Updating scaling code

Author: djthorpe

pkg/ffmpeg/decoder.go

@@ -130,14 +130,12 @@ func (decoder *decoder) ResampleS16Mono(sample_rate int) error {
 		decoder.frame.ChannelLayout(), decoder.frame.SampleFormat(), decoder.frame.SampleRate(), // destination
 		decoder.codec.ChannelLayout(), decoder.codec.SampleFormat(), decoder.codec.SampleRate(), // source
 	); err != nil {
-		return err
+		return fmt.Errorf("SWResample_set_opts: %w", err)
 	}
 
 	// Initialize the resampling context
 	if err := ff.SWResample_init(ctx); err != nil {
-		return err
-	} else if err := ff.AVUtil_frame_get_buffer(decoder.frame, false); err != nil {
-		return err
+		return fmt.Errorf("SWResample_init: %w", err)
 	}
 
 	// Return success
@@ -168,11 +166,6 @@ func (decoder *decoder) Rescale(width, height int) error {
 		decoder.rescaler = ctx
 	}
 
-	// Allocate frame buffer
-	if err := ff.AVUtil_frame_get_buffer(decoder.frame, false); err != nil {
-		return err
-	}
-
 	// Return success
 	return nil
 }
@@ -207,15 +200,15 @@ func (decoder *decoder) re(src *ff.AVFrame) (*ff.AVFrame, error) {
 func (decoder *decoder) resample(dest, src *ff.AVFrame) error {
 	dest_samples, err := ff.SWResample_get_out_samples(decoder.resampler, src.NumSamples())
 	if err != nil {
-		return err
+		return fmt.Errorf("SWResample_get_out_samples: %w", err)
 	}
 
 	dest.SetNumSamples(dest_samples)
 	dest.SetPts(decoder.get_next_pts(src))
 
 	// Perform resampling
 	if err := ff.SWResample_convert_frame(decoder.resampler, src, dest); err != nil {
-		return err
+		return fmt.Errorf("SWResample_convert_frame: %w", err)
 	}
 
 	//fmt.Println("in_samples", src.NumSamples(), "out_samples", dest.NumSamples())
@@ -227,13 +220,13 @@ func (decoder *decoder) resample(dest, src *ff.AVFrame) error {
 
 func (decoder *decoder) rescale(dest, src *ff.AVFrame) error {
 	// Copy properties from source
-	if err := AVUtil_frame_copy_props(dest, src); err != nil {
-		return err
-	}
+	//if err := ff.AVUtil_frame_copy_props(dest, src); err != nil {
+	//	return fmt.Errorf("failed to copy props: %w", err)
+	//}
 
 	// Perform resizing
-	if err := ff.SWScale_scale_frame(decoder.rescaler, dest, src); err != nil {
-		return fmt.Errorf("failed to scale frame: %w", err)
+	if err := ff.SWScale_scale_frame(decoder.rescaler, dest, src, false); err != nil {
+		return fmt.Errorf("SWScale_scale_frame: %w", err)
 	}
 
 	// Return success

pkg/ffmpeg/reader.go

@@ -200,9 +200,6 @@ func (r *reader) Decode(fn FrameFunc) DecoderFunc {
 			} else if err != nil {
 				return err
 			}
-
-			// Unreference the frame
-			ff.AVUtil_frame_unref(r.frame)
 		}
 	}
 }

sys/ffmpeg61/swscale_core.go

@@ -1,6 +1,7 @@
 package ffmpeg
 
 import (
+	"fmt"
 	"unsafe"
 )
 
@@ -56,9 +57,56 @@ func SWScale_scale(ctx *SWSContext, src [][]byte, src_stride []int, src_slice_y,
 	))
 }
 
-// Scale source data from src and write the output to dst.
-func SWScale_scale_frame(ctx *SWSContext, dest, src *AVFrame) error {
-	if ret := C.sws_scale_frame((*C.struct_SwsContext)(ctx), (*C.struct_AVFrame)(dest), (*C.struct_AVFrame)(src)); ret != 0 {
+// Scale source data from src and write the output to dst. Need to find out
+// why the native version is returning -22 error TODO
+func SWScale_scale_frame(ctx *SWSContext, dest, src *AVFrame, native bool) error {
+	if native {
+		if ret := C.sws_scale_frame((*C.struct_SwsContext)(ctx), (*C.struct_AVFrame)(dest), (*C.struct_AVFrame)(src)); ret != 0 {
+			return AVError(ret)
+		}
+	} else {
+		if err := SWScale_frame_start(ctx, dest, src); err != nil {
+			return fmt.Errorf("SWScale_frame_start: %w", err)
+		}
+		if err := SWScale_send_slice(ctx, 0, uint(src.Height())); err != nil {
+			return fmt.Errorf("SWScale_send_slice: %w", err)
+		}
+		if err := SWScale_receive_slice(ctx, 0, uint(dest.Height())); err != nil {
+			return fmt.Errorf("SWScale_receive_slice: %w", err)
+		}
+		SWScale_frame_end(ctx)
+	}
+
+	// Return success
+	return nil
+}
+
+// Initialize the scaling process for a given pair of source/destination frames.
+func SWScale_frame_start(ctx *SWSContext, dest, src *AVFrame) error {
+	if ret := C.sws_frame_start((*C.struct_SwsContext)(ctx), (*C.struct_AVFrame)(dest), (*C.struct_AVFrame)(src)); ret != 0 {
+		return AVError(ret)
+	} else {
+		return nil
+	}
+}
+
+// Finish the scaling process for a pair of source/destination frames.
+func SWScale_frame_end(ctx *SWSContext) {
+	C.sws_frame_end((*C.struct_SwsContext)(ctx))
+}
+
+// Indicate that a horizontal slice of input data is available in the source frame
+func SWScale_send_slice(ctx *SWSContext, slice_start, slice_height uint) error {
+	if ret := C.sws_send_slice((*C.struct_SwsContext)(ctx), C.uint(slice_start), C.uint(slice_height)); ret < 0 {
+		return AVError(ret)
+	} else {
+		return nil
+	}
+}
+
+// Request a horizontal slice of the output data to be written into the frame
+func SWScale_receive_slice(ctx *SWSContext, slice_start, slice_height uint) error {
+	if ret := C.sws_receive_slice((*C.struct_SwsContext)(ctx), C.uint(slice_start), C.uint(slice_height)); ret < 0 {
 		return AVError(ret)
 	} else {
 		return nil