pr, pw := io.Pipe()
	// Copy input to compressor
	opts := compressOpts
	if encrypted {
		// The values used for padding are not a security concern,
		// but we choose pseudo-random numbers instead of just zeros.
		rng := rand.New(rand.NewSource(time.Now().UnixNano()))
		opts = append([]s2.WriterOption{s2.WriterPadding(compPadEncrypted), s2.WriterPaddingSrc(rng)}, compressOpts...)
	}
	comp := s2.NewWriter(pw, opts...)

					if err := json.Unmarshal(buf.Bytes(), &ei); err == nil && ei.V2Obj != nil {
						verID := uuid.UUID(header.VersionID).String()
						if verID == "00000000-0000-0000-0000-000000000000" {
							// If the version ID is all zeros, use the signature as version ID.
							verID = fmt.Sprintf("null/%08x", header.Signature)
							v0 = verID
						}
						idx := ei.V2Obj.EcIndex