4.5

73Compressor User Guide
When QuickTime settings are set to HEVC, the Profile pop-up menu sets the color depth
of the output file (the number of bits used to represent color in each color channel—red,
green, and blue). There are two options:
• 8-Bit Color: Provides a good balance between picture quality and file size. (This
option is available only on recent Mac computers that support hardware encoding
of HEVC.)
• 10-Bit Color: Provides better picture quality but with larger file sizes. (Because this
option uses software encoding, performance may be significantly slower than 8-bit
hardware encoding.)
Note: HEVC encoding requires a computer running MacOS 10.13 or later.
• Entropy mode: When Codec is set to H.264, use this pop-up menu to set the entropy
mode to CABAC (which provides higher-quality output), or CAVLC (which is faster and
more compatible for playback on older devices).
• Data rate: This pop-up menu allows you to choose a data rate for your video based on
any of four options:
• Custom: Setting data rate to Custom enables a value field that limits your video
signal to a set number of kilobits per second (kbps). Higher rates allow higher-
quality video but generate larger files that are slower to download or transmit.
• Computer playback: Creates a larger file with higher quality.
• Web publishing: Creates a smaller file (of lower quality) suitable for hosting on
a website.
• Proxies: Creates a smaller file suitable for a proxy workflow. Available only for H.264
and HEVC encoding.
• Automatic: Attempts to identify and apply the lowest possible data rate while
maintaining maximum visual quality.
Important: When you set a data rate, you override other codec quality properties
because the codec compresses the file as much as it needs to based on its
data-rate limit.
• Key frame interval: Enter a value in the text field to set the key frame interval (number
of frames) at which you want key frames created in your output file. Alternatively, you
can select Automatic to have Compressor choose the key frame interval rate (the
displayed value is 0 with Automatic on; the actual value is determined during the
encoding process).
• Quality: When Codec is set to Animation, HEVC, or Photo-JPEG, this slider controls one
of the following options:
• Animation or Photo-JPEG: Use the slider to set the quality level of your output.
Select from least (smaller file size) to best (larger file size).
• HEVC: Use the slider to set the quality level of the alpha channel of your output.
Select from least (smaller file size) to best (larger file size).
• Multi-pass: Turns on multi-pass encoding that uses additional analysis of video frames
to produce a high-quality output file. For faster (single-pass) transcoding, turn this
feature off by deselecting the checkbox.