Chapter 6: Encoding Clips

This chapter describes how to use the RealProducer graphical application to encode media clips. It explains how to define a job, choose audio and video inputs, set encoding options, and select encoding audiences. Chapter 7 provides details about each audience, and Chapter 8 explains how to start and monitor the encoding process.

For More Information: You can also encode clips using the command-line application, which Chapter 14 describes. For instructions on sending an encoded stream to a server for broadcast, refer to Chapter 11.

Using Jobs

Each time you encode a clip or broadcast, RealProducer creates a job that records the encoding settings. The bottom portion of the RealProducer graphical application is a job manager that shows the current jobs, and allows you to perform actions with these jobs, such as running them in sequence.

Optionally, you can save each job to a separate job file, which is an XML- formatted text file that you can manually edit as described in Appendix B. Once you have saved a job file, you can reload it to apply the same settings to another clip or broadcast. Although using a job file is optional, you'll find job files highly effective if you encode a lot of clips or broadcasts.

Creating a New Job File

Whenever you encode a clip or broadcast, RealProducer creates a job automatically, letting you choose whether or not to save the job settings to a file. You can also create a job file without actually encoding any streams. This allows you to define job profiles to use later. The following steps describe the basic procedure for creating, editing, and saving a job file.

To create a new job:

Start a new job file by choosing File>New Job or selecting an audio or video input to encode, as described in "Selecting Inputs and Destinations". A new, untitled job appears in the job manager, which is described in "Using the Job Manager".

Define your encoding settings as described in this chapter. You can set up your audiences, define clip information, turn on video filters, create input and output file names, and so forth.

If you use RealProducer Plus, you can save your job by choosing File>Save Job or pressing Ctrl+s. Or, close RealProducer Plus and click Save when prompted to save the job file. RealProducer Basic does not allow you to save job files.

Using the Save dialog, save your job file anywhere on your computer or network. The job file is automatically saved with the file extension .rpjf.

Tip: Give the job file a descriptive title that will help you to remember the purpose of the job. For example, you might name a job file GeneralVideoForDialUpModems.rpjf.

Note: You can share a saved job by giving the job file to another RealProducer user. If you defined inputs and outputs, the user needs access to those same sources and destinations to run the job.

Using and Modifying Existing Jobs

Once you have saved a job file using RealProducer Plus, you can use it as the basis for additional encoding jobs. When you load a saved job file, you can override the job settings on a case-by-case basis. Suppose that a certain job file has all the basic settings you want, but for a certain clip you also want to turn on the video noise reduction filter. You just load the job file, turn on the noise reduction filter through the graphical application, and encode the clip. When you're done, you can discard the changes, save them, or write the job to a new job file.

Tip: RealProducer supplies a number of predefined job files that are stored in the samples/jobs subdirectory under the RealProducer main directory. You can use these files as templates for your own jobs, or create your own jobs from scratch using the graphical user interface.

To open and modify an existing job file:

If you have recently used the job you want to reuse, choose File>Recent Jobs>... and select from the list of jobs. Otherwise, give the File>Open Job command and select the job file.

Make any necessary changes, which may include the following:

If you defined inputs and outputs in the job file, RealProducer uses these same inputs and outputs. You can easily change this by deleting the input and output names and defining new ones, as described in "Selecting Inputs and Destinations".

It's a good idea to double-check the audience settings for the job to ensure that you are encoding the output properly. For more information, see "Choosing Audiences".

A job file can record specific clip information, as described in "Setting Basic Encoding Parameters". You may need to add or change this information each time you encode with an existing job file.

When you finish making necessary changes, choose File>Save Job (Ctrl+s) to save the changes to the existing job file. If you want to create a new job file, choose File>Save Job As... (Ctrl+Shift+s) and save the file under a new file name.

Changing the Overall Default Settings

RealProducer predefines many default settings, such as the audiences used. You can change the overall defaults to those set in the current job by choosing Settings>Default Settings>Save Current as Default. This is useful if you encode a lot of clips the same way. By saving your job settings as the default, you do not have to open a job file to use those settings. To restore the original, default settings, select Settings>Default Settings>Restore Original Default.

For More Information: The section "Default Audiences and Options" lists the audiences and encoding options used with the standard, default settings.

Running Multiple Jobs

RealProducer Plus can run multiple jobs in batch mode, processing one output after another. Batch encoding is useful when you have a number of clips that you want to encode with similar settings. RealProducer Basic can open one job file at a time, however.

To encode a batch of jobs:

Open or create multiple jobs. Each job appears in the Job Manager, which is described in "Using the Job Manager".

Tip: To create a number of jobs with the same settings, open a job, then drag-and-drop media files into RealProducer. For each input file, RealProducer creates a new job with the same settings as the open job. You can also duplicate a job's settings by right-clicking on a job title in the job manager and selecting Duplicate from the context menu. In this case, you may need to change the input and output clips.

In the job manager, select the jobs that you want to encode. To do this, click each job while holding down the Ctrl key. You can also select a group of contiguous jobs by clicking the first job, then clicking the last job while you hold down the Shift key.

Tip: To remove a job from the batch encoding run, highlight the job in the job manager and choose Edit>Delete.

Encode the batch of jobs by clicking the Encode button. Each job runs in order.

For More Information: For more about encoding and monitoring a job, refer to Chapter 8.

Tip: You don't have to wait for a job to finish encoding to perform other tasks with RealProducer. While one job runs, you can add a job or create a new job.

Using the Job Manager

The job manager, which appears at the bottom of the RealProducer main window, keeps track of the encoding jobs you are using in the current session. Through this manager, you can quickly control more than one job at a time. The job manager display four information fields for each job:


`Job`	This is the job file name. Until you save the job file, the job name is `Untitled`. To change settings for a job, click its job name, then make your changes.
`Status`	This field provides a description of the job status, such as `Ready`, `Not Ready`, `Analyzing`, `Encoding`, and `Done`.
`Start`	This field indicates the time that the job began encoding.
`End`	This field records the time the job stopped encoding.

Job Manager (detail)

Tip: When you right-click a selected job in the job manager, RealProducer displays a context menu that allows you to perform basic functions with the job, such as starting the encoding, saving the job, and so on.

Selecting Inputs and Destinations

For the media input, you can use digitized files or data from an audio or video capture device. For outputs, you can specify an encoded clip, a live broadcast to a server, or both. Chapter 11 explains how to choose a server as a destination to create a live broadcast.

For More Information: For information about acceptable audio and video input formats, refer to "Audio and Video Input Formats".

Using a File as the Input

Source files are digitized media files on your hard disk, network, or input medium such as CD or DVD. If you have video editing software, you can use that software to edit and optimize the file before encoding it.

Tip: For tips about producing high quality input files, refer to "Audio Optimization" and "Video Recording Tips".

To use a digitized file as the encoding input:

If you have multiple jobs open, click the appropriate job file name in the job manager.

In the RealProducer main window, click the Input File radio button. Then click the Browse button to display a standard browsing dialog in which you can find the file you want to add as the input. You can also display the browsing dialog by giving the menu command File>Open Input File or the keyboard shortcut Ctrl+i. By default, the browse dialog shows only the media files that have acceptable input formats.

Note: You cannot re-encode a RealMedia clip. If you need to encode a clip for a different audience, for example, you must use as input the original, digitized file.

When you have located the input file through the browsing dialog, click Open. The field next to the Input File button displays the path and file name. If you have not already loaded a job file, an untitled job opens in the job manager.

Once you have selected a source, you can click Source Properties to display information about the input, including the file size and duration, audio sampling rate and bit depth, and video dimensions and frame rate.

Using Live Audio or Video as the Input

Another source for media input is live or prerecorded audio or video sent to your computer's audio or video capture card. You can encode these media inputs as clips, or send the encoded stream to a server for broadcast.

To capture from an audio device:

If you have multiple jobs open, click the appropriate job file name in the job manager.

In the RealProducer main window, click the Devices radio button.

Select the audio capture device from the pull-down list. This list provides the names of all audio captures devices, such as "SoundBlaster," that RealProducer has detected.

If you want to adjust the sound recording capabilities of your audio device, click the Settings button next to the listed audio device. A submenu lists the available settings dialogs, which may include vendor-specific controls that differ for each audio capture device. For instructions about using vendor-specific controls, consult the device's user manual.

Select the Recording Mixer menu option. This opens the recording control window in which you can specify how audio is mixed from different audio sources.

Select which recording inputs to use by checking the Select box for each input.

Adjust the sound level by moving the sliders up or down. When you have finished setting the values, close the recording control window.

Tip: If the volume is too high, the recorded sound may be clipped and appear distorted. If the volume is too low, it will be difficult to hear. Use the audio meter described in "Monitoring Audio" to monitor the level during encoding.

If you want to encode the input for a specific amount of time, click the Duration box and enter the number of hours, minutes, and seconds in the timing fields. The timer begins when you start the encoding process, and automatically stops the process when the specified time elapses. Otherwise, encoding stops when you click the Stop button.

Once you have selected a source, you can click Source Properties to display information about audio properties that will be captured.

To capture from a video device:

If you have multiple jobs open, click the appropriate job file name in the job manager.

In the RealProducer main window, select the Devices radio button.

Select the video device for your computer from the pull-down list. This list provides the names of all video captures devices that RealProducer has detected.

If you want to adjust the video recording capabilities, click the Settings button next video device name. This displays a submenu of available settings dialogs, which can vary with each capture device. For information about vendor-specific controls, consult the device's user manual.

For most video capture devices, you can select the video dimensions in pixels. This will determine how large your input video will be. Select the same size you want for your encoded output clip. For more information, refer to "Video Encoding Dimensions".

Select the video format to determine how the capture card converts the video into digital video. Some common formats include RGB, YUY2, BTYUV, YUV9, and YUV12.

Tip: Use YUV12 if it is available. This is the native color format for RealVideo codecs. Choosing this option improves performance by removing the need to convert the color format before encoding.

Select the video source. Some video capture devices allow you to plug in various sources, such as an S-video input from a video camera, a cable television cable, or a Web camera. When you have finished setting the options, close the window.

If you want to encode the input for a specific amount of time, click the Duration box and enter the number of hours, minutes, and seconds in the timing fields. The timer begins when you start the encoding process, and automatically stops the process when the specified time elapses. Otherwise, encoding stops when you click the Stop button.

Once you have selected a source, you can click Source Properties to display information about video properties that will be captured.

Creating a Destination Clip

You can save your encoded output to a clip, as the following sections describe. Or, you can send the output to a server for broadcast as described in Chapter 11. A clip or server output is called a destination, and you can save your encoded input to multiple destinations. For example, you send live input to a server for broadcast, and simultaneously write it to a clip for archive purposes. The encoded data sent to each destination is identical.

Note: When you use RealProducer Plus, you can encode any number of clip and server destinations for the output. With RealProducer Basic, you can define one clip destination and one server destination in each job.

Tip: When you use a job file with the command-line application, you can specify multiple outputs, which can have different encoding settings. For example, one output might be a clip with large dimensions for broadband connections, while the second output is a clip with smaller dimensions for dial-up connections. See "Media Profile" for more information.

Modifying a Clip Destination

By default, RealProducer automatically defines an output clip when you select an input file. The output clip uses the input's base file name and the appropriate extension. For example, if you choose movie.mpeg as your input, RealProducer sets up movie.rm or movie.rmvb (depending on your encoding choices) as the output destination, creating the clip in the same directory as the input.

To modify a clip's properties, such as its name or output location, double-click the clip icon in the destinations area. You can also highlight the clip name, and click the pencil icon below the destinations window. Either action displays a browse dialog in which you can navigate to the directory where you want to save the clip. If you rename the clip, you can enter just the base file name. RealProducer appends the appropriate file extension (.rm for CBR clips or .rmvb for VBR clips), based on your encoding choices.

For More Information: Through the RealProducer preferences, you can change the directory where the clip is created, or turn off the automatic destination feature. See "Changing the File Location Preferences".

Creating a New Destination Clip

The following procedure describes how to create a new RealAudio or RealVideo clip as a destination for an encoded input file or live capture. It is generally necessary to encode just one destination clip. All destinations for a job have identical encoding settings. You can therefore create a second clip by duplicating the output clip through your operating system.

To define a clip as a destination:

If you have multiple jobs open, click the appropriate job file name in the job manager.

Select File>Add File Destination. You can also click the RealPlayer icon in the destinations area. This opens a save dialog.

Browse to the directory where you want to save the output clip.

Enter the base file name. RealProducer automatically adds the correct file extension (.rm for CBR clips or .rmvb for VBR clips), based on your encoding choices.

Click Save. Your new destination appears in the destinations area. If a destination already exists for the job, the new destination appear below it.

Deleting a Destination Clip

To delete a destination clip, select the job in the job manager if multiple jobs are open. Next, click the clip name in the destination window to highlight it. Then, either press Delete on your keyboard or click the trash can icon below the destination window.

Adding Clip Information

RealProducer can encode clip information directly into a clip or broadcast. This is highly recommended for all jobs because the clip information tells the viewer about the stream and can help search engines categorize clip. If you are running multiple jobs, first choose the job you want by clicking the job name in the job manager. Then, either choose Settings>Show Clip Information or click the Clip Information button. You can then enter the following information:


Title	In this field, enter the title of the clip or broadcast. Because this title appears in the RealPlayer interface, it is best to use a short title.
`Author`	This field holds the name of the person or organization that created the clip.
`Copyright`	Here, enter the copyright string, such as `(c) 2004 ABC Corporation`.
`Keywords`	The keywords field holds words that certain audio and video search engines can read to categorize the clip. Add a few words that will help your audience search for your clip. Separate each term with spaces. Unless you are adding a proper name, use lowercase for each term. Avoid overly generic terms such as `video` or `music`.
`Description`	This field holds a description of the clip that appears when the viewer displays extended clip information. This allows you to describe the clip in detail without creating a long title.
`Rating`	Selecting a rating in the pull-down list is highly recommended for any content not intended for all age groups. You can choose one of the following. `No Rating` is the default: `–No Rating –All Ages –Older Children –Younger Teens –Older Teens (15 and up) –Adult Supervision Recommended –Adults Only`

Tip: Using the RMEvents utility described in Chapter 13, you can add information to a clip that has already been encoded. You can also specify clip information through a Ram file, as described in Introduction to Streaming Media.

How Clip Information Displays in RealPlayer

RealNetworks highly recommends that you always include a title. If a title is not encoded in the clip or specified through other means (such as a Ram file), RealPlayer displays the clip's file name, which is of less use to the viewer than the title. The clip information appears in the following areas of RealPlayer:

The title appears in the title bar above the RealPlayer playback controls.

Title and author information appears in the "Now Playing" list, which is part of the RealPlayer media browser pane. Viewers can double-click a clip title to play that clip.

Title information appears in the recent clips list at the bottom of the RealPlayer File menu.

Extended clip information appears when the viewer chooses File>Clip Properties>View Clip Info (Ctrl+i).

Filtering Video Input

When you encode video input, you can use a number of filters that can improve the quality of the video that comes from your source. All video filters are optional. If you are working with multiple jobs, select the appropriate job in the job manager. Then, display the video filters palette by clicking the Video Filters button or selecting Settings>Show Video Filters (Ctrl+f).

Video Filters

Tip: Changes to the video filters are recorded immediately. You do not need to close the palette to save your changes for the job. You can leave the palette open as you continue to set up a job or switch to another job.

Cropping

The cropping feature, available only on RealProducer Plus, allows you to crop out portions along the edge of a video. Cropping removes any unwanted areas, and can reduce the amount of data encoded, boosting clip quality.

To crop a video, check the Cropping box. You can then set the cropping borders by clicking and dragging the yellow lines on the source video image. Or, enter cropping pixel values directly into the following boxes:


`Left`	Represents the number of pixels from the left edge of the video to start the cropping. You can specify up to 32 pixels less than the total width.
`Width`	Defines the total width of the cropped video, measured from the point set by the `Left` property. If the width value is not a multiple of 4, the next lower multiple is used. For example, a value of 162 results in a video 160 pixels wide.
`Top`	Sets the number of pixels from the top edge of the video to start the cropping. You can specify up to 32 pixels less than the total height.
`Height`	Indicates the total height of the video, measured from the point set by the `Top` property. If the value is not a multiple of 4, the next lower multiple is used. For example, a value of 127 results in a video 124 pixels high.

For More Information: You can scale a cropped or non-cropped video smaller or larger as described in "Resizing the Video". Refer to "Video Encoding Dimensions" for recommended video sizes.

Black-Level Correction

Check the Black level correction box to increase the video contrast by making black areas darker. This filter is useful if the source video appears washed out.

De-Interlace and Inverse-Telecine

The de-interlace and inverse-telecine filters remove artifacts that may occur in videos larger than 320-by-240, and NTSC-format video transferred from film, respectively. If you need to use them, click the Automatic radio button to have RealProducer apply the filters only if needed. To use just one of the filters, check the Manual button and select the filter you want.

For More Information: The sections "De-interlace Filter" and "Inverse-Telecine Filter" explain these filters.

Video Noise

Video noise appears as static ("snow") in your input video. The noise filter removes these artifacts prior to encoding. Do not apply this filter if the input does not contain noise because the filter can degrade the quality of undistorted video. You can choose the Low setting if the static is light, or the High setting if it is more pronounced.

For More Information: For more on the difference between low and high noise settings, refer to "Noise Filters".

Setting Basic Encoding Parameters

When you create a new job, you should set a few basic parameters that affect the overall encoding. If you have multiple jobs open, select the appropriate job in the job manager as described in "Using the Job Manager". After you set your input, click the Audiences button or choose Settings>Show Audiences (Ctrl+e). This opens the Audiences palette. You set the basic parameters in the top half of the palette. In the bottom half, you select your audiences as described in "Choosing Audiences".

Encoding Settings on Upper Half of Audiences Palette

Tip: Changes to the basic settings are recorded immediately. You do not need to close the palette to save your changes for the job. You can leave the palette open as you continue to set up a job or switch to another job.

Setting Audio Parameters

The Audio Mode setting indicates the type of audio being encoded: Voice, Music, or No Audio. You should ensure that this is set correctly for each job. For example, using the Voice setting for a musical soundtrack can degrade the music quality because a voice codec does not capture the wider frequency range found in music.

In general, you should leave the Use high quality resampler for audio box checked. This provides the best results if the audio input does not have the correct sampling rate for the codec, as described in "Sampling Rate". Unchecking this box speeds processing time, which may be necessary during a live broadcast. Doing so may lower the quality of the audio, though.

Tip: If your audio content is mixed, use the Music setting to capture the greatest frequency range. If you are encoding at a bit rate of 256 Kbps or higher, you may want to choose Music even for voice-only content. This generally provides more bandwidth for the soundtrack, improving the quality. It takes away bandwidth from the visual track, however.

Choosing Video Options

The Video Mode pull-down list on the Audiences palette affects how video is encoded. The default value of Normal Motion Video produces the best results for most audiences. You can leave this value set even when you encode an audio- only clip because RealProducer automatically detects that no visual track is present. You should select the No Video option only if you want to encode just the audio portion from the video input.

At slow streaming rates for modem audiences, you can choose one of the following options when encoding a video. These options primarily affect fast- action videos:

Choose Sharpest Image if you want to encode the crispest image. The frame rate will be lower, though, making the video jerkier. For more information, see "Visual Clarity".

Choose Smoothest Motion if you want to keep the frame rate as high as possible. The image may become more blurry, however. For details, refer to "Encoded Frame Rates".

If you have a large video (320-by-240 or larger), you can resize the video smaller when streaming at low bandwidths. Or, you can choose Slide Show to encode a frame every few seconds. This creates a slide show with no motion, but the highest possible image quality.

Selecting a RealVideo Codec

In the Video codec pull-down list, you select the RealVideo codec to use. The section "RealVideo Codecs" explains the codec differences. The default is RealVideo 10, which provides the highest possible video quality and is compatible with RealOne Player and later. RealVideo 10 is the only option on RealProducer Basic. With RealProducer Plus, you can choose RealVideo 9 or RealVideo 8.

Tip: Use RealVideo 8 to create videos that are compatible with RealPlayer 8 and later on desktop machines, as well as with RealPlayer for mobile devices such as smartphones and personal digital assistants.

Using Two-Pass Encoding

In the Audiences palette, you can turn off two-pass encoding, which the section "Two-Pass Encoding" describes. RealNetworks recommends that you keep two-pass encoding enabled, turning it off only if you need to decrease your encoding time. Video quality will decline, however.

Tip: Two-pass encoding cannot be used with live broadcasts and is automatically disabled. You therefore do not need to uncheck this option when broadcasting.

Resizing the Video

Normally, the encoded video uses the same height and width dimensions as the video input. If you use RealProducer Plus and you want to change the size of the encoded video, check the Resize video to box and enter a pixel value for the new height and width. You can scale the video smaller, which may be necessary when streaming to slow bandwidths, as described in "Video Capture". Note that if you scale the output video much larger than the input size, it may appear blurry.

If you keep the Maintain aspect ratio box checked, you can enter just the height or width value for the resize. RealProducer automatically calculates the other value to maintain the ratio between the two dimensions. By unchecking this box, you can enter width and height values independently. If you do not maintain the aspect ratio, however, the output will be distorted.

RealNetworks recommends that you keep the High quality resize box checked. This produces superior results, but significantly increases the encoding time. Uncheck the box only if you need to decrease the encoding time. Note that the video quality will decline, however. The section "Resize Filter" provides background information about resizing.

Note: You can also crop out portions of the video input before resizing the video. See "Filtering Video Input" for more information. Refer to "Video Encoding Dimensions" for recommended video sizes.

Choosing Audiences

Before you encode a clip or broadcast, you choose the audience or audiences to use. For each audience, RealProducer encodes a separate stream based on the speed of the network connection or a certain level of quality that you want to preserve. For example, RealProducer encodes video at 34 Kbps for 56 Kbps dial-up modem users, and at 225 Kbps for 256 Kbps DSL or Cable Modem users. RealProducer predefines a variety of audience templates. The following sections explain how to add audiences to encoding jobs.

For More Information: Chapter 7 provides details about each audience that you can choose. See "Creating and Editing Audiences" for information about creating your own audience templates.

Default Audiences and Options

If you do not choose your own audiences for an encoding job, RealProducer uses a set of default encoding values. On RealProducer Plus, these presets encode a clip or broadcast for streaming to both dial-up modems and broadband connections. The clip or broadcast will be compatible with RealOne Player and later. The following are the default values:


General settings:	SureStream CBR clip for multiple audiences Two-pass encoding No predefined clip information
Audiences:	16k Substream for 28k Dial-up 28k Dial-up 56k Dial-up 256k DSL or Cable (RealProducer Plus only)
Audio encoding:	Music codecs (codec used depends on the audience) High-quality audio resampling
Video encoding:	RealVideo 10 Normal motion video No video resizing No video prefilters High encoding complexity Maximum start-up latency of 4 seconds

Tip: The section "Changing the Overall Default Settings" explains how to change these default settings.

Adding an Audience to a Job

If you have multiple jobs open, select the appropriate job in the job manager as described in "Using the Job Manager". Then click the Audiences button or choose Settings>Show Audiences (Ctrl+e). This opens the Audiences palette. In the top half of this palette, you choose basic encoding settings as described in "Setting Basic Encoding Parameters". In the bottom half, you select your audiences.

Audience Selection on Lower Half of Audiences Palette

The left-hand section of the Audiences palette lists the available audience templates. Each template has a name that describes the audience, such as 56k Dial-up, and lists the template's average bandwidth usage. The right-hand section of the palette lists the audiences chosen for the job. By default, RealProducer uses the audiences described in the section "Default Audiences and Options" to create a SureStream clip.

To add an audience to the job, click the audience name in the left-hand windows and click the right arrow button. To add multiple audiences to the same job, you can choose only the audiences not listed as variable bit rate (VBR) audiences. To delete an audience from the job, highlight the template name in the right-hand section, and click the trash can icon or press your keyboard's Delete key.

Note: Using RealProducer Plus, you can add any number of CBR audiences to a SureStream clip. With RealProducer Basic, you are limited to three audiences.

Tip: To view the properties for an audience added to the job, double-click the audience name. Or, highlight the name and click the pencil icon. Chapter 7 lists the properties for each audience.

©2004 RealNetworks, Inc.
For more information, visit RealNetworks
Click here if the Table of Contents frame is not visible at the left side of your screen.