Apple Compressor (4.0) User Manual
Page 85
Chapter 5
Custom settings and output formats
85
HD sources and MPEG-2
Compressor has several different options and workflows for transcoding HD video source files
into MPEG-2 files.
•
HD on Blu-ray: Compressor can output MPEG-2 files for creating HD-resolution Blu-ray discs
from either HD or SD source media. Compressor can retain the various frame sizes and frame
rates of HD video when transcoding to MPEG-2. Compressor also supports the higher bit rates
required by the Blu-ray format. For more information about creating output for Blu-ray discs,
see
on page 70. For information about adding the Blu-ray job action to a
job, see
Post-transcoding actions overview
on page 184.
Note: The other output file format option for Blu-ray discs is H.264, also known as MPEG-4 Part 10.
•
HD to SD downconversion: For those situations in which you’re editing HD sources in Final
Cut Pro and want to create an SD DVD from them, Compressor provides high-quality
downconversion. Compressor retains as much detail as possible during scaling and correctly
preserves progressive or interlaced formats when encoding to MPEG-2 for DVD.
When you import source media into the Batch window, you can click the source’s name in the
Batch window to see resolution, frame rate, and duration information in the lower-left corner
of the Preview window.
Elementary, transport, and program streams
There are three common MPEG-2 stream types that are used to deliver MPEG-2-encoded video:
•
Elementary streams: These streams contain only one MPEG-2 content channel and no audio.
•
Transport streams: These streams can contain several MPEG-2 content channels and associated
audio. All the channels are multiplexed together, allowing the receiver to choose which to play
back. Compressor supports creating single-channel transport streams that can also include
associated audio.
Transport streams can also recover from interruptions during playback, making them ideally
suited for broadcast and streaming applications where noise or network congestion can lead
to interruptions.
•
Program streams: These streams contain only one MPEG-2 content channel and its associated
audio. Program streams require an error-free delivery method and are primarily used for
storage or processing within a computer.
By default, the Compressor MPEG-2 encoder creates elementary MPEG-2 streams. In the Extras
tab of the MPEG-2 Encoder Pane, you can configure the MPEG-2 encoder to create transport
or program streams and choose whether they should include audio. For more information, see
on page 89.
Note: The SD DVD and Blu-ray options in the Stream Usage pop-up menu output only
elementary streams. If you choose either of these and then configure the output to be either
a transport or program stream, the Stream Usage setting changes to Generic. For more
information, see
on page 89.