Setting the Compression Quality when Encoding a Movie Clip

Problem

You want to set the compression quality when encoding a movie clip.

Solution

There are two ways of setting the compression quality when encoding a movie. The first way is to specify the bit rate of the encoder. The bit rate is typically measure in kilobits so the parameter to set is kbitRate:

encoder = Draft.VideoEncoder( '//path/to/video/save.mov', kbitRate = 85 )

The other way to set the compression quality is with the quality keyword:

encoder =  Draft.VideoEncoder( '//path/to/video/save.mov', quality = 80 )

Discussion

The compression quality parameter is an integer value between 0 and 100. Greater values correspond to higher quality. When using a specified quality Draft will vary the bitrate to maintain the desired quality. This works in most instances.

Specifying the bitrate provides a lot of control, but is only recommended if you the specific bitrate your movie needs to be. kbitRate is more dependent on the codec than quality. For example, the Avid DNxHD® codec accepts only certain kbitRate values. On the other hand H.264 accepts almost any value for kbitRate but issues arise with very low and very high values. If you don’t need to use a specific bitrate then use the quality keyword and let Draft do the work for you.

These two settings are exclusive and only one of quality or kbitRate can be specified.

See Also

Draft.VideoEncoder