From 4614471ad9dac96d65e22c41f4284a61daa2298d Mon Sep 17 00:00:00 2001
From: WithoutPants <53250216+WithoutPants@users.noreply.github.com>
Date: Thu, 7 Mar 2024 09:02:45 +1100
Subject: [PATCH] Fix ffmpeg error when trying to scale and copy video (#4660)

---
 internal/manager/task_transcode.go | 23 +++++++++++++----------
 pkg/scene/generate/transcode.go    | 27 ++++++---------------------
 2 files changed, 19 insertions(+), 31 deletions(-)

diff --git a/internal/manager/task_transcode.go b/internal/manager/task_transcode.go
index edda08fbb..2897cd2b9 100644
--- a/internal/manager/task_transcode.go
+++ b/internal/manager/task_transcode.go
@@ -26,7 +26,7 @@ func (t *GenerateTranscodeTask) GetDescription() string {
 	return fmt.Sprintf("Generating transcode for %s", t.Scene.Path)
 }
 
-func (t *GenerateTranscodeTask) Start(ctc context.Context) {
+func (t *GenerateTranscodeTask) Start(ctx context.Context) {
 	hasTranscode := HasTranscode(&t.Scene, t.fileNamingAlgorithm)
 	if !t.Overwrite && hasTranscode {
 		return
@@ -72,23 +72,26 @@ func (t *GenerateTranscodeTask) Start(ctc context.Context) {
 
 	w, h := videoFile.TranscodeScale(transcodeSize.GetMaxResolution())
 
-	options := generate.TranscodeOptions{
-		Width:  w,
-		Height: h,
-	}
+	// if scale is being set, then we can't use stream copy
+	scaleSet := w == 0 && h == 0
 
-	if videoCodec == ffmpeg.H264 { // for non supported h264 files stream copy the video part
+	if scaleSet && videoCodec == ffmpeg.H264 { // for non supported h264 files stream copy the video part
 		if audioCodec == ffmpeg.MissingUnsupported {
-			err = t.g.TranscodeCopyVideo(context.TODO(), videoFile.Path, sceneHash, options)
+			err = t.g.TranscodeCopyVideo(ctx, videoFile.Path, sceneHash)
 		} else {
-			err = t.g.TranscodeAudio(context.TODO(), videoFile.Path, sceneHash, options)
+			err = t.g.TranscodeAudio(ctx, videoFile.Path, sceneHash)
 		}
 	} else {
+		options := generate.TranscodeOptions{
+			Width:  w,
+			Height: h,
+		}
+
 		if audioCodec == ffmpeg.MissingUnsupported {
 			// ffmpeg fails if it tries to transcode an unsupported audio codec
-			err = t.g.TranscodeVideo(context.TODO(), videoFile.Path, sceneHash, options)
+			err = t.g.TranscodeVideo(ctx, videoFile.Path, sceneHash, options)
 		} else {
-			err = t.g.Transcode(context.TODO(), videoFile.Path, sceneHash, options)
+			err = t.g.Transcode(ctx, videoFile.Path, sceneHash, options)
 		}
 	}
 
diff --git a/pkg/scene/generate/transcode.go b/pkg/scene/generate/transcode.go
index 6528f91da..f08d2c05b 100644
--- a/pkg/scene/generate/transcode.go
+++ b/pkg/scene/generate/transcode.go
@@ -32,19 +32,19 @@ func (g Generator) TranscodeVideo(ctx context.Context, input string, hash string
 }
 
 // TranscodeAudio will copy the video stream as is, and transcode audio.
-func (g Generator) TranscodeAudio(ctx context.Context, input string, hash string, options TranscodeOptions) error {
+func (g Generator) TranscodeAudio(ctx context.Context, input string, hash string) error {
 	lockCtx := g.LockManager.ReadLock(ctx, input)
 	defer lockCtx.Cancel()
 
-	return g.makeTranscode(lockCtx, hash, g.transcodeAudio(input, options))
+	return g.makeTranscode(lockCtx, hash, g.transcodeAudio(input))
 }
 
 // TranscodeCopyVideo will copy the video stream as is, and drop the audio stream.
-func (g Generator) TranscodeCopyVideo(ctx context.Context, input string, hash string, options TranscodeOptions) error {
+func (g Generator) TranscodeCopyVideo(ctx context.Context, input string, hash string) error {
 	lockCtx := g.LockManager.ReadLock(ctx, input)
 	defer lockCtx.Cancel()
 
-	return g.makeTranscode(lockCtx, hash, g.transcodeCopyVideo(input, options))
+	return g.makeTranscode(lockCtx, hash, g.transcodeCopyVideo(input))
 }
 
 func (g Generator) makeTranscode(lockCtx *fsutil.LockContext, hash string, generateFn generateFn) error {
@@ -129,19 +129,11 @@ func (g Generator) transcodeVideo(input string, options TranscodeOptions) genera
 	}
 }
 
-func (g Generator) transcodeAudio(input string, options TranscodeOptions) generateFn {
+func (g Generator) transcodeAudio(input string) generateFn {
 	return func(lockCtx *fsutil.LockContext, tmpFn string) error {
-		var videoArgs ffmpeg.Args
-		if options.Width != 0 && options.Height != 0 {
-			var videoFilter ffmpeg.VideoFilter
-			videoFilter = videoFilter.ScaleDimensions(options.Width, options.Height)
-			videoArgs = videoArgs.VideoFilter(videoFilter)
-		}
-
 		args := transcoder.Transcode(input, transcoder.TranscodeOptions{
 			OutputPath: tmpFn,
 			VideoCodec: ffmpeg.VideoCodecCopy,
-			VideoArgs:  videoArgs,
 			AudioCodec: ffmpeg.AudioCodecAAC,
 		})
 
@@ -149,14 +141,8 @@ func (g Generator) transcodeAudio(input string, options TranscodeOptions) genera
 	}
 }
 
-func (g Generator) transcodeCopyVideo(input string, options TranscodeOptions) generateFn {
+func (g Generator) transcodeCopyVideo(input string) generateFn {
 	return func(lockCtx *fsutil.LockContext, tmpFn string) error {
-		var videoArgs ffmpeg.Args
-		if options.Width != 0 && options.Height != 0 {
-			var videoFilter ffmpeg.VideoFilter
-			videoFilter = videoFilter.ScaleDimensions(options.Width, options.Height)
-			videoArgs = videoArgs.VideoFilter(videoFilter)
-		}
 
 		var audioArgs ffmpeg.Args
 		audioArgs = audioArgs.SkipAudio()
@@ -164,7 +150,6 @@ func (g Generator) transcodeCopyVideo(input string, options TranscodeOptions) ge
 		args := transcoder.Transcode(input, transcoder.TranscodeOptions{
 			OutputPath: tmpFn,
 			VideoCodec: ffmpeg.VideoCodecCopy,
-			VideoArgs:  videoArgs,
 			AudioArgs:  audioArgs,
 		})