnd.ms-sstr+xml | Smooth Streaming | | .mp3 | audio/mp3 | MP3 (Chrome workaround) |

Camera RAW stills are also covered: cr2, cr3, nef, nrw, arw, srf, sr2, raf, rw2, orf, pef, ptx, x3f, 3fr, fff, iiq, mrw, mef, dng, raw, rwl, k25, kdc, bay, erf, srw, mos — each mapped to its vendor image/x-* type.

Deliberate differences from mime

Some mappings intentionally shadow standard ones for broadcast use. If you serve 3D models, pcap captures, or proxy autoconfig files, this package is not for you:

• .stl → application/x-ebu-stl (not model/stl)
• .cap → application/x-cap (not application/vnd.tcpdump.pcap)
• .pac → application/x-pac (not application/x-ns-proxy-autoconfig)
• .opus → audio/opus (not audio/ogg)
• .flac → audio/flac (not audio/x-flac)
• .exr → image/x-exr (not image/aces)
• .mp3 → audio/mp3 (not audio/mpeg, see Chromium #227004)

In the reverse direction, common media extensions are preferred over mime-db's first entries:

• video/quicktime → mov (not qt)
• audio/mpeg → mp3 (not mpga)
• audio/aac → aac (not adts)

extension() also accepts common alias spellings that have no forward mapping: video/nut, video/dnxhd, video/dv, video/hevc (→ h265), video/x-m2ts, audio/pcm-s16le/-s24le/-s32le (without the x- prefix), and image/x-dpx.

API

lookup(name: string): string | null

Returns the MIME type for the given filename, path, or bare extension, or null if unknown. Matching is case-insensitive and follows the standard mime package's path semantics: the extension is what follows the last dot of the basename, provided that dot is not the basename's first character (a dotfile with a path, like /path/.nut, is extensionless). A name without such an extension is treated as a bare extension only when it has no path component (nut and .nut both resolve).

Also exported as getType.

extension(mimeType: string): string | null

Returns the file extension for the given MIME type, or null if unknown. Matching is case-insensitive and ignores parameters (e.g. ; charset=...).

Also exported as getExtension.

License

MIT