Modify timing and frame rate

You can modify the duration of a transcoded file by adjusting controls in the General inspector. You can modify the frame rate of a transcoded file by adjusting controls in the Video inspector.

Choose a new duration for a transcoded file

  1. Do one of the following:

    • In the batch area, click an output row to select a setting in a job. With this method, the modifications you make will be used for outputting only that job.

    • In the Settings pane, select a custom setting from the Custom group. (If the Settings pane is hidden, press Shift-Command-1.) With this method, the modifications you make will be saved to the custom setting for future use.

  2. In the inspector pane, click General to open the General inspector.

    If the inspector pane is not visible, click the Inspector button in the upper-right corner of the Compressor window.

  3. In the Retiming section of the General inspector, modify the “Set duration to” property in one of the following ways:

    • Enter a specific percentage of the source footage in the percentage field, or choose a preset percentage from the pop-up menu (with a downward arrow).

      Note: Selecting a setting from this pop-up menu does not change the frame rate of the output file. If you want to create a file at a frame rate other than the source’s original rate, you must change the setting in the Video inspector.

    • Click to select the button next to the timecode field and enter a specific duration for the outgoing file. (The percentage field above will automatically update.)

      Note: This option is available only when you’re modifying a setting that’s part of a job.

    • Click to select the “So source frames play at [frame rate] fps” button.

      Note: The frame rate used in this option is the value set in the “Frame rate” property in the Video inspector.

Change the frame rate for a transcoded file

  1. Select an output row in a job in the batch area, or select a custom setting in the Settings pane.

  2. In the Video inspector, do one of the following:

    • Choose an item from the “Frame rate” pop-up menu.

      Automatic, the default setting, matches the frame rate of the transcoded file to that of the source file. You can also choose any of several commonly used frame rates, including 23.976 fps, 24 fps, and so on.

    • Type a custom frame rate into the field to the right of the “Frame rate” pop-up menu.

      Note: Some formats (such as Apple Devices settings) do not permit custom frame rates.

    Note: Frame rate conversion can have a subtle or dramatic effect depending on how big a difference there is between the original and new frame rates, and also depending on the specific nature of the footage being converted. Footage with a lot of movement yields a much more visible change than footage with little movement in the frame. Frame rate conversion may also add visible artifacts in the transcoded file; from stuttering (sometimes called “juddery”) playback, to repeated frames, ghost images, or other unnatural-looking elements. These effects can be somewhat mitigated by adjusting the “Retiming quality” property in the Quality section of the Video inspector.

  3. Select a value from the “Field order” pop-up menu to choose a progressive or interlaced frame rate.

    If the current setting does not allow field order modification, this control remains dimmed. If you want to convert a file with an interlaced format into a progressive format, see About deinterlacing.

Note: The properties in the Retiming section of the General inspector are always affected by the “Frame rate” property, as well as the “Retiming quality” property in the Video inspector.