Chapter 5: Defining the Input for an Encoding Job

This chapter describes how to define what the input will be for your encoding job. You will learn what you can use as the source for the input and how to adjust the input video.

Overview: Input and Sources

The input for a job is a media source that will be encoded into streaming media by Helix Producer. Whatever source you want to use will become the input for the job. The following diagram shows you three different jobs, each with a different type of source for the input.

Sources used as inputs

This section discusses the different types of sources you can use for an input, shows you how to add an input to a job, and shows you how to use video filters to adjust the input's video.

Setting the Source for the Input

There are two types of media sources that you can use to create streaming media with Helix Producer. You can use either files or an audio/video capture device.

This section is an introduction to these sources that you can use when you set up an encoding job with Helix Producer.

Using a File as the Input

Source files are pre-existing media files that are compatible with Helix Producer and can be encoded into RealMedia. These files are generally created with other media-generating tools.

To add a file as the input:

1. On the Helix Producer main window, select Input File in the Input section.
2. Click the Browse button to locate the file you want to add as the input.
3. Change to the folder where the media file is located, select it, and click Open.

The path and file name of the media file is listed in the Input File field.

A default destination file appears in the Output section using the input file's name with a .rm extension.

You can use a variety of media file as sources for the input. The following lists are based on software you have installed on your computer.

Platform-Independent File Formats

The following file formats can be used as sources on any platform supported by Helix Producer. No other software needs to be installed to use these formats.

• Uncompressed AVI
• Uncompressed QuickTime 3, 4, and 5
• WAVE audio files

DirectShow Supported File Formats

The following file formats can be used as sources only on the Windows operating system. At a minimum, you must have DirectX 6 installed. Some formats require that DirectX 8 is installed. For the latest version of DirectX, go to www.microsoft.com or use the link provided at www.realnetworks.com.

• Compressed AVI (.avi)
• AIFF (.aif, .aifc, .aiff)
• Moving Pictures Experts Group (.mpg, .mpeg, .m1v, .mp2, .mp3, .mpa, .mpe, .mpv2, .m3u)
• Audio for Windows (.wav)
• QuickTime 2 Content (.mov, .qt)

Using Live Audio/Video as the Input

Another source that you can use for the input is live audio and/or video. To send audio and video directly to your computer, you will need the following:

• a media device (such as a VCR, video camera, or microphone)
• for capturing live audio, a sound card
• for capturing live video, a video capture card, unless you can connect a video device directly to your computer via an IEEE -1394 (Firewire, iLink), or a USB port

To add an Audio device as the input:

1. In the Helix Producer main window, select Devices in the Input section.
2. Select the audio device for your computer from the pull-down list (for example, SoundBlaster).
3. If you want to adjust the sound recording capabilities of your audio device, click the Settings button next to the listed audio device.

A menu appears listing available settings dialogs for your audio device.

4. Select the Recording Mixer menu option.

The Recording Control window opens. In this window you can specify how audio is mixed from different audio sources.

5. Select which recording inputs to use by choosing the Select box for each input.
6. Adjust the sound level by moving the sliders up or down.

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 level meter in the Helix Producer window to monitor the level during encoding.

7. Close the Recording Control window and return to the Helix Producer.

To add a Video device as the input:

1. On the Helix Producer main window, select Devices in the Input section.
2. Select the video device for your computer from the pull-down list.
3. If you want to adjust the video recording capabilities of your video capture device, click the Settings button next to the listed video capture device.

A menu appears listing available settings dialogs for your video capture device.

Note: Every video capture device will have a unique way of modifying how the video is captured. The rest of this procedure will explain a few common settings. Consult your device's manual for more information.

4. Select the video dimensions, in pixels. This will determine how large your input video will be. Some common sizes are: 160 x 120, 320 x 240, and 640 x 480.
5. Select the video format. This is how the capture card converts the video into digital video. Some common formats are: RGB, YUY2, BTYUV, YUV9, and YUV12.
6. 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 cam.

Adjusting Input Video

Once an input is added to a job, Helix Producer gives you a variety of filters to improve the quality of video that comes from your source. You can crop the input video to a size more to your liking, and you can apply an array of filters to the input video. The rest of this section shows describes these methods.

Cropping the Input Video

Helix Producer's cropping feature allows you to record any portion of a video image that you wish. When you crop video, you reduce the amount of data that needs to be encoded, while also removing unwanted image area.

Your input must contain video to use cropping, and the smallest size that you can crop an image to is 32 x 32.

To crop an input video image:

1. From the main window, click the Video Filters button.

The Video Filters palette opens.

2. Select the checkbox labelled Cropping.

Yellow lines appear on the preview section of the Video Filters dialog.

Note: The part of the video region that these yellow lines outline is the part of the video that will be encoded.

3. Using the mouse cursor, select and drag these yellow lines to crop the input video to the desired size.
4. You can also type in the Left, Top, Width, and Height dimensions of the desired video size in pixels.

Using the Black Level Correction Filter

The Black Level Correction filter is used to adjust the brightness of the input, effectively making black areas in the video appear "blacker." This filter is useful if the video appears washed out, without much saturation.

To turn on the Black Level Correction filter:

1. From the main window, click the Video Filters button.

The Video Filters palette opens.

2. Select the checkbox labelled Black Level Correction.

The Black Level Correction filter is enabled.

Using the Deinterlace and Inverse Telecine Video Filters

The Deinterlace filter removes "artifacts" that can be present when encoding digitized NTSC or PAL formatted video. These artifacts are horizontal lines seen surrounding a moving object.

Most movies are filmed at 24 frames per second (fps). When a film is converted into NTSC video at 30 fps, fields are alternately duplicated and shared. The film-to-video conversion process is called telecining. The Inverse Telecine filter removes redundant fields added during a telecine process, improving the quality of the frames that are encoded.

The Inverse Telecine filter is only used when encoding input video with a frame rate of 30 fps.

To turn on the Deinterlace and Inverse Telecine filters:

1. From the main window, click the Video Filters button.

The Video Filters palette opens.

2. Select the checkbox labelled Deinterlace/Inverse Telecine.
3. You have two options:

1. Select Automatic, and Helix Producer will use these filters if the input looks like it has artifacts or it looks like it was created with a telecine conversion.
2. Select Manual, and then select either filter that you want to be applied.

When selected, the filters are enabled.

Using the Video Noise Reduction Filter

Video noise appears as static in your input video. This noise can appear in video for a variety of reasons: poor capture cards, cameras, or storage. The noise filter removes this noise from the input video prior to encoding.

It is recommended that you do not use the video noise filter unless your video has some distortion or static. Using this filter (especially the High setting) will degrade the quality of undistorted video.

To adjust the Video Noise Reduction filter:

1. From the main window, click the Video Filters button.

The Video Filters palette opens.

2. Select the checkbox labelled Video Noise Reduction.
3. You have two options:

1. Select Low, and Helix Producer will filter out some video noise.
2. Select High, and Helix Producer will filter out a significant amount of noise. As mentioned above, the High setting will degrade undistorted video.

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