Preview video and audio

You can preview all or part of your composition as you work, without rendering to final output. Though it is common to speak of rendering as if this term only applies to final output, the processes of creating previews to show in the Footage, Layer, and Composition panels are also kinds of rendering.

Many of the controls for previewing are in the Preview panel.

Note: For additional keyboard shortcuts for use on keyboard without numeric keypads, see Previews (keyboard shortcuts).

Use RAM preview to play video and audio

RAM preview allocates RAM to play video and audio in the Timeline, Layer, or Footage panel at real-time speed. The number of frames that can be stored for real-time playback depends on the amount of RAM available to the application and the settings in the Preview panel.

In the Preview panel, you can specify two sets of RAM preview options: RAM Preview Options and Shift+RAM Preview Options. For example, you may decide to set RAM Preview Options for full frame rate and full resolution, and set Shift+RAM Preview Options to skip one out of every two frames and preview at half resolution.

In the Layer and Footage panels, RAM previews play untrimmed footage.

  1. To modify RAM preview options, click the RAM Preview Options menu in the center of the Preview panel and choose RAM Preview Options or Shift+RAM Preview Options. You can change any of the following:
    Mute Audio 
    Include audio in or exclude audio from RAM preview.

    Frame Rate
    Choose Auto to use the composition frame rate.

    Skip
    The number of frames to skip between a rendered frame and the next rendered frame. Choose 0 to render all frames.

    Resolution
    Choose Auto to use the resolution set in the Resolution/Down Sample Factor menu at the bottom of the viewer panel.

    From Current Time
    Select From Current Time to play from the current time; otherwise, RAM Preview plays the work area or from the beginning of the composition, layer, or footage item.

    Full Screen
    Play RAM preview at the full size of the composition, layer, or footage item on a screen that is the panel background color. You can change the panel background color using the Brightness control in the Appearance preferences.

  2. Do one of the following:

    • To preview using RAM Preview Options, click the RAM Preview button in the Preview panel or press 0 (zero) on the numeric keypad.

    • To preview using Shift+RAM Preview Options, Shift-click the RAM Preview button in the Preview panel or press Shift+0 (zero) on the numeric keypad.

  3. To stop a RAM preview, do one of the following:

    • To leave the current-time indicator at the last-played frame, press the spacebar.

    • To leave the current-time indicator where it was before you started the RAM preview, click the RAM preview button or press any button other than the spacebar.

Note: The performance of RAM previews performed with the Render Multiple Frames Simultaneously preference selected may be decreased if antivirus software is running.
Press the asterisk key (*) on the numeric keypad during a RAM preview to place a marker at the currently previewed frame. This is a convenient way to place markers corresponding to important points in an audio track. (See Layer markers and composition markers.)

RAM preview a specified number of frames

Press Alt (Windows) or Option (Mac OS) while initiating a RAM preview to preview the specified number of frames up to and including the current frame. The default number of frames previewed with this command is 5. The preference for changing this number is in the Alternate RAM Preview section of the Preview preferences. (See Previews preferences.)

Note: If the current frame is within a backward-propagating Roto Brush span and the Layer panel View menu is set to Roto Brush, then this command in the Layer panel previews the frames including and after the current frame. (See Roto Brush strokes, spans, and base frames.)

Save a RAM preview as a movie

After Effects can save RAM previews as uncompressed AVI files (Windows) or MOV files (Mac OS). When saving a RAM preview, keep in mind the following:

  • After Effects uses the composition frame size and the Resolution setting in the default render settings template to determine the final dimensions in pixels of a saved RAM preview. If the Resolution setting in the render settings template is Current Settings, then the Resolution setting in the Preview panel is used. If the Resolution setting in the Preview panel is Auto, then the Resolution setting in the Composition Settings dialog box is used. The saved RAM preview doesn’t consider the zoom level.

  • RAM preview doesn’t generate interlaced fields, so a saved RAM preview never contains fields.

Note: The 3D View of the active composition panel must be set to Active Camera for Save RAM Preview to work, even if the composition doesn’t contain 3D layers.
  1. After you generate a RAM preview, choose Composition > Save RAM Preview.
  2. Enter a name, specify a location, and click Save.

Loop options for previews

Click the Loop Options button in the Preview panel until it shows the desired state:

Loop 
Repeatedly plays preview from beginning to end.

Play Once 
Plays preview once.

Ping Pong 
Repeatedly plays preview, alternating between backward and forward play.

Preview only audio

When you preview only audio, it plays immediately at real-time speed, unless you’ve applied Audio effects other than Stereo Mixer, in which case you may have to wait for audio to render before it plays.

Note: If audio must be rendered for a preview, then only the amount of audio specified by the Duration setting in the Previews preferences is rendered and played for the preview. The default is 30 seconds.

Set the sample rate for audio for the entire project in the Project Settings dialog box (File > Project Settings). CD-quality sound is 44.1 KHz, 16-bit stereo.

The Audio Hardware and Audio Output Mapping preferences determine the behavior of audio previews. These preferences do not affect final output. The output module settings determine the quality of audio in final output. For best-quality audio previews, choose an ASIO device if one is available in the Default Device menu in the Audio Hardware preferences. Otherwise, choose one of the devices for your system, such as the After Effects WDM Sound device (Windows) or one of the Built-in devices (Mac OS).

  • To preview only audio from the current time, choose Composition > Preview > Audio Preview (Here Forward) or press the decimal point key (.) on the numeric keypad.
  • To preview only audio in the work area, choose Composition > Preview > Audio Preview (Work Area) or press Alt+decimal point (.) (Windows) or Option+decimal point (.) (Mac OS) on the numeric keypad.

Use standard preview to play video

Standard preview (commonly called spacebar play) plays video in the active Composition, Layer, or Footage panel from the current time. Standard preview does not play audio.

Standard previews play at a speed as close to the speed of real time as possible. However, for complex compositions, the speed of the preview may be much less than real-time speed.

 Click the Play button  in the Preview panel, or press the spacebar.

Manually preview (scrub) video and audio

  • To manually preview (scrub) video in the Timeline panel or go to a specific frame, drag the current-time indicator.
  • To scrub audio in the Timeline panel, Ctrl+Alt-drag (Windows) or Command+Option-drag (Mac OS) the current-time indicator.
  • To scrub audio and video in the Timeline panel, Ctrl-drag (Windows) or Command-drag (Mac OS) the current-time indicator.

    If you stop moving the current-time indicator while keeping the mouse button depressed, a short section of audio loops.

To manually preview (scrub) only the frames that are already rendered and cached into the RAM cache, press the Caps Lock key before dragging the current-time indicator. This prevents After Effects from trying to render other frames when you drag over or past them. This technique is useful when you want to manually preview some frames that you rendered using RAM preview settings that used an option to skip every other frame.

Audio panel options

During previews, the Audio panel volume unit (VU) meter actively displays audio volume levels. At the top of the VU meter, signals indicate when the audio is clipping—a distortion that occurs when the audio signal exceeds the maximum level that the audio device allows.

To view the VU meter and levels controls in more detail, increase the height of the Audio panel.

Audio panel 
A.
VU meter

B.
Level controls

C.
Level units

D.
Audio panel menu

E.
Level values

Choose Options in the Audio panel menu to specify the following options:

Units
Choose whether to display audio levels in decibels or in percentages. 100% equals 0 decibels (0 dB).

Slider Minimum
The minimum audio level to display in the Audio panel.

Additional tips and options for previewing

With all previewing methods—as with rendering to final output—a layer is only visible in rendered previews if its Video layer switch is selected.

Some factors that influence the speed with which previews are rendered include layer switches, Fast Previews settings, preference settings, and composition settings.

One of the simplest and most influential of the preview settings controls is the Resolution/Down Sample Factor setting menu at the bottom of the Composition panel. Choose a value other than Full from this menu to see all previews at a lower resolution. (See Resolution.)

To turn pixel-aspect ratio correction on or off for previews, click the Toggle Pixel Aspect Ratio Correction button  at the bottom of the panel. The quality of the pixel aspect ratio correction is determined by the Zoom Quality preference. (See Viewer Quality preferences.)

When possible, preview on the same kind of device that your audience will use to view your final output. For example, you can preview on an external video monitor. To see your composition as it will appear on a mobile device—such as a mobile phone—first render your composition to final output, and then use Adobe Device Central to view the movie.

If you create compositions for mobile devices using Device Central, you can preview the compositions within After Effects with guides and settings that simulate some aspects of the target mobile devices. (See Create compositions for playback on mobile devices.)

If color management is enabled, you can preview a composition, layer, or footage item as it will appear in the output color space. (See Simulate how colors will appear on a different output device.)

Note: Select Show Rendering Progress In Info Panel And Flowchart (Edit > Preferences > Display (Windows) or After Effects > Preferences > Display (Mac OS)) to see additional information in the Info panel or the project Flowchart panel during rendering, either for previews or for final output.