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https://github.com/junka/ffmime
Get mime type codecs for MSE in webassembly
https://github.com/junka/ffmime
codecs ffmpeg mime-types wasm webassembly
Last synced: 2 months ago
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Get mime type codecs for MSE in webassembly
- Host: GitHub
- URL: https://github.com/junka/ffmime
- Owner: junka
- License: isc
- Created: 2023-08-06T15:18:21.000Z (over 1 year ago)
- Default Branch: main
- Last Pushed: 2024-08-07T05:42:59.000Z (6 months ago)
- Last Synced: 2024-11-15T20:37:03.968Z (3 months ago)
- Topics: codecs, ffmpeg, mime-types, wasm, webassembly
- Language: C++
- Homepage:
- Size: 5.06 MB
- Stars: 4
- Watchers: 1
- Forks: 0
- Open Issues: 0
-
Metadata Files:
- Readme: README.md
- License: LICENSE
Awesome Lists containing this project
README
### About MIME codecs
When we use MSE (Media Source Extension) for developing a media player, the api **MediaSource.isTypeSupported** needs extra information about the media file.
We will need a MIME codec string like
```
video/mp4; codecs="avc1.64001E, mp4a.40.2"
audio/mp4; codecs=mp4a.40.42
video/webm; codecs="vp8, vorbis"
```
see More [web format codec](https://developer.mozilla.org/en-US/docs/Web/Media/Formats/codecs_parameter).
see [Wiki](https://wiki.whatwg.org/wiki/video_type_parameters)
It consists of the MIME type part and codecs string part.
---
### MIME type supported
Media files would have text(VTT subtitle), image, audio and video files, so it is supposed to recognize them like below。
```
text/
image/
audio/
video/
```
And codecs string like below.
```
av01.P.LLT.DD[.M.CCC.cp.tc.mc.F]
cccc[.pp]* (Generic ISO BMFF)
mp4v.oo[.V] (MPEG-4 video)
mp4a.oo[.A] (MPEG-4 audio)
avc1[.PPCCLL] (AVC video)
hev1.P.T.Ll.Bb (HEVC video)
and other no spec using codec name
```
### How to use
How to know the the mime type and codecs.
For those who have installed nodejs, you may run npx like below.
```
npx ffmime
```
For those who have installed the ffmpeg libraries and want to build from source, run
```
git clone https://github.com/junka/ffmime.git
cd ffmime
make mime
./ffmime mediafile
```
### wasm
We can use it in javascript code.
```
npm install ffmime
```
Then in the code, like in electron we can get the MIME type and codecs string.
The returned string can be used for the MSE API **MediaSource.isTypeSupported()**.
```
import {GetMimeCodecs} from 'ffmime'
const mimeType = await GetMimeCodecs(filename)
console log(mimeType)
```
To build wasm from source,
```
docker build -f Dockerfile --output package .
```
wasm js files are built into package directory and then you can publish and import the package.
Only muxer and demuxer configured as enabled in ffmpeg, so we could have a minified wasm binary which is less than 2MB size. This is much more reasonable than a full ffmpeg. Here we only need a probe for the mimetype and codecs string.
### Extra note
Some format could have a side effect.
- For example, a `mkv` format could output `video/x-matroska; codecs="avc1.640029, mp4a.40.2"` which is not supported by Chrome, but you can replace `x-matroska` with `mp4` to make it pass the check of the Chrome.
- However, when the mimetype is `video/mp4`, if the mp4 container box is **NOT** **fragmented**, the media file would not be decoded right by MSE.
- A `mp3` format could output `audio/mpeg; codecs=85` which `85` is the codec id. For use in browser, just strip the codecs. `audio/mpeg` will be supported by the browser.
- Raw `pcm` can hardly probed without any hint. so it will return empty string.