Windows Media Encoder

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Windows Media Encoder

Microsoft® Windows Media® Encoder 9 Series is a powerful production tool for converting both live and prerecorded audio and video into Windows Media files or streams. The following sections introduce conceptual information about the encoding process and provide steps for using Windows Media Encoder.

z Getting started. Explains how you can set up an encoding session in a few short steps by using quick starts or the New Session Wizard. Also describes changes to Windows Media Encoder, describes the system requirements, and provides information about the various panels that make up the user interface.

z Concepts. Provides general information about working with the encoder.

z Configuring sources. Provides information about the input sources supported by the encoder, including files, devices, screens, and script commands.

z Customizing a session. Describes how to configure a new encoding session or customize an existing session to meet your needs.

z Output options. Describes the output options available to you when encoding: encoding to a file or broadcasting a live event (by using either push or pull distribution).

z System configuration options. Describes system configuration options, including security for the encoding computer, running multiple instances of the encoder on a computer, batch

encoding, and the steps you can take to achieve optimal system performance.

z Frequently asked questions and troubleshooting. Provides a link to the Microsoft Web site where you can find suggestions for resolving issues that might arise when using the encoder. z Technical support options. Lists phone numbers and Web sites that you can use if you

require additional support.

z Accessibility for people with disabilities. Provides information about features, products, and services that make Windows Media Encoder more accessible for people with disabilities. z Glossary. Provides definitions and terms related to the encoder.

Getting started

This section includes information about how you can set up an encoding session in a few short steps by using quick starts or the New Session Wizard. It also includes information about what is new in this version of Windows Media Encoder, feature requirements, hardware and software requirements, and describes the various panels that make up the encoder interface.

Encoding with quick starts or the New Session

Wizard

Before encoding content, you must set up an encoding session. The easiest way to do so is to use quick starts or the New Session Wizard. Quick starts are session files that are included with Windows Media Encoder. They are designed to address common encoding scenarios and already include most of the settings you need to begin encoding without delay. All you need to do is provide specifics about your content, such as file names or server names. You can also use the New Session Wizard, which walks you through the steps necessary to set up four of the most common encoding scenarios.

The quick starts and wizard are available from the New Session dialog box (if enabled) that is displayed when you first open the encoder or from the main encoder window by clicking New Session on the toolbar.

After you set up your encoding session, you are ready to encode content. If you plan to run the same session again, you can save the settings to a session file and then use the session at a later date. Session files are saved with a .wme extension.

Using the New Session Wizard to encode

The New Session Wizard walks you through the steps necessary to set up four of the most common encoding scenarios. The four common encoding scenarios are:

z Broadcast a live event. Captures audio or video from devices installed on your computer and then broadcast the content live, either by pushing the stream to a server running Microsoft Windows Media Services or by enabling Windows Media servers and players to pull the stream directly from the encoder.

z Capture audio or video. Captures audio or video from devices installed on your computer and then convert the captured content to a Windows Media file for later distribution.

z Convert file. Converts an audio or video file to Windows Media Format for later distribution. z Capture screen. Captures screen images, including mouse pointer movements, on the

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To change session properties, you can either run the New Session Wizard again or use the Properties panel to edit your settings. If you plan to reuse the session, save your settings in a session file.

Note

z To open the New Session Wizard, on the toolbar, click New Session, and then click one of the four wizards. You can use Custom session to set up a custom encoding session.

What's new

Windows Media Encoder 9 Series includes enhancements that are both powerful and easy to use. This section summarizes the changes to the encoder for this release.

z Targeting various encoding scenarios has been made easier with the addition of new

destinations. In addition, four quick starts are available that help you begin encoding without delay. Each quick start is designed to address a common encoding scenario.

z New codecs have improved the quality of encoded audio and video content.

z Support for dragging source files and session files to the encoder window makes it easy to begin encoding quickly.

z New constant-bit-rate (CBR) and variable-bit-rate (VBR) encoding modes enable you to fine-tune settings depending on the playback scenario you are targeting.

z A device control feature enables you to run devices directly from the encoder. (The device must be connected to an IEEE 1394 digital video port, or you can use a video tape recorder (VTR) that supports the Sony RS422 protocol and that is connected through a COM port.) You can also use the built-in edit decision list (EDL) to arrange and encode clips in any order. z Multichannel audio encoding is available through the Windows Media Audio 9 Professional

and Windows Media Audio 9 Lossless codecs.

z Digital rights management (DRM) is available for you to protect encoded content. z New push distribution feature helps you to initiate the connection with a Windows Media

server from the encoder.

z Language support lets you specify the language of your content.

z Four utilities are included to provide additional features such as creating custom profiles, splitting and combining streams in different files, and indexing files after encoding.

z Temporary storage of content to hard disk helps you to ensure the quality of encoded content. z Support of transform plug-ins enables developers to write plug-ins that modify audio and

video content, which you can use to add special effects during encoding. z Support for sourcing from additional file formats has been implemented.

z Support for nonsquare pixel output helps you to encode letterboxed content while maintaining the aspect ratio of the source video.

z Frame-level seeking can be implemented by creating or preserving time codes for some sources.

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z Multiple bit rate (MBR) content now supports multiple audio formats and video resolutions. z Support for the Microsoft Windows® XP Plug and Play feature enables devices to be

automatically detected by the encoder when running. In addition, the encoder is automatically launched when a new device is connected to the computer.

Feature requirements

The following table provides information about the Windows Media Encoder features that have specific Microsoft Windows Media Player, operating system, or codec requirements.

Feature Windows Media Player Operating

systems Codecs 6.4 7.1/Windows XP 9 Series Interlaced output video X Microsoft Windows XP Windows Media Video 9 Nonsquare pixel output X Multiple-resolution MBR content X MBR audio X DRM support X X X

Multichannel audio X Microsoft

Windows XP

Windows Media Audio 9 Professional or Windows Media Audio 9 Lossless

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1 Earlier players or operating systems will render 16-bit, 48-kHz content

Note that content encoded with the Windows Media Audio and Video 9 Series codecs (except for the Windows Media Audio 9 codec) is not supported in Windows Media Player version 6.4. For

Windows Media Player version 7.1 and Windows Media Player for Windows XP, content encoded with any of the codecs requires users to download the codec before playback. Content encoded using VBR encoding with the Windows Media Audio 9 codec may have glitches or silence during

playback in Windows Media Player version 6.4. For Windows Media Player version 7.1 and

Windows Media Player for Windows XP, content encoded with the Windows Media Audio 9 codec does not require a user to download the codec.

The following table lists the supported encoding methods for the codecs that are included with the encoder.

(24-bit, 96 kHz)1 Windows XP Audio 9 Professional

Dynamic range control X Microsoft Windows XP Windows Media Audio 9 Professional CBR encoding (one- or two-pass)

X X X See the following

table

Quality-based VBR X X See the following

table

Bit rate-based VBR X X See the following

table Peak bit rate-based

VBR

X X See the following

table Codec One-pass CBR Two-pass CBR Quality-based VBR Bit rate-based VBR

Peak bit rate-based VBR Windows Media

Audio 9 Professional

Yes Yes Yes Yes Yes

Windows Media Audio 9 Lossless

No No Yes No No

Windows Media Audio 9

Yes Yes _Yes1 _Yes1 _Yes1

Windows Media Audio 9 Voice

Yes No No No No

Windows Media Video 9

Yes Yes Yes Yes Yes

Windows Media Video 8.1

Yes Yes Yes Yes Yes

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1 Some glitches or silence may occur during playback in Windows Media Player version 6.4.

Hardware and software requirements

You can find up-to-date information about hardware and software requirements at several Web sites:

z For information about system requirements, see the system requirements page at the Microsoft Web site.

z For a list of supported audio and video capture cards, see the hardware providers page at the Microsoft Web site.

z For a list of supported portable devices, see the portable devices page at the Microsoft Web site.

About encoder views

The main window of Windows Media Encoder has numerous panels that provide information about the current session. The panels that are displayed when you encode depend on the type of content being encoded, the number of sources set up for the current session, and your personal preferences. You can display additional panels or hide the ones that are displayed. Any changes you make to the window are saved between sessions.

z Properties panel. Includes properties that you can use to adjust the settings related to the current session or to set up a custom session.

z Video panel. Displays the content you are encoding. Depending on the type of content, you can customize the window to show just the pre-encoded content, the encoded content, or both. Video 9 Screen

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In some instances, the source content or encoded output is not displayed during encoding. z Sources panel. Lists each source in the current session. You can switch between sources while

encoding by clicking the appropriate source button.

z Audio panel. Contains controls for monitoring and adjusting the volume of the audio stream you are encoding.

z Device panel. Appears when you have a device connected to your computer either through an IEEE 1394 port or a COM port using a video tape recorder (VTR) that supports the Sony RS422 protocol. You can control the play, pause, stop, fast-forward, rewind, and eject functions of your device in this panel. You can also create an edit decision list (EDL) to automatically encode specific time segments of your content on one or more video tapes. z Monitor panel. Contains status information about the session.

z Script panel. Appears if you enabled scripts as a source type when you set up the current session. You can insert a script command into the stream during encoding from this panel.

To display or hide a panel, on the View menu, click the panel you want to display or hide.

About the encoder utilities

Four utilities are included with Windows Media Encoder:

z Windows Media Profile Editor. Use to create custom profiles for use in encoding sessions. z Windows Media File Editor. Formerly called the Windows Media ASF Indexer, you can use

this tool to edit a Windows Media file. For example, you can trim the start and end points of the file; add markers, and script commands; control the dynamic range of audio content; and, for multichannel audio files, control how the channels are folded down for stereo playback. z Windows Media Stream Editor. You can use this tool to split or combine streams in existing

Windows Media files to create a file. For example, you can split an MBR file into multiple single-bit-rate files. Or, you can create multiple files, each with the same video stream but a different audio stream (for example, to create a single file with multiple languages).

z Windows Media Encoding Script. Formerly called the Windows Media Encoding Utility, you can use this command-line utility (Wmcmd.vbs) to encode and broadcast content. This utility is installed in the same location as the encoder, which is C:\Program Files\Windows Media Components\Encoder by default.

To access an encoder utility

1. Click Start, point to Programs, point to Windows Media, and then point to Utilities. 2. Click the utility you want to use.

Note

z You can access help for the Windows Media Encoding Script from the same location.

Documentation conventions

The following conventions are used in this Help system.

Concepts

This section provides general information about working with Windows Media Encoder 9 Series.

Understanding codecs

Uncompressed audio and video content can consume a lot of bandwidth when streaming or create large files. By compressing the content, it can be broadcast over common Internet bandwidths or saved to a Windows Media file of a reasonable size. You can compress content by applying compression algorithms to the data, taking into account the desired output quality and available bandwidth. Before the content is played, it is decompressed by using decompression algorithms. These compression and decompression algorithms are called codecs. The following table provides more detailed information about the codecs available in Windows Media Encoder.

Codec Description

Windows Media Audio 9 Professional

Provides a full surround sound experience and dynamic range control. Intelligently folds down multichannel audio to 2 (stereo) or 1 (mono), depending on the speaker configuration of the playback device. Intended for data rates of 128 to 768 Kbps.

Windows Media Audio 9 Lossless

Provides lossless encoding of audio content. Supports multichannel audio encoding and dynamic range control.

Windows Media Audio 9

Provides a 20 percent improvement in compression over the Windows Media Audio 8 codec. Supports VBR audio encoding.

Windows Media Audio 9 Voice

Offers superior quality for audio content with a voice emphasis. Provides for mixed-mode encoding of voice and music. Intended for playback at bit rates at 20 Kbps or lower.

Creates high-quality video for streaming, download-and-play, and physical format delivery scenarios. Provides a 15 to 50 percent

improvement in compression over the Windows Media Video 8.1 codec, with the more significant improvement occurring at higher bit rates. Enables playback of interlaced content on televisions and set-top boxes.

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Note

z In some instances, the Sipro Labs ACELP codec appears in the list of codecs. For example, if you import a profile that was created by using Windows Media Encoder version 7.1. If this occurs, it is recommended that you use the Windows Media Audio 9 Voice codec instead.

About sessions

Before you can encode, you must set up an encoding session. As part of setting up the session, you must do the following:

z Specify the source of your audio or video content. You can source from devices, files, or both devices and files. You can also capture screens directly from your desktop.

z Choose the output option. Select whether to broadcast the content or encode it to a file. If you broadcast the content, you can push the stream to a Windows Media server, and you can enable Windows Media servers and players to pull the stream from the encoder. You can also choose to archive a copy of the broadcast for later use.

In addition, you should check compression and quality settings before you encode. Default settings are applied, but it may be necessary to adjust the settings to meet your needs. For example, if you are planning to distribute your content for download-and-play on a computer, you may want to use bit rate-based VBR encoding and set the video and audio quality level to the higher bit rate.

After you have identified the source of your content and specified the output, you have a number of options for customizing a session. For example, you can optimize audio and video to improve the quality of the encoded content.

After configuring the session to meet your needs, you can start encoding. If you want to run the same Windows Media Video

8.1

Supports a wide variety of network bandwidths. Deinterlaces interlaced content before encoding.

Enables users of Windows Media Player 7 to view encoded video content without first having to download the latest codecs. Best choice when the encoding computer cannot support the performance

requirements of the newer Windows Media Video codecs. Windows Media Video

9 Screen

Provides improved handling of shaded images, screen motion, and scrolling for screen captures. Supports one-pass CBR and VBR

encoding with no frame dropping. This codec is fully optimized for both streaming and download-and-play scenarios.

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session again, you can save the session to a session file either before or after you encode.

Note

z It is not necessary to create a session each time you encode. The encoder includes quick starts and the New Session Wizard, which address common encoding scenarios.

Comparing Windows Media servers and Web

servers

You can deliver content from a server running Windows Media Services or from a Web server to a player. The server and player can be either on the Internet or an intranet, and they can be separated by a firewall. Although a Windows Media server is designed specifically for streaming Windows Media-based content, a standard Web server is not. If you decide to use a Web server, you should be aware of the differences in the way the content is delivered, which can affect the quality of the playback.

Windows Media servers

A Windows Media server meters the delivery of packets according to feedback information it receives while sending a stream to a player. When a player receives packets in this way, the

presentation is much more likely to be smooth. Because bandwidth use is controlled, more users can connect concurrently to your site and receive streams that are free of interruptions.

If you plan to deliver your content as a unicast stream from a Windows Media server, you can encode a multiple-bit-rate (MBR) stream. This provides users with better quality content during times of network congestion. When MBR content is received by a player, only the bit rate that is the most appropriate for network bandwidth conditions is streamed. The process of selecting the

appropriate stream is handled by the Windows Media server and the player and is invisible to the user.

When streaming single-bit-rate streams or files, a Windows Media server is designed to handle network congestion smoothly. If congestion occurs during the broadcast, the stream is "thinned", which means that the frame rate is reduced. If this is insufficient, the video portion of the stream is frozen and only the audio portion is streamed.

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Web servers

A Web server is designed to download as much data as it can, as quickly as possible. This is the preferred method for sending packets containing static images, text, and Web page script, but it is not the best method for sending packets containing streaming media. Streaming media should be

delivered in real time, not in large bursts, and the player should receive packets just ahead of rendering them.

Web servers do not support MBR streams. When a file streams from a Web server, the quality of the delivery is not monitored and no adjustment to the bit rate can be made. Web servers cannot use the preferred delivery protocol, User Datagram Protocol (UDP), so the delivery of a stream is more likely to be interrupted by periods of silence while the player buffers data. In addition, Web servers do not support live broadcasts and multicast streams.

Note

z Windows Media Services 9 Series in Windows .NET Server 2003 includes several features, called Fast Streaming, which can combine some of the advantages of downloading and streaming. For more information about Fast Streaming, see Windows Media Services Help.

About CBR or VBR encoding

Using Windows Media Encoder, you can encode audio and video content at either a constant bit rate (CBR) or a variable bit rate (VBR).

CBR encoding

CBR encoding is designed to work most effectively in a streaming scenario. With CBR encoding, the bit rate remains fairly constant and close to the target bit rate over the course of the stream, within a small window of time set by the buffer size. The disadvantage of CBR encoding is that the quality of the encoded content is not constant. Because some pieces of content are more difficult to compress than others, some parts of a CBR stream are of lower quality than others. In addition, CBR encoding results in inconsistent quality from one stream to the next. In general, quality variations are more pronounced at lower bit rates.

VBR encoding

Use VBR encoding when you plan to distribute the content for downloading and playing either locally or on a device that has a constrained reading speed, such as a CD or DVD player. (You can also use the peak VBR encoding mode when you plan to stream the content.) VBR encoding is most

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advantageous when encoding content that is a mix of simple and complex data, for example, a video that switches between slow and fast motion. With VBR encoding, fewer bits are automatically allocated to less complex portions of the content, leaving enough bits available to produce good quality for more complicated ones. This means that content that has consistent complexity (for example, a "talking head" news story) would not benefit from VBR encoding. When used on mixed content, VBR encoding produces a much better encoded output given the same file size when compared to CBR encoding. In some cases, you can end up with a VBR-encoded file that has the same quality as a CBR-encoded file in half the file size.

Encoding mode options

With CBR encoding, you can use one- or two-passencoding. You have three VBR encoding options: quality-based VBR (one-pass), bit rate-based (two-pass), and peak bit rate-based VBR (two-pass). Not all codecs support two-pass CBR encoding or VBR encoding.

About one- or two-pass encoding

With Windows Media Encoder, you can do one- or two-pass encoding, either with CBR or VBR encoding. (The quality-based VBR encoding mode is one-pass; the bit based and peak bit rate-based VBR encoding modes are two-pass.)

With one-pass encoding, the content passes through the encoder once, and compression is applied as the content is encountered. With two-pass encoding, the content is analyzed during the first pass, and then encoded in the second pass based on the data gathered in the first pass. Two-pass encoding can result in better quality content because the encoder takes its time to find the optimal combination of bit rate, frame rate, buffer size, and image quality based on the scene composition. However, two-pass encoding takes longer because the encoder goes through all of the content twice.

Two-pass encoding is not available in the following situations:

z The stream is broadcast

z There are multiple sources in a session z The source is set to loop

z Script commands are included in the stream

z Source content is from devices, unless you have enabled device control z The source file has a .bmp file name extension

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In addition, two-pass encoding is only available with certain codecs. For a list of the codecs that support two-pass encoding, see Feature requirements.

Note

z If you are using two-pass encoding, you will not see the output video in the encoder during the first pass.

Configuring sources

Using Windows Media Encoder, you can encode live content in real time, stored content, or capture screens. Real-time sources of content include anything that you can plug into your audio or video card, including a CD player, microphone, VCR, video camera, video player, or television. Stored sources are audio or video files. You can also capture screens directly from your desktop, and insert script commands while encoding.

Keep in mind that the higher the quality of the source content, the higher the quality of the output content. This means that you should start with the highest quality source file or, if sourcing from devices, set your device to capture the highest quality possible.

When configuring a source, you first identify the source types (audio, video, or script) that make up the source. A source must consist of at least one audio or video source type. You can add an

unlimited number of sources to an encoding session, either before or after encoding begins, but each subsequent source is based on the combination of source types you created in the session. For example, if your first source contained only audio, then all subsequent sources in the session are based on audio only. For multisource sessions, it is recommended that you configure your first source to use all three source types. If additional sources do not use a source type, you can encode a blank stream for that source type.

Sourcing from a file

Using Windows Media Encoder, you can source from files with .wma, .wmv, .asf, .avi, .wav, .mpg, .mp3, .bmp, and .jpg file name extensions. (Sourcing from a file with a .mpg file name extension requires a compatible MPEG-2 decoder on the encoding computer.)

If you are encoding a Windows Media file, any header attributes associated with the file (for

example, markers, script commands, and so on) are lost in the process. You can use Windows Media File Editor to add the following attributes back to the file: title, author, copyright, and description.

When sourcing from a file, you can trim the start and end times of the file to ensure that you encode only the part of the file you want.

For more information about obtaining an MPEG-2 decoder, see the Microsoft Web site.

Note

z Files that contain images with odd-sized dimensions are not supported. For example, an image that is 300 x 321 pixels is not supported, but an image that is 300 x 320 pixels is supported.

To source from a file

1. On the toolbar, click Properties, and then click the Sources tab. 2. In Source from, click File.

-or-

Click Both device and file to source audio and video from two different files.

3. To locate the source file click Browse.

4. If you want to trim the start or end of the file, click Mark In/Out. Only the remaining portion of the file is encoded.

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or Audio check box.

Note

z You can also drag a source file to the encoder.

Sourcing from multichannel audio files

Using Windows Media Encoder, you can encode multichannel audio, which means you can encode audio for a surround sound playback in six (5.1 audio) or eight (7.1 audio) channels. The format is specifically designed for CD, DVD, high definition television, and digital cinema audio programs. Your content source must be one of the following:

z A single 6-channel or 8-channel file that has a WAVE_FORMAT_EXTENSIBLE format. For more information, see the Microsoft Web site. If you are sourcing from an 8-channel file, it is recommended that the sampling rate and bits per sample of the source file and the encoded content match.

z Six mono channel .wav files. To create the files, use an audio editing program to fold down your audio to six files, one for each channel. When you set up your source in the encoder, you specify which channel each file is associated with. Each .wav file cannot exceed 2 gigabytes (GB) in size. This option is not available with 7.1 audio.

z An existing multichannel Windows Media Audio file. Use an existing file to encode the file at a different bit rate. It is not possible to encode an existing multichannel Windows Media Audio file if the encoder is on a computer running Windows 2000.

You must use either the Windows Media Audio 9 Professional codec or the Windows Media Audio 9 Lossless codec and an audio format that supports multichannel encoding when encoding

multichannel content. In addition, the user playing your content must have Microsoft Windows XP and a player that is based on the Windows Media Format 9 Series Software Development Kit (SDK). Otherwise, the audio will be folded down automatically to two channels for stereo speakers.

The encoder automatically folds the channels down to two for playback with stereo speakers. If you are encoding 5.1 audio, you can control the fold-down distribution between the surround, center, and subwoofer channels on the Processing tab of the Properties panel. If you encoded the content to a file, you can also use Windows Media File Editor to control the fold-down distribution in the output file.

To source from multichannel audio files

1. On the toolbar, click Properties, and then click the Sources tab. 2. In Source from, click Devices.

3. In Audio, click Multichannel WAV Source, and then click Configure. 4. For each channel, enter the source .wav file.

5. Click the Compression tab.

6. In Destination, click either File download, Hardware devices, Windows Media server, or Web server, depending on the playback scenario.

7. In Audio, click Multichannel audio. 8. Click Edit, and then click the bit rate tab.

9. In Audio format, click the 5.1 or 7.1 audio format you want to use.

Note

z The encoder automatically folds the channels down to two for playback with stereo speakers. If you are encoding 5.1 audio, you can modify the default fold-down distribution on the Processing tab.

Sourcing from devices

When you source content from devices, you must first choose the audio or video devices you want to use. After choosing the devices, you can set their properties directly from the encoder. The properties for some devices, such as audio and video cards, are global and apply not only to all sources in your encoding session but to all programs on your computer. (For example, brightness, contrast, capture dimensions, and audio mixer settings.)

You can use devices and capture cards only once in a session. For example, if you create two sources—one source is a live event in which a speaker is introducing a new video, and the second source is the video—you need a separate card and device for each source.

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can set up an edit decision list (EDL) in which you identify the portions of tape that you want to encode.

You can configure audio and video device properties by using the New Session Wizard, the

Properties panel, or the Configure Devices command on the Tools menu. Devices must already be installed on your computer to configure them in the encoder. You cannot use the encoder to add or remove hardware; use Control Panel instead.

If you have installed a supported TV tuner card, you can change the TV channels by using the encoder.

To source from devices

3. In Video and Audio, click the devices you want to source from.

To change the TV channel being encoded

3. In Video, click the TV tuner card you want to source from. 4. Click Configure.

5. In Channel, type the channel you want to encode. 6. In Inputs, select the tuner option, and then click OK.

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Enabling device control

By using the device control feature, you can run certain types of devices directly from the encoder. Device control enables you to control the play, pause, stop, fast-forward, rewind, and eject functions of your device from the encoder. To enable device control, the device must be connected to an IEEE 1394 digital video port, or you can use a video tape recorder (VTR) that supports the Sony RS422 protocol and that is connected through a COM port. You can also use the built-in edit decision list (EDL) of the device control feature to arrange and encode your clips in any order.

When you have enabled device control, you can use two-pass encoding if you have done the following:

z Chosen to encode to a file

z Chosen to store content temporarily z Set up an EDL for the content Note

z If a device you are using in the session does not appear in the Configure Devices dialog box, close the dialog box, click Apply, and then open the dialog box again.

To enable device control

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If the device does not appear in the list, check that the device is turned on. It may be necessary to quit and restart the encoder after turning the device on.

4. Click Apply.

5. On the Device panel, click Setup.

6. In the list, select the device or COM port through which the device is connected, and then click OK.

7. Use the controls on the panel to control the device.

Note

z To control a digital device from the encoder, the device must be set to VTR mode; VTRs must be set to TC mode.

Setting up an EDL

If you have enabled device control, you can specify, by time stamp, the exact place within your audio or video content that you want encoding to begin and end. To do so, you must create an edit decision list (EDL), which identifies the portions of tape you want to encode.

It is not recommended that you use an EDL for a broadcast because the encoder requires extra time to seek to the EDL points during encoding. During a broadcast, this could cause excessive buffering on a player.

You can add as many EDL entries as you want in any order—not necessarily in the order in which they occur in the tape. You can also set up an EDL that sources from multiple tapes. During the encoding session, the encoder will prompt you when it is time to change the tape.

You should use a prestriped tape when setting up an EDL. To prestripe a tape, you can record the tape continuously from beginning to end when you first buy the tape. This ensures that the time code in the tape is continuous. If the tape is not prestriped, then the device will generate a new time code every time you set up an EDL for the device.

To set up an EDL

1. Set up a device control session that encodes to a file.

2. On the View menu, click Monitor panel, and then click the EDL tab. 3. Click Edit EDL.

4. In the Device area, click Play to begin playing the tape.

You can also begin playing the tape at a specific point by using other playback controls, such as the Seek to and Fast forward buttons.

5. When you find the frame you want, click Mark Into specify that frame as the starting point of the clip.

The tape will continue playing.

6. Click Mark Out at the frame you want to serve as the end point of the clip.

7. If you are using several tapes, provide a unique ID (such as 1, 2, 3, or A, B, C) in Tape ID. 8. Click Add EDL Entry to add the clip to the edit decision list.

9. To edit the clip, click it in the list, and then click the Edit button. 10. Repeat steps 4 through 8 to add more clips.

11. When you are satisfied with the list, click OK and then, on the toolbar, click Start Encoding.

During encoding, the EDL tab of the Monitor panel displays status information for the clips.

Capturing screens

You can capture your entire desktop screen, individual windows, or a region of the screen and broadcast the screen or encode it to a file just as you would any other content. You can use the screen capture feature for:

z Capturing from .avi files that were created with a third-party screen-capture utility. z Capturing a window (or the entire desktop) directly from your desktop.

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When you capture a window, you can save the session for later use. Keep in mind, however, that the title of the window and its coordinates are saved along with all the other configuration information in the session file. When you reload the session file for a subsequent screen-capture session, the

encoder looks for a window that matches the stored title. If the encoder does not find one, it captures a window that matches the stored coordinates.

When you capture the entire desktop and save the session, the display size and color settings for your monitor are saved in the session file. If, after saving the session, you decide to change the screen size or color, you must create a new session to include these settings.

If your screen saver is displayed while you are capturing a window or the entire desktop, the screen saver will be encoded. Therefore, it is recommended that you turn off your screen saver when capturing a window or the entire desktop.

Notes

z Artifacts can be introduced when an analog signal is run through a scan converter and converted to National Television Standards Committee (NTSC) format. These artifacts are amplified during encoding and can degrade the quality of the encoded video.

z When you are done capturing a screen, be sure to click Stop encoding on the toolbar. Simply minimizing the window being captured does not end the encoding session.

Improving performance when encoding screens

Because of the amount of data being manipulated and the CPU power required, capturing screens is a performance-intensive process. Use the following guidelines to ensure that the screen image you capture will encode and play well:

z Use a fast processor.

z Use the Windows Media Video 9 Screen codec.

z Set your monitor to use a lower display size. For example, capturing at a 1024 x 768 resolution yields more data than capturing at 640 x 480.

z Set your color display to 16-bit or 8-bit color. Or, to further improve the CPU usage set the encoder to run in 256-color mode. Keep in mind that running in 256 colors can introduce a palette change when switching between programs that have different color schemes. The encoder does not support palette changes for real-time screen capture. Therefore, you should use 16-bit colors or capture to an .avi file first, then use the encoder to convert the file to Windows Media Format.

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z Use a low frame rate. You may have to experiment with the setting to determine the frame rate that meets your needs.

z Capture a smaller image. z Use a higher bit rate.

z Avoid multiple scene changes, such as opening and closing windows in rapid succession during the capture.

z Capture screens or regions only from the primary monitor when using a dual-monitor scenario. z Disable hardware acceleration. (However, enable hardware acceleration after completing the

screen capture for best results with other programs.) z Quit all video programs you are not using.

z Set up the output frame size to be the same as the source. Do not use the encoder to resize the source video.

To encode an .avi file containing screen content

1. On the toolbar, click Properties, and then click the Sources tab. 2. In Source from, click File, and then enter the name of the .avi file. 3. Click the Compression tab.

4. In Destination, click either Windows Media server or Web server, depending on your playback scenario.

5. In Video, click Screen capture.

6. Click Apply, and then on the toolbar, click Start Encoding.

Note

z When capturing from .avi files created by using a third-party screen capture tool, use run-length encoding (RLE) compression or RGB uncompressed formats for files you plan to later convert through the encoder.

To capture a screen on the desktop

3. In Video, click Screen Capture, and then click Configure to specify the window or region of the screen that you want to capture.

4. Click the Compression tab.

5. In Destination, click either Windows Media server or Web server, depending on your playback scenario.

6. In Video, click Screen capture.

7. Click Apply, and then on the toolbar, click Start Encoding.

The encoder window minimizes while you are encoding. If you are encoding a file, restoring the encoder window usually pauses the encoder. However, if your screen capture session is also sourcing audio from a file, then restoring the encoder window will not pause the encoder. For a broadcast session, encoding continues, even if you restore the encoder window. To stop or pause encoding, click the encoder button on the taskbar. Then, on the toolbar, click either Stop Encoding or Pause Encoding.

Inserting script commands

You can insert script commands into a stream while you are encoding. The encoder supports the following types of script commands:

z Captions. Free-form text strings that are displayed in a player along with your encoded content. For the captions to be visible, users must have enabled captions in their player. z Closed captioning. If your capture card supports capturing closed captioning data, you can

encode the closed captioning.

z URLs. When inserted into a stream, the user's default browser opens and the requested URL loads into the browser. If you have embedded the player within a browser, the requested URL replaces the player, and users cannot view the rest of the stream. 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.

z Custom script commands. In addition to supporting captions and URLs, a player

automatically processes FILENAME, EVENT, and OPENEVENT script commands. You can use the FILENAME command to open a specific digital media file at the time you specify. You can use the EVENT command to create custom script commands. For example, you can insert an advertisement into the stream. Note that the code for the specified event must be defined in the Windows Media metafile for the stream for the player to perform the

specified event. The OPENEVENT command precedes the actual EVENT command. The OPENEVENT command allows the player to prebuffer the content so that when the specified

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event occurs, the switch between streams appears to be seamless.

For detailed information about the script commands supported by Windows Media Player 9 Series, see the Windows Media Player 9 Series Software Development Kit (SDK). For information about the script commands supported by Windows Media Services 9 Series, see the Windows Media Services 9 Series SDK.

Because script commands are saved in the stream, they are not available for editing.

Inserting script commands into an encoding session requires that you select scripts as a source type when setting up your session. You cannot include scripts when you set up a session using the New Session Wizard, but you can add scripts to the session through the Sources tab of the Properties panel.

To insert script commands while encoding

-or-

To insert script commands while sourcing from a file, click Both device and file.

3. Select the Script check box, and then click Script Panel. 4. Click Apply, and then click Start Encoding.

5. On the Script panel, click the button for the kind of script you want to insert. You can insert a caption (text string), URL, or custom script command.

6. Do one of the following:

z If you are inserting a caption or URL, type the text or URL that you want to insert. z If you are inserting a custom script, type the script command type and value.

7. Click Insert at the point you want to insert the script into the stream. The Total scripts entry on the Monitor panel increments with each script command that you insert.

To encode closed captioning data

3. Select the Script check box, and then click the name of the capture card that supports closed captioning.

4. If you want to configure the card, click Configure.

Using multiple sources in a session

You can use multiple sources in a session. Although only one source streams at a time, as you encode, you can switch between sources to stream different content. For example, before broadcasting a company meeting, you can set up sources for the main content as well as for

welcome, intermission, and goodbye content. When you broadcast the event, you can start with the welcome source, switch to the main speaker when appropriate, switch to the intermission source during a break, and then switch to the goodbye source when the event finishes.

If you are using the Windows Media Audio 9 Voice codec in a multisource session, the mode (voice-only or mixed voice and music) of the first source determines the mode of the subsequent sources. For example, if you choose the voice-only or mixed mode for the first source, subsequent sources will be encoded in the same mode. However, if you specify the mixed mode for the first source and set up an optimization definition file for that source, subsequent sources in the session will be encoded in the voice-only mode.

To switch between multiple sources while encoding

1. On the View menu, click Sources Panel.

2. On the Sources panel, click the source you want to start with, and then click Start Encoding. 3. To switch to a different source, on the Sources panel, click the button for that source.

To set the order of multiple sources

1. On the toolbar, click Properties, and then click the Sources tab.

2. In the list of sources, click the source you want to move, and then click the Up arrow button or Down arrow button .

Customizing a session

This section provides information about options you have for customizing an encoding session to meet your needs. If you customize a session and want to reuse it frequently, you can save the session to a session file and then add it to the list of quick starts.

To open an existing session

1. On the File menu, click Open.

2. In File name, enter the name and location of the session file you want to open.

Session files have a .wme file name extension.

3. Click Open.

Note

z You can also open a session file by dragging it to the encoder.

To save a session

1. On the File menu, click Save.

2. In File name, enter a name and location for the file, and then click Save.

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To start, stop, or pause encoding

z To start encoding, on the toolbar, click Start Encoding. A message notifies you that encoding has started.

-or-

To stop encoding, on the toolbar, click Stop. A message notifies you when encoding has stopped. A summary of the session results is available in the Encoding Results dialog box.

-or-

To pause encoding, on the toolbar, click Pause. Note that it is only possible to pause encoding when you are sourcing from devices or screen captures and encoding to a file. If any source in your session is a file, it is not possible to pause encoding.

To create a custom quick start

1. Create a session that meets your encoding needs, and then save the session.

2. Save the session file to the Templates directory, which is in the same location as Windows Media Encoder. By default, this is C:\Program Files\Windows Media

Components\Encoder\Templates.

Your quick start will appear in the list of quick starts in the New Session dialog box.

Cropping and resizing video before encoding

Using Windows Media Encoder, you can crop the edges of your input video image. For example, noise often occurs at the edges of an image, so you can crop one or more edges to eliminate the affected rows. You can specify how much to crop from each side of an image, or you can use default values for cropping. After cropping, you can resize the height and width of the output video. By default, the output video image is stretched to match the frame size specified in the profile. However, you can resize the video so that the output image matches the dimensions of the cropped image. Or, you can have the video resize automatically to make use of the bandwidth specified in the profile. You can also specify custom resize dimensions.

MBR video and multiple sources

If you are encoding MBR video, you can resize the output frame size for each bit rate separately. This means that an MBR file or stream can contain video images of varying sizes.

If you have multiple sources in a session, the output dimensions of the first source determine those of the subsequent sources. Therefore, it is only possible to resize the first source in a multisource

session.

Detecting the input size

When you source from a file, the encoder can detect the size of the source video before encoding begins; when you source from devices or screen captures, the input size cannot be detected before encoding. For this reason, when sourcing from devices or screen captures, you should specify the input size when you crop and resize video. When you do so, the encoder will detect the actual input size when encoding begins. If the actual input size is different than the size you specified, the

percentage of cropping you specified (rather than the actual pixel values) will be applied to the actual input size.

For example, assume you indicated that the input size was 100 x 200 pixels, and specified the following crop values:

z Top: 4 (2 percent of height) z Bottom: 4 (2 percent of height) z Left: 10 (10 percent of width) z Right: 10 (10 percent of width )

If the encoder detected that the actual input size is 200 x 400, the actual crop values would match the percentage of cropping, as follows:

z Top: 8 (2 percent of height) z Bottom: 8 (2 percent of height) z Left: 20 (10 percent of width) z Right: 20 (10 percent of width )

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If your capture card supports hardware cropping, it is recommended that you use the hardware to crop the video. Refer to the documentation for your capture card for information about hardware cropping.

If your capture card does not support hardware cropping, or if you are sourcing from a file, the cropped video will not be displayed in the Input area on the Video panel until you start encoding.

Resizing

For best results, do not resize your output video. Resizing can result in suboptimal output. However, if you are encoding to a file by using the Windows Media Video 9 codec, and the time required to encode is not important, you can improve the quality of resized content by adjusting the encoder performance setting for the Encode to file option to better quality. Note that the encoding time increases significantly if you use this method.

Caution

z You should not resize the image when you are encoding a screen, which can result in poor quality in the encoded content.

To match the frame size of the source video

1. On the toolbar, click Properties, and then click the Compression tab. 2. Click Edit, and then click the bit rate tab.

3. Select the Same as video input check box.

Preserving the pixel aspect ratio of video

If your video source has nonsquare pixels, you can preserve its pixel aspect ratio. Check the documentation for your video device to determine whether it uses nonsquare pixels.

The pixel aspect ratio is the width (x) of the pixel with respect to its height (y). A square pixel has a ratio of 1:1, but a nonsquare (rectangular) pixel does not have the same height and width. This concept is similar to the frame aspect ratio, which is the total width of an image with respect to its height. However, these aspect ratios are not necessarily tied together. For example, a widescreen image with a frame aspect ratio of 16:9 can be made of square or nonsquare pixels.

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If you encode a video source with nonsquare pixels as though the pixels are square, the output will distort, as shown in the following diagram.

If you know the frame aspect ratio (Ix:Iy) and exact height and width of your image source, you can use the following formula to determine the x and y values of the pixel aspect ratio.

PixelAspectRatioX / PixelAspectRatioY = (Ix * height) / (Iy * width)

For example, if your image is 720 by 360 pixels, and the frame aspect ratio is widescreen (16:9), then PixelAspectRatioX=8 and PixelAspectRatioY=9:

PixelAspectRatioX / PixelAspectRatioY = (16*360) / (9*720) = 8/9 Notes

z If you set the size of the output video to be the same as the source video, and the source video has nonsquare pixels, then the pixel aspect ratio of your source video is automatically

preserved in the output video.

z Preserving the pixel aspect ratio of video increases the file size or stream bit rate.

To preserve the pixel aspect ratio of video

1. On the toolbar, click Properties, click the Compression tab, and then click Edit.

2. On the General tab, select the Allow nonsquare pixel output check box, and then click OK. 3. Click the Video Size tab, and then in Pixel aspect ratio, specify the pixel aspect ratio of your

input video. If you are using a custom pixel aspect ratio, the values you type must be between 1 and 255.

Optimizing video and audio

You can use Windows Media Encoder to deinterlace source video that is interlaced, apply an inverse telecine filter to content that is telecined, or maintain the interlacing in your source video.

If you are not sure whether your source content is interlaced or telecined, you can use the encoder to detect the format by clicking Detect on the Processing tab of the Properties panel.

If your audio content is primarily voice, combined with some music, you can use the Windows Media Audio 9 Voice codec and optimize the content for voice.

Deinterlacing or maintaining the interlacing in

video

A video frame can be either interlaced or progressive. An interlaced video frame contains two fields per frame captured at different time instants. When the video is being rendered, the lines of one field are displayed first, and then the lines of the second field are displayed. In contrast, with a progressive video frame, the lines in each frame are painted sequentially. Interlaced content is common because the NTSC and PAL standards use interlaced video signals.

Deinterlacing video

When interlaced video is played on a progressive-scan display, such as a computer, it can appear to flicker as the fields are rendered. Deinterlacing is the process of creating a progressive frame of video out of an interlaced frame, which reduces the flickering. The encoder has three deinterlace filters. The filter used by the encoder depends on the difference between the input and output frame size and frame rate.

z Normal deinterlacing. This is the default filter used when you select the deinterlace option. This filter blends the even and odd fields of an interlaced frame to create a progressive frame, as shown in the following diagram.

z Half-size deinterlacing. This filter is used when the number of lines specified for the output video is half (or less) than those of the input video. For example, this filter is used when the resolution of the input video frames is 640x480 pixels and the output resolution is 320x240 pixels. This filter uses an algorithm that blends the fields, rather than simply removing one field of data. This results in higher-quality output video.

z Half-size, double frame rate deinterlacing. This filter is used when the number of lines specified for the output video is half (or less) than those of the input video and the output frame rate is twice as high as the input frame rate. This filter produces a frame from each field of the video sequence, as shown in the following diagram.

Windows Media Encoder