Using a first-order filter for DC rejection
authorJean-Marc Valin <jmvalin@jmvalin.ca>
Mon, 12 Mar 2018 15:39:08 +0000 (11:39 -0400)
committerJean-Marc Valin <jmvalin@jmvalin.ca>
Mon, 12 Mar 2018 16:01:45 +0000 (12:01 -0400)
commita4b5282f94deea91e4e5271d7ff7f72a8d1f9b6b
tree43492d547fc9a62038e740f885ddd69c73cf510e
parente1c0770a49f5aad8053c204bb11c7c552020b684
Using a first-order filter for DC rejection

A second-order DC rejection filter is uselsss unless we have complex
poles. However, complex poles means we have to compute the filter as a
single pass (rather than two casdaded first-order filters), which has
numerical issues that would require a higher complexity to solve.
So rather than waste cycles with a second-order filter (with a longer
impulse response), we just go with a first-order filter.
src/opus_encoder.c