Changing Settings in the Video Processing Tab

The Video Processing tab determines how clips’ media files are processed and rendered within your sequence. This affects color space conversions, maximum white level, bit depth, and the quality of motion parameter adjustments.

Figure. Sequence Settings dialog showing the Video Processing tab.

Rendering Y′CBCR Footage in the RGB Color Space

When super-white Y′CBCR values are converted to RGB, any values above 235 are mapped to 255. Any variation in luma above 235 is therefore clamped, or clipped, resulting in solid patches of white where there was once detail in the bright parts of the image. If these RGB values are converted back to Y′CBCR, all white values of 255 are mapped to a single value (usually 235, which is white in Y′CBCR). The newly converted white values are lower than the white values originally captured, causing areas of the picture that had super-white values to darken slightly and to appear flat where there was once detail in the highlights. This is known as luma clamping. You can avoid this by editing your Y′CBCR footage natively in the Y′CBCR color space.

Choosing RGB Versus Y′CBCR Color Space

Each color space has a certain range, or gamut, of colors that can be represented. Some colors represented in the Y′CBCR color space cannot be represented in RGB and are said to be out of gamut. If the color space of your media files doesn’t match the color space of your sequence, Final Cut Pro maps the media file color values to the color space of the sequence. In some cases, colors get “clipped” to the nearest value during conversion. This can cause very saturated colors to become less intense and is referred to as chroma clamping.

Compositing in Y′CBCR and RGB Color Spaces

Many compositing operations in Final Cut Pro work the same way in Y′CBCR as they do in RGB. However, in some cases, slightly different results may occur. This is because the Y′CBCR and RGB color spaces are not identical, and some compositing operations that generate highly saturated colors may show different clamping behavior in Y′CBCR than they do in RGB.

For example, using the Add composite mode to combine 75 percent cyan and 75 percent white will “clamp” to white in RGB, but to a bright cyan color in Y′CBCR. For this reason, it’s important to verify the results of the composite by doing a test render in the color space you will do the final render in.

For more information about limiting Y′CBCR and RGB values, see Using the Broadcast Safe Filter and Using the RGB Limit Filter.

Changing Video Processing Settings

You can change video processing settings for an individual sequence, or you can change video processing settings for a sequence preset.

To change video processing settings for an individual sequence
  1. Choose Sequence > Settings, then click the Video Processing tab.

  2. Select the appropriate options, then click OK.

For a detailed description of options in the Video Processing tab, see the following sections:

To change the default video processing settings for a sequence preset
  1. Choose Final Cut Pro > Audio/Video Settings, then click the Sequence Presets tab.

  2. Double-click a sequence preset in the list of presets.

    The Sequence Preset Editor window opens.

  3. Click the Video Processing tab, then choose the appropriate settings.

About Color Space and Bit Depth Settings

These options determine the color space and video bit depth used for rendering and real-time playback.

Always Render in RGB

If your sequence uses an RGB video codec such as Photo JPEG or Animation, this option is always selected. However, if your sequence uses a Y′CBCR codec, you can use this option to process your footage using the RGB color space instead. For example, if you’re using a filter that only processes in RGB color space in combination with filters that process in Y′CBCR color space, you can make the appearance of the Y′CBCR filters more consistent with that of the RGB filters by selecting this option. However, in most cases, you should render using the native color space of your sequence’s codec.

Render in 8-bit YUV

Most codecs supported by Final Cut Pro use 8 bits per color sample, so this option is usually selected by default. However, if you are doing any compositing or adding footage with higher bit depths, you may want to use high-precision (32-bit) processing to maximize quality.

8-bit YUV is the fastest Y′CBCR processing option, so you may want to use this during offline editing and then switch to high-precision rendering before rendering for output.

Render 10-bit material in high-precision YUV

Use this option whenever your sequence or source footage uses a 10-bit Y′CBCR codec such as the Apple ProRes 422 codec or an Uncompressed 10-bit codec. Several third-party codecs also capture and output 10-bit video.

Render all YUV material in high-precision YUV

This is the highest-quality option for processing video in Final Cut Pro. This option processes all 8- and 10-bit video at 32-bit floating point. In certain situations, such as when applying multiple filters to a single clip or compositing several clips together, a higher bit depth will improve the quality of the final render file even though the original clip has only 8 bits of color information. The tradeoff is that 32-bit rendering is slower than 8-bit rendering, so you’re essentially trading speed for quality.

Note: Selecting this option does not add quality to clips captured at 8-bit resolution when they are output back to video; it simply improves the quality of rendered effects.

About Bit Depth and 32-Bit Floating-Point Processing

Final Cut Pro supports high-resolution video processing of Y′CBCR sequences by performing calculations in 32-bit floating-point number space. Compared to 8- and 10-bit integer calculations, 32-bit floating-point numbers have an extremely high level of precision, which helps to avoid rounding errors that can accumulate as you add more layers to a composite or add multiple filters to a clip. In most cases, you should choose to render your sequence using 32-bit floating-point space (called high-precision YUV ) for final rendering before output or export.

When using the Y′CBCR color space, Final Cut Pro supports either 8- or 10-bit video media files. To determine which color space and bit depth your video interface supports, see the documentation that came with the interface. For more information on which filters and transitions support 10-bit resolution, see Video Filters Available in Final Cut Pro and Refining Transitions Using the Transition Editor.

Maximum RGB White Level Settings

When you add graphics or generator clips created in the RGB color space (for example, imported graphics files or generator clips created with generators such as the Text generator), the “Process Maximum White as” pop-up menu determines whether the maximum white value of these clips should be 100 percent or 109 percent. Use this pop-up menu to make sure the white levels of your RGB footage match those of your Y′CBCR video. Because most still images and generators use the RGB color space and most video footage is recorded in the Y′CBCR color space, it is important to check this pop-up menu whenever you add graphics to your sequence.

Y′CBCR and RGB video systems assign maximum white levels to different digital codes, as shown here with an 8-bit video example.

Description
Percentage
RGB 8-bit value
Y′CBCR 8-bit value
Super-black
-7%
n/a
1-15
Black
0%
0
16
White
100%
255
235
Super-white
109%
n/a
236-254

A 100 percent white value in Y′CBCR video is the legal limit for broadcast television and generally corresponds to the analog broadcast legal limit of 100 IRE. However, camcorders and decks allow white levels above this level (up to 109 percent) to avoid clipping occasional highlights. For example, even if you set your camcorder exposure so that it appears no level is above 100 percent, highlights from shiny objects can go beyond 100 percent. Having the extra headroom from 100 percent to 109 percent allows you to capture these highlights without losing details in the white.

Choosing White

If you are creating video for broadcast, you need to make sure that any Y′CBCR levels in your sequence are reduced to 100 percent (8-bit 235, or “white”). In this case, choosing the White option from the “Process Maximum White as” pop-up menu maps RGB white (255) values from imported still images to 100 percent white (235) in the Y′CBCR color space. This means that your RGB graphics will have a maximum white level of 100 percent in Y′CBCR color space, which is the broadcast-legal limit.

Choosing Super-White

If you aren’t concerned about broadcast-legal limits and you want your imported RGB graphics to match Y′CBCR white levels that are above 100 percent, you should choose the Super-White option from the “Process Maximum White as” pop-up menu. In this case, RGB white values of 255 are mapped to Y′CBCR values of 254 (109 percent). Keep in mind that any white levels in your RGB graphics will not be broadcast-legal.

Motion Filtering Quality Pop-Up Menu

Options in this pop-up menu control the render quality of scaling, rotation, and other effects in the Motion tab.

  • Normal: This option uses standard scaling and transformation algorithms and yields medium-quality results compared to the other options.
  • Best: This option performs very high-quality motion transformations on your clips. Use this option for final rendering before output or export.
  • Fastest: This option performs fast, low-quality motion transformations on your clips. This option improves rendering time, so it is useful when you are sketching out motion effects.

How Rotation Affects Motion Filtering Quality

When you adjust a clip’s Rotation parameter, the clip is automatically rendered using the Fastest setting, regardless of the option chosen from the Motion Filtering Quality pop-up menu of the Video Processing tab of the current sequence settings. For example:

  • If you adjust a clip’s Scale, Center, or Anchor Point parameter: The clip is rendered using the motion filtering quality option chosen in the Video Processing tab of the current sequence settings.
  • If you adjust only a clip’s Rotation parameter: The clip is rendered using the Fastest motion filtering quality setting.
  • If you adjust a clip’s Rotation parameter as well as additional motion parameters: The clip is rendered using the Fastest motion filtering quality setting because the Rotation parameter has been adjusted.