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Audio options for encoding – Adobe Premiere Pro CS3 User Manual

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ADOBE PREMIERE PRO CS3

User Guide

425

Encoding Passes

Specifies the number of times the encoder will analyze the clip before encoding. Multiple passes

increase the time it takes to encode the file, but generally result in more efficient compression and higher image
quality. (Adobe After Effects doesn’t support multiple encoding passes.)

Target Bitrate

Specifies the number of megabits per second of playback for the encoded file.

Maximum Bitrate

Specifies the maximum number of megabits per second of playback you want the encoder to

allow.

Minimum Bitrate

Specifies the minimum number of megabits per second of playback you want the encoder to

allow. The minimum bitrate differs according to the format. For MPEG-2-DVD, the minimum bitrate must be at
least 1.5

Mbps.

M frames

Specifies the number of B frames (Bi-directional frames) between consecutive I frames (Intra-frames)

and P frames (Predicted frames).

N frames

Specifies the number of frames between I frames (Intra-frames). This value must be a multiple of the M

frames value.

Closed GOP Every

Specifies the frequency of each Closed Group of Pictures (Closed GOP), which cannot reference

frames outside of the closed GOP. A GOP consists of a sequence of I, B, and P frames. (This option is available if
you choose MPEG-1 or MPEG-2 as the format.)

Automatic GOP Placement

When selected, sets the placement of Group of Pictures (GOP) automatically. (This

option is available if you choose MPEG-1 as the format.)

Note: MPEG-1 and MPEG-2 formats include numerous advanced options not listed here. In most cases, selecting a
format or preset designed for your target output sets the appropriate options automatically. For detailed information
on options not listed, consult the specifications for the MPEG-1 (ISO/IEC 11172) and MPEG-2 (ISO/IEC 13818)
formats.

Audio options for encoding

In the Export Settings dialog box, the options available in the Audio tab depend on the format you’ve specified.
Some common audio options include the following:

Codec

Specifies the codec used to encode the audio:

AAC (Advanced Audio Coding)

A high-quality encoding format supported by many mobile devices. This codec is

the default for the H.264 format.

SurCode for Dolby Digital 5.1

A high-quality encoding format developed for multichannel digital sound and the

most common encoder for DVD-video. (This codec is available only in Adobe Premiere Pro.)

MainConcept MPEG Audio

A high-quality encoder developed by MainConcept media technologies, and included

with Adobe Premiere Pro, After Effects, and Soundbooth.

PCM (pulse-code modulation) Audio

A lossless audio format. Files of this format tend to be larger than files of the

other formats.

Audio Format

Determines the audio type.

Bit Rate

Specifies the output bit rate of the audio. Generally, higher bit rates increase both quality and file size. This

option is available for Dolby® Digital, MainConcept MPEG, and some Windows Media audio codecs.

Note: Options not documented here are specific to the selected format. For detailed information, consult the specifica-
tions for the selected format.

April 1, 2008