I use Audacity now since Years for Audio 25FPS to 23,976 conversion.
In Version 2.0.6 … all works as expected, but in the new Version i have big Problems in the Sound.
Using Change Tempo w/o “High Quality” Switch results in extreme crappy Outputs with dropouts in the Dialogues.
If i use High Quality Switch the Drops are gone but the File has some kind of Phase applied. The resulting Audio sounds like it would come out of a Tincan.
In the new version, the “High Quality” setting uses the same algorithm as “Sliding Time Scale/Pitch Shift”. This often (but not always) gives better results than the “ordinary” algorithm.
The ordinary algorithm (“High Quality” not selected) is identical in the new version as in 2.0.6.
The cause of that difference must be due something else, because the code for the “normal” stretching has not been modified for a very long time.
(28th Jun 2013: Support added for fractional BPM. Audacity 2.0.6 released 25th Sept 2014)