if frame size isn't divisable by 2 then use JPEG instead.

Overlord-Client/cmd/agent/capture/capture.go

@@ -536,6 +536,10 @@ func buildFrame(img *image.RGBA, display int, quality int) (wire.Frame, time.Dur
 	codec := blockCodec()
 
 	if codec == "h264" {
+		if width%2 != 0 || height%2 != 0 {
+			log.Printf("capture: h264 skipped for odd dimensions (%dx%d), falling back to jpeg", width, height)
+			codec = "jpeg"
+		} else {
 			h264Bytes, err := encodeH264Frame(img)
 			if err == nil && len(h264Bytes) > 0 {
 				prevMu.Lock()
@@ -555,6 +559,7 @@ func buildFrame(img *image.RGBA, display int, quality int) (wire.Frame, time.Dur
 			})
 			codec = "jpeg"
 		}
+	}
 
 	if !enableBlocks {
 		jpegBytes, err := encodeJPEG(img, quality)
@@ -636,6 +641,10 @@ func buildFrameHVNC(img *image.RGBA, display int, quality int) (wire.Frame, time
 
 	now := time.Now()
 	if codec == "h264" {
+		if width%2 != 0 || height%2 != 0 {
+			log.Printf("hvnc capture: h264 skipped for odd dimensions (%dx%d), falling back to jpeg", width, height)
+			codec = "jpeg"
+		} else {
 			h264Bytes, err := encodeH264Frame(img)
 			if err == nil && len(h264Bytes) > 0 {
 				prevMu.Lock()
@@ -656,6 +665,7 @@ func buildFrameHVNC(img *image.RGBA, display int, quality int) (wire.Frame, time
 			})
 			codec = "jpeg"
 		}
+	}
 
 	prevMu.Lock()
 	pf := prevFrame