feat(server): transcode bitrate and thread settings (#2488)

* support for two-pass transcoding

* added max bitrate and thread to transcode api

* admin page setting desc+bitrate and thread options

* Update web/src/lib/components/admin-page/settings/setting-input-field.svelte

Co-authored-by: Michel Heusschen <59014050+michelheusschen@users.noreply.github.com>

* Update web/src/lib/components/admin-page/settings/setting-input-field.svelte

Co-authored-by: Michel Heusschen <59014050+michelheusschen@users.noreply.github.com>

* two-pass slider, `crf` and `threads` as numbers

* updated and added transcode tests

* refactored `getFfmpegOptions`

* default `threads`, `maxBitrate` now 0, more tests

* vp9 constant quality mode

* fixed nullable `crf` and `threads`

* fixed two-pass slider, added apiproperty

* optional `desc` for `SettingSelect`

* disable two-pass if settings are incompatible

* fixed test

* transcode interface

---------

Co-authored-by: Michel Heusschen <59014050+michelheusschen@users.noreply.github.com>

server/libs/domain/src/system-config/system-config.service.spec.ts

@@ -7,17 +7,20 @@ import { ISystemConfigRepository } from './system-config.repository';
 import { SystemConfigService } from './system-config.service';
 
 const updates: SystemConfigEntity[] = [
-  { key: SystemConfigKey.FFMPEG_CRF, value: 'a new value' },
+  { key: SystemConfigKey.FFMPEG_CRF, value: 30 },
   { key: SystemConfigKey.OAUTH_AUTO_LAUNCH, value: true },
 ];
 
 const updatedConfig = Object.freeze({
   ffmpeg: {
-    crf: 'a new value',
+    crf: 30,
+    threads: 0,
     preset: 'ultrafast',
     targetAudioCodec: 'aac',
     targetResolution: '720',
     targetVideoCodec: 'h264',
+    maxBitrate: '0',
+    twoPass: false,
     transcode: TranscodePreset.REQUIRED,
   },
   oauth: {
@@ -85,7 +88,7 @@ describe(SystemConfigService.name, () => {
 
     it('should merge the overrides', async () => {
       configMock.load.mockResolvedValue([
-        { key: SystemConfigKey.FFMPEG_CRF, value: 'a new value' },
+        { key: SystemConfigKey.FFMPEG_CRF, value: 30 },
         { key: SystemConfigKey.OAUTH_AUTO_LAUNCH, value: true },
       ]);