check for movement every 1s apart

testdata/ffmpeg.d/cmd/prune/main.go

@@ -14,6 +14,7 @@ import (
 	"strconv"
 	"strings"
 	"syscall"
+	"time"
 )
 
 func main() {
@@ -57,18 +58,7 @@ func Run(ctx context.Context, args []string) error {
 						seriesFiles = append(seriesFiles, file)
 					}
 				}
-				if seriesHasMovement, err := func() (bool, error) {
+				if seriesHasMovement, err := seriesHasMovement(ctx, seriesFiles); err != nil {
-					for i := 1; i < len(files); i++ {
-						f := files[i-1]
-						g := files[i]
-						if hasMovement, err := hasMovement(ctx, f, g); err != nil {
-							return false, fmt.Errorf("failed to check for movement between %s and %s: %w", f, g, err)
-						} else if hasMovement {
-							return true, nil
-						}
-					}
-					return false, nil
-				}(); err != nil {
 					return err
 				} else if seriesHasMovement {
 					for _, seriesFile := range seriesFiles {
@@ -92,6 +82,41 @@ func Run(ctx context.Context, args []string) error {
 	return nil
 }
 
+func seriesHasMovement(ctx context.Context, files []string) (bool, error) {
+	if len(files) < 1 {
+		return false, nil
+	}
+
+	f := files[0]
+	fStat, err := os.Stat(f)
+	if err != nil {
+		return false, err
+	}
+	fTime := fStat.ModTime()
+	for i := 1; i < len(files); i++ {
+		g := files[i]
+		gStat, err := os.Stat(g)
+		if err != nil {
+			return false, err
+		}
+		gTime := gStat.ModTime()
+
+		if gTime.Sub(fTime) < time.Second {
+			continue
+		}
+
+		if hasMovement, err := hasMovement(ctx, f, g); err != nil {
+			return false, fmt.Errorf("failed to check for movement between %s and %s: %w", f, g, err)
+		} else if hasMovement {
+			return true, nil
+		}
+
+		f = g
+		fTime = gTime
+	}
+	return false, nil
+}
+
 func hasMovement(ctx context.Context, a, b string) (bool, error) {
 	sizeOfCmd := exec.CommandContext(ctx, "identify", a)
 	sizeOfOutput, err := sizeOfCmd.CombinedOutput()

testdata/ffmpeg.d/cmd/prune/main_test.go

@@ -6,6 +6,7 @@ import (
 	"os"
 	"path"
 	"testing"
+	"time"
 )
 
 func TestRun(t *testing.T) {
@@ -23,16 +24,27 @@ func TestRun(t *testing.T) {
 		t.Fatal(err)
 	}
 
+	now := time.Now()
 	if err := os.WriteFile(path.Join(d, "series.0.jpg"), a, os.ModePerm); err != nil {
 		t.Fatal(err)
+	} else if err := os.Chtimes(path.Join(d, "series.0.jpg"), now, now.Add(-4000*time.Millisecond)); err != nil {
+		t.Fatal(err)
 	} else if err := os.WriteFile(path.Join(d, "series.1.jpg"), a, os.ModePerm); err != nil {
 		t.Fatal(err)
+	} else if err := os.Chtimes(path.Join(d, "series.1.jpg"), now, now.Add(-3500*time.Millisecond)); err != nil {
+		t.Fatal(err)
 	} else if err := os.WriteFile(path.Join(d, "series.2.jpg"), b, os.ModePerm); err != nil {
 		t.Fatal(err)
+	} else if err := os.Chtimes(path.Join(d, "series.2.jpg"), now, now.Add(-3000*time.Millisecond)); err != nil {
+		t.Fatal(err)
 	} else if err := os.WriteFile(path.Join(d, "series.3.jpg"), b, os.ModePerm); err != nil {
 		t.Fatal(err)
+	} else if err := os.Chtimes(path.Join(d, "series.3.jpg"), now, now.Add(-2500*time.Millisecond)); err != nil {
+		t.Fatal(err)
 	} else if err := os.WriteFile(path.Join(d, "zlast.0.jpg"), b, os.ModePerm); err != nil {
 		t.Fatal(err)
+	} else if err := os.Chtimes(path.Join(d, "zlast.0.jpg"), now, now.Add(-2000*time.Millisecond)); err != nil {
+		t.Fatal(err)
 	}
 
 	if err := Run(context.Background(), []string{path.Dir(d)}); err != nil {