I am trying to programmatically load an audio file, apply tempo effect and read the output to the buffer for the further processing. I uploaded the gist of the example here: https://gist.github.com/EgorLakomkin/124a4b86dd8869d5536e2edceec0cc84

If I use tempo values < 1 I get the correct number of samples from the output, but if I change it for example to 1.2 I suddenly get a very small number of sample and 0 if I use the value of 1.0. I am wondering if there is a bug in my chain configuration or data reading from the output? It is my first experience with libsox and I tried to follow examples, but I got stuck here.

Thank you in advance for the help!

Regards, Egor