Latency results from the methods used to encode and decode the data. Subsequent DVD players now decode DTS natively or pass it through to an external decoder. The first is named encode process, the second decode. E-AC-3 decoders can also decode AC-3 bitstreams. Xpdf can decode LZW and read encrypted PDFs. The Viterbi algorithm is the optimum algorithm used to decode convolutional codes. A protocol analyzer is useful to collect, analyze, decode and store signals. WinDVD can decode Dolby TrueHD and DTS-HD MA and output it as LPCM. It supports the following different multimedia formats which it can natively decode and play back. Television sets with only analog tuners cannot decode digital transmissions. Also, the Xbox 360 cannot decode DTS from DTS audio CDs. Interpreting code is slower because the interpreter must decode each statement and then perform it. It can decode a H264 1080p video at up to 40 fps. The interrogator's processor will then decode the reply and identify the aircraft. FFmpeg version 3.3 or later can decode XPM.