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| author | ruben <code@rbn.im> | 2019-05-21 22:56:55 +0200 |
|---|---|---|
| committer | Brendan Abolivier <babolivier@matrix.org> | 2019-05-21 21:56:55 +0100 |
| commit | 74827428bd3e11faab65f12204449c1b9469b0ae (patch) | |
| tree | 0decafa542436a0667ed2d3e3cfd4df0f03de1e5 /mediaapi/README.md | |
| parent | 4d588f7008afe5600219ac0930c2eee2de5c447b (diff) | |
use go module for dependencies (#594)
Diffstat (limited to 'mediaapi/README.md')
| -rw-r--r-- | mediaapi/README.md | 27 |
1 files changed, 27 insertions, 0 deletions
diff --git a/mediaapi/README.md b/mediaapi/README.md new file mode 100644 index 00000000..8d6cc627 --- /dev/null +++ b/mediaapi/README.md @@ -0,0 +1,27 @@ +# Media API + +This server is responsible for serving `/media` requests as per: + +http://matrix.org/docs/spec/client_server/r0.2.0.html#id43 + +## Scaling libraries + +### nfnt/resize (default) + +Thumbnailing uses https://github.com/nfnt/resize by default which is a pure golang image scaling library relying on image codecs from the standard library. It is ISC-licensed. + +It is multi-threaded and uses Lanczos3 so produces sharp images. Using Lanczos3 all the way makes it slower than some other approaches like bimg. (~845ms in total for pre-generating 32x32-crop, 96x96-crop, 320x240-scale, 640x480-scale and 800x600-scale from a given JPEG image on a given machine.) + +See the sample below for image quality with nfnt/resize: + + + +### bimg (uses libvips C library) + +Alternatively one can use `gb build -tags bimg` to use bimg from https://github.com/h2non/bimg (MIT-licensed) which uses libvips from https://github.com/jcupitt/libvips (LGPL v2.1+ -licensed). libvips is a C library and must be installed/built separately. See the github page for details. Also note that libvips in turn has dependencies with a selection of FOSS licenses. + +bimg and libvips have significantly better performance than nfnt/resize but produce slightly less-sharp images. bimg uses a box filter for downscaling to within about 200% of the target scale and then uses Lanczos3 for the last bit. This is a much faster approach but comes at the expense of sharpness. (~295ms in total for pre-generating 32x32-crop, 96x96-crop, 320x240-scale, 640x480-scale and 800x600-scale from a given JPEG image on a given machine.) + +See the sample below for image quality with bimg: + + |