About the MPEG-2 Encoder Pane

This section contains detailed information about the various tabs within the MPEG-2 Encoder pane in the Inspector window. You make your MPEG-2 settings using these tabs, by either modifying an existing setting or creating a new setting in the Settings tab.

Figure. MPEG-2 Encoder pane in the Inspector window.

MPEG-2 Encoder Pane Basic Settings

The MPEG-2 pane opens with the default Video Format tab on top and contains the following items.

  • Extension field: Displays the MPEG-2 file extension (.m2v) automatically after the MPEG-2 output format is selected from the File Format pop-up menu.
  • Allow Job Segmenting: This checkbox allows you to turn off job segmenting. It is relevant only if you are using Compressor with distributed processing and with multi-pass encoding. (The distributed processing feature is limited to computers that have Final Cut Studio installed.) For more information, see Job Segmenting and Two-Pass or Multi-Pass Encoding.
  • Video Format, Quality, GOP, and Extras: These buttons open the Video Format, Quality, GOP, and Extras tabs. Their settings are explained in the following sections.

Stream Usage

Choosing a setting from the Stream Usage pop-up menu ensures the encoded MPEG-2 stream will be suitable for how you intend to use it.

Figure. Stream Usage pop-up menu.

The options in the Stream Usage pop-up menu include the following:

  • Generic: The Generic option allows you complete access to all the MPEG-2 settings. This is the only option that supports the MPEG-2 640 x 480 video format in addition to the SD and HD video formats. It is also the only option that supports creating transport and program streams. It supports the complete bit-rate range of 2.0 Mbps to 40.0 Mbps.
  • SD DVD: The SD DVD option restricts the encoding options to those allowed by the SD DVD specification. These include the NTSC and PAL video formats and a bit-rate range of 2.0 Mbps to 9.0 Mbps.
  • Blu-ray: The Blu-ray option restricts the encoding options to those allowed by Blu-ray video discs. These include the SD and HD video formats and a bit-rate range of 10.0 Mbps to 40.0 Mbps.
  • HD DVD: The HD DVD option restricts the encoding options to those allowed by the HD DVD specification. These include the SD and HD video formats and a bit-rate range that changes depending on the selected video format.
    • For HD video formats: The bit-rate range is from 10.0 Mbps to 29.4 Mbps.
    • For SD video formats: The bit-rate range is from 2.0 Mbps to 15.0 Mbps.

Video Format Tab

You use the Video Format tab to make settings related to video formats, frame rates, aspect ratio, field dominance, and timecode. All of these, except the timecode setting, can be set to automatically configure themselves based on the video being encoded. The Video Format tab contains the following controls.

Figure. Video Format tab.
  • “Choose start timecode” checkbox and field: If you leave the checkbox deselected (the default), Compressor embeds the source media file’s existing timecode into the output media file. Selecting this checkbox allows you to override the source media file’s existing timecode and enter a new timecode in the timecode field. This field remains dimmed unless the checkbox is selected, and if it is left blank, the output media file uses the default timecode of 00:00:00:00.
  • “Drop frame” checkbox: If you have already selected the “Choose start timecode” checkbox, and you want your timecode to be drop frame (rather than non-drop frame), you must also select this checkbox.

    Timecode is a numbering system for labeling the frames in a video sequence. The type of timecode designed for 30 fps video has a frame counter that counts from 0 to 29 and then increments the seconds counter and returns to 0. This type of timecode, also known as non-drop frame timecode, maintains an accurate measure of elapsed time for true 30 fps video. However, the NTSC frame rate is 29.97 fps, and so drop frame timecode was defined to provide a more accurate measure of elapsed time for NTSC. Drop frame timecode skips frame numbers 0 and 1 once a minute on the minute, except for every 10 minutes. For example, drop frame timecode 01:08:59;29 is followed by 01:09:00;02, skipping timecodes 01:09:00;00 and 01:09:00;01.

    Note: Drop frame timecode applies only if you are using interlaced NTSC video.

Quality Tab

The Quality tab allows you to set the bit rate for your video so that it can be transcoded to a suitable data size and quality.

In addition to the controls, the lower-right corner shows an estimate of how many minutes of video would fit on a 4.7 GB DVD using the current settings. This time assumes a single AIFF audio stream to be used with the MPEG-2 stream.

The Quality tab contains the following controls:

Figure. Quality tab.
  • Average Bit Rate slider and field: Choose the average bit rate by dragging the slider or entering a number into the accompanying field. The range available to you depends on the Stream Usage setting. See Stream Usage for more information.
    Figure. Average Bit Rate slider and Maximum Bit Rate slider.

    Note: The average bit-rate setting directly controls the size of the encoded file. The maximum bit-rate setting does not affect the encoded file’s size.

  • Maximum Bit Rate slider and field: Choose the maximum bit rate by dragging the slider or entering a number into the accompanying field. See About Choosing the Bit Rates for more information. The range available to you depends on the Stream Usage setting. See Stream Usage for more information.

    Note: This slider is only available with the VBR modes and cannot be set lower than the average bit rate.

GOP Tab

You use the GOP (group of pictures) tab to select a GOP format, structure, and size. It contains the following controls. See Understanding GOPs and Frame Types for more information.

Note: If you choose any of the HD video formats in the Video Format tab, the settings in the GOP tab cannot be changed and default to a closed IBBP GOP structure with a size of 12 (for PAL) or 15 (for NTSC).

Figure. GOP tab.
  • Open and Closed buttons: Closed GOPs do not contain any frame that refers to a frame in the previous or next GOP, while open GOPs begin with one or more B-frames that reference the last P-frame of the previous GOP. Closed GOPs created by the Compressor MPEG-2 encoder begin with an I-frame. Choose your GOP type (open or closed) based on whether and how you create chapter markers for DVD authoring with DVD Studio Pro, and whether you intend to use multiple video angles in your title. See Open and Closed GOPs for more information.
    • Open: Select this button to create open GOPs.
    • Closed: Select this button to create closed GOPs.
  • Pattern field: This field cannot be edited but displays the actual GOP pattern based on your chosen GOP structure and size.

Extras Tab

You use the Extras tab to control the inclusion or exclusion of specific MPEG-2 authoring information. The Extras tab contains the following controls.

Figure. Extras tab.
  • Add DVD Studio Pro metadata: Selecting this checkbox allows Compressor to parse specific MPEG-2 authoring information during the transcoding process to accelerate the import process into DVD Studio Pro. However, these MPEG-2 files will be incompatible with versions of DVD Studio Pro 1.5 or earlier. Leaving the checkbox unselected means the information will be parsed later in DVD Studio Pro.

    Note: MPEG-2 streams with additional DVD Studio Pro metadata are only compatible with DVD Studio Pro 2 (or later) versions. MPEG-2 streams with this checkbox selected will not be compatible with versions prior to DVD Studio Pro 2 or with other DVD authoring tools. All Apple settings have this box checked by default. To make your MPEG-2 files compatible with other DVD authoring tools, deselect this checkbox, and then save the setting.

  • Include chapter markers only: Selecting this checkbox excludes unnamed compression markers from the stream but still retains the chapter markers. Leaving the checkbox unselected allows all markers to be recognized in the output media file. See More About GOPs and Markers and Adding Chapter or Podcast Markers to a Clip for more information about chapter markers.
  • YUV 4:2:2 Color encoding (Not for DVD use): Select this checkbox to enable 4:2:2 color encoding. This option is supported in the creation of MPEG-2 elementary, program, and transport streams, but it is only available when the Stream Usage pop-up menu is set to Generic.
  • Multiplexed MPEG-1/Layer 2 Audio: Use this checkbox to create a multiplexed stream (rather than an elementary stream). You can make the output file either a transport stream or a program stream. See About Elementary, Transport, and Program Streams for information on the differences between the different stream types.

    The audio in this stream is MPEG-1 Layer 2, with a sample rate of 44.1 kHz or 48 kHz (depending on the source) and a bit rate of 384 kbps. To create an audio-only (MPEG-1/Layer 2 Audio) elementary stream, see Creating the MPEG-1 Audio for DVD Setting.

    Important: Generic is the only Stream Usage setting that supports transport and program streams. Selecting the Multiplexed MPEG-1/Layer 2 Audio checkbox sets your stream usage to Generic if it is currently anything else.