Inconsistent bit-depth in ffprobe output

Hi,

The 'bit depth' / 'audio bits per sample' does't show consistent result for all videos. Sometimes it shows s16, sometimes fltp.

What does 'fltp' mean ?

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$ ./ffprobe.exe C://Samples//Wildlife.wmv
ffprobe version 1.2 Copyright (c) 2007-2013 the FFmpeg developers
built on Mar 28 2013 00:34:08 with gcc 4.8.0 (GCC)
...

Duration: 00:00:30.09, start: 0.000000, bitrate: 6977 kb/s
Stream #0:0(eng): Audio: wmav2 (a[1][0][0] / 0x0161), 44100 Hz, 2 channels, fltp, 192 kb/s
Stream #0:1(eng): Video: vc1 (Advanced) (WVC1 / 0x31435657), yuv420p, 1280x720, 5942 kb/s, 29.97 tbr, 1k tbn, 1k tbc
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Thanks,
Rajiv