Copyright: ©2001 Sonic Foundry, Inc.
Citation: ©2001 Sonic Foundry, Inc.


About this File

This file contains context-sensitive help topics that are used by the Sonic Foundry MPEG plug-in.

Revised December 10, 2001


Multiplexer Type

Choose the type of MPEG file you want to create.


Sector Size

Enter a value to specify the size of the MPEG pack or sector in bytes.

For a streaming MPEG file, you can set this value between 306 and 4096.

For VCDs, set this value to 2324 bytes.

For DVDs, set this value to 2048 bytes.


Packets / Pack

Enter a value to specify how many packets are put into each pack.


Sectors Delay

Enter a value to specify the number of sectors to display before the first sector is written.


Video Delay

Enter a value to specify a delay (in milliseconds) to apply to the video stream timestamps. You can use a delay to correct audio/video synchronization problems.


Video Buffer Size

Enter a value to specify the video buffer size (in KB) coded in the pack header.


Audio Delay

Enter a value to specify a delay (in milliseconds) to apply to the audio stream timestamps. You can use a delay to correct audio/video synchronization problems.


Audio Buffer Size

Enter a value to specify the audio buffer size (in KB) coded in the pack header.


User MUX Rate

Enter a value to specify the multiplexer rate in bits per second:

•	Use 0 for the MPEG-1 and MPEG-2 presets.

•	Use 3486 for the VCD preset.

•	Use 6972 for SVCDs.

•	Use 25200 for DVDs.


Align Sequence Headers to Packets

Select this check box if you want sequence headers to be aligned to the start of a PES video packet.


Frame Timestamps

Choose a setting from the drop-down list to specify which frames will have PTS/DTS timestamps.


AUDIO Tab


Include Audio Stream

Select this check box if you want to include the audio stream in the encoded MPEG file.

The controls on the Audio tab are available only when this check box is selected.


Audio Mode

Choose a setting from the drop-down list to specify how audio should be encoded:

•	Stereo: contains two distinct audio channels.

•	Joint Stereo: a stereo file that is encoded to take advantage of the redundant and irrelevant information in the two channels.

•	Dual Channel: contains two distinct audio channels, and each channel has separate content (e.g. one channel might be in English and the other channel might be in French).

•	Mono: contains a single audio channel.


Psychoacoustic Model

Choose a setting from the drop-down list to specify the psychoacoustic model that will be used for audio compression.


Audio Layer

Choose a setting from the drop-down list to specify the MPEG audio layer that will be used for audio encoding.


Bitrate

Choose a setting from the drop-down list to specify the maximum bitrate for the audio data in your encoded file.


Emphasis

Choose a setting from the drop-down list to specify the type of de-emphasis to use during encoding.

During encoding, a filter is applied to improve the signal-to-noise ratio at high frequencies.


Sample Rate

Choose a setting from the drop-down list to specify the number of samples per second used to store the audio data in your encoded file.

For most applications, choose 44100 Hz. If your source material was recorded at 32 kHz or 48 kHz, choose the appropriate setting.


Embed CRC Error Protection

Select this check box to enable CRC error protection in your encoded file.

Cyclic redundancy code (CRC) is required by the SVCD and DVD specification and is used to determine if data is corrupt.


Set Copyright Bit

Select this check box to indicate that your encoded file contains copyrighted information.

This bit is for informational purposes only and does not affect encoding or decoding.


Set Original Bit

Select this check box to indicate that your encoded file contains original information.

This bit is for informational purposes only and does not affect encoding or decoding.


VIDEO Tab


Include Video Stream

Select this check box if you want to include a video stream in your encoded MPEG file.

The controls on the Video tab are available only when this check box is selected.


Video Type

Choose a setting from the drop-down list to specify the type of MPEG video to encode:

MPEG-1	General MPEG-1 video
VCD	VCD-compatible MPEG-1 video
MPEG-2	General MPEG-2 video
SVCD	SVCD-compatible MPEG-2 video
DVD	DVD-compatible MPEG-2 video


Parameters Constrained

Select this check box to limit the video parameters to a specific set of values.

This setting applies to MPEG-1 or VideoCD formats and is used to ensure that your encoded file meets the requirements of the MPEG-1 specification.


Aspect Ratio

Choose a setting from the drop-down list to determine the aspect ratio of your target display.


Frame Rate

Choose a setting from the drop-down list to specify the number of frames that will be encoded for each second of video.


Width

Enter a value in the box to specify the width (in pixels) of the encoded video frames.


Height

Enter a value in the box to specify the height (in pixels) of the encoded video frames.


I Frames

Enter a value to specify the number of frames between I-frames.

I-frames contain all the data to draw a complete video frame.


B Frames

Enter a value to specify the number of B-frames that will be inserted between consecutive I- and  P-frames.

P-frames are predicted from past frames. B-frames can be coded from past or future frames.


Profile

Choose a setting from the drop-down list to set the MPEG-2 syntax required for decoding the stream:

High Profile	Use for video-production equipment that requires 4:2:2.
Main Profile	Use for most television, VCR, and cable TV applications.
Simple Profile	Low-cost memory, e.g. no B pictures


Level

If you’re encoding an MPEG-2 file, choose a setting from the drop-down list to set parameters —  such as bitrate, sample rate, and the maximum allowed motion vector range — for your destination:

High Level	HDTV production rates: 1920 x 1080 x 30 Hz
High 1440 Level	HDTV consumer rates:  1440 x 960 x 30 Hz
Main Level	CCIR 601 rates: 720 x 480 x 30 Hz
Low Level	SIF video rate: 352 x 240 x 30 Hz


IDH VIDEO1 PROGRAMSEQUENCE
Field Order

Choose a setting from the drop-down list to determine the field order of the frames when drawn on the screen.

Progressive Only should be specified when the video will be viewed on a computer.

Interlaced, top field first and Interlaced, bottom field first are used when the video will be viewed on a television. Consult the hardware’s documentation for the proper interlacing method.


Video Quality

Drag the slider to determine the quality of the video when rendered.

Higher image quality settings require more system resources while rendering effects and transitions, increasing the rendering time.


Constant Bitrate

Select this radio button and choose a setting from the drop-down list if you want to encode your file using a single bitrate.

Many MPEG-1 players can play only constant bitrate files. If you’re encoding in MPEG-1 format, select this button.


Bitrate

If you’ve selected the Constant bitrate radio button, choose a setting from the drop-down list if you want to encode your file using a single bitrate.


Variable Bitrate

Select this radio button if you want the encoder to vary your file’s bitrate to accommodate high- and low-motion changes in video. Variable bitrate files can produce higher picture quality and smaller file sizes than constant bitrate files.


Macroblock Quantization

Enter a value to specify the macroblock quantization value to use in Variable bitrate mode.

Frames are quantized by this value as a starting point. If the bitrate is too low, the value is decreased to quantize less. If the bitrate is too high, the value is increased to quantize more.


Maximum Bitrate

Specify the maximum allowable bitrate for encoding.

When the Variable bitrate radio button is selected, the encoded file’s bitrate cannot exceed this value regardless of the amount of motion in your video.


Minimum Bitrate

Specify the minimum allowable bitrate for encoding.

When the Variable bitrate radio button is selected, the encoded file’s bitrate cannot be below this value regardless of the amount of motion in your video.


Average Bitrate

Specify the average bitrate that you want the encoder to use when encoding your video.


Advanced Video Tab


Write Sequence End Code

Specifies whether the encoder writes a sequence end code at the end of the stream.


Sequence Header

Select this check box to insert a sequence header before every group of pictures (GOP). Some DVD-authoring software requires sequence headers at specified intervals.


Alternate Scan Pattern: B Frames

Select this check box to use the alternate scan pattern (better for interlaced video) on B frames.


Alternate Scan Pattern: I Frames

Select this check box to use the alternate scan pattern (better for interlaced video) on I frames.


Alternate Scan Pattern: P Frames

Select this check box to use the alternate scan pattern (better for interlaced video) on P frames.


Color Primaries

Choose a setting from the drop-down list to indicate the color format of your source media.

This setting is a flag to the video decoder and does not affect the video encoding at all.


DC Coefficient

Choose a setting from the drop-down list to specify the precision of the DC coefficient in MPEG-2 intracoded macroblocks.

If your project contains low motion, you can increase this setting to improve image quality.


Video Format

Choose a setting from the drop-down list to indicate the format of the video you are encoding.

This setting is a flag to the video decoder and does not affect the video encoding.


Coefficients

Choose a setting from the drop-down list to set the matrix coefficients to use in deriving luminance and chrominance signals from RGB values.

If you’re encoding to MPEG-1, use the default setting.

If you’re encoding to MPEG-2, the decoder will use the appropriate conversion. Consult your video hardware documentation to determine whether the device requires a specific setting.


Non-Linear Quantization: B Frames

Select this check box if you want to use non-linear quantization scale types for B frames.

This setting is applicable to MPEG-2 only and allows more precise quantization at low levels.


Non-Linear Quantization: I Frames

Select this check box if you want to use non-linear quantization scale types for I frames.

This setting is applicable to MPEG-2 only and allows more precise quantization at low levels.


Non-Linear Quantization: P Frames

Select this check box if you want to use non-linear quantization scale types for P frames.

This setting is applicable to MPEG-2 only and allows more precise quantization at low levels.


Optimize to Table 1: B Frames

Select this check box to use the variable-length encoding table for B frames.

This setting is applicable to MPEG-2 only and uses compression of 0.3 to 0.6 bits per pixel. Clear the check box to use the previous encoding table (the previous table may work better for some videos—especially if the compression per pixel is outside 0.3 to 0.6 bits per pixel).


Optimize to Table 1: I Frames

Select this check box to use the variable-length encoding table for I frames.

This setting is applicable to MPEG-2 only and uses compression of 0.3 to 0.6 bits per pixel. Clear the check box to use the previous encoding table (the previous table may work better for some videos—especially if the compression per pixel is outside 0.3 to 0.6 bits per pixel).


Optimize to Table 1: P Frames

Select this check box to use the variable-length encoding table for P frames.

This setting is applicable to MPEG-2 only and uses compression of 0.3 to 0.6 bits per pixel. Clear the check box to use the previous encoding table (the previous table may work better for some videos—especially if the compression per pixel is outside 0.3 to 0.6 bits per pixel).


Allow Field Base to Motion Compensation

Select this check box if you want to use field- and frame-based motion prediction when predicting frames.

When the check box is cleared, only frame-based motion prediction is used.


Transfer

Choose a setting from the drop-down list to set the opto-electronic transfer characteristic of the video being encoded. This setting is for informational purposes only and does not affect the encoding or decoding process.


VBV Buffer Size

Choose a setting from the drop-down list to set the size of the video buffer verifier.

This buffer ensures that enough data is being fed to the encoder.


Write Sequence Display Extension

Select this check box to write a sequence display extension for every every GOP (group of pictures).

This setting must be turned on to create valid VideoCD, SVCD, and DVD MPEG files.


Extra Tab


Always Apply System Header


Compute SVCD Scan Offsets


Default VBV Delay


Half-Pel Searching


Max MUX File Size


Min Frame


Motion Search


Pad Frame


Pad VCD Audio Sectors


Video Pulldown


Rate Control


Repeat First Field


Reset Clocks to Initial Values


Set Broken Link Flags


Start Time


Write Program End Code


Write Picture Display Extensions


Display Width


Display Height


Save as Separate Elementary Streams

Select this check box if you want to create separate files for the audio and video portions of your project. Instead of rendering a single .mpg file, this option will create an .m1v (MPEG-1) or .m2v (MPEG-2) file for the video stream and an .mpa file for the audio stream.