let mut envelopes = ParsedEnvelope::from_transaction(tx).into_iter().peekable();
    let mut floating_inscriptions = Vec::new();
    let mut inscribed_offsets = BTreeMap::new();
    let mut total_input_value = 0;
    let mut id_counter = 0;

    for (input_index, tx_in) in tx.input.iter().enumerate() {
      // skip subsidy since no inscriptions possible
      if tx_in.previous_output.is_null() {
        total_input_value += Height(self.height).subsidy();
        continue;
      }

      // find existing inscriptions on input (transfers of inscriptions)
      for (old_satpoint, inscription_id) in Index::inscriptions_on_output(
        self.satpoint_to_sequence_number,
        self.sequence_number_to_entry,
        tx_in.previous_output,
      )? {
        let offset = total_input_value + old_satpoint.offset;
        floating_inscriptions.push(Flotsam {
          offset,
          inscription_id,
          origin: Origin::Old { old_satpoint },
        });

        inscribed_offsets
          .entry(offset)