Windows Media Video 9 is already supported by a wide variety of players and devices. Content creators can use this profile to deliver either progressive or interlaced content at data rates as low as one-third that of the MPEG-2 codec—with the same quality as MPEG In the past, interlaced video content was always de-interlaced before encoding with the Windows Media Video codec.
Now, encoding applications such as Windows Media 9 Series, and third-party encoding solutions can support compression of interlaced content without first converting it to progressive content. Maintaining interlacing in an encoded file is important if the content is ever rendered on an interlaced display, such as a television. Transport independence also enables the delivery of Windows Media Video 9 Advanced Profile over systems that are not Windows Media-based, such as standards-based broadcast infrastructures through native MPEG-2 transport streams , wireless infrastructures using real-time transfer protocol [RTP] , or even DVDs.
The following table compares Windows Media Video 9 Advanced Profile to competing compression technology. The Windows Media Video 9 Screen codec is optimized for compressing sequential screen shots and highly static video that is captured from the computer display, which makes it ideal for delivering demos or demonstrating computer use for training.
The codec takes advantage of the typical image simplicity and relative lack of motion to achieve a very high compression ratio. During the encoding process, the codec automatically switches between lossy and lossless encoding modes, depending on the complexity of the video data. For complex data, the lossless mode preserves an exact copy of the data. For less complex data, the lossy mode discards some data to achieve a higher compression ratio.
By automatically switching between these two modes, the codec maintains video quality while maximizing compression. Overall, the Windows Media Video 9 Screen codec delivers better handling of bitmap images and screen motion, even on relatively modest CPUs.
It is also up to times more efficient than the commonly-used run length encoding. Instead of processing uncompressed video, it transforms still images into video by using pan, zoom, and cross-fade transitions between clips to create an unlimited number of effects.
The results can then be delivered at data rates as low as 20 kilobits per second Kbps. The following table outlines what your audience will experience when playing Windows Media Video 9 Series content on earlier Microsoft Windows operating systems or with earlier versions of Windows Media Player.
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Clear instructions. Easy to follow. No jargon. The following options are available, listed in order of compatibility with other hardware and software:. Most of the options available on the Rip menu are also available in a slightly different arrangement on the Rip Music tab of the Options dialog box.
Instead of choosing the bit rate from a menu, you use the Audio Quality slider, shown in Figure , to select a bit rate. Moving the slider to the left produces smaller files with lower quality; moving it to the right produces larger files with better audio quality. The Rip Settings section of this dialog box duplicates choices available from the Rip menu on the Player taskbar. If you right-click the icon for an audio CD in Windows Explorer and choose Explore from the shortcut menu, you'll see that each track is listed as a small file with the file type CD Audio Track, the.
Most of that information is completely wrong and represents a confused attempt by Windows Explorer to make sense of a format it wasn't designed to read. CD Audio is not a file format; instead, these pointers serve as shortcuts to the actual files, which are stored in a format that is essentially identical to a WAV file. You can't copy a CD track directly to your hard drive from Windows Explorer, and the default ripping options compress the resulting file so that it loses some quality.
Either format will work if your goal is to create a nearly identical copy of a CD using burning software. Notice we said "a nearly identical copy" The process of ripping a track from a CD is not perfect, especially if the media is scratched.
Tiny errors caused by the mechanical operation of the drive components—a single bit here and a couple of bits there—will inevitably creep in when you rip a file, even if you use a lossless format. Similar errors can result when you use the "copy CD" option available in most commercial CD-burning software. Perfectionists who want to make a perfect copy of a single music track or an entire CD need to take special precautions to prevent these errors from occurring.
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