Create a Live Encoding session
Once you have decided on a streaming mode and established your video sources, you can begin your Live Encoding session. If you have not done either of those two steps, you should first see Streaming modes before getting started with this task.
To create a Live Encoding session, you will generally have to do the following. Scroll down through this topic to follow the workflow tasks sequentially.
Enter the Live Encoding mode. The Live Encoding mode presents a different workspace than the standard Microsoft Expression Encoder workspace. You have to enter the Live Encoding workspace before you can build and broadcast your content.
Set up the live and file-based sources that you will have to compose your broadcast. To capture a live video feed, you must connect a camera to your workstation and configure it so that you can view an image. To stream pre-recorded audio or video files, use the controls in Expression Encoder to specify the files you want to open, to arrange them in the order in which you want them to play, and to specify what actions you want them to take after they have played.
Set up the encoding options. Here you choose whether you want to encode audio or encode video, or both. You can also choose to intersperse your live broadcasts with captions.
Add metadata to your streamed file.
Add captions to your streamed file. You can add text that will display, on your command, at any time during the broadcast. If you choose to archive your file, these captions become part of the archived stream. If you open your file in Expression Encoder, you will see the captions listed as script commands and displayed as markers. You can then modify the command text, realign the commands on the Timeline, and add new commands.
Set the output options. In the Output panel, you set the streaming mode. You can either pull your content from Expression Encoder and send it to an available local port, or push your content to a Windows Media server. Then, if you want to save the encoded file for future on-demand delivery, possibly as a Microsoft Silverlight package, specify the appropriate archive options.
Begin your Live Encoding presentation. Start your camera or open your files to begin encoding and subsequently recording and broadcasting your presentation in real time. As you broadcast, you can switch sources and insert captions into the stream on the fly.
Archive and modify your presentation. Depending on the output options that you set, after you finish your broadcast, Expression Encoder saves an encoded version in the location you specify. You have several options for working with the file from that point. For example, you can create several streaming broadcasts in a single session while you are in Live Encoding mode and specify each subsequent file to open as a job so that when you exit Live Encoding mode, you can then package those files in Silverlight templates to prepare the files for an on-demand, rich web presentation, or for any other kind of distribution.
To enter the Live Encoding mode
- On the View menu, click Live Encoding Mode. When you first enter this mode, the Output panel displays the necessary set of tasks you must perform to initiate streaming. The tasks display as links, and when you click a task, the area of the user interface that corresponds to the task will illuminate. The links are helpful in orienting you to the workspace and tasks, and to quickly prepare your broadcast after you are familiar with the Live Encoding functionality. However, at first, you should refer to the following tasks to understand your options.
To set live video sources
Connect your camera device, such as a USB Webcam, or a Firewire (IEEE 1394) digital video camera. Although you can connect multiple live sources, you can stream only one at a time.
In the Settings panel, click the Live Sources tab.
Live Source 1 appears selected by default if this is the first time that you are starting the Live Encoding mode.
In the Device Configuration section, set the following options:
In the Video Device list, click the video device you want to use. Do the same in the Audio Device list. Once you choose your video device, the live image from that source appears in a window in the sources area.
Click the Configure button under the video or audio device list to set options that may be particular to the chosen device.
In the Audio Level section, drag the slider to adjust the audio levels.
To add another live source, click Add. Repeat step 4 to configure the device. In the sources area, Expression Encoder displays the image captured by each subsequent live source that you configure.
To edit configuration information for a device, click the appropriate Live Source button and repeat step 4. To remove a source, select it in the list and click Remove.
You can remove any source from the list except Live Source 1.
To set file-based sources
In the Settings panel, click the File Sources tab.
Click Add. A file source button appears in the file list and a corresponding panel appears in the File Sources viewing area. The panel displays a thumbnail of your file source, and also its duration and the end action that you specify in the following steps.
Under File Source Settings, set the following options:
Name Specify a name for the file source.
**File **Click this button to locate a saved file. You can open any file that Expression Encoder can import. For more information about acceptable file formats, see Supported file formats.
**Play then **Select an action to occur when your file reaches the end of its duration. Select Hold if you want the source to freeze at the final frame. Select Jump To to begin playing another source, and then select the source to play in the following list. You can choose only file sources that you have already imported. Select Loop to have the source perform a looping playback or, if your source is a still image, to display continuously.
**Resize Mode **Select how you want Expression Encoder to resize images whose original dimensions differ from the output dimensions.
**Duration **This option only appears if you choose a still image as a file source. Enter the length of time that you want the image to display. If you enter no duration, the image displays indefinitely.
To add another file source, click Add and repeat step 3. To modify the file source information, select the source name in the list or select the source file thumbnail in the File Sources viewing area and make the changes in the File Source Settings section.
To set encoding options
Click the Encoding tab.
Choose whether you want to encode audio, video, or both. Also, select the Script Stream check box if you want to intersperse your live broadcast with captions. When you select this check box, new options appear in the Output panel. These options enable you to add and broadcast captions. For information about how to add captions for live broadcast, see the following task.
If you choose to encode audio or video, make sure that you have chosen a corresponding live device in the Live Sources tab (see "To set live video sources" or "To set file-based sources," later in this topic).
Do any of the following. To access the advanced options, click the Show/Hide advanced properties button . Some options may be disabled depending on whether you chose to encode audio or video:
Video Click an encoding profile for your streamed content. If you chose to archive your encoded file, Expression Encoder also saves your file using this profile. Expression Encoder uses variants of the VC-1 format to encode your media. VC-1 creates high-quality encoded video at bit rates that may range from very low to very high. The VC-1 encoding format is considered a standard for professional broadcast and delivery, and also is optimized for Silverlight playback scenarios. All profiles are CBR (constant bit rate) only.
Default Profile Select this check box if you want Expression Encoder to use a standard-quality audio encoding profile. Clear the check box if you want to specify your own audio profile.
Audio Click an encoding profile for your streamed content. If you chose to archive your encoded file, Expression Encoder also saves your file using this profile. This list is disabled if you select the Default Profile check box.
Video Complexity (Advanced) Specifies the encode complexity of the video stream. This value can range from Fastest (0) to Best (5). Higher values give you higher quality video but can require significantly more processing time. 0 and 1 are optimized for Live Encoding where you have to process the frames in real time and 2-5 are optimized for offline encoding.
Min Packet Size (Advanced) Specifies the minimum size in bytes of User Datagram Protocol (UDP) packets that stream across the network. This setting applies to single bit-rate content that is streamed from a Windows Media server. Enter a value to represent, in bytes, the smallest packet size that Expression Encoder allows when streaming.
Max Packet Size (Advanced) Specifies the maximum size in bytes of UDP packets that stream across the network. This setting applies to single bit-rate content that is streamed from a Windows Media server. Enter a value to represent, in bytes, the largest packet size that Expression Encoder allows when streaming.
Under Profile Settings, Video Dimensions, Video Framerate and Bitrate, and Audio Bitrate data for your streaming broadcast are listed. Use the information in this section to guide you in making optimal profile choices for your broadcast.
To add metadata
Click the Metadata tab in the Settings panel.
Type your metadata in the appropriate boxes. The metadata that you add is stored with the file if you decide to archive it.
To add captions
In order to add captions, you must first select the Script Stream option (see "To set encoding options," earlier in this topic). Below the Output panel, note the Type and Command columns that appear.
In the Type column, click the blank space and type a name for the caption. Then, in the Command column, click the blank space and type the exact text of the caption. Note that a new row appears underneath the one that you are working with. Repeat this procedure for each caption that you want to create. After you have specified a type, you can choose it again from the menu, in order to prevent retyping it. Generally, you want your captions to be pertinent to your video or audio. This may be easier to do in advance if you know your source material, but if you are doing a live broadcast, you may want to add captions on the fly. In that case, you can follow these steps to add captions as you broadcast.
To delete a row, click the Remove button.
The caption will not display in the Output panel as you record your presentation. The caption displays only when the video is played back in a Silverlight environment. However, if you decide to archive the file, you will see the caption text in addition to the corresponding marker when you open the file in the default view of Expression Encoder. You can then modify the caption text and the markers.
To set output options
Click the Output tab in the Settings panel.
Select the Streaming check box to enable the streaming settings.
Select the streaming mode that you want to use. For an in-depth explanation of the streaming modes, see Streaming modes. Depending on what mode you select, specify the following options:
Broadcast Enter a local port to which you want to send your streaming content. For Max Connections, enter the maximum number of users you will allow to log on to your system.
Publishing Point For Location, type the full address of the Media Services server to which you will be pushing content. Click Pre Connect to enter any authentication information and establish a connection to the server. If you do not click Pre Connect now, you will be prompted for authentication information, if necessary, when you start your streaming session.
Launch Preview Click this button to preview your broadcast in a Silverlight template. You cannot alter the template.
If you want to save your streaming presentation as a file, select the File Archive check box and specify the following options:
Filename Type a file name and output file path. To browse to a location, click the Browse button .
**Append output to job on close **Select this check box if you want to open the archived file as a new job in Expression Encoder. Once you finish your streaming broadcast and exit the Live Encoding mode, your archived file either appears as a job in the standard Expression Encoder workspace or, if you already opened a job before entering the Live Encoding mode, is appended to the open job. You can then apply other modifications to your file, such as adding markers, overlays, or a Silverlight template.
Under Error/Frame Count, choose either of the following options:
In the On Error list, select the action that you want to occur when there is an error during streaming. To freeze the stream, select On Hold. To switch to another source, select Jump To, and then, in the list that appears underneath, choose the live or file source that you want to begin playing. To exit the streaming presentation, click Stop.
Select the Show frame count check box if you want to view a running count of the number of captured frames and the number of dropped frames in your broadcast. The numbers display underneath the live source window and underneath the Start button.
To begin your Live Encoding presentation
Make sure that you have set all your options. To change any options, see the previous tasks.
In the File Sources area, click the play button on the source that you want to stream first. The file should read "Cued" to alert you that it is ready to play.
Above the Settings panel, click Start. If you are pushing your content to a Windows Streaming server, and you did not pre-connect, you may be prompted now to enter authentication information.
Begin your presentation. Monitor your performance in the Output panel. The viewer pane displays your live and file-based sources as they play, and the green bar to the right of the viewer pane displays the audio levels. If necessary, click the Play button on any source that you want to play during your performance. The file that you click replaces the currently playing source.
To mark a spot for a script command, such as a caption, to activate, click the Send button corresponding to the row that contains the command that you want to activate at the time that you want to activate it. When the file is played back, the script command executes until you click Send on another row.
When you are finished, click Stop.
To modify your archived presentation
Complete your streaming broadcasts.
Below the transport controls, click Exit Live Mode.
Do one of the following:
If, on the Output tab in the Settings panel, you did not select the Append output to job on close check box, you must import your video in order to work with it. On the File menu, click Import and browse to the encoded file.
If, on the Output tab, you selected the Append output to job on close check box, you will see your encoded files listed in the Media Content panel as a single job or appended to a job that you already opened.
You can now work with your files as you would any other files that you import into Expression Encoder.
Under Profile in the Settings panel, Expression Encoder assigns Source Profile as the video encoding profile.