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Acquisition Phase

Acquisition​

Source files submitted for encoding are acquired (downloaded) from the acquisition storage provider. There are two methods for deciding which files in the folder should be downloaded: file naming convention and regex.

Ignored files​

Files that were not downloaded from the acquisition folder are listed in the ContentAcquired event.

Failing the job on ignored files​

You can make the encoding job fail if any files from the acquisition folder were skipped (because no regular expression matched them or they had unsupported file extensions) by setting FailOnIgnoredFiles in MediaMappings to true. This can help safeguard against errors with regex definitions and source file types.

Analysis​

All the files that were downloaded are analyzed. During this process, all the tracks in the files are inspected and their individual media types, properties and languages are detected.

Media type detection​

All the tracks are inspected for their individual media types (video, audio, descriptive audio, subtitle, closed caption).

The media type detection is also explained in the article about media detection.

Which source tracks get selected?​

From all the video tracks the best one gets selected as the source track. This is because there can be only one video (of which there are just different bitrate renditions).

From all the audio tracks all the tracks that meet the audio representation configuration are selected.

From all the text tracks all tracks are selected.

Best video track​

The best video track is, in this order of preference:

  1. Duration is longer than others by at least 1 minute (this excludes e.g. trailers).
  2. Bitrate is higher than others.
  3. Random pick from the tracks that have similar duration and bitrate.