Fix image thumbnail generation (#2524)

* Better logging for thumbnail generation errors
* Reduce verbosity for thumbnail generation
* Provide stdin during thumbnail generation

internal/api/routes_image.go

@@ -4,6 +4,7 @@ import (
 	"context"
 	"errors"
 	"net/http"
+	"os/exec"
 	"strconv"
 
 	"github.com/go-chi/chi"
@@ -50,6 +51,11 @@ func (rs imageRoutes) Thumbnail(w http.ResponseWriter, r *http.Request) {
 			// don't log for unsupported image format
 			if !errors.Is(err, image.ErrNotSupportedForThumbnail) {
 				logger.Errorf("error generating thumbnail for image: %s", err.Error())
+
+				var exitErr *exec.ExitError
+				if errors.As(err, &exitErr) {
+					logger.Errorf("stderr: %s", string(exitErr.Stderr))
+				}
 			}
 
 			// backwards compatibility - fallback to original image instead

internal/manager/task_scan_image.go

@@ -4,6 +4,7 @@ import (
 	"context"
 	"database/sql"
 	"errors"
+	"os/exec"
 	"path/filepath"
 	"time"
 
@@ -158,6 +159,11 @@ func (t *ScanTask) generateThumbnail(i *models.Image) {
 			// don't log for animated images
 			if !errors.Is(err, image.ErrNotSupportedForThumbnail) {
 				logger.Errorf("error getting thumbnail for image %s: %s", i.Path, err.Error())
+
+				var exitErr *exec.ExitError
+				if errors.As(err, &exitErr) {
+					logger.Errorf("stderr: %s", string(exitErr.Stderr))
+				}
 			}
 			return
 		}

pkg/ffmpeg/generate.go

@@ -5,6 +5,7 @@ import (
 	"context"
 	"errors"
 	"fmt"
+	"io"
 	"os/exec"
 	"strings"
 )
@@ -35,8 +36,14 @@ func (f FFMpeg) Generate(ctx context.Context, args Args) error {
 }
 
 // GenerateOutput runs ffmpeg with the given args and returns it standard output.
-func (f FFMpeg) GenerateOutput(ctx context.Context, args []string) ([]byte, error) {
+func (f FFMpeg) GenerateOutput(ctx context.Context, args []string, stdin io.Reader) ([]byte, error) {
 	cmd := f.Command(ctx, args)
+	cmd.Stdin = stdin
 
-	return cmd.Output()
+	ret, err := cmd.Output()
+	if err != nil {
+		return nil, fmt.Errorf("error running ffmpeg command <%s>: %w", strings.Join(args, " "), err)
+	}
+
+	return ret, nil
 }

pkg/ffmpeg/transcoder/image.go

@@ -20,6 +20,8 @@ func ImageThumbnail(input string, options ImageThumbnailOptions) ffmpeg.Args {
 	videoFilter = videoFilter.ScaleMaxSize(options.MaxDimensions)
 
 	var args ffmpeg.Args
+	args = append(args, "-hide_banner")
+	args = args.LogLevel(ffmpeg.LogLevelError)
 
 	args = args.Overwrite().
 		ImageFormat(options.InputFormat).

pkg/hash/videophash/phash.go

@@ -44,7 +44,7 @@ func generateSpriteScreenshot(encoder ffmpeg.FFMpeg, input string, t float64) (i
 	}
 
 	args := transcoder.ScreenshotTime(input, t, options)
-	data, err := encoder.GenerateOutput(context.Background(), args)
+	data, err := encoder.GenerateOutput(context.Background(), args, nil)
 	if err != nil {
 		return nil, err
 	}

pkg/image/thumbnail.go

@@ -117,5 +117,5 @@ func (e *ThumbnailEncoder) ffmpegImageThumbnail(image *bytes.Buffer, format stri
 		Quality:       ffmpegImageQuality,
 	})
 
-	return e.ffmpeg.GenerateOutput(context.TODO(), args)
+	return e.ffmpeg.GenerateOutput(context.TODO(), args, image)
 }