Creating Templates

Each template is comprised of an audio codec, video bit rate, total bit rate, quality and frame rate. The quality of the RealVideo encoding is affected by these settings and the actual content. Below are content elements that can affect the quality of the encoding at 19 Kbps:

Content Type	Expected Encoding Results
Low motion, fixed camera shot	Good clean frames, with high frame rates
Fixed camera shot some motion	Clean frames, somewhat slower frame rates
Multiple camera shots low motion	Clean frames with 1 fps or less
Zoom with low motion	Clean frames with moderate frame rate
Fixed camera shot high motion	Clean frames with moderate frame rate
Multiple shots high motion	Clean frames with less than 1 fps

* Subjective results based on content elements

If you consider bandwidth higher than 28.8 Kbps, the RealVideo encoder produces significantly better frames with higher frame rates.

When deciding which parameters to set, the total bit rate must be considered. The total bit rate is the actual bit rate at which the AVI is encoded. If the target bit rate is 28.8 Kbps, then the total bit rate should be 19 Kbps. The following are the recommended total bit rates for common bandwidths.

Targeted Bit Rate	Total Bit Rate
28.8 Kbps	19
56.0 Kbps	45
64.0 Kbps	56
128.0 Kbps	105

Targeted and total bit rates.

After selecting the total bit rate according to the table above, choose an audio codec.

Audio Algorithms
6.5 Kbps voice
8 Kbps music
12 Kbps music
18.2 Kbps voice
16 Kbps music High response
16 Kbps music Low response
16 Kbps music Medium response
20 Kbps music stereo
40 Kbps music mono
40 Kbps music stereo
80 Kbps music mono
80 Kbps music stereo

Since the RealAudio codecs have discreet bandwidths, the video bit rate will be the difference between the total bit rate and the bit rate used by the chosen audio codec:

In the RealVideo Encoder, the video bit rate is calculated automatically.

Next the frame rate should be chosen. Not all content types will support high frame rates for a given bandwidth. The highest frame rate that can be achieved at 19 Kbps, is 7.5 frames per second (fps) for talking head type content. Different content types require different frame rates. For example, while talking heads at 19 Kbps might support 7.5 fps, music videos only support 1 fps or less. Below are the default setting for some common content types found in the RealVideo Encoder.

Creating New Templates

1. In the Templates pane, click the Advanced button. The Advanced Setting window appears:

   

2. Enter the name of the new template in the Template Name field.

   Note: It is recommended that you don't modify the pre-defined templates. If you want to change some of the settings, save the template as a new template. This way, you do not overwrite the predefined templates.

3. Select the Audio Compression Type.

4. Select the Video Compression Type. RealVideo Encoder 1.0 has two video compression types available, RealVideo and ClearVideo 1.0. The bit rate of the RealVideo 1.0 codec varies depending on the video codec and total bit rate selected. Clear Video 1.0 is used for low frame rate for live broadcasting only.

5. Select the total bitrate for the encoded video file.

6. Select the Quality by sliding the indicator.

7. Select the Frame Rate by sliding the indicator.

8. Click the Save button. Your template is saved.

9. Click the Apply button to select this template to be used with the current session.

10. Click the Close button to close the Advanced Setting window.

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