package transcoder import ( "os" "os/exec" "path" "strconv" "strings" "time" log "github.com/sirupsen/logrus" "github.com/owncast/owncast/config" "github.com/owncast/owncast/core/data" "github.com/owncast/owncast/utils" ) var _timer *time.Ticker // StopThumbnailGenerator will stop the periodic generating of a thumbnail from video. 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. _timer = time.NewTicker(20 * time.Second) quit := make(chan struct{}) go func() { for { select { case <-_timer.C: if err := fireThumbnailGenerator(chunkPath, variantIndex); err != nil { log.Errorln("Unable to generate thumbnail:", err) } case <-quit: log.Debug("thumbnail generator has stopped") _timer.Stop() return } } }() } func fireThumbnailGenerator(segmentPath string, variantIndex int) error { // JPG takes less time to encode than PNG outputFile := path.Join(config.TempDir, "thumbnail.jpg") previewGifFile := path.Join(config.TempDir, "preview.gif") framePath := path.Join(segmentPath, strconv.Itoa(variantIndex)) files, err := os.ReadDir(framePath) if err != nil { return err } var modTime time.Time var names []string for _, f := range files { if path.Ext(f.Name()) != ".ts" { continue } fi, err := f.Info() if err != nil { continue } if fi.Mode().IsRegular() { if !fi.ModTime().Before(modTime) { if fi.ModTime().After(modTime) { modTime = fi.ModTime() names = names[:0] } names = append(names, fi.Name()) } } } if len(names) == 0 { return nil } mostRecentFile := path.Join(framePath, names[0]) ffmpegPath := utils.ValidatedFfmpegPath(data.GetFfMpegPath()) outputFileTemp := path.Join(config.TempDir, "tempthumbnail.jpg") thumbnailCmdFlags := []string{ ffmpegPath, "-y", // Overwrite file "-threads 1", // Low priority processing "-t 1", // Pull from frame 1 "-i", mostRecentFile, // Input "-f image2", // format "-vframes 1", // Single frame outputFileTemp, } ffmpegCmd := strings.Join(thumbnailCmdFlags, " ") if _, err := exec.Command("sh", "-c", ffmpegCmd).Output(); err != nil { return err } // rename temp file if err := utils.Move(outputFileTemp, outputFile); err != nil { log.Errorln(err) } makeAnimatedGifPreview(mostRecentFile, previewGifFile) return nil } func makeAnimatedGifPreview(sourceFile string, outputFile string) { ffmpegPath := utils.ValidatedFfmpegPath(data.GetFfMpegPath()) outputFileTemp := path.Join(config.TempDir, "temppreview.gif") // Filter is pulled from https://engineering.giphy.com/how-to-make-gifs-with-ffmpeg/ animatedGifFlags := []string{ ffmpegPath, "-y", // Overwrite file "-threads 1", // Low priority processing "-i", sourceFile, // Input "-t 1", // Output is one second in length "-filter_complex", "\"[0:v] fps=8,scale=w=480:h=-1:flags=lanczos,split [a][b];[a] palettegen=stats_mode=full [p];[b][p] paletteuse=new=1\"", outputFileTemp, } ffmpegCmd := strings.Join(animatedGifFlags, " ") if _, err := exec.Command("sh", "-c", ffmpegCmd).Output(); err != nil { log.Errorln(err) // rename temp file } else if err := utils.Move(outputFileTemp, outputFile); err != nil { log.Errorln(err) } }