Allow for specifying custom base url in install process (#2)

* Allow for specifying custom base url in install process

* update readme

* more detail in readme

* always log base url

README.md

@@ -22,7 +22,10 @@ This module is installed via npm:
 $ npm install ffmpeg-ffprobe-static
 ```
 
-*Note:* During installation, it will download the appropriate `ffmpeg` binary from the [`b4.3.1` GitHub release](https://github.com/descriptinc/ffmpeg-ffprobe-static/releases/tag/b4.3.1). Use and distribution of the binary releases of FFmpeg are covered by their respective license.
+*Note:* During installation, it will download the appropriate `ffmpeg`/`ffprobe` binary from the [`b4.3.1` GitHub release](https://github.com/descriptinc/ffmpeg-ffprobe-static/releases/tag/b4.3.1). Use and distribution of the binary releases of FFmpeg are covered by their respective license.
+
+Alternatively, it will fetch binaries from `FFMPEG_FFPROBE_STATIC_BASE_URL` if set as an environment variable. The default base URL is https://github.com/descriptinc/ffmpeg-ffprobe-static/releases/download/. The install script will fetch binaries from `BASE_URL/binary-release-tag` (the `binary-release-tag` is set in package.json and can customized by setting `FFMPEG_BINARY_RELEASE`).
+
 
 ### Electron & other cross-platform packaging tools
 

install.js

@@ -142,7 +142,9 @@ const releaseName = (
 )
 const arch = process.env.npm_config_arch || os.arch()
 const platform = process.env.npm_config_platform || os.platform()
-let baseUrl = `https://github.com/descriptinc/ffmpeg-ffprobe-static/releases/download/${release}`;
+const base = process.env.FFMPEG_FFPROBE_STATIC_BASE_URL || 'https://github.com/descriptinc/ffmpeg-ffprobe-static/releases/download/';
+console.log(`[ffmpeg-ffprobe-static] Using base url: ${base}`);
+const baseUrl = new URL(release, base).href;
 const ffmpegUrl = `${baseUrl}/ffmpeg-${platform}-${arch}`
 const ffprobeUrl = `${baseUrl}/ffprobe-${platform}-${arch}`
 const readmeUrl = `${baseUrl}/${platform}-${arch}.README`

package.json

@@ -1,6 +1,6 @@
 {
   "name": "ffmpeg-ffprobe-static",
-  "version": "4.3.1-rc.2",
+  "version": "4.3.1-rc.3",
   "description": "ffmpeg static binaries for Mac OSX and Linux and Windows",
   "main": "index.js",
   "types": "index.d.ts",