Apple Compressor (4.0) - Manual (Page 17)

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Importing overview
The first step in the traditional Compressor transcoding process is to import at least one source
media file into the Batch window, thus creating a batch.
If you’re using the batch template workflow, the first step is to choose a batch template. For more
information, see
Quick and easy batch template workflow on page 14.
Here are some tips for importing source media:
•
About highly compressed source files: It’s strongly recommended that you do not use highly
compressed files, such as MPEG files, as your source files, because they can cause artifacts in
the encoded video.
•
When importing QuickTime reference movies: If you submit a reference movie for distributed
processing, the Apple Qmaster distributed processing system automatically copies the
appropriate media files to the processing cluster. For the best performance, you can avoid
this file transfer step by making sure that the media files specified in the reference movie are
available to each node of the Apple Qmaster cluster. For more information, see
How the Apple
Qmaster system distributes batches on page 221.
•
When importing MPEG-2 files: When you import an MPEG-2 file, Compressor must parse the
file before you can play it in the Preview window. Parsing the file involves determining its
frame structure and other necessary information about the file. Because the frame structure
can change throughout the file, Compressor must scan the entire file, which can take several
minutes for longer files.
This doesn’t happen with MPEG-2 elementary files encoded using Compressor that had the
“Add DVD Studio Pro metadata” checkbox selected. For more information, see
MPEG-2 Encoder
pane on page 89.
•
When importing Dolby Digital Professional source media: You can use Dolby Digital Professional
AC-3 audio files as source media files for your jobs. There are two common reasons to do this:
•
To test a file you just encoded: Because you cannot preview the Dolby Digital Professional output
settings, importing an encoded file into a job allows you to play it and verify the settings.
•
To convert a Dolby Digital audio file to another format: Because not all media players include
Dolby Digital decoders, you may find that you need to transcode the file to another format.
Import source media
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