Working with Markers and Poster Frames

Compressor can import and create several different kinds of markers. In addition, Compressor can import entire lists of chapter markers. Compressor also supports setting a poster frame for a clip.

Output File Formats That Support Markers

Not all output file formats support markers. Following is a list of those that do support them.

  • MPEG-2

  • MPEG-4 when configured for podcasting (audio-only with the Enhanced Podcast checkbox selected)

  • QuickTime Movies

  • H.264 for Apple Devices

You can set and configure markers for other output file formats, but they will not be included in the encoded output file.

Types of Markers

Compressor can import and create the following types of markers.

  • Chapter markers: Chapter markers allow easy access to index points throughout a DVD, QuickTime movie, or video podcast. QuickTime Player can interpret any text track containing time stamps as a chapter track. Chapter markers can also have artwork and a URL assigned to them that appear when playing a podcast.

    These markers appear as purple in the Preview window timeline and are the type created when you manually add markers using Compressor.

  • Podcast markers: Like chapter markers, podcast markers can have artwork and a URL assigned to them. Podcast markers cannot be used to access frames within the clip, though, and they do not appear as chapter markers in QuickTime.

    You can use podcast markers to provide a slideshow (with URLs) for users to view when playing audio podcasts.

    These markers appear as red in the Preview window timeline.

  • Compression markers: Compression markers are also known as manual compression markers. These are markers you can add in the Compressor Preview window to indicate when Compressor should generate an MPEG I-frame during compression. See Understanding GOPs and Frame Types for more information on I-frames.

    These markers appear as blue in the Preview window timeline.

  • Edit/Cut markers: Edit/Cut markers are also known as automatic compression markers. These markers are intended to be at each cut or transition point in a sequence. During transcoding, Compressor uses Edit/Cut markers to generate MPEG I-frames at these points, improving compression quality.

    These markers appear as green in the Preview window timeline.

Manually Adding and Removing Markers

The Preview window includes comprehensive marker support, including the ability to manage markers already added to the source media file, manually add or remove markers, and import chapter marker lists. When you add a marker to a clip, it appears as a chapter marker by default. You can then change the marker to a compression or podcast marker if you wish (see Adding Compression or Podcast Markers to a Clip).

To add a chapter marker to your clip
  1. Open the Preview window.

  2. Choose the Show Chapter/Podcast Markers item from the Marker pop-up menu, so that there is a checkmark by it.

  3. Choose a clip from the Batch Item pop-up menu or click the Batch Item selection button until the clip you want appears in the pop-up menu.

  4. Do one of the following to determine where the marker is to be placed:

    • Drag the playhead where you want to add a marker.

    • Enter a timecode value in the playhead timecode field.

  5. Do one of the following to add a marker:

    • Click the Marker button and choose “Add marker” from the pop-up menu.

    • Press M.

    A purple chapter marker appears in the timeline.

    Figure. Preview window showing purple marker.
  6. Choose Edit from the Marker pop-up menu (or press Command-E).

    A dialog for editing the marker appears.

  7. Enter a name for the chapter marker in the Name field.

    Figure. Dialog for editing marker.

    For chapter markers, this name appears in the output media file where it can be seen with QuickTime Player and in playback devices.

  8. If you want to assign an image to the chapter marker, choose one of the following from the Image pop-up menu:

    • None: No image is associated with the marker.
    • Frame in source: By default, the frame displayed is the frame on which the marker is placed. To use a different frame as the image, enter a different timecode value.
    • From File: Drag an image to the image well. You can also click Choose to open a file-selection dialog and select a still-image file to assign to the marker.
  9. Click OK to close the dialog.

You can convert a chapter marker to a compression or podcast marker by choosing Edit from the Marker pop-up menu.

To remove a marker from your clip
  1. Click either the “Move to Previous Marker” or “Move to Next Marker” control to move the playhead to the marker you want to remove.

  2. Do one of the following to remove the marker:

    • Click the Marker button and choose “Remove marker” from the pop-up menu.

    • Press M.

The marker disappears.

To import a chapter marker list
  1. Open the Preview window.

  2. Choose a clip from the Batch Item pop-up menu or click the Batch Item selection button until the clip you want appears in the pop-up menu.

  3. Choose Import Chapter List from the Marker pop-up menu.

    A file selection dialog opens so that you can locate and select the chapter marker file for that source media file.

  4. Select the chapter marker file and click Open.

The markers are imported and added to the Preview window timeline.

Note: While all markers imported by using a chapter marker list are configured as chapter markers, you can use the marker edit dialog to change them to podcast or compression markers. Additionally, you can add URLs and artwork to them as needed.

Important: The timecode values in the list must be based on the source media file’s timecode.

Adding Compression or Podcast Markers to a Clip

To manually add a compression or podcast marker to a clip, you first add a chapter marker (as described in the previous section) and then you edit the marker.

Note: A podcast can have both chapter and podcast markers. The only difference is that the viewer can navigate directly to a chapter marker but cannot navigate to a podcast marker. For more information, see Types of Markers.

To manually add a compression or podcast marker to a clip
  1. Choose the Show Chapter/Podcast Markers and Show Compression Markers items from the Marker pop-up menu, so that there is a checkmark by them.

    Figure. Marker pop-up menu.
  2. Do one of the following to determine where the marker is to be placed:

    • Drag the playhead where you want to add a marker.

    • Enter a timecode value in the playhead timecode field.

  3. Do one of the following to add a marker:

    • Click the Marker button and choose “Add marker” from the pop-up menu.

    • Press M.

    A purple chapter marker appears in the timeline.

  4. Choose Edit from the Marker pop-up menu (or press Command-E).

    A dialog for editing the marker appears.

    Figure. Dialog for editing marker.
  5. Choose Compression or Podcast from the Type pop-up menu.

  6. Enter a name for the marker in the Name field.

    For podcast markers, this name does not appear to the viewer.

  7. Optionally, enter a URL in the URL field.

    This URL applies only to podcasts. The marker’s name appears over the artwork where the viewer can click it to open a web browser to the URL’s website.

  8. If you want to assign an image to the chapter marker, choose one of the following from the Image pop-up menu:

    • None: No image is associated with the marker.
    • Frame in source: By default, the frame displayed is the frame on which the marker is placed. To use a different frame as the image, enter a different timecode value.
    • From File: Drag an image to the image well. You can also click Choose to open a file-selection dialog and select a still-image file to assign to the marker.
  9. Click OK to close the dialog.

    The marker in the timeline changes to blue if it’s a compression marker, or red if it’s a podcast marker. You can use the Previous Marker and Next Marker buttons to select other markers in the timeline to edit.

    You also have the option of importing a chapter marker list. These lists can use either the QuickTime TeXML format (an XML-based format for constructing 3GPP-compliant timed text tracks in a QuickTime movie file) or a plain text chapter list file. See Creating Plain Text Chapter Marker Lists for information.

Creating Plain Text Chapter Marker Lists

You can create a list of timecode points that Compressor can import to create markers. The timecode values need to match the timecode of the track’s video clip. The list of timecode values must be a plain text file; you can create it with TextEdit (as long as you save the file as plain text). If you create the list with a more advanced word-processing application, be sure to save the file as a plain ASCII text file with no formatting.

Figure. Plain text file containing chapter marker list.

The file must follow these rules.

  • Each marker must be on a new line that starts with a timecode value in the 00:00:00:00 format. These values identify the marker positions.

  • After the timecode value, you can include a name for the marker. You can use a comma, space, or tab character to separate the timecode value from the marker name.

  • Any lines that do not begin with a timecode value are ignored. This makes it easy for you to add comments to the list.

  • The timecode values do not have to be listed in chronological order.

Setting the Poster Frame

You can use Compressor to set the poster frame for a movie. This is the frame that appears in iTunes to represent the movie. If you do not set the poster frame, iTunes uses the frame ten seconds from the movie’s first frame.

To set the poster frame
  1. Position the Preview window’s timeline to the frame you want to be the poster frame.

  2. Choose “Set poster frame” from the Marker pop-up menu.

A vertical line with a center dot appears in the timeline.

To move the playhead to the poster frame
  • Choose “Go to poster frame” from the Marker pop-up menu.

    Note: This setting is not available if the poster frame has not been set.

To remove the poster frame setting
  • Choose “Clear poster frame” from the Marker pop-up menu.

    Note: This setting is not available if the poster frame has not been set.