Toontrack has introduced Drumtracker, a stand-alone, multi-track audio to MIDI converter designed to let you replace drum sounds. It’s available for Windows and Mac for $149 USD / €99 EUR.
The built-in filters in Drumtracker allow you to detect the most common instruments and specify the velocity threshold for each section of your song. In addition, you may save your own filter presets.
Drumtracker lets you select which part or parts of a drum audio track to convert, down to each single hit. You can change the velocity, delete, add or move trigger points to your requirements, giving you manual control of tracking and converting audio to MIDI, to supplement automatic detection.
Audition the triggered parts using Drumtracker built-in sample library, then, when you are happy with the result, convert the MIDI rendered by Drumtracker to the mapping system of your favorite drum sampler.