Merge pull request #36 from mutablelogic/ffmpeg61

Fixed bug with resampling

Author: djthorpe

etc/test/jfk.wav

@@ -111,15 +111,17 @@ func (d *Decoder) Close() error {
 // Decode a packet into a set of frames to pass back to the
 // DecoderFrameFn. If the packet is nil, then the decoder will
 // flush any remaining frames.
-// TODO: Optionally use the user defined packet function
-// if they want to use AVParser
-// TODO: The frame sent to DecoderFrameFn needs to have the
-// correct timebase, etc set
+// TODO: Optionally use the user defined packet function if they want to use AVParser
 func (d *Decoder) decode(packet *ff.AVPacket, fn DecoderFrameFn) error {
 	if fn == nil {
 		return ErrBadParameter.With("DecoderFrameFn is nil")
 	}
 
+	// Set the timebase for the packet
+	if packet != nil {
+		packet.SetTimeBase(d.timeBase)
+	}
+
 	// Submit the packet to the decoder (nil packet will flush the decoder)
 	if err := ff.AVCodec_send_packet(d.codec, packet); err != nil {
 		return ErrInternalAppError.With("AVCodec_send_packet:", err)
@@ -142,6 +144,9 @@ func (d *Decoder) decode(packet *ff.AVPacket, fn DecoderFrameFn) error {
 			return ErrInternalAppError.With("AVCodec_receive_frame:", err)
 		}
 
+		// Set the timebase for the frame
+		d.frame.SetTimeBase(packet.TimeBase())
+
 		// Obtain the output frame. If a new frame is returned, it is
 		// managed by the rescaler/resizer and no need to unreference it
 		// later.
@@ -161,12 +166,6 @@ func (d *Decoder) decode(packet *ff.AVPacket, fn DecoderFrameFn) error {
 			continue
 		}
 
-		// Copy across the timebase and pts
-		// TODO
-		//	fmt.Println("pts=", d.frame.Pts())
-		//	(*ff.AVFrame)(dest).SetPts(d.frame.Pts())
-		//	(*ff.AVFrame)(dest).SetTimeBase(d.timeBase)
-
 		// Pass back to the caller
 		if err := fn(d.stream, dest); errors.Is(err, io.EOF) {
 			// End early, return EOF

pkg/ffmpeg/decoder.go

@@ -168,3 +168,38 @@ func Test_reader_005(t *testing.T) {
 		t.FailNow()
 	}
 }
+
+func Test_reader_006(t *testing.T) {
+	assert := assert.New(t)
+
+	// Read a file
+	r, err := os.Open("../../etc/test/jfk.wav")
+	if !assert.NoError(err) {
+		t.FailNow()
+	}
+	defer r.Close()
+
+	input, err := ffmpeg.NewReader(r)
+	if !assert.NoError(err) {
+		t.FailNow()
+	}
+	defer input.Close()
+
+	// Map function - only audio streams
+	mapfn := func(stream int, par *ffmpeg.Par) (*ffmpeg.Par, error) {
+		if par.Type() == media.AUDIO {
+			t.Logf("Stream %v[%d] => %v", par.Type(), stream, par)
+			return par, nil
+		}
+		return nil, nil
+	}
+
+	framefn := func(stream int, frame *ffmpeg.Frame) error {
+		t.Log("Got frame", frame)
+		return nil
+	}
+
+	if err := input.Decode(context.Background(), mapfn, framefn); !assert.NoError(err) {
+		t.FailNow()
+	}
+}

pkg/ffmpeg/reader_test.go

@@ -107,7 +107,7 @@ func (r *resampler) Frame(src *Frame) (*Frame, error) {
 	}
 
 	// Check buffer
-	// TODO UGLY CODE ALERT
+	// TODO: UGLY CODE ALERT
 	if r.dest.NumSamples() < num_samples {
 		sample_fmt := r.dest.SampleFormat()
 		sample_rate := r.dest.SampleRate()

pkg/ffmpeg/resampler.go

@@ -68,6 +68,12 @@ 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 {
+		return err
+	}
 	if err := AVError(C.swr_convert_frame((*C.struct_SwrContext)(ctx), (*C.struct_AVFrame)(dest), (*C.struct_AVFrame)(src))); err != 0 {
 		return err
 	} else {