diff --git a/cmd/ffmpeg/resample_audio/main.go b/cmd/ffmpeg/resample_audio/main.go
index 198eb73..b3abf51 100644
--- a/cmd/ffmpeg/resample_audio/main.go
+++ b/cmd/ffmpeg/resample_audio/main.go
@@ -92,7 +92,7 @@ func main() {
 		}
 
 		// convert to destination format
-		n, err := ff.SWResample_convert(ctx, dest, dest_nb_samples, src, src_nb_samples)
+		n, err := ff.SWResample_convert(ctx, dest, src)
 		if err != nil {
 			log.Fatal(err)
 		}
diff --git a/pkg/ffmpeg/writer.go b/pkg/ffmpeg/writer.go
index c004348..f1bf62a 100644
--- a/pkg/ffmpeg/writer.go
+++ b/pkg/ffmpeg/writer.go
@@ -230,7 +230,7 @@ func (w *Writer) String() string {
 // Return a "stream" for encoding
 func (w *Writer) Stream(stream int) *Encoder {
 	for _, encoder := range w.encoders {
-		if encoder.stream.Index() == stream {
+		if encoder.stream.Id() == stream {
 			return encoder
 		}
 	}
@@ -327,21 +327,18 @@ func encode(in EncoderFrameFn, out EncoderPacketFn, encoders map[int]*Encoder) e
 	var frame *Frame
 	var err error
 	if !next_encoder.eof {
-		frame, err = in(next_stream)
+		// Get the frame based on the id (rather than index) of the stream
+		frame, err = in(next_encoder.stream.Id())
 		if errors.Is(err, io.EOF) {
 			next_encoder.eof = true
 		} else if err != nil {
-			return fmt.Errorf("stream %v: %w", next_stream, err)
+			return fmt.Errorf("stream %v: %w", next_encoder.stream.Id(), err)
 		}
 	}
-	// If frame not ready, try again
-	if frame == nil {
-		return nil
-	}
 
 	// Send a frame for encoding
 	if err := next_encoder.Encode(frame, out); err != nil {
-		return fmt.Errorf("stream %v: %w", next_stream, err)
+		return fmt.Errorf("stream %v: %w", next_encoder.stream.Id(), err)
 	}
 
 	// If eof then delete the encoder
@@ -351,7 +348,11 @@ func encode(in EncoderFrameFn, out EncoderPacketFn, encoders map[int]*Encoder) e
 	}
 
 	// Calculate the next PTS
-	next_encoder.next_pts = next_encoder.next_pts + next_encoder.nextPts(frame)
+	if frame != nil {
+		next_encoder.next_pts = next_encoder.next_pts + next_encoder.nextPts(frame)
+	}
+
+	// Return success
 	return nil
 }
 
diff --git a/pkg/ffmpeg/writer_test.go b/pkg/ffmpeg/writer_test.go
index d6e4b3e..b22441a 100644
--- a/pkg/ffmpeg/writer_test.go
+++ b/pkg/ffmpeg/writer_test.go
@@ -86,8 +86,8 @@ func Test_writer_002(t *testing.T) {
 	}
 	defer audio.Close()
 
-	// Write 15 mins of frames
-	duration := float64(15 * 60)
+	// Write 15 secs of frames
+	duration := float64(15)
 	assert.NoError(writer.Encode(context.Background(), func(stream int) (*ffmpeg.Frame, error) {
 		frame := audio.Frame()
 		if frame.Ts() >= duration {
@@ -166,7 +166,7 @@ func Test_writer_004(t *testing.T) {
 	}
 	defer w.Close()
 
-	// Create a writer with an audio stream
+	// Create a writer with an audio and video stream
 	writer, err := ffmpeg.Create(w.Name(),
 		ffmpeg.OptMetadata(ffmpeg.NewMetadata("title", t.Name())),
 		ffmpeg.OptStream(1, ffmpeg.VideoPar("yuv420p", "640x480", 30)),
@@ -200,6 +200,7 @@ func Test_writer_004(t *testing.T) {
 		case 2:
 			frame = audio.Frame()
 		}
+		t.Log("frame = ", stream, frame)
 		if frame.Ts() >= duration {
 			t.Log("Frame time is EOF", frame.Ts())
 			return nil, io.EOF
diff --git a/sys/ffmpeg61/swresample_convert.go b/sys/ffmpeg61/swresample_convert.go
index 6f5ad54..a12c30d 100644
--- a/sys/ffmpeg61/swresample_convert.go
+++ b/sys/ffmpeg61/swresample_convert.go
@@ -68,17 +68,22 @@ func SWResample_get_out_samples(ctx *SWRContext, in_samples int) (int, error) {
 
 // Convert the samples in the input AVFrame and write them to the output AVFrame.
 func SWResample_convert_frame(ctx *SWRContext, src, dest *AVFrame) error {
-	// TODO: This is likely a terrible idea but the only thing I can get to work
-	// at the moment. Later find out why swr_convert_frame isn't working.
 	// Ref: https://stackoverflow.com/questions/77502983/libswresample-why-does-swr-init-change-in-ch-layout-order-so-it-no-longer-m
-	if err := SWResample_config_frame(ctx, src, dest); err != nil {
+	if err := AVError(C.swr_convert_frame((*C.struct_SwrContext)(ctx), (*C.struct_AVFrame)(dest), (*C.struct_AVFrame)(src))); err == 0 {
+		return nil
+	} else if err != AVERROR_INPUT_CHANGED && err != AVERROR_OUTPUT_CHANGED {
+		return err
+	} else if err := SWResample_config_frame(ctx, src, dest); err != nil {
 		return err
 	}
+
+	// Try again
 	if err := AVError(C.swr_convert_frame((*C.struct_SwrContext)(ctx), (*C.struct_AVFrame)(dest), (*C.struct_AVFrame)(src))); err != 0 {
 		return err
-	} else {
-		return nil
 	}
+
+	// Return success
+	return nil
 }
 
 // Configure or reconfigure the SwrContext using the information provided by the AVFrames.