Windows Media File Editor
Information in this document, including URL and other Internet Web site references, is subject to change without notice. Unless otherwise noted, the example companies, organizations, products, people and events depicted herein are fictitious and no association with any real company, organization, product, person or event is intended or should be inferred. Complying with all applicable copyright laws is the responsibility of the user. Without limiting the rights under copyright, no part of this document may be reproduced, stored in or introduced into a retrieval system, or transmitted in any form or by any means (electronic, mechanical, photocopying, recording, or otherwise), or for any purpose, without the express written permission of Microsoft Corporation.
Microsoft may have patents, patent applications, trademarks, copyrights, or other intellectual property rights covering subject matter in this document. Except as expressly provided in any written license agreement from Microsoft, the furnishing of this document does not give you any license to these patents, trademarks, copyrights, or other intellectual property.
© 2000-2002 Microsoft Corporation. All rights reserved.
Microsoft, MS-DOS, Windows, Windows Media, Windows NT, ActiveSync, ActiveX, Direct3D, DirectDraw, DirectInput, DirectMusic, DirectPlay, DirectShow, DirectSound, DirectX, FrontPage, JScript, Microsoft Press, MSN, NetShow, Outlook, PowerPoint, Visual Basic, Visual C++, Visual InterDev, Visual J++, Visual Studio, WebTV, Win32, and Win32s are either registered trademarks or trademarks of Microsoft Corporation in the U.S.A. and/or other countries.
The names of actual companies and products mentioned herein may be the trademarks of their respective owners.
Windows Media File Editor
Working with markers
Trimming a file
Inserting script commands
Adding display information
Folding multichannel audio down for stereo speakers
Controlling volume differences
Importing and exporting header files
Moving scripts from the stream to the header
Accessibility for people with disabilities
Accessibility features in Windows Media File Editor
Using keyboard shortcuts
Accessibility features in Windows Media File Editor Help
Keyboard shortcuts for using the Help window
Accessible products and services from Microsoft
Accessibility in Microsoft Windows
Adjusting Microsoft products for people with accessibility needs
Free step-by-step tutorials
Microsoft documentation in alternative formats
Assistive technology for Windows
Customer service for people who are deaf or hard-of-hearing
Getting more accessibility information
Glossary
Microsoft® Windows Media® File Editor is a tool that enables you to open and edit a Windows Media file with a .wmv, .wma, or .asf file name extension. For example, you can trim the start and end points of a file, and add attributes, markers, and script commands. You can also import and export header files if you want to save your edits or reuse edits you previously made.
Before you can use Windows Media File Editor, you must install the latest version of Microsoft Windows Media Player. To download the Player, see the Microsoft Web site.
Notes
When you save a file, it is automatically indexed at each key frame. By indexing the file, you can make use of the fast-forward and rewind features of a player while viewing the file.
It is not possible to edit a file that has been protected with digital rights management (DRM).
Working with markers
Trimming a file
Inserting script commands
Adding display information
Folding multichannel audio down for stereo speakers
Controlling volume differences
Importing and exporting header files
Moving scripts from the stream to the header
You can add markers, including the marker name and the time at which you want the marker to be located. Markers are useful for breaking up large Windows Media files into logical pieces. For example, if you are creating a Windows Media file from a presentation, you can add a marker for each major topic. When the file is played, users can pick a topic from a list and go to the pertinent portion of the file, rather than having to guess at the location.
Markers you have inserted are displayed along the marker bar. You can drag a marker to a different time location. To edit or remove a marker, double-click the marker indicator.
Windows Media File Editor
To add or edit a marker
To add or edit a marker
Click the Markers tab, and then click Markers.
Do one of the following:
To add a marker, click Add and then type the marker text and the time (in hh:mm:ss:t) at which you want the text to appear during playback of the file.
To edit a marker, highlight the marker, click Edit, and then modify the text or time values.
Working with markers
You can trim the start and end of a file to ensure that only the portion you want plays. When you save a file that you have trimmed, the trimmed portion is removed from the file.
Trimming will start at the key frame that is closest to the mark-in point you specify. Keep in mind that you must begin trimming after the first key frame or the file will not be trimmed.
Windows Media File Editor
To trim a file
To trim a file
Click the Markers tab.
To trim the start time of the file, do one of the following:
In the player window, click the play button, and then click Mark In at the point you want the file to be trimmed.
Drag the progress indicator of the Seek bar to the point at which you want the file to be trimmed, and then click Mark In.
In the time box, type the time at which you want the file to be trimmed, click Seek, and then click Mark In.
To trim the end time of the file, drag the progress indicator of the Seek bar to the point at which you want the file to be trimmed, and then click Mark Out.
Trimming a file
Using Windows Media File Editor, you can insert script commands into your Windows Media file. You can insert any script type and value. A player will automatically process the following types of script commands:
URL. If you insert the URL script command, a Web page will open when the file is played at the time you specify. If the file is rendered in a player that is embedded within a browser, the requested URL replaces the player, and users cannot view the rest of the file. You can get around this either by displaying the requested URL in a separate frame in the same browser instance or by opening an additional instance of the browser.
Text. If you create a TEXT script command, you can insert text strings that will appear in the Player along with your encoded content. For the captions to be visible, users must have enabled captions in their player.
Custom. You can insert custom script commands such as FILENAME, EVENT, and OPENEVENT (or any other script type and value). Use the FILENAME command to open a specific digital media file at the time you specify. The EVENT and OPENEVENT script commands can be used, for example, to insert an advertisement during playback. The OPENEVENT command precedes the actual EVENT. The OPENEVENT command allows the Player to prebuffer the content so that when the specified event occurs, the switch appears to be seamless. Note that the code for the specified event must be defined in the Windows Media metafile in order for the player to perform the specified event.
For detailed information about the script commands supported by Windows Media Player, see the Windows Media Player Software Development Kit (SDK). For information about script commands supported by Windows Media server, see the Windows Media Services SDK.
To insert a script command, you specify the type of command, the time at which you want the command to occur, and the parameter for the command. To insert a custom script command, type the script type and value in the Script Command Properties dialog box.
Script commands that you insert are displayed along the script command bar. You can drag a script command to a different time location. To edit or remove a script command, double-click the script command indicator.
Note
For playback on Windows Media Player 9 Series, users must first enable script commands to be invoked.
Windows Media File Editor
To add a script command
To edit a script command
To add a script command
Click the Markers tab, and then click Script Commands.
Click Add.
In Time, type the time (in hh:mm:ss:t) at which you want the script command to occur during playback of the file.
In Type, enter the script command you want.
In Parameter, type the parameter you want. For example, if you are adding a TEXT script command, type the text you want.
Inserting script commands
To edit a script command
Click the Markers tab, and then click Script Commands.
In the list, click the script command you want to edit, and then click Edit.
Modify the time, type, or parameter values.
Inserting script commands
You can add general information about your content, such as the title, description, and author. During playback, the information can be displayed in Windows Media Player and any other players based on the Windows Media Format SDK.
Windows Media File Editor
To add display information
To add display information
Click the Attributes tab and then, in General, type the information you want to display.
Adding display information
If you are editing a multichannel audio file, you can use the audio coefficients settings on the Attributes tab to customize how the six channels are folded down into two channels for playback with stereo speakers. Default values, which are calculated during encoding, will typically ensure a satisfactory playback experience. Note that the channels are automatically folded down during playback for users with stereo speakers (as configured in their Control Panel). This option is not available with a 7.1-channel audio file.
The values you specify are not absolute values. Instead, the overall gain of the channels is normalized to avoid distortion. The values you type must be between 0 and -144 decibels.
Windows Media File Editor
To specify fold-down values
To specify fold-down values
Click the Attributes tab and then, in 5.1 audio, specify the values you want to use.
Note
The values you specify are automatically converted to a negative value.
Folding multichannel audio down for stereo speakers
If you encode a file by using the Windows Media Audio 9 Professional or Windows Media Audio 9 Lossless codec, the peak and average values of the audio signal are calculated during encoding, and those values are placed in the header of the file. During file playback, users can can limit the difference between the softest and loudest sounds (the dynamic range) in the file using the Quiet Mode feature in the Player. This is useful, for example, for movie content that has a wide dynamic range; a user can limit the maximum loudness while maintaining voice intelligibility. (This feature is only available when the file is played on a computer running Microsoft Windows® XP, and using a player that is built on the Windows Media Format SDK.)
The Quiet Mode feature of the Player has three settings that affect dynamic range: off, little, and medium. By default, the settings affect the audio dynamic range during playback as follows:
Off. If the user has not turned the Quiet Mode feature on, then the peak and average values that were calculated during encoding are used during playback.
Little difference. The peak value of the audio signal is limited to 6 decibels above the average level.
Medium difference. The peak value of the audio signal is limited to 12 decibels above the average level.
When you use Windows Media File Editor to edit the file, you can specify different peak and average values than those that were calculated during encoding. Typically, it is recommended that you only adjust the peak value. Adjusting the average value will not compress the difference between loud and soft sounds. Instead it will cut or boost the overall average volume of the entire piece, which may produce undesirable distortion during playback. Changing the peak value affects the following changes to the settings of the Quiet Mode feature:
Off. If the user has not turned the Quiet Mode feature on, then the peak and average values that were calculated during encoding are used during playback.
Little difference. The peak value of the audio signal is limited to the median of the peak and average values you specified in Windows Media File Editor.
Medium difference. The peak value of the audio signal is limited to the peak value you specified in Windows Media File Editor.
Windows Media File Editor
To control volume differences
To control volume differences
Click the Attributes tab and then, in Audio dynamic range control, specify the peak value you want to use. (It is recommended that you do not adjust the average value.)
Notes
The value you type must be between 0 and -90 decibels. The peak value should always be a higher number (that is, less negative) than the average value.
Click Restore Defaults if you want to use the values that were calculated during encoding.
Controlling volume differences
Edits you make using Windows Media File Editor are stored in the header of the file you have edited (except for edits related to trimming a file). After you have completed editing a file, you can export the header information by using the Export header file command on the File menu. This is useful if you want to save a record of the information or if you want to reuse the information. To reuse a header file, use the Import header file command on the File menu.
The following paragraphs explain what happens to data that is already in the header of your Windows Media file when you import another header file:
Attributes such as title, author, copyright, or description. The existing values are overwritten with the values in the header file you import. (Any custom attributes in the imported header file are also imported, but not displayed in the user interface.)
Script commands. Existing script commands are not typically overwritten when you import a header file that has script commands in it. However, if you import a header file that has a script command at the same time, type, and parameter as a script command that is already in the Windows Media file, the existing script command is overwritten.
Markers. Existing markers are not overwritten when you import a header file with markers in it, unless there are two markers at the same time and with the same names. In this case, only one of the markers is saved.
Windows Media File Editor
To import or export a header file
To import or export a header file
On the File menu, click Import header file, and then enter the name of the header file you want to import.
-or-
On the File menu, click Export header file, and then enter a name for the header file you are exporting.
Importing and exporting header files
Script commands inserted during encoding (using Windows Media Encoder) are in a separate stream and therefore are not displayed when you open the file with Windows Media File Editor. Windows Media File Editor only displays script commands that are in the header for the file. If you want to edit the script commands, you can use Windows Media File Editor to move the script commands to the header of the file, after which they are available for editing.
Windows Media File Editor
To move scripts from the stream to the header
To edit a script command
To move scripts from the stream to the header
On the File menu, click Move Scripts to Header.
In File name, type the name of the output file.
You can now edit the script commands.
Moving scripts from the stream to the header
To edit a script command
Microsoft is committed to making its products and services easier for everyone to use. The following topics provide information about the features, products, and services that make Microsoft Windows Media File Editor more accessible for people with disabilities:
Accessibility features in Windows Media File Editor
Accessibility features in Windows Media File Editor Help
Accessible products and services from Microsoft
Note
The information in this section applies only to users who license Microsoft products in the United States. If you obtained this product outside the United States, your package contains a subsidiary information card listing Microsoft support services telephone numbers and addresses. You can contact your subsidiary to find out whether the products and services described in this section are available in your area. Accessibility information is available in other select languages, including Japanese and French. For more information, see the see the Microsoft Web site.
In addition to accessibility features and utilities in Windows, the following feature makes Windows Media File Editor more accessible for people with disabilities:
Using keyboard shortcuts
Accessibility for people with disabilities
By using the following keyboard shortcuts in Windows Media File Editor, you can quickly accomplish many common tasks.
|
To do this. |
Use this keyboard shortcut. |
|
Display Help. |
F1 |
|
Move forward through options. |
TAB |
|
Move backward through options. |
SHIFT+TAB |
|
Switch between tabs. |
CTRL+TAB |
|
Scroll up one item in a list. |
UP ARROW |
|
Scroll down one item in a list. |
DOWN ARROW |
|
Dismiss a dialog box (Cancel). |
ESC |
|
Cut the selected items and copy them to the Clipboard. |
CTRL+X |
|
Copy the selected items to the Clipboard. |
CTRL+C |
|
Paste the contents of the Clipboard at the selected location. |
CTRL+V |
|
Close current window. |
ALT+F4 |
|
Display shortcut menu. |
SHIFT+F10 |
|
Select or clear the selection of an item. |
SPACEBAR |
|
Display shortcut keys. |
ALT |
|
Switch to High Contrast mode. |
LEFT ALT+LEFT SHIFT+PRINT SCREEN |
Accessibility for people with disabilities
Windows Media File Editor Help includes features that make it accessible to a wider range of users, including those who have limited dexterity, low vision, or other disabilities.
In addition, Windows Media File Editor Help is available on the Web at the Microsoft Web site.
Accessibility for people with disabilities
By using the following keyboard shortcuts in Help, you can quickly accomplish many common tasks.
|
To do this. |
Use this keyboard shortcut. |
|
Display the Help window. |
F1 |
|
Switch between the Help topic and the Contents, Search, and Index tabs. |
F6 |
|
Select the next hidden text or hyperlink. |
TAB |
|
Select the previous hidden text or hyperlink. |
SHIFT+TAB |
|
Perform the action for the selected Show All, Hide All, hidden text, or hyperlink. |
ENTER |
|
Display the Options menu to access any Help toolbar command. |
ALT+O |
|
Hide or show the pane containing the Contents, Search, and Index tabs. |
ALT+O, and then press T |
|
Display the previously viewed topic |
ALT+O, and then press B |
|
Display the next topic in a previously displayed sequence of topics. |
ALT+O, and then press F |
|
Return to the specified home page. |
ALT+O, and then press H |
|
Stop the Help window from opening a Help topic (useful if you want to stop a Web page from downloading). |
ALT+O, and then press S |
|
Open the Internet Options dialog box for Microsoft Internet Explorer, where you can change accessibility settings. |
ALT+O, and then press I |
|
Refresh the topic (useful if you have linked to a Web page). |
ALT+O, and then press R |
|
Print all topics in a book or a selected topic only. |
ALT+O, and then press P |
|
Close the Help window. |
ALT+F4 |
Accessibility features in Windows Media File Editor Help
To change the appearance of a Help topic
To customize the colors, font styles, and font sizes used in Help, open the Help window.
Click Options, and then click Internet Options.
On the General tab, click Accessibility. Select Ignore colors specified on Web pages, Ignore font styles specified on Web pages, and Ignore font sizes specified on Web pages. You also can choose to use the settings specified in your own style sheet.
To change the colors used in Help, see To change the color of the background or text in Help. To change the font, see To change the font in Help.
Accessibility features in Windows Media File Editor Help
To change the color of the background or text in Help
Open the Help window.
Click Options, and then click Internet Options.
On the General tab, click Accessibility. Then select Ignore colors specified on Web pages. You also can choose to use the settings specified in your own style sheet.
To customize the colors used in Help, on the General tab, click Colors. Clear the Use Windows Colors check box, and then select the font and background colors you want to use.
Note
If you change the background color of the Help topics in the Help window, the change also affects the background color when you view a Web page in Microsoft Internet Explorer.
Accessibility features in Windows Media File Editor Help
To change the font in Help
Open the Help window.
Click Options, and then click Internet Options.
On the General tab, click Accessibility. To use the same settings as those used in your instance of Microsoft Internet Explorer, select Ignore font styles specified on Web pages and Ignore font sizes specified on Web pages. You also can choose to use the settings specified in your own style sheet.
To customize the font style used in Help, on the General tab, click Fonts, and then click the font style you want.
Note
If you change the font of the Help topics in the Help window, the change also affects the font when you view a Web page in Microsoft Internet Explorer.
Accessibility features in Windows Media File Editor Help
The following topics provide information about the features, products, and services that make this Microsoft product more accessible for people with disabilities:
Accessibility in Microsoft Windows
Adjusting Microsoft products for people with accessibility needs
Free step-by-step tutorials
Microsoft documentation in alternative formats
Assistive technology for Windows
Customer service for people who are deaf or hard-of-hearing
Getting more accessibility information
The information in this section applies only to users who license Microsoft products in the United States. If you obtained this product outside the United States, your package contains a subsidiary information card listing Microsoft support services telephone numbers and addresses. You can contact your subsidiary to find out whether the type of products and services described in this section are available in your area. Accessibility is available in other select languages, including Japanese and French. For more information, see the Microsoft Web site.
Accessibility for people with disabilities
Many accessibility features have been built into Microsoft Windows, starting with the introduction of Windows 95. These features are useful for individuals who have difficulty typing or using a mouse, are blind or have low vision, or who are deaf or hard-of-hearing. The features can be installed during setup. For more information about the various accessibility features of Microsoft Products, such as Microsoft Windows XP Professional, Windows XP Home Edition, Windows Millennium Edition, Windows 2000, Windows 98, and Windows 95, see the Microsoft Web site.
Accessible products and services from Microsoft
Accessibility options and features are built into many Microsoft products, including the Windows operating system. Accessibility options and features are useful for individuals who have difficulty typing or using a mouse, are blind or have low vision, or who are deaf or hard-of-hearing.
Accessible products and services from Microsoft
Microsoft offers a series of step-by-step tutorials to help you learn how to adjust the accessibility options and settings on your computer. The tutorials provide detailed procedures on how to adjust options, features, and settings to meet the needs of people with disabilities and accessibility needs. This information is presented in a side-by-side format so that you can see at a glance how to use the mouse, the keyboard, or a combination of both.
To find step-by-step tutorials for Microsoft products, see the Accessibility section of the Microsoft Web site.
Accessible products and services from Microsoft
In addition to the standard formats, documentation for many Microsoft products is available in other formats to make it more accessible. If you have difficulty reading or handling printed materials, you can obtain the documentation for many Microsoft products in other, more accessible formats. You can download many of these books from the Microsoft Web site.
Microsoft produces an index of accessible documentation on the Accessibility section of the Microsoft Web site.
In addition, you can obtain additional Microsoft publications from Recording for the Blind & Dyslexic, Inc. These documents are distributed to registered, eligible members of their distribution service on audiocassettes or on floppy disks. The collection contains more than 80,000 titles, including Microsoft product documentation and books from Microsoft Press. For information about eligibility and availability of Microsoft product documentation and books from Microsoft Press, contact:
Recording for the Blind & Dyslexic,
Inc.
20 Roszel Road
Princeton, NJ 08540
Phone from within the United States: (800) 221-4792
Phone from outside the United States and Canada: (609) 452-0606
Fax: (609) 987-8116
Recording for the Blind & Dyslexic Web site
Web addresses can change, so you might be unable to connect to the Web site or sites mentioned here.
Accessible products and services from Microsoft
A wide variety of accessibility aids, or assistive technology products, are available to make computers easier to use for people with disabilities.
Microsoft provides a searchable catalog of accessibility aids that run on Microsoft Windows operating systems at the Accessibility section of the Microsoft Web site.
Among the different types of products available for the MS-DOS, Windows, and Windows NT operating systems are:
Programs that enlarge the information displayed or alter the color of information on the screen for people with visual impairments.
Programs that describe information on the screen in Braille or synthesized speech for people who are blind or have difficulty reading.
Hardware and software utilities that modify the behavior of the mouse and keyboard.
Programs that enable people to type by using a mouse or their voice.
Word or phrase prediction software that enable users to type more quickly and with fewer keystrokes.
Alternative input devices, such as single switch or puff-and-sip devices, for people who cannot use a mouse or a keyboard.
If you use assistive technology, before you upgrade either your software or hardware, be sure to contact your assistive technology vendor to check compatibility with products on your computer. Your assistive technology vendor can also help you learn how to adjust your settings to optimize compatibility with your version of Windows or other Microsoft products.
If you are deaf or hard-of-hearing, complete access to Microsoft product and customer services is available through a text telephone (TTY/TDD) service.
You can contact Microsoft Sales Information Center on a text telephone by dialing (800) 892-5234 between 6:30 AM and 5:30 PM Pacific time, Monday through Friday, excluding holidays.
For technical assistance in the United States, you can contact Microsoft Product Support Services on a text telephone at (800) 892-5234 between 6:00 AM and 6:00 PM Pacific time, Monday through Friday, excluding holidays. In Canada, dial (905) 568-9641 between 8:00 AM and 8:00 PM Eastern time, Monday through Friday, excluding holidays. Microsoft support services are subject to the prices, terms, and conditions in place at the time the service is used.
Accessible products and services from Microsoft
The Accessibility section of the Microsoft Web site provides information about accessible technology to help improve the lives of people with disabilities by making computers a positive force in employment, education, and recreation. The information on this site benefits people with disabilities and their friends and family members, people in outreach organizations, educators, and advocates.
A free monthly newsletter is offered through e-mail to help you keep up to date with accessibility topics about Microsoft products at the Accessibility section of the Microsoft Web site.
Accessible products and services from Microsoft
To find a term in the glossary, click the letter of the alphabet that is the first letter in the term you want to look up.
You can also read glossary terms within the text of Help by clicking the underlined glossary term links. After you click a glossary link, the glossary term and definition appear in a pop-up window. To close the window, click anywhere on the screen.
|
A |
B |
C |
D |
E |
F |
G |
H |
I |
J |
K |
L |
M |
|
N |
O |
P |
Q |
R |
S |
T |
U |
V |
W |
X |
Y |
Z |
The file name extension of a profile.
The file name extension of a configuration file used by Windows Media Encoding Script.
The file name extension of an audio file in Windows Media Format. The audio content of the file is encoded with the Windows Media Audio codec.
The file name extension for a Windows Media Encoder session file.
The file name extension of a video file in Windows Media Format.
A Windows Media metafile that gives a player the information needed to receive content. Announcement files contain Extensible Markup Language (XML) scripts.
The ratio of the width of an image to its height.
A multimedia file format for storing sound and moving pictures in RIFF format.
See definition for: Audio Video Interleaved (AVI)
A network's capacity for transferring an amount of data in a given time.
The number of bits transferred per second.
Text that accompanies images or videos, either as a supplemental description or a transcript of spoken words.
See definition for: constant bit rate (CBR)
An abbreviation for compressor/decompressor. Software or hardware used to compress and decompress digital media.
A process for removing redundant data from a digital media file or stream to reduce its size or the bandwidth used.
A text file used by Windows Media Encoding Script that specifies the content to be encoded and the command-line options to be invoked.
A characteristic of a data stream in which the bit rate remains nearly uniform for the duration of the stream.
See also: variable bit rate (VBR)
Audio, video, images, text, or any other information that is contained in a digital media file or stream.
To combine the interlaced fields in a video frame so that, during playback, the lines of the video frame are painted sequentially.
See also: interlace
A video frame that contains only the changes from the previous frame. In contrast, a key frame contains all the data necessary to construct that frame.
The difference (in decibels) between the quietest and loudest sounds in a single piece of audio content.
To convert audio and video content to a specified digital format.
The number of video frames displayed per second. Higher frame rates generally produce smoother movement in the picture.
A part of the file structure that contains information required by an application to decompress and render the content. The header in a protected file also contains information required to get a license.
See definition for: Institute of Electrical and Electronics Engineers (IEEE) 1394
A high-speed serial bus standard that provides enhanced computer connectivity for a wide range of devices, including consumer electronics audio/video (A/V) appliances, storage peripherals, other computers, and portable devices.
A type of streaming that detects network conditions and adjusts the properties of a video or audio stream to maximize quality.
To display a video frame in two fields. One field contains the even lines of the frame, the other field contains the odd lines. During playback, the lines in one field are displayed first, then the lines in the second field are displayed.
A revised version of the Internet Protocol (IP) designed to address growth on the Internet. Improvements include a 128 bit IP address size, expanded routing capabilities, and support for authentication and privacy.
The process that removes the frames that were added when 24-fps film was converted to 30-fps video.
See definition for: Internet Protocol version 6 (IPv6)
A video frame containing all the data needed to construct an image without reference to previous frames.
See also: delta frame
The delay that occurs while data is processed or delivered.
A video display format in which black bars appear above and below the video image while it is played. The letterbox format maintains the original aspect ratio of an image when it is displayed in a window with a different aspect ratio.
Data attached to protected content that describes how the content can be used.
To repeat a stream continuously.
A process for compressing data in which information is arranged in a more concise form and restored to its original state upon decompression.
A process for compressing data in which information deemed unnecessary is removed and cannot be recovered upon decompression. Typically used with audio and visual data in which a slight degradation of quality is acceptable.
A text string that is associated with a designated time in Windows Media-based content. Markers often denote convenient points to begin playback, such as the start of a new scene.
See definition for: multiple bit rate (MBR)
Data about data. Title, subject, author, and size are examples of a file's metadata.
A content delivery method in which a single stream is transmitted from a media server to multiple clients. The clients have no connection with the server. Instead, the server sends a single copy of the stream across the network to multicast-enabled routers, which replicate the data. Clients can then receive the stream by monitoring a specific multicast IP address and port.
An audio reproduction system that processes several, typically more than two, channels of sound. For example, 5.1 multichannel audio refers to a surround sound system in which there are five primary channels and a subwoofer channel.
A characteristic of a data stream in which the same content is encoded at several different bit rates in order to optimize content delivery.
The dominant television standard in the United States and Japan. NTSC delivers 30 interlaced frames per second at 525 lines of resolution.
See definition for: National Television Standards Committee (NTSC)
An encoding method in which content is analyzed and compressed in the same pass through the encoder.
See also: two-pass encoding
See definition for: Phase Alternating Line (PAL)
See definition for: pulse code modulation (PCM)
The dominant television standard in Europe and China. PAL delivers 25 interlaced frames per second at 625 lines of resolution.
The size and arrangement of pixel color components. The format is specified by the total number of bits used per pixel and the number of bits used to store the red, green, blue, and alpha components of the color of the pixel.
To extend the amount of encoded video by a specified number of frames.
To capture or play a number of video frames or a portion of audio data before encoding or rendering begins, in order to allow the source device to stabilize. Also used as a noun to describe the portion of the data to be prerolled.
A group of settings that match content type and bit rate with appropriate audio and video codecs.
A tool provided with Windows Media Encoder that creates and edits the encoding profiles.
See also: profile
An organized memory location that translates a client request for content into the physical path on the server hosting the content. A publishing point essentially acts as a redirector.
To deliver data to a client only upon client request.
A technique for digitizing audio into an uncompressed format by assigning a value to the amplitude of the signal at fixed intervals.
To deliver data to a client without a client request for the data.
A color model that describes color information in terms of the red (R), green (G), and blue (B) intensities that make up the color.
The process of measuring the amplitude of an analog signal at regular intervals for the purpose of converting the signal into a digital format.
The frequency of sampling. The higher the sampling rate (that is, the more samples taken per unit of time), the more closely the digitized result resembles the original.
Named data that is associated with a designated time in Windows Media-based content. The data can be used by players to perform a specific action such as displaying a Web page.
Audio and video content that can be captured and encoded from devices installed on your computer or from a file.
Digital media that is in the process of being delivered in a continuous flow across a network.
Information about the properties of a stream, such as the codecs used, frame rate, and frame size. A player uses stream format information to decode a stream.
A file used by a player to decode a multicast stream.
See also: stream format
The film-to-video conversion system that adds frames to video to compensate for the differences in frame rates between film and video.
A digital signal applied to a stream. The signal assigns a number to every frame of video, representing hours, minutes, seconds, and frames.
An encoding method in which content is analyzed in one pass through the encoder, after which compression is applied in the second pass. See also one-pass encoding.
See definition for: User Datagram Protocol (UDP)
See definition for: Universal Naming Convention (UNC)
A method used by media servers for providing content to connected clients in which each client receives a discrete stream. No other client has access to that stream.
The full name of a resource on a network. It conforms to the \\servername\sharename syntax, where servername is the name of the server and sharename is the name of the shared resource. UNC names of directories or files can also include the directory path under the share name, with the following syntax: \\servername\sharename\directory\filename.
A connectionless transport protocol in the TCP/IP protocol stack that is used in cases where some packet loss is acceptable, for example, with digital media streams.
A characteristic of a data stream in which the bit rate fluctuates, depending upon the complexity of the data.
See definition for: variable bit rate (VBR)
A codec used to compress and decompress audio streams.
A file containing audio, video, or script data that is stored in Windows Media Format. Depending on their content and purpose, Windows Media files use a variety of file name extensions, such as: .wma, .wme, .wms, .wmv, .wmx, .wmz, or .wvx.
The format used by Microsoft Windows Media Technologies (or a third-party product that incorporates a licensed Windows Media technology) to author, store, edit, distribute, stream, or play timeline-based content.
In Windows Media Technologies, a file that provides information about Windows Media files and their presentation. File name extensions for Windows Media metafiles include .asx, .wax, .wvx, .wmx, and .nsc.
A codec used to compress and decompress sequences of screen images.
A codec used to compress and decompress video streams.
A color model that describes color information in terms of its brightness (luminance, or Y), and color (chrominance, or U and V).
|
