the Microsoft Zune (limited to stereo), Xbox 360, Windows Mobile-powered devices with Windows Media Player 10 Mobile, newer Toshiba Gigabeat and Motorola devices, and devices running recent versions of the Rockbox alternative firmware. In addition, WMA Pro is a requirement for the WMV HD certification program. On the software side, Verizon utilizes WMA 10 Pro for its V CAST Music Service, and Windows Media Player 11 has promoted the codec as an alternative to WMA for copying audio CD tracks. WMA Pro is supported in Silverlight as of version 2 (though only in stereo mode). In the absence of the appropriate audio hardware, WMA Pro can automatically downmix multichannel audio to stereo or mono, and 24-bit resolution to 16-bit during playback. A notable example of WMA Pro being used instead of WMA Standard is the NBC Olympics website which uses WMA 10 Pro in its low-bitrate mode at 48 kbit/s. Windows Media Audio Lossless Windows Media Audio 9 Lossless is a lossless incarnation of Windows Media Audio, an audio codec by Microsoft, released in early 2003. It compresses an audio CD to a range of 206 to 411 MB, at bit rates of 470 to 940 kbit/s. The result is a bit-for-bit duplicate of the original audio file; in other words, the audio quality on the CD will be the same as the file when played back. WMA Lossless uses the same .WMA file extension as other Windows Media Audio formats. It supports 6 discrete channels and up to 24-bit/96 kHz lossless audio. The format has never been publicly documented, although an open-source decoder has been reverse-engineered for non-Microsoft platforms by the libav and ffmpeg projects. Windows Media Audio Lossless (WMA Lossless) is a lossless audio codec that competes with ATRAC Advanced Lossless, Dolby TrueHD, DTS-HD Master Audio, Shorten, Monkey's Audio, FLAC, Apple Lossless, and WavPack (Since late 2011, the last three have the advantage of being open source software and available for nearly any operating system.) Designed for archival purposes, it compresses audio signals without loss of quality from the original using VBR. When decompressed, the audio signal is an exact replica of the original. The first version of the codec, WMA 9 Lossless, and its revisions support up to 96 kHz, 24-bit audio for up to 6 discrete channels (5.1 channel surround) with dynamic range compression control. The typical compression ratio for music varies between 1.7:1 and 3:1.