| year | 2008 |
| author(s) | J. Wagner, V. Lindenstruth, M. Richter, T. Steinbeck, J. Thäder |
| title | Lossless Data Compression for ALICE HLT |
| KIP-Nummer | HD-KIP 08-67 |
| KIP-Gruppe(n) | F12 |
| document type | Paper |
| source | https://edms.cern.ch/document/948159 |
| Abstract (en) | This report introduces the High Level Trigger (HLT) component for lossless ALICE time projection chamber read out (ALTRO) data compression which is mainly based on the algorithm by D.A. Huffman. It is demonstrated that the direct input of the 10 bit ADC values from the ALTRO data blocks reaches comparable compression ratios to converting the outcome of the ALTRO chip into an 8 bit format before compressing. In order to assure a stable run without any error, the principle of the original algorithm was slightly modified to grant a code for every ADC value. Furthermore, the code is run time optimised for online processing, having already proved its HLT suitablity in a real configuration with 2 Hz running speed in the TPC commissioning in September 2007 |
