When we published the information on Skype releasing SILK audio Codec free we mentioned that the company mentioned that it is better than other codecs.
We were wondering about the claims without proof and we are sure many did, specially, we guess those developers of other codecs.
Skype will have none of it and has released some data and information on tests conducted by an independent lab. The comparision tests were done among Speex, AMRWideband, Silk. The graph above is the tests done under ideal conditions and the graph below depicts the same tests under data loss and seem to be doing better under the condition.(MOS (Mean Opinion Score) listening test was performed for Wideband speech signals by Dynastat, an independent 3rd party laboratory. Confidence intervals (95%) are +/- 0.1 MOS. All bitrates are measured and averaged over frames containing active speech. SILK and Speex were run in the highest complexity mode. Packet Loss and Office Noise tests were done with all codecs running at 18.25 kbps.)
But the dynamic adapatability of the codec under normal conditions that a audio in a normal speech meets is really noteble.
• Low Delay: 25 ms (20 ms frame size + 5 ms look-ahead)
• Lightweight and highly portable
– Data ROM: 14 kWords
– Data RAM: 9 kWords (static) + 5 kWords (scratch)
– Fixed Point ANSI C Code
• More information at Skype, Download SILK Data Sheet
Tuesday, March 03, 2009