4.5

74Compressor User Guide
• Include Dolby Vision 8.4 metadata: Select this checkbox to have Compressor include
Dolby Vision 8.4 metadata in the output file. Dolby Vision 8.4 is a format designed to
optimize HDR content for Apple devices. If this checkbox is selected, “Color space” is
set to Rec. 2020 HLG, Codec is set to HEVC, and Profile is set to 10-Bit Color.
• Frame Reordering: Select this checkbox to potentially provide a better-quality output
file by allowing Compressor to reorder video frames during transcoding. This option is
only available when Codec is set to H.264 or HEVC.
Important: If you select “Allow frame reordering,” your output file may be more
efficiently compressed but may not be compatible with decoders on older hardware.
• Preserve Alpha: Select this checkbox to preserve any alpha channel information in your
source and pass the alpha to the output. This checkbox is enabled when Codec is set
to ProRes 4444 or Animation. If your computer is running macOS 10.15 or later, this
checkbox is also enabled when Codec is set to HEVC. When Preserve Alpha is turned
on, the Quality slider is enabled.
• Add clean aperture information: Select this checkbox to define clean picture edges in
the output file. This property adds information to the output file to define how many
pixels to hide, ensuring that no artifacts appear along the edges. When you play the
output file in QuickTime Player, the pixel aspect ratio will be slightly altered. This
process doesn’t affect the actual number of pixels in the output file—it only controls
whether information is added to the file that a player can use to hide the edges of
the picture.
Cropping and Padding
Customize the final cropping, sizing, and aspect ratio using the Cropping & Padding
properties in Compressor. Cropping removes video content from an image. Padding
scales the image to a smaller size while retaining the output image’s frame size. For more
information about these properties, see Intro to modifying frame size in Compressor.
• Cropping: This pop-up menu sets the dimension of the output image. The custom
option allows you to enter your own image dimensions in the fields; other options use
predetermined sizes. The Letterbox Area of Source option detects image edges and
automatically enters crop values to match them. This is useful if you want to crop out
the letterbox area (the black bars above and below a widescreen image) of a source
media file.
• Padding: This pop-up menu sets the scaling of the output image while retaining the
output image’s frame size. The custom option allows you to enter your own scaling
dimensions in the fields; other options use predetermined dimensions.
Quality
The following properties determine how Compressor resizes, retimes, and otherwise
adjusts the video when transcoded:
• Resize filter: This pop-up menu sets the resizing method. There are several options:
• Nearest Pixel (Fastest): Samples the nearest neighboring pixel when resizing an
image. This option provides the fastest processing time, but it is more likely to
show aliasing artifacts and jagged edges.
• Linear: Adjacent pixel values are averaged using a linear distribution of weights.
Produces fewer aliasing artifacts than Nearest Pixel, with a small increase in
processing time.