HLS video handling/storage/state refactor (#151)

* WIP with new transcoder progress monitor

* A whole different WIP in progress monitoring via local PUTs

* Use an actual hls playlist parser to rewrite master playlist

* Cleanup

* Private vs public path for thumbnail generation

* Allow each storage provider to make decisions of how to store different types of files

* Simplify inbound file writes

* Revert

* Split out set stream as connected/disconnected state methods

* Update videojs

* Add comment about the hls handler

* Rework of the offline stream state.  For #85

* Delete old unreferenced video segment files from disk

* Cleanup all segments and revert to a completely offline state after 5min

* Stop thumbnail generation on stream stop. Copy logo to thumbnail on cleanup.

* Update transcoder test

* Add comment

* Return http 200 on success to transcoder. Tweak how files are written to disk

* Force pixel color format in transcoder

* Add debugging info for S3 transfers. Add default ACL.

* Fix cleanup timer

* Reset session stats when we cleanup the session.

* Put log file back

* Update test

* File should not be a part of this commit

* Add centralized shared performance timer for use anywhere

* Post-rebase cleanup

* Support returning nil from storage provider save

* Updates to reflect package changes + other updates in master

* Fix storage providers being overwritten

* Do not return pointer in save. Support cache headers with S3 providers

* Split out videojs + vhs and point to specific working versions of them

* Bump vjs and vhs versions

* Fix test

* Remove unused

* Update upload warning message

* No longer valid comment

* Pin videojs and vhs versions

core/ffmpeg/thumbnailGenerator.go

@@ -13,36 +13,44 @@ import (
 	"github.com/owncast/owncast/config"
 )
 
+var _timer *time.Ticker
+
+func StopThumbnailGenerator() {
+	if _timer != nil {
+		_timer.Stop()
+	}
+}
+
 //StartThumbnailGenerator starts generating thumbnails
 func StartThumbnailGenerator(chunkPath string, variantIndex int) {
 	// Every 20 seconds create a thumbnail from the most
 	// recent video segment.
-	ticker := time.NewTicker(20 * time.Second)
+	_timer = time.NewTicker(20 * time.Second)
 	quit := make(chan struct{})
 
 	go func() {
 		for {
 			select {
-			case <-ticker.C:
+			case <-_timer.C:
 				if err := fireThumbnailGenerator(chunkPath, variantIndex); err != nil {
 					log.Errorln("Unable to generate thumbnail:", err)
 				}
 			case <-quit:
 				//TODO: evaluate if this is ever stopped
 				log.Debug("thumbnail generator has stopped")
-				ticker.Stop()
+				_timer.Stop()
 				return
 			}
 		}
 	}()
 }
 
-func fireThumbnailGenerator(chunkPath string, variantIndex int) error {
+func fireThumbnailGenerator(segmentPath string, variantIndex int) error {
 	// JPG takes less time to encode than PNG
 	outputFile := path.Join(config.WebRoot, "thumbnail.jpg")
 	previewGifFile := path.Join(config.WebRoot, "preview.gif")
 
-	framePath := path.Join(chunkPath, strconv.Itoa(variantIndex))
+	framePath := path.Join(segmentPath, strconv.Itoa(variantIndex))
 	files, err := ioutil.ReadDir(framePath)
 	if err != nil {
 		return err