Feed frames until receiving a packet

pkg/codec/svtav1/svtav1.go

@@ -88,36 +88,39 @@ func (e *encoder) Read() ([]byte, func(), error) {
 		return nil, func() {}, io.EOF
 	}
 
-	img, release, err := e.r.Read()
-	if err != nil {
-		return nil, func() {}, err
-	}
-	defer release()
-	yuvImg := img.(*image.YCbCr)
+	for {
+		img, release, err := e.r.Read()
+		if err != nil {
+			return nil, func() {}, err
+		}
+		defer release()
+		yuvImg := img.(*image.YCbCr)
 
-	if err := errFromC(C.enc_send_frame(
-		e.engine,
-		(*C.uchar)(&yuvImg.Y[0]),
-		(*C.uchar)(&yuvImg.Cb[0]),
-		(*C.uchar)(&yuvImg.Cr[0]),
-		C.int(yuvImg.YStride),
-		C.int(yuvImg.CStride),
-	)); err != nil {
-		return nil, func() {}, err
-	}
+		if err := errFromC(C.enc_send_frame(
+			e.engine,
+			(*C.uchar)(&yuvImg.Y[0]),
+			(*C.uchar)(&yuvImg.Cb[0]),
+			(*C.uchar)(&yuvImg.Cr[0]),
+			C.int(yuvImg.YStride),
+			C.int(yuvImg.CStride),
+		)); err != nil {
+			return nil, func() {}, err
+		}
 
-	var buf *C.EbBufferHeaderType
-	if err := errFromC(C.enc_get_packet(e.engine, &buf)); err != nil {
-		return nil, func() {}, err
-	}
-	if buf == nil {
-		return []byte{}, func() {}, nil
-	}
+		var buf *C.EbBufferHeaderType
+		if err := errFromC(C.enc_get_packet(e.engine, &buf)); err != nil {
+			return nil, func() {}, err
+		}
+		if buf == nil {
+			// Feed frames until receiving a packet
+			continue
+		}
 
-	encoded := C.GoBytes(unsafe.Pointer(buf.p_buffer), C.int(buf.n_filled_len))
-	C.svt_av1_enc_release_out_buffer(&buf)
+		encoded := C.GoBytes(unsafe.Pointer(buf.p_buffer), C.int(buf.n_filled_len))
+		C.svt_av1_enc_release_out_buffer(&buf)
 
-	return encoded, func() {}, err
+		return encoded, func() {}, err
+	}
 }
 
 // TODO: Implement bit rate control