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WMV, ASF & MP3
WMV Video Format WMV Format is a video format developed by Microsoft and is designed to handle all types of video content. The files can be highly compressed and can be delivered as a continuous flow of data. WMV files can be of any size and can be compressed to match many different bandwidths (connection speeds). The WMV format is a derivative of the MPEG-4 (Motion Picture Expert Group) format. However, it's more efficient than MPEG-4 in encoding video and, while similar to the ASF format (Microsoft's Advanced Streaming Format), it allows for decreased file size. Using WMV is an excellent way to get file sizes down to reasonable levels while retaining watchable quality.
ASF (Advanced Streaming/Systems Format)
Advanced Streaming Format (ASF, later renamed into Advanced Systems Format) is Microsoft's proprietary digital audio/digital video wrapper, especially meant for streaming. ASF is part of the Windows Media framework.
The format does not specify how the video or audio should be encoded, but instead just specifies the structure of the video/audio stream. This means that ASF files can be encoded with basically any audio/video codec and still would be in ASF format.
ASF files can also contain objects representing metadata, such as the artist, title, album and genre for an audio track, or the director of a video track, much like the ID3 tags of MP3 files.
MP3 (MPEG Audio Layer 3)
MPEG Audio Layer 3 is an algorithm for audio compression that is part of the MPEG-1 and MPEG-2 specifications. MP3 was originally developed in Germany in 1991 by the Fraunhofer Institute as a technology that uses perceptual audio coding to compress CD-quality sound by a factor up to 12, while providing almost the same fidelity and quality. Compression efficiency of lossy data compression encoders is typically defined by the bitrate, because compression rate depends on bit depth and sampling rate of the input signal.
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