mirror of
https://github.com/matrix-org/dendrite.git
synced 2024-11-23 06:41:56 -06:00
e1ec98e248
Fix Docker files which had been forgotten in #594 and update scripts and docs to remove references to gb.
I also removed the `jenkins` directory which is outdated. We can revert f8d7e99
if we realise that it was a mistake to do so.
28 lines
1.6 KiB
Markdown
28 lines
1.6 KiB
Markdown
# 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:
|
|
|
|
![](nfnt-96x96-crop.jpg)
|
|
|
|
### bimg (uses libvips C library)
|
|
|
|
Alternatively one can use `go 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:
|
|
|
|
![](bimg-96x96-crop.jpg)
|