Rendering

Rendering is the process of computing frames of video and sections of audio so that they can be played smoothly in Final Cut Pro. Once rendered, the audio and video are stored in render cache files.

To set the sequence render quality: When Final Cut starts rendering, where does is start? For the most part, you can create sequences in Final Cut Pro without knowing anything about how rendering occurs or in what order.

To set the sequence render quality: The Render Quality Editor lets you specify four render qualities for the current project. ◦1 Open the Sequence menu and choose Render Quality. ◦2 Select the desired render quality This lets you work at lower frame rates, smaller frame sizes, and with various rendering options disabled for some effects, while viewing full-frame video at another quality level

Editing Render Quality Levels Final Cut Pro has four render quality levels. You can customize the definition of each render quality.

To edit the sequence render quality levels: Do one of the following: ◦Open the Sequence menu and choose Edit Render Qualities from the Render Quality submenu. ◦Choose Project Properties from the Edit menu and click the Edit Render Qualities button.

Open the Render Quality pop-up menu in the Sequence tab in the Timeline and choose Edit Render Quality.

Specify the options for each render quality and click OK. ◦Quality Name: You can assign names to each render quality. ◦Draft Render: Check this box to render filters at the lowest possible quality. This is useful to speed up previewing, but should be left unchecked before final rendering and export. ◦Field Rendering: Check this box to turn field rendering on. ◦Motion Blur: Check this box to apply motion blur when rendering. ◦Include Filters: Check this box to include filters when rendering. ◦Enable Frame Blending: Check this box to enable motion smoothing effects where the speed of the video has been changed. ◦Play Base Layer Only: Check this box to render the base tracks (V1 and A1) and cuts only. No transitions are rendered. Motion will not be applied to clips or sequences when played back in the Viewer. ◦High Quality Playback: Renders the playback at the highest quality. It plays back DV clips at the highest visual quality, but at the expense of frame rate on the computer monitor. ◦Frame Rate: Allows you to render at frame rates proportional to the sequence editing timebase. ◦Resolution: Allows you to render at a resolution proportional to the sequence’s frame size.

Video Rendering Video frames in sequences are rendered in the following order: ◦The top layer of video (the highest numbered track) is processed first and then composited onto the track below it. ◦Within each track, motion effects, filters, and transitions are processed, in that order.

Audio Rendering In many cases, audio can be played in real time without rendering. Rendering is necessary in the following circumstances: ◦If the sequence has more audio tracks than the number of tracks specified in the Real-time Audio Mixing preference

Real-time audio capabilities can be explained based on track equivalent costs. Track costs can accumulate quickly when combining any or all of the following items: ◦Each track to mix has a cost of 1. ◦Filters have a certain cost depending on complexity. Most filters have a cost of 3 tracks. ◦Compressor/Limiter, Expander/Gate, Vocal De-Esser, and Vocal De-Popper have costs of 6 tracks each. ◦Each track referencing a sub-sequence counts as the cost of all audio tracks in the sub-sequence. Use the mixdown audio feature to reduce this cost. ◦A stereo track referenced as a sub-sequence has a cost of 4 tracks (two for each channel).

Rendering Indicators As you create a sequence, the following indicators appear when rendering is required: ◦The rendering indicator above the Timeline ruler indicates which sections of the sequence require rendering in order to play back smoothly. Red indicates that the section needs to be rendered; gray indicates that no rendering is required.

◦When video material that requires rendering is playing in the Viewer or Canvas, and the Play Base Layer Only option in Render Quality Editor is not enabled for the current render quality, a blue background with the word “Unrendered” appears, indicating that the video can’t play in real time. ◦When audio material that requires rendering is playing in the Viewer or Canvas, a steady beeping sound occurs, indicating that the material can’t play in real time.

Rendering To render an entire sequence: ◦Choose Render All from the Sequence menu. A progress bar is displayed while the sequence is being rendered. Click Cancel to stop rendering. All rendered frames are saved, even if rendering is canceled.

To render a section of a sequence: ◦1 Select one or more contiguous clips or transitions, or set the In and Out points to the area that you want to render. ◦2 Choose Render Selection from the Sequence menu, or press Command-R. A progress bar is displayed while the sequence is being rendered. Click Cancel to stop rendering.

Specifying Storage Locations for Render Files Final Cut Pro lets you specify multiple disk locations for storing render cache files. When render files are created, they are stored on the disk with the most available space. You can specify up to five disks for storing either captured video, captured audio, or render cache files. If no disk locations are specified, Final Cut Pro saves the render files in a folder called Render Files, which is located in the same folder as the Final Cut Pro application.

Using Cache Manager to Manage Rendered Files You use the Cache Manager to delete unwanted render files or to free disk space. The Cache Manager finds files from unopened projects as well as open projects. If you run out of disk space, a dialog box opens in which you can delete old render cache files.

To view or delete render cache files: ◦1 Choose Cache Manager from the Tools menu. ◦2 Click next to the file name in the Remove column to designate a file to be deleted. ◦3 When you click OK, all of the files tagged for removal are deleted from your hard disk.

Automatically Rendering Before Playing The render ahead preference tells Final Cut Pro to render a specified amount of material ahead of the current playhead position before attempting to play it. For example, with the render ahead preference set to 5 seconds, when you click Play, all material up to 5 seconds ahead of the playhead position is rendered first. This preference is an alternative to explicitly specifying a section of the sequence to render and choosing Render Selection from the Sequence menu. The rendered material is added to the render cache just as explicitly rendered material is.