Handle empty queue

pkg/codec/svtav1/bridge.h

@@ -110,6 +110,9 @@ int enc_encode(Encoder *e, EbBufferHeaderType **out, uint8_t *y, uint8_t *cb, ui
   }
 
   sret = svt_av1_enc_get_packet(e->handle, out, 0);
+  if (sret == EB_NoErrorEmptyQueue) {
+    return 0;
+  }
   if (sret != EB_ErrorNone) {
     return ERR_GET_PACKET;
   }

pkg/codec/svtav1/svtav1.go

@@ -108,6 +108,9 @@ func (e *encoder) Read() ([]byte, func(), error) {
 	if err := errFromC(ret); err != nil {
 		return nil, func() {}, err
 	}
+	if buf == nil {
+		return []byte{}, func() {}, nil
+	}
 
 	encoded := C.GoBytes(unsafe.Pointer(buf.p_buffer), C.int(buf.n_filled_len))
 	C.svt_av1_enc_release_out_buffer(&buf)