Compressor 4 - About the H.264 for Apple Devices Encoder Pane

About the H.264 for Apple Devices Encoder Pane

This section contains detailed information about the elements of the H.264 for Apple
Devices Encoder pane in the Inspector window. You make your H.264 settings using this
pane, by either modifying an existing setting or creating a new setting in the Settings
tab.

You make your H.264 for Apple Devices settings using the controls described below,
either by duplicating an existing setting and modifying it or by creating a new setting in
the Settings tab of the Settings window. The H.264 for Apple Devices Encoder pane
contains the following items.

• Extension: This field displays the H.264 for Apple Devices file extension (.m4v)

automatically after the H.264 for Apple Devices output format is chosen from the File
Format pop-up menu or the (+) pop-up menu in the Settings tab of the Settings window.

• Allow Job Segmenting: This checkbox allows you to turn off job segmenting. It is relevant

only if you are using Compressor with distributed processing and with multi-pass
encoding. For more information, see

Job Segmenting and Two-Pass or Multi-Pass

Encoding

.

• Device: Select one of the following device options from the pop-up menu:

• iPod/iPhone (VGA): This option creates video output files with a frame width of 640

pixels.

• iPod/iPhone (Anamorphic): This option creates video output files with a frame width

of 640 (anamorphic) pixels.

• iPod/iPhone (QVGA): This option creates video output files with a frame width of 320

pixels.

• Apple TV SD: This option creates video output files with a frame width of 640 pixels

with a higher bit rate range than the iPod/iPhone 640 (VGA) option.

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• Apple TV SD (Anamorphic): This option creates video output files with a frame width

of 720 (anamorphic) pixels.

• Apple TV HD: This option creates video output files with a frame width of 1280 pixels,

except when the aspect ratio is set to 4:3. In that case, the video output files have
frame dimensions of 960 x 720 (anamorphic) pixels for frame rates above 24 fps and
1280 x 720 (square) pixels for lower frame rates.

• Apple TV 3rd Generation: This option, intended for the third-generation Apple TV and

iPad models, creates video output files with a frame width of 1080 pixels.

• iPhone (Local/WiFi): This option creates video output files with a frame width of 480

pixels.

• iPhone (Cellular): This option creates video output files with a frame width of 176

pixels.

• iPad/iPhone with Retina display: This option creates video output files with a frame

width of 1280 pixels.

• Aspect Ratio: Use the Aspect Ratio pop-up menu to choose the exact pixel dimensions

of the output media file. The available options depend on which device option you
selected. See

Aspect Ratios for Apple Devices

for more information.

The Aspect Ratio setting also has an Automatic button. Clicking the Automatic button
causes the encoder to choose the aspect ratio that matches the source video file.

Important:

The automatic mode for the Aspect Ratio setting is able to choose from a

wider variety of values to better match the source video (with the values determined
and displayed when this output format is applied to a source media file). For the best
results, it is recommended that you use the automatic mode for the Aspect Ratio setting.

The Aspect Ratio
Automatic button

Note: By default, the Frame Controls feature is set to Automatic. The Frame Controls
Retiming Control will be engaged only if the source file is interlaced.

• Frame Rate: Use this pop-up menu to choose from the options listed below.

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The Frame Rate setting also has an Automatic button. Clicking the Automatic button
causes the encoder to choose the frame rate that matches the source video file.

The Frame Rate
Automatic button

• 29.97: Used for NTSC-based video

• 25: Used for PAL-based video

• 24: Used for PAL-based video

• 23.98: Used for NTSC-based video

• 15: Used for web-based video

• Bit Rate: Use this slider to choose the bit rate to use for the output video, or enter a

number in the text field. The available ranges depend on the Device setting. The setting
you should choose depends on how the output is to be used. Higher bit rates produce
better picture quality, but they also produce larger output files.

• Audio: Use this pop-up menu to choose from the four audio bit-rate options listed

below.

• None: Use this option to exclude audio from the output media file.

• 24 Kbps: Creates an audio bitstream at 24 Kbps for the iPhone (Cellular) device option.

• 128 Kbps: Creates an audio bitstream at 128 Kbps.

• 256 Kbps: Creates an audio bitstream at 256 Kbps.

• Frame Sync: Also known as the key frame interval, the Frame Sync value represents how

often a key frame is inserted in the H.264 stream. The lower the number, the more
smoothly the video can be manipulated (scrubbed) during playback (more frequent
key frames). The higher the number, the more efficient the compression (less frequent
key frames). The available range is from 2 to 10 seconds; the default is 5 seconds.

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