Configurable ffmpeg (#13722)

* Install multiple ffmpeg versions and add config to make it configurable

* Update docs

* Run ffprobe too

* Cleanup

* Apply config to go2rtc as well

* Fix ffmpeg bin

* Docs

* Restore path

* Cleanup env var

* Fix ffmpeg path for encoding

* Fix export

* Formatting

frigate/output/preview.py

@@ -78,6 +78,7 @@ class FFMpegConverter(threading.Thread):
 
         # write a PREVIEW at fps and 1 key frame per clip
         self.ffmpeg_cmd = parse_preset_hardware_acceleration_encode(
+            config.ffmpeg.ffmpeg_path,
             config.ffmpeg.hwaccel_args,
             input="-f concat -y -protocol_whitelist pipe,file -safe 0 -threads 1 -i /dev/stdin",
             output=f"-threads 1 -g {PREVIEW_KEYFRAME_INTERVAL} -bf 0 -b:v {PREVIEW_QUALITY_BIT_RATES[self.config.record.preview.quality]} {FPS_VFR_PARAM} -movflags +faststart -pix_fmt yuv420p {self.path}",