services

services_vulnerable/tiktak/video/vtt.go

@@ -0,0 +1,65 @@
+package video
+
+import (
+	"bytes"
+	"context"
+	"fmt"
+	"math"
+	"os/exec"
+	"strings"
+)
+
+func getDuration(ctx context.Context, inp string) (res float64, err error) {
+
+	args := []string{"-v", "error", "-show_entries", "format=duration", "-of", "default=noprint_wrappers=1:nokey=1", inp}
+
+	cmd := exec.CommandContext(ctx, "ffprobe", args...)
+
+	out, err := cmd.Output()
+
+	if err != nil {
+		return -1, err
+	}
+
+	_, err = fmt.Fscan(bytes.NewReader(out), &res)
+	return
+}
+
+func GetDuration(ctx context.Context, inp string) (res float64, err error) {
+	select {
+	case semaphore <- struct{}{}:
+		ctx, cancel := context.WithTimeout(ctx, ProcessingDeadline)
+		defer func() {
+			cancel()
+			<-semaphore
+		}()
+		return getDuration(ctx, inp)
+	case <-ctx.Done():
+		return 0, ctx.Err()
+	}
+}
+
+func GenerateVtt(ctx context.Context, inp string, s string) ([]string, error) {
+	duration, err := GetDuration(ctx, inp)
+	if err != nil {
+		return nil, err
+	}
+	lines := strings.Split(s, "\n")
+	vttLines := make([]string, len(lines))
+	delta := duration / float64(len(lines))
+	for i := range vttLines {
+		s1 := generateStamp(float64(i) * delta)
+		s2 := generateStamp(float64(i+1) * delta)
+		vttLines[i] = fmt.Sprintf("%s --> %s\n", s1, s2)
+		vttLines[i] += lines[i] + "\n"
+	}
+	return vttLines, err
+
+}
+
+func generateStamp(p float64) string {
+	m := math.Floor(p / 60)
+	s := math.Mod(p, 60.0)
+	return fmt.Sprintf("%02.0f:%06.3f", m, s)
+
+}