diff --git a/ffmpeg/ffmpeg.go b/ffmpeg/ffmpeg.go
index e5c03a6685..2ab2912a0a 100755
--- a/ffmpeg/ffmpeg.go
+++ b/ffmpeg/ffmpeg.go
@@ -248,12 +248,15 @@ type MediaFormatInfo struct {
 	Width, Height  int
 }
 
+
+// h.264 only allows even resolutions, so both functions round up the results
+// to the nearest even number
 func (f *MediaFormatInfo) ScaledHeight(width int) int {
-	return int(float32(width) * float32(f.Height) / float32(f.Width))
+	return int(float32(width) * float32(f.Height) / float32(f.Width) + 1) & (^1)
 }
 
 func (f *MediaFormatInfo) ScaledWidth(height int) int {
-	return int(float32(height) * float32(f.Width) / float32(f.Height))
+	return int(float32(height) * float32(f.Width) / float32(f.Height) + 1) & (^1)
 }
 
 func GetCodecInfo(fname string) (CodecStatus, MediaFormatInfo, error) {
@@ -540,6 +543,11 @@ func (l *CodingSizeLimit) Clamp(p *VideoProfile, format MediaFormatInfo) error {
 	if err != nil {
 		return err
 	}
+	// check if we _should_ clamp at all
+	if (l.WidthMin <= w) && (w <= l.WidthMax) && (l.HeightMin <= h) && (h <= l.HeightMax) {
+		// given video resolution is within encoder limits, no need for intervention
+		return nil
+	}
 	// detect correct rotation
 	outputAr := float32(w) / float32(h)
 	inputAr := float32(format.Width) / float32(format.Height)
@@ -569,7 +577,7 @@ func (l *CodingSizeLimit) Clamp(p *VideoProfile, format MediaFormatInfo) error {
 
 // 7th Gen NVENC limits:
 var nvidiaCodecSizeLimts = map[VideoCodec]CodingSizeLimit{
-	H264: {146, 50, 4096, 4096},
+	H264: {146, 145, 4096, 4096},
 	H265: {132, 40, 8192, 8192},
 }
 
diff --git a/ffmpeg/ffmpeg_test.go b/ffmpeg/ffmpeg_test.go
index 098e81d15a..507f68a4e7 100644
--- a/ffmpeg/ffmpeg_test.go
+++ b/ffmpeg/ffmpeg_test.go
@@ -1855,7 +1855,7 @@ func TestResolution_Clamp(t *testing.T) {
 	test(l, Size{1000, 500}, landscape, Size{700, 350})
 	test(l, Size{1000, 500}, portrait, Size{250, 500})
 	test(l, Size{500, 1000}, landscape, Size{700, 350})
-	test(l, Size{600, 300}, portrait, Size{250, 500})
+	test(l, Size{600, 300}, portrait, Size{600, 300})
 	test(l, Size{300, 600}, portrait, Size{250, 500})
 
 	// Test impossible limits for aspect ratio == 2