Apple Final Cut Pro 6 - Manual (Page 1881)

398 Part V Appendixes
MPEG-2 supports the same audio layers as MPEG-1 but also includes support for
multichannel audio. MPEG-2 Part 7 also supports a more efficient audio compression
algorithm called Advanced Audio Coding, or AAC.
MPEG-2 elementary stream files often have extensions such as .m2v and .m2a, for video
and audio, respectively.
MPEG-4
MPEG-4 inherited many of the features in MPEG-1 and MPEG-2 and then added a rich
set of multimedia features such as discrete object encoding, scene description, rich
metadata, and digital rights management (DRM). Most applications support only a
subset of all the features available in MPEG-4.
Compared to MPEG-1 and MPEG-2, MPEG-4 video compression (known as MPEG-4 Part 2)
provides superior quality at low bit rates. However, MPEG-4 also supports high-resolution
video as well. For example, Sony HDCAM SR uses a form of MPEG-4 compression.
MPEG-4 Part 3 defines and enhances AAC audio originally defined in MPEG-2 Part 7.
Most applications today use the terms AAC audio and MPEG-4 audio interchangeably.
MPEG-4 Part 10, or H.264
MPEG-4 Part 10 defines a high-quality video compression algorithm called Advanced
Video Coding (AVC). This is more commonly referred to as H.264. H.264 video
compression works similarly to MPEG-1 and MPEG-2 encoding but adds many
additional features to decrease data rate while maintaining quality. Compared to
MPEG-1 and MPEG-2, H.264 compression and decompression require significant
processing overhead, so this format may tax older computer systems.
Video Formats Supported by Final Cut Pro
Final Cut Pro supports any video format that uses an installed QuickTime codec.
QuickTime natively supports codecs used by a number of video devices, such as DV,
DVCPRO 50, DVCPRO HD, HDV, and IMX devices. With these formats, the distinction
between file format and tape format is blurred, and transferring from tape to hard disk or
other media is essentially a file transfer, allowing you to edit footage natively. For more
information, choose HD and Broadcast Formats from the Final Cut Pro Help menu.
When you work with videotape formats such as Digital Betacam, D-5, Betacam SP, and so
on, you need a third-party video interface to connect to the SDI or analog component
video connectors on the deck. In this case, the video interface must convert the incoming
or outgoing video signal to or from a QuickTime codec. Many video interfaces come with
codecs for high-quality compressed and uncompressed editing.