From 3060f37ae8a2a03716682391a74e9486770c9571 Mon Sep 17 00:00:00 2001 From: Chris Cannam Date: Tue, 28 Jun 2022 14:07:05 +0100 Subject: [PATCH] Docs on R3 --- README.md | 21 +++++++++++++++++++-- 1 file changed, 19 insertions(+), 2 deletions(-) diff --git a/README.md b/README.md index 16671ff..9792421 100644 --- a/README.md +++ b/README.md @@ -124,8 +124,25 @@ duration, shifts it up in pitch by a whole tone, and writes the output to `output.wav`. Several further options are available: run `rubberband -h` for help. -In particular, different types of music may benefit from different -"crispness" options (`-c` flag, with a numerical argument from 0 to 6). + +The most important are the options `-2` and `-3`. These select between +two different processing engines, known as the R2 (Faster) engine and +the R3 (Finer) engine. The R3 engine produces higher-quality results +than R2 for most material, especially complex mixes, vocals and other +sounds that have soft onsets and smooth pitch changes, and music with +substantial bass content. However, it uses much more CPU than the R2 +engine. + +The R2 engine was the only method available in Rubber Band Library up +to versions 2.x, and for compatibility it remains the default (in the +case that neither `-2` nor `-3` is requested explicitly) whenever the +command-line tool is invoked as `rubberband`. The R3 engine is the +default if the tool is invoked as `rubberband-r3`. + +Many further options are available, most of which only have an effect +when using the R2 engine. In particular, different types of music may +benefit from different "crispness" options (`-c` flag, with a +numerical argument from 0 to 6). ## 3. Using Rubber Band Library