I used jriver convert format to extract audio from a film stored as a full BD folder. It's an 8 channel track and I simply selected wav as the output with no DSP applied. The resulting file seems about the right size (~ 9.2G for a 140min 7.1 track at 48kHz and 24bit depth) but it reports as approx 18mins long in a variety of other software.
e.g. in ffprobe
Input #0, wav, from '/home/matt/junk/The Hunger Games.wav':
Duration: 00:18:16.90, bitrate: 71864 kb/s
Stream #0:0: Audio: pcm_s24le ([1][0][0][0] / 0x0001), 48000 Hz, 8 channels, s32 (24 bit), 9216 kb/s
Looking at the wav header (e.g. as per
http://soundfile.sapp.org/doc/WaveFormat/) I see
chunk size = 2C 80 51 4B = 1263632428
which equates to a wav about 18 mins long
the value for Subchunk2Size is consistent with the error above as it has a value of 1263628288
The rest of the header is accurate but this error in the header throws off many parsers.
I'll try a few more files to see if this is consistently wrong or whether it's limited to certain conditions.